Safeguarding press brakes without sacrificing productivity

Technology advances can keep the operator safe and the press brake running

Even though the U.S. has some very strict machine guarding regulations, the U.S. Department of Labor reports that press brake operators in this country suffer more than 350 amputations per year—and these are only the reported injuries. The question is why?

For one, by their design, press brakes are very dangerous machines, much more so without proper safeguarding equipment. Injuries result because of unguarded access to the point of operation at the front of the machine and the operator’s ability to reach around the safety device to get to the point of operation at the side or back of the machine. Also, the back-gauge system creates pinch points and poses a risk to the operator with its hazardous motion. Although rare, operators also can experience blunt force trauma after being struck by ejected materials.

But perhaps the greatest threat linked to running press brakes is having the operator’s hand trapped between the part being bent and the frame of the machine (see Figure 1). If the force is great enough or the part is sharp enough, impalement or an amputation can occur.

Another factor contributing to the dangers of press brakes is the metal fabricator’s failure to perform an upfront risk assessment. This type of assessment is the critical first step in any safeguarding project and, unfortunately, seldom completed. An overall risk assessment considers hazard severity, frequency of exposure, and probability of injury, as suggested by ANSI B11.0-2015. Risk or machine safeguarding assessments should be done before commissioning any new machinery, after upgrading existing machinery, after changing the work area, and after any accident or serious incident.

Yet another dynamic contributing to press brake injuries is lack of press brake maintenance, in particular testing safety devices to ensure they are working properly and in the correct position. An unmaintained press brake, especially one with damaged tooling, can put both the machine and operator at risk for serious injury.

All of these issues can be addressed in a few moments. It is time well spent to ensure that the machine is safe to operate. Having said that, not all shops will commit to that type of preparedness and maintenance. So it’s not a question of if an operator will get hurt by a press brake; it’s a question of when.

What Are the Safety Standards?
The Occupational Safety and Health Administration (OSHA) does not specifically address mechanical or hydraulic press brakes, but the machines are commonly cited under the general duty clause 1910.212, which covers failure to provide adequate protection for plant employees from known machine hazards. Most commonly, the industry follows the ANSI standard for press brakes, ANSI B11.3, for safeguarding method guidance and then ANSI B11.19 for design criteria.

The original B11.3 standard was approved in 1973 and revised in 1982 and again in 2002. The current 2012 standard, ANSI B11.2-2012, includes the new topics of close proximity point of operation, active opto-electronic protective devices (AOPD), and a safeguarding means called safe speed.

Safe speed is protection for the operator when safeguarding is not provided by a light curtain, such as after the optical system is muted for the bending operation to occur. Safe speed must be monitored automatically, so the press brake ram does not exceed 10 mm/s and for the machine closing movement to be stopped if this limit is exceeded. To insert these new safe speed requirements into B11.3, the committee drew on experience with this requirement in Europe and its corresponding EN 12622 standard.

Does Safeguarding Hinder Productivity?
A widespread misconception in the industry is that safeguarding a press brake prevents or hinders employees from making production quotas. However, an Aberdeen Group research study (“Integrated Safety Systems: Ensuring Safety and Operational Productivity”) concluded that companies that have taken steps to invest in safeguarding not only improve plant safety, but realize superior operational performance and overall equipment effectiveness (OEE). The 20 percent of best-in-class companies that had the highest OEE also had the lowest safety incident rate. The top companies typically had an OEE on average of 90 percent and an injury incident rate of 0.05 percent, while the bottom 20 percent of companies had an OEE of 76 percent and an injury frequency rate of 3 percent, which is 60 times higher. Top manufacturers were also able to achieve a 2 percent unscheduled asset downtime rate, versus a 14 percent rate for the laggard group in the study.

Figure 1
When it comes to older bending machinery, nothing really acts as a barrier between the press brake and the machine’s operator.

What makes these statistics possible is modern safeguarding tools. Some of these options are awareness and barrier guards, light curtains, two-hand controls, and laser AOPD.

First, however, a word or two about retrofitting. When retrofitting older machines, installers must take great caution to ensure that the new technology does not decrease the safety of the machine or add new hazards. Sometimes an older machine simply cannot be brought up to today’s standards. At that point the installer must evaluate the situation and ensure the full machine installation becomes safer overall than its original state with the new safeguarding. If not, he needs to step back and consider the options. ANSI B11.3-2012 gives direction on this topic.

Awareness Barrier. The backs of press brakes cannot be left wide open. Two hazards often lurk here: reaching the dies from the back and the possibility of a multi-axis back gauge moving and creating pinch points. As to exactly what is required on the back of equipment often depends on local OSHA interpretation. At the very least, an awareness barrier, like a railing, chain, or cable with a “danger” or “warning” sign complete with pictographs, not just verbiage, should be installed. Awareness barriers are bare-minimum methods in reducing risk.

Barrier Guards. Although not versatile, barrier guards on the ends of most press brakes are effective when used in conjunction with other safeguarding devices (see Figure 2). They also can be used to mount/support light curtains, adding to their value. Barriers can have openings for material to be fed into the die area, but do not allow for hands into that area.

Barrier guards reduce the risk of the operator getting his hands pinched when he reaches between the punch and die from either side of the press brake or reaches between the back-gauge system and tool. By OSHA’s definition, a guard must prevent people from reaching over, under, through, or around it. Guards must meet one of two measurement scales—the OSHA guard opening scale or the ANSI/CSA guard opening scale—to ensure that a small hand can’t reach far enough through any opening to get hurt.

Barrier guards can be fixed or interlocked. The interlocked design prevents misuse and is required to be either electrically interlocked or fixed in place using a fastener that requires a tool for removal. They’re often hinged or sliding to allow easy access to the point of operation for machine setup (access to limit switches or other levers and dials), tool change, or maintenance tasks.

Light Curtains. These safeguarding tools have been around since the mid-1950s. They consist of a vertically mounted transmitter and receiver with closely spaced beams of laser creating a flat sensing field. When fingers, hands, or arms reach through that sensing field, the press cycle is prevented or stopped to avoid operator injury.

One of the reasons that press brakes make a good application for light curtains is that they can be stopped midcycle very quickly. Hydraulic press brakes stop quickly if maintained properly. Mechanical press brakes may not. Air clutch machines have reasonable stop times, but mechanical friction clutch (MFC) machines are known for stopping very slowly. Quite often light curtains can’t be used on MFC press brakes because the safety distance can end up being 2 to 3 feet.

Like any safeguarding device, light curtains should be “function-tested” before every operating shift to ensure that they are continuing to provide protection. Make/model-specific function-test procedures are usually available on each light curtain manufacturer’s website.

Two-Hand Controls. These controls are considered a safer means of cycling a press than a footswitch because both hands must be in a safe position to use them. When a press is cycled with a footswitch, hands can be anywhere. It’s possible to use a two-hand control as a safeguarding device as well during press brake operation.

Figure 2
The barriers on the side of this press brake have light curtains attached to them, providing the press brake operator with two layers of protection.

Most operations require that the part be held when bending, so two-hand control is rarely used to cycle a press brake or used as the point-of-operation safeguard. The part would have to be fixtured and supported by a backgauge to use a two-hand control.

Laser AOPD. The newest entry into the press brake safety category is the laser AOPD (see Figure 3). Inclusion of laser AOPD technology in the B11.3-2012 is a welcome addition to the standard that now gives press brake manufacturers, dealers, and users a clear guideline to implementing this technology safely for retrofit applications (B11.3 subclause 8.8.7 —Close Proximity Point of Operation AOPD Safeguarding Device).

It is important to note here that AOPDs are an acceptable method of safeguarding hydraulic press brakes only per ANSI B11.3 and also following most manufacturers’ specifications.

A unique feature of AOPDs is that they are designed to be mounted with zero safety distance, unlike light curtains that must be mounted at a calculated safety distance (see Figure 4), as outlined in ANSI B11.3. Safe speed safeguarding is based on a ram speed of 10 mm/s or less, providing that speed is carefully monitored. Again, this new method of protection can be applied only to hydraulic press brakes (and potentially servo-drive press brakes). Because of their close proximity point of operation, AOPD systems are best-suited for applications such as box bending, bending with flanges, or where light curtain effectiveness is diminished due to excessive blanking or muting.

Press brakes are very dangerous machines, much more so without proper safeguarding equipment. When safeguarding equipment is engineered, installed, and operated correctly, it provides positive, business-enhancing benefits while mitigating risks and reducing insurance and energy costs. Metal fabricators also should recognize the payback of reducing costs associated with accidents, medical expenses, and regulatory noncompliance.

For more information about safeguarding press brakes, please contact us at 1-800-922-7533.

Ten Most Reported Worker’s Compensation Injuries

Last year in America 2.9 million employees (U.S Bureau of Labor Statistics) suffered a workplace injury from which they never recover, at a cost to business of nearly $60 billion (Liberty Mutual Insurance). These statistics are staggering. To help gain a better perspective on the realities of workplace danger, we have compiled a list of the ten most reported worker’s compensation injuries, as reported by a leading insurance company.

By raising awareness of these dangers, we hope we can help you identify hazards in your workplace and take measures to control the risks preferably by eliminating them – but if that is not possible, by reducing them as far as possible.

1. Overexertion– These are injuries due to excessive physical effort such as lifting, pulling, pushing, turning, wielding, holding, carrying or throwing. The Liberty Mutual Workplace Safety Index, which is compiled using Bureau of Labor Statistics (BLS) data, workers’ compensation claims reported to the National Academy of Social Insurance and compensation benefits paid by Liberty Mutual, indicates that overexertion accounts for more than 25 percent of direct workers’ compensation costs paid out annually.

2. Slips – Slipping accidents are the second leading cause of workers’ compensation claims and the top cause of workplace injuries for workers 55 and older, as reported by the National Flooring Safety Institute. In a hard fall, a worker may sustain injuries to the knee or ankle, wrist or elbow, back or shoulder, hip or head. Employers need safety guidelines to ensure spills are promptly cleaned and no debris is present which can be dangerous.

3. Falling – In 2013, 595 workers died in elevated falls, and 47,120 were injured badly enough to require days off of work. A worker doesn’t have to fall from a high level to suffer fatal injuries. While half of all fatal falls in 2016 occurred from 20 feet or lower, 11% were from less than 6 feet. Not surprisingly, construction workers are most at risk for fatal falls from height – more than seven times the rate of other industries. These types of accidents can be reduced by the use of proper personal protection gear, training and employee diligence.

4. Bodily Reaction– Coming in at number four are reaction injuries caused by slipping and tripping without falling, often leading to muscle injuries, body trauma, and a variety of other medical issues. Although these injuries may sound non-serious, insurance companies paid out $3.89 billion in workers’ compensation in 2016 for bodily reaction incidences (Liberty Mutual Insurance).

5. Falling Object Injuries – There are more than 50,000 “struck by falling object” injuries every year in the United States, says the Bureau of Labor Statistics. That’s one injury caused by a dropped object every 10 minutes. How serious is the danger? Consider this: an eight-pound wrench dropped 200 feet would hit with a force of 2,833 pounds per square inch – the equivalent of a small car hitting a one-square-inch area. Proper personal protection gear usage, such as a hard hat, can be instrumental in keeping the employee safe.

6. Distracted Walking Injuries – They may seem funny in slapstick comedies, but distracted walking injuries in the workplace were recently labeled a “significant safety threat” by the National Safety Council. These injuries occur when a person accidentally runs into walls, doors, cabinets, glass windows, tables, chairs or other people. Head, knee, neck, and foot injuries are common results. As with distracted driving accidents, it is difficult to track the number of occupational injuries caused by distracted walking, since workers might be reluctant to admit they were looking down at their cell phones when they were injured.

7. Vehicle Accidents – Accidents are common in workplace environments using cranes, trailers and trucks. According to the Bureau of Labor Statistics more than 1,700 deaths a year result from occupational transportation incidents. Employee Safe Driver training courses are likely to reduce vehicle accidents that may injure employees. Managers are required to conduct routine vehicle maintenance to ensure vehicles are operating safely and properly.

8. Machinery Accidents – Machines used in the workplace are often operated without safety guards and devices, exposing their operators and others to serious injury. Common injuries involve clothing or hair becoming caught in moving parts. Many of the amputations that occur on machinery can be prevented by updating machines with appropriate safeguarding. Electrical updates for magnetic motor-starters, main power disconnects, and emergency-stops, also help to prevent injury. OSHA regulations and ANSI safety standards spell out safety modifications that can prevent needless accidents. Learn more about how Rockford Systems, a leader in machine safeguarding, will help you create a safer workplace with their extensive line of innovative safeguarding solutions.

9. Repetitive Motion Injuries – Thousands of employees suffer from injuries that occur gradually and make it difficult to do daily tasks, such as typing, twisting wires, using hand tools, or bending over to lift objects. These are called repetitive motion injuries and strain muscles and tendons. Over time it will lead to back pain, lumbar injuries, tendonitis, bursitis, vision problems, or carpal tunnel syndrome. Repetitive motion injuries may be temporary or permanent. Employee training and the use of proper ergonomic tools can help keep these incidents low.

10. Workplace Violence – According to OSHA, workplace violence is any act or threat of physical violence, harassment, intimidation, or other threatening disruptive behavior that occurs at the work site. It ranges from threats and verbal abuse to physical assaults and even homicide. Nearly 2 million American workers report having been victims of workplace violence each year. Unfortunately, many more cases go unreported. Workplace violence employee training and employee diligence in watching out for suspicious activities can help keep these incidents at bay. One of the best protections employers can offer their workers is to establish a zero-tolerance policy toward workplace violence.

Workplace injuries can leave the lives of employees and their families shattered. Employers have legal obligations to ensure a safe workplace for their employees – and also for anyone else who may visit the workplace such as customers, contractors and members of the public.

Work Safety Topics

Did you know that June is National Safety Month? Rockford Systems has partnered with the National Safety Council to promote safety to our valued customers!

Nearly 13,000 American workers are injured each day, and each injury is preventable. Here are some of the safety topics NSC is focusing on.

Fatigue
Adults need seven to nine hours of sleep each day to reach peak performance, but nearly one-third report averaging less than six hours. The effects of fatigue are far-reaching and can have an adverse impact in all areas of our lives.
· Safety performance decreases as employees become tired
· You are three times more likely to be in a car crash if you are fatigued
· Chronic sleep-deprivation causes depression, obesity, cardiovascular disease and other illnesses

Drugs at Work
Drug use at work is a safety topic that is gaining attention. Lost time, job turnover, re-training and healthcare costs are three of the primary implications of drug use regularly confronted by employers. The typical worker with a substance use disorder misses about two work weeks (10.5 days) for illness, injury or reasons other than vacations and holidays.
· Workers with substance use disorders miss 50% more days than their peers, averaging 14.8 days a year
· Workers with pain medication use disorders miss nearly three times as many days – 29 days
· Workers in recovery who report receiving substance use treatment miss the fewest days of any group – 9.5

Driving
Many employers have adopted safe driving policies that include bans on cell phone while driving and on the job. NSC has created a Safe Driving Kit with materials to build leadership support for a cell phone policy and tools to communicate with employees.

Workplace Violence
Every year, 2 million American workers report having been victims of workplace violence. This violence fits into four categories: criminal intent, customer/client, worker-on-worker and personal relationship (most involving women).
The deadliest situations involve an active shooter.

Every organization needs to address workplace violence through policy, training and the development of emergency action plans. While there is no way to predict an attack, you can be aware of warning signals that might signal future violence.

Slips, Trips and Falls
You might be surprised to learn that falls account for the third-highest total unintentional deaths every year in the United States. Fatalities as a result of falls are surpassed only by poisoning (including deaths from drugs and medicines) and motor vehicle crashes.

Fall safety should be a top priority. Construction workers are at the most risk for fatal falls from height, but falls can happen anywhere, and it is important to recognize potential hazards, both on the job and off. Plan ahead and use the right equipment.

Ergonomics and Overexertion
Overexertion causes 35% of all work-related injuries and is the No. 1 reason for lost work days. Regular exercise, stretching and strength training can prevent injury. Likewise, ergonomic assessments can ward off ergonomics injuries, often caused by excessive lifting, lowering, pushing, pulling, reaching or stretching.

Struck by Objects
While employers are responsible for providing a safe work environment, employees can take steps to protect themselves at work. Paying attention is vitally important for those operating machinery as well as those working around power tools and motor vehicles.

Source: National Safety Council

Avoiding Pinch-Point Injuries on Riveters and Welders

Pinching your finger in a door can be painful but certainly not life threatening. Pinch-point injuries involving industrial machinery are another story, one that rarely has a happy ending.

What is a pinch point?
A pinch point is “any point at which it is possible for a person or part of a person’s body to be caught between moving parts of a machine, or between the moving and stationary parts of a machine, or between material and any part of the machine,” according to OSHA. A pinch point can be located anywhere on a machine, including the point of operation. If any part of the worker’s body, typically hands or fingers, occupies that space during the pinching movement, there is a high probability of injury, such as fractures, amputations, contusions, lacerations or even death. Pinch-point hazard injuries can occur on a variety of different machine types, ranging from large hydraulic presses to small specialized machines, such as riveters and welders.

Hand safety regulation
There are several important U.S. hand protection standards designed to help employers keep workers’ hands safe at work: ANSI/ISEA 105-2011, American National Standard for Hand Protection Selection Criteria, and OSHA’s 29 CFR 1910.138.

Physical Barriers: Eliminate the hazard by ensuring proper machine guarding is in place or keeping your hands away from pinch point hand injury and prevention altogether.

Awareness: Pay attention to where your hands are around any moving parts or any objects that have the potential to move. Do not place your hands where you cannot see them.

Spot Welding
Personal Protective Equipment (PPE): Make sure you are always wearing your safety gear and inspect it before each use. Although the last line of defense against a pinch point injury, PPE (proper gloves, footwear) is a necessity to ensure others notice your position and your extremities are protected. Make sure clothing is properly fitted as to not get caught in machinery, moving parts, items that open/close, etc.

Properly block any equipment or parts where stored energy could be released. OSHA defines stored energy as hazardous energy sources including electrical, mechanical, hydraulic, pneumatic, chemical, thermal or other sources in machines and equipment that can be hazardous to workers. During the servicing and maintenance of machines and equipment, unexpected startup or release of stored energy could cause injury to employees. Lockout-tagout procedures need to be put into place to control hazardous energy and prevent unexpected start up.

Properly installed physical barriers or machine guards can help prevent workers from reaching into, through, over, under or around the pinch point.

Riveters & welders
We will be looking at “Good, Better, Best” approaches to safeguarding two machine types that present unavoidable pinch-point hazards – spot welders and pneumatic riveters. It is important to appreciate the magnitude of force between spot welding electrodes or riveting tips.

Spot welders require high forces between the moving electrodes ranging from a few hundred pounds to several thousand pounds. Because the force is concentrated on a small contact surface, the pounds per square foot can be extremely high. For example, a fairly typical electrode of 800 pounds with an electrode that has a ¼ inch diameter contact face will deliver 16,306 pounds per square foot. This is easily enough to severely crush or amputate a finger. Similarly, pneumatic riveting machines produce several thousand pounds of force concentrated on small-diameter mandrils. A typical rivet force of 2,000 pounds will deliver over 40,000 pounds per square inch.

Two-hand control and light curtains can be used to safeguard riveters and welders capable of stopping on the down-stroke (hazardous portion of the cycle, creates the pinch point).

Good: Drop-probe devices
Drop-probes provide economical, simple to understand and use, reliable protection for the operator. Drop-probe devices function by allowing a sensing probe to drop by gravity around the point-of-operation hazard of a riveter or welder prior to each intended machine cycle. The sensing probe cycle is initiated when the foot switch is pressed. If the sensing probe encounters the operator’s fingers and fails to drop past a preset position, the machine will not complete the cycle until the obstruction is cleared and the cycle is re-initiated.

Drop-probe devices can be used on machines that run in an automatic mode, but they only provide risk reduction for the first stroke.

The drawbacks of traditional drop-probe devices are:
– Stroke adjustment is limited to 1-5/16 inches.
– Uses a 50-percent duty rotary solenoid. It needs an equal amount of work time vs. rest time, so it’s not an ideal solution for high-volume welding or riveting applications.

Better: Adjustable stroke drop-probes
Identical in most ways to standard drop-probes, adjustable models offer an externally adjustable stroke, via a clamp collar, typically from 0 to 4.0 inches to accommodate any fixture, tooling, or changes in the profile of the workpieces.

Advantages of this device are:
– Longer stroke adjustment (4-½ inches versus 1-5/16 inches).
– Uses an air cylinder to move the drop probe, which is better suited for high-volume applications.

Best: Continuity monitoring
The most unique and highly effective guarding device measures electrical continuity between the two electrodes to verify they are actually touching the part to be welded, or in the case of a riveter, continuity between the upper and lower mandrils. If anything, such as the operator’s finger, blocks the movement of the electrode, the system will not detect continuity. In other words, it must detect metal between the copper tips or riveting mandrils rather than a finger.

When the foot pedal is closed, the electrodes are close under low force (50 pounds or less).
– If continuity is detected within a customer-set maximum detect time, the air pressure rises to the full welding or riveting level and the process runs through completion.
– If continuity is not detected within this maximum time, low pressure will be released and the electrode or mandril returns to the fully open position.

The continuity signal in a spot welder is picked up from wires on the welding transformer secondary pads, eliminating the need for wire connections at the electrodes. For riveters the sensing wires are connected to the frame of the rivet machine and the electrically-isolated lower tooling holder. In both cases the system will fail safe (lock out) if either of the pick-up wires is disconnected or if they are shorted together.

Rockford Systems offers the Unitrol SOFT TOUCH Pinch-Point Safety System that is the first and only fully passive safeguarding equipment designed to prevent a pneumatic riveter, welder or other small machine from applying full force if it detects fingers in the machine’s point-of-operation area. SOFT TOUCH measures electrical continuity between electrodes to verify they are actually touching the part to be welded — and not the operator’s fingers. If anything other than metal is present between the electrodes, their sensors will not detect continuity and the electrodes will open automatically. This simple step prevents the machine from delivering high-pressure riveting or welding force onto the operator’s fingers.

Conclusion

Pinch-point injuries are common and employers have an obligation to keep worker’s hands safe from pinch-point hazards. As outlined by ANSI B.11, task-based risk assessments are the critical first step in any safety evaluation and can identify hazards, such as pinch-point hazards. Risk-control factors, such as machine guarding, proper training and awareness of hand locations, and lockout tagout procedures, all help prevent pinch-point injuries. Devices, such as SOFT TOUCH, are the best method of safeguarding against pinch-point injuries as it features a 100% passive, fail safe method of detecting continuity.

SAFETY IN NUMBERS: Stop Time Measurements

Stop-Time Measurements Keep Safeguarding Equipment in Peak Performance

We’ve all heard the phrase “what a difference a day makes,” yet when it comes to industrial safeguarding, the concern isn’t days, hours or even minutes. It is the milliseconds it takes for a machine operation to stop. That fraction of a second can make the difference between a life-changing injury or a safe machine cycle, the difference between a valued employee going home or being taken to the emergency room.

How can we assure the right outcome? How do we determine if a machine will stop in time?

The answer is specialized equipment called “Stop-Time Measurement” devices (STM). An STM is used to determine the total response time from the triggering of a machine’s operating control or a safeguarding device… to the exact moment when a dangerous movement comes to a halt. Take, for example, the time it takes for a press brake cycle to stop when a finger or hand enters the point-of-operation zone, or the time between when a light curtain is activated and when the machine comes to a complete standstill.

Once the stop-time data is captured by an STM in either milliseconds or inches, it is applied to an established formula to calculate the minimum safety distance required to install safety devices. A record of the measurement can be printed out, or alternatively, the device can be plugged into a PC where the measurements can be recorded and documented.

Doing the Math
According to OSHA, the majority of machine-related accidents happen as a result of a reflex action or when the operator is not paying attention. For example, a machine operator may instinctively reach into the machine when there is an issue. Or they will be so focused on a task that they’ll cross the threshold into a hazardous area without being aware of it. In these events, it is critical that a machine’s safety devices stop operations before the hazard is reached. In addition, accidents may not be the fault of the operator at all. There are instances where integrators do not program the field of coverage — the area being monitored by the light curtain, for instance — at the proper safety distance and puts the operator unknowingly at danger.

So what is the correct distance? The basic calculation for ‘safety distance’ comprises approach speed, overall stop time and penetration depth factor.

The standard formula is below:
DS = K (T) + DPF
where:
DS = the safety distance
K = the maximum speed that an individual can approach the hazard
T = the total time to stop the hazardous motion
DPF = the depth penetration factor of the safeguarding device

There are other variations on this calculation; for example, where a light curtain is in operation, the calculation requires both the resolution and the response time of the light curtain to be factored. Most STM devices perform calculations internally so the operator doesn’t need to concern themselves with all the details of the math, only the results to act upon.

In the United States there are two formulas that are used to properly calculate the safety distance. The first, the OSHA formula, is the minimum requirement for the calculation of the safety distance. The second is the ANSI formula, which incorporates additional factors to be considered when calculating the safety distance. Rockford Systems recommends the use of the ANSI system since it is the more comprehensive of the two. The formula is included in ANSI standards B11.19-2010 and Robotic Industries Association (RIA) R15.06-1999 (R2009), as well as CSA Z142-10, Z432-04 and Z434-03.

Stop-Time Measurement Service
For all linear and rotating motion equipment, Rockford Systems offers STM service for newly installed safety devices as well as for the periodic validation of existing safety devices. Periodic safety distance validation with an STM is required for AOPD systems, light curtains, 2-hand control systems, emergency stop devices, pressure-sensitive protective strips or mats, interlocking guards, doors and gates, as well as other safety devices and controls equipment used during production. This is necessary since factors like maintenance, brake wear, and alterations can increase the machine’s stopping time. If a machine stops slower than it did when it was originally commissioned then components will need to be adjusted to continue providing the correct level of safety. Stop time measurement is able to detect changes at an early stage, so that appropriate action can then be taken. For these and other reasons it is important to perform at least an annual stop time analysis. Rockford Systems STM services are mainly employed on reciprocating (stroking or cycling) machines, such as mechanical or hydraulic presses and press brakes, but can also be used on machines that rotate, such as lathes, mills, and drills.

Location of a safety component, whether hard guarding or electronic, is based upon the machine’s stopping time. Simply stated, a safety component should be placed far enough away from the risk area that it is not possible to reach the hazard before the machine has stopped. Safety devices are then installed using the minimum safe distance. Reference our OSHA Safety Distance Guide Slide Chart.

Regularly checking shop machinery with Stop-Time Measurements and maintaining a log of the results empowers a company to be proactive in establishing a safety maintenance program. It ensures that safeguarding equipment on machinery works as designed to achieve greater worker safety, productivity and profits.

I, COBOT

I, COBOT: The Rise of Industrial Robotics and the Need for Employee Safeguarding

In general, OSHA’s view on robot safety is that if the employer is meeting the requirements of ANSI/RIA R15.06, the manufacturer has no issues.

Tech executive and billionaire entrepreneur Elon Musk recently took to Twitter calling for the regulation of robots and Artificial Intelligence (AI), saying their potential, if left to develop unchecked, threatens human existence. Google, Facebook, Amazon, IBM, and Microsoft joined in with their own dire forecasts and have jointly set up the consortium “Partnership on AI to Benefit People and Society” to prevent a robotic future that looks not unlike the “Terminator” movie series. National media heightened panic by broadcasting a video released by a cybersecurity firm in which a hacked industrial robot suddenly begins laughing in an evil, maniacal way and uses a screwdriver to repeatedly stab a tomato. The video demonstrated how major security flaws make robots dangerous, if not deadly.

Is all this just media hyperbole, or are robots really that hazardous to our collective health? Are productivity-driven manufacturers unknowingly putting employees at risk by placing robots on the plant floor? What kind of safeguarding is required? Should robots be regulated, as Elon Musk believes?

‘Dumb’ Machines vs. Cobots
Until now, the robots used in manufacturing have mostly been “dumb” robots—that is, room-sized, programmed machinery engineered to perform repetitive tasks that are dirty, dangerous, or just plain dull. Typical applications would include welding, assembly, material handling, and packaging. Although these machines are very large and certainly have enough power to cause injuries, the instances of employees actually being injured by robots is relatively rare. In fact, during the past three decades, robots have accounted for only 33 workplace deaths and injuries in the United States, according to data from the Occupational Safety and Health Administration (OSHA).

So, you might ask, why the sudden uproar when there are already 1.6 million industrial robots in use worldwide? Most of the clamor behind calls for regulation stems from a new generation of robots called “cobots” (collaborative robots) that are revolutionizing the way people work. Unlike standard industrial robots, which generally work in cages, cobots have much more autonomy and freedom to move on their own, featuring near “human” capabilities and traits such as sensing, dexterity, memory, and trainability.

The trouble is, in order for cobots to work productively, they must escape from their cages and work side by side with people. This introduces the potential for far more injuries. In the past, most injuries or deaths happened when humans who were maintaining the robots made an error or violated the safety barriers, such as by entering a cage. Many safety experts fear that since the cage has been all but eliminated with cobots, employee injuries are certain to rise.

Because cobots work alongside people, their manufacturers have added basic safety protections in order to prevent accidents. For instance, some cobots feature sensors so that when a person is nearby, the cobot will slow down or stop whatever function it is performing. Others have a display screen that cues those who are nearby about what the cobot is focusing on and planning to do next. Are these an adequate substitute for proven safeguarding equipment? Only time will tell.

There is another, more perilous problem with robots in general: Robots are basically computers equipped with arms, legs, or wheels. As such, robots are susceptible to being hacked. But unlike with a desktop computer, when a robot is hacked it has the ability to move around. For instance, a disgruntled ex-employee could hack into a robot and re-program it to harm people and destroy property. The more functionality, intelligence, and power a robot has, the bigger its potential threat.

Types of Injuries
OSHA lists four types of accidents resulting from robot use in the Technical Manual “Industrial Robots and Robot System Safety” (Section IV: Chapter 4).
1. Impact or collision accidents. Unpredicted movements, component malfunctions, or unpredicted program changes related to the robot’s arm or peripheral equipment could result in contact accidents.
2. Crushing and trapping accidents. A worker’s limb or other body part can be trapped between a robot’s arm and other peripheral equipment, or the individual may be physically driven into and crushed by other peripheral equipment.
3. Mechanical part accidents. The breakdown of the robot’s drive components, tooling or end-effector, peripheral equipment, or its power source is a mechanical accident. The release of parts, failure of gripper mechanism, or the failure of end-effector power tools (e.g., grinding wheels, buffing wheels, deburring tools, power screwdrivers, and nut runners) are a few types of mechanical failures.
4. Other accidents. Other accidents can result from working with robots. Equipment that supplies robot power and control represents potential electrical and pressurized fluid hazards. Ruptured hydraulic lines could create dangerous high-pressure cutting streams or whipping hose hazards. Environmental accidents from arc flash, metal spatter, dust, electromagnetic, or radio-frequency interference also can occur. In addition, equipment and power cables on the floor present tripping hazards.

Robot Safety Regulations
Robots in the workplace are generally associated with machine tools or process equipment. Robots are machines, and as such, must be safeguarded in ways similar to those presented for any hazardous remotely controlled machine, falling under the OSHA General Duty Clause (5)(a)(1), which requires employers provide a safe and healthful workplace free from recognized hazards likely to cause death or serious physical harm. Also applicable are OSHA 1910.212 (a)(1) “Types of Guarding” and 1910.212 (a)(3)(ii) “The point of operation of machines whose operation exposes an employee to injury shall be guarded.”

Various techniques are available to prevent employee exposure to the hazards that can be imposed by robots. The most common technique is through the installation of perimeter guarding with interlocked gates. A critical parameter relates to the manner in which the interlocks function. Of major concern is whether the computer program, control circuit, or the primary power circuit is interrupted when an interlock is activated. The various industry standards should be investigated for guidance; however, it is generally accepted that the primary motor power to the robot should be interrupted by the interlock.

In general, OSHA’s view on robot safety is that if the employer is meeting the requirements of ANSI/RIA R15.06, Industrial Robots and Robot Systems—Safety Requirements, then the manufacturer has no issues. For guidance on how to select and integrate safeguarding into robot systems, refer to the Robotic Industries Association’s Technical Report: RIA TR R15.06-2014 for Industrial Robots and Robot Systems—Safety
Requirements and Safeguarding.

Published by the American National Standards Institute (ANSI) and Robotic Industries Association (RIA), ANSI/RIA R15.06 is a consensus standard to provide guidance on the proper use of the safety features embedded into robots, as well as how to safely integrate robots into factories and work areas. The latest revision of the standard, ANSI/RIA R15.06-2012, references for the first time ISO 10218-1 & 2 to make it compliant with international standards already in place in Europe. Part 1 of ISO 10218 details the robot itself; Part 2 addresses the responsibilities of the integrator.

There are also new requirements in ANSI/RIA R15.06-2012 for collaborative robots; in this case, ISO 10218 and the ISO/TS 15066 Technical Specification. This standard clarifies the four types of collaboration: Safety Monitored Stop, Hand Guiding, Speed & Separation Monitoring, and Power & Force Limiting. ISO/TS 15066 holds key information, including guidance on maximum allowable speeds and minimum protective distances, along with a formula for establishing the protective separation distance and data to verify threshold limit values for power and force limiting to prevent pain or discomfort on the part of the operator.

The requirement for risk assessments is one of the biggest changes in the new RIA standard. The integrator, or the end user if they are performing the job of an integrator, now must conduct a risk assessment of each robotic system and summarize ways to mitigate against these risks. This may involve procedures and training, incorporating required machine safeguarding, and basic safety management. Risk assessments calculate the potential severity of an injury, the operator’s exposure to the hazard, and the difficulty in avoiding the hazard to arrive at a specific risk level ranging from negligible to very high.

In the future, as cobot use rapidly expands throughout industry, regulation of this technology will grow more focused and specific. Consider this: Although cobots currently represent only 3 percent of all industrial robots sold, they are projected to account for 34 percent of the industrial robots sold by 2025, a market that itself is set to triple in size and dollar volume over that period.

Conclusion
The next 10 years will be pivotal for American manufacturing, and success largely depends on companies’ ability to navigate the transition from traditional manufacturing to Industry 4.0-style automation and the widespread use of robots. While few people have as dire a view as Elon Musk on the subject, it is critical that employee safety is not lost in the excitement as we shepherd robots out of their cages to work hand in hand with humans.

Lack of Machine Guarding Again Named to OSHA’S Top 10 Most Cited Violations List

Every year around this time, the awards season kicks off with the Emmys, Golden Globes and the grand daddy of them all, the Oscars, eagerly announcing their lists of nominations. At the same time — and on a far more somber note — another roll call is issued, this one from the Occupational Safety & Health Administration (OSHA). Unlike Hollywood’s awards celebrations, however, no one wants to be nominated for OSHA’s Top Ten Most Cited Violations list, let alone take home the top prize.

OSHA revealed its 2017 Top 10 list at the National Safety Congress & Expo in the Indiana Convention Center. The top ten are:

1. Fall Protection – (1926.501): 6,072 violations
2. Hazard Communication (1910.1200): 4,176 violations
3. Scaffolding (1926.451): 3,288 violations
4. Respiratory Protection (1910.134): 3,097 violations
5. Lockout/Tagout (1910.147): 2,877 violations
6. Ladders (1926.1053): 2,241 violations
7. Powered Industrial Trucks (1910.178): 2,162 violations
8. Machine Guarding (1910.212): 1,933 violations
9. Fall Protection – Training Requirements: 1,523 violations
10. Electrical – Wiring Methods (1910.305): 1,405 violations

While reviewing the list, it is important to remain aware that the Federal Occupational Safety & Health Administration (OSHA) is a small agency. When tallied up to include its state partners, OSHA only has 2,100 inspectors who responsible for the health and safety of 130 million American workers, employed at more than 8 million work sites. This translates to about one compliance officer for every 59,000 workers. As a result, some serious injuries are not reported and thousands of potential violations go without citation or fines. In fact, numerous studies have shown that government counts of occupational injury are underestimated by as much as 50 percent. Employers are required to record all injuries meeting the OSHA’s ‘recordable injury’ criteria (except minor first-aid cases) on the OSHA 300 Log, and those meeting the ‘reportable’ criteria (e.g., hospitalizations or deaths), are to be reported to OSHA immediately, or within 24 hours of occurrence, as per the criteria defined in 29 CFR 1904. But it doesn’t mean all of them do.

MACHINE (UN)SAFEGUARDING IN TOP 10 MOST CITED VIOLATIONS
The absence of required machine safeguarding remains a perennial member of OSHA’s Top 10 Most Cited Violations, and 2017 was no exception. It was named number eight on the list with a total of 1,933 violations. These violations refer to OSHA 1910.212 for failing to have machines and equipment adequately guarded. Any machine part, function, or process that might cause injury should be safeguarded. When the operation of a machine may result in a contact injury to the operator or others in the area, the hazard should be removed or controlled.

A lack of machine safeguarding also held the dubious distinction of making the list of OSHA’s ten largest monetary penalties for the year — not once but four times. In fact, the largest proposed monetary penalty, a staggering $2.6 million (USD), arose from an incident where a worker was crushed to death while clearing a sensor fault in a robotic conveyor belt. OSHA alleges that the company failed to use energy control procedures to prevent robotic machinery from starting during maintenance. The manufacturer also was cited for exposing employees to crushing and amputation hazards as a result of improper machine guarding, plus failing to provide safety locks to isolate hazardous energy.

Despite these headline fines, the repercussions for employers putting workers in harm’s way remain small under the 1970 Occupational Safety and Health Act. The average federal fine for a serious workplace safety violation was $2,402 in fiscal year 2016, according to the most recent report by the AFL-CIO. And the median penalty for killing a worker was $6,500.

According to the most recent Bureau of Labor Statistics data, manufacturing plants reported approximately 2,000 accidents that led to workers suffering crushed fingers or hands, or had a limb amputated in machine-related accidents. The rate of amputations in manufacturing was more than twice as much (1.7 per 10,000 full-time employees) as that of all private industry (0.7). The bulk of these accidents occurred while removing jammed objects from a machine, cleaning or repairing the machine, or performing basic maintenance. These injuries were all largely preventable by following basic machine safeguarding precautions. Rockford Systems is committed to helping organizations reduce injuries and fatalities due to a lack of or non-compliant machine safeguarding. By creating a culture of safety in the workplace, Rockford Systems can help plant managers significantly reduce the number of on-the-job injuries and fatalities that occur annually, plus guard against hefty fines, lost production and increased insurance premiums.

Which leads to the question… “Where do we begin?”

TRAINING AND EDUCATION

Ignorantia juris non excusat (“ignorance of the law excuses not”). Recognizing that education is key to safety, Rockford Systems has offered its Machine Safeguarding Seminars for more than two decades. Thousands of safety professionals have attended the seminars from industries as diverse as aerospace and metal fabrication, to government and insurance.

Held ten times a year at our Rockford, Illinois headquarters, the 2.5 day seminars address key topics in safeguarding with a focus on OSHA 29 CFR and ANSI B-11 standards as they relate to specific machine applications and production requirements. Safeguarding equipment, both old and new, is not only explained in depth in the classroom, but demonstrated under power on the shop floor. Most of these machines are equipped with more than one type of safeguarding product so that attendees can see how different guards and devices can be applied.

Roger Harrison, Director of Training for Rockford Systems and an industrial safeguarding expert with over 25,000 hours of training experience, conducts the Machine Safeguarding Seminar.

>Another valuable educational resource is OSHA-10 General Industry and OSHA-30 General Industry training courses, both of which cover machine guarding. All of our training can be provided at your site, if preferred. To learn more about the Rockford Systems training curriculum, please visit https://www.rockfordsystems.com/seminars/

Rockford Systems also provides a variety of FREE machine safeguarding resources for your organization. Please visit our RESOURCES page to find videos, blogs, quick reference sheets, and more or visit our YouTube channel to download past webinar recordings.

ASSESSMENTS
If your organization is interested in safeguarding solutions, consider a Machine Risk Assessment or Machine Safeguarding Assessment as the critical first step in any machine guarding process as outlined in ANSI B11. Most assessments, but not all, follow the basic steps outlined below.

Step 1 – Provide Machine List
To get started, please provide Rockford Systems a list of all machines (manufacturer, model number, and machine description of each machine) to be assessed. This machine list is needed to determine the estimated resource requirement for the onsite audit. Upon receipt of your machine list, an Assessment Proposal will be provided, generally within 24 hours of receipt. Please email your machine list and any machine photos (optional) to sheryl.broers@rockfordsystems.com.

Step 2 – Schedule Onsite Visit
During the assessment, a machine safeguarding specialist will visit your site and conduct a complete audit of all machines identified on the list and evaluate their compliance in five guarding areas (Safeguards, Controls, Disconnects, Starters, and Covers). The assessment is based on OSHA 1910.212 General Requirements (a)(1), ANSI B11 Safety Standards for Metalworking, ANSI/RIA R15.06-2012 Safety Standards for Industrial Robots, and NFPA 79. If Rockford Systems, LLC has additional specific safeguarding requirements above and beyond OSHA 1910.212 and ANSI B11, please provide them before the site visit and we will incorporate them into the assessment.

Also, during the assessment, we may request copies of electrical, pneumatic and/or hydraulic schematics and operator manuals for specific machines. This information is needed for our Engineering Department to review the control circuit for electrical compatibility of equipment being offered, to verify control reliability of the control circuit, to determine interfacing requirements of suggested equipment. If requested, this information would be needed before advancing to Step 3 below.

Step 3 – Receive Compliance Report and Safeguarding Project Proposal
Upon completion of the assessment, a Compliance Report and Safeguarding Project Proposal will be provided to that identifies where each machine is in, or not in, compliance with the above stated regulations and standards. Where not in compliance, we will suggest guarding solutions to bring the machines into compliance, along with associated costs and timeframes.

We look forward to assisting your organization with its safeguarding needs. A team member will call you within 24 hours to further discuss your needs and applications. We are here to help businesses large and small address machine safety challenges and to remove the burden of managing the growing legal complexity of OSHA, ANSI and NFPA requirements from simple turnkey solutions to build-to-spec customized solutions.

Please contact sheryl.broers@rockfordsystems.com or call 1-815-874-3648 (direct) to get started on an assessment today.

PRODUCTS
If you are looking for Machine Safeguarding Products, please visit our PRODUCTS page that offers over 10,000 safeguarding solutions for drill presses, grinders, lathes, milling machines, press brakes, power presses, radial arm drills, riveters and welders, robots, sanders, saws and more.

RETURN ON INVESTMENT
Not sure if the investment in machine safeguarding provides a return on the investment (ROI), it absolutely does and we can help you calculate it. Please read our detailed blog post on this topic.

For more information on how avoid machine injuries and fatalities, please visit www.rockfordsystems.com.

Press Brake Safeguarding To Prevent Injuries

Including In-Depth Analysis of Light Curtains vs. Laser AOPD

Press brakes are unforgiving machines and a common source of workplace amputations of hands, fingers and arms. United States Department of Labor statistics indicate an average of 368 instances of amputations annually from press brake accidents. And these are only the reported accidents.

WHY ARE PRESS BRAKES SO DANGEROUS?
The primary reasons are access to the point of operation at the front of the machine, as well as reaching around the safety device to get to the point of operation at the ends of the machine. In addition, there are pinch points and hazardous motion created by the back-gauge system.

But the dangers don’t stop there. However well intentioned, fabricators often employ lower cost, used or refurbished press brakes where the primary controls and/or condition of the machine and safety system may be suspect. Plus, original equipment manufacturers (OEM’s) generally consider the point of operation aspect of the press brake safety system to be the end-user’s responsibility. The end-user may assure, incorrectly, that the machinery arrived into the shop ready for commissioning. Lastly, press brakes have always been operator intensive, sometimes involving multiple operators, and operator behavior is not always predictable. That is why it is good practice to make one operator the leader of the crew.

OSHA/ANSI SAFETY REGULATIONS
OSHA’s machinery and machine guarding regulations (29 CFR 1910 Subpart O) require one or more guarding methods to protect employees from exposure to hazardous machine energy during the operation of press brakes. There isn’t a great deal of detail to the OSHA regulations so fabricators in search of answers would be better served by turning to ANSI B11.3-2012 which covers safeguarding of power press brakes. The B11.3 adopted EN 12622 (European standard), giving it even more specific instructions to follow and minimizing any vague, grey areas.

ANSI B11.3 is the only safety system standard specifically applicable to power press brakes used in America, and it excludes mechanical power presses; hydraulic power presses, hand brakes; tangent benders; apron brakes; and other similar types of metal bending machines. It discusses hazards associated with the point of operation at length and identifies alternative guards and devices. For example, the ‘close proximity point of operation AOPD’ safeguarding devices, which we will discuss later in this blog, and a means of safeguarding referred to as ‘Safe Speed.’ We should note that ANSI B11.0-2015 recommends risk assessments of press brakes among other equipment, offered by Rockford Systems.

PRESS BRAKE PROTECTION OPTIONS
Today, there several ways to safeguard a press brake, some better than others. All have advantages and drawbacks.

The most basic type of safeguarding is a fixed and interlocked barrier guard coupled with two-hand controls. This is not a functional solution for fabricators as a work piece is hand held in close proximity to the point of operation during the braking process and can potentially whip up as bending is taking place.

Another approach are pull backs and restraints. Both are restrictive and have limitations and for that reason, operators dislike them. Both devices shackle the operator to a machine and restricts mobility. Yet another approach is the two-hand down/foot-through device. In some cases, this will work. However, this method raises ergonomic issues and it is very slow. Not what you want in a busy, production-driven fabrication shop.

SHEDDING LIGHT ON SAFETY
A modern light curtain is a photoelectric presence-sensing device that protects against access into hazardous points and areas of the press brake. They can range from very compact to larger, more robust and resistant models that can withstand demanding ambient conditions. We should note that a stop-time measurement (STM) device is needed to calculate the safety distance on a regular basis, just as it is needed with two-hand controls.

Safety Light Curtains safeguard personnel using an LED transmitter and receiver. Any interruption of the plane of light by an object equal to/or larger than the “minimum object sensitivity” initiates an output signal. That could be a hand or a finger or a misplaced tool that will either cause the machine to stop or prevent a cycle until the blockage is removed. The operator must be outside the protected area through the entire stroke of the press brake ram. The safety distance between the light curtain and the machine depends on the application, the type of light curtain, and the machine’s stopping performance.

OSHA has a set of regulations for light curtains that are listed here:
1. The machine must be able to stop the movement of the ram anywhere in the stroke.
2. The stopping time of the ram must be known.
3. The stopping time of the ram must be monitored for deviation in stopping time on each stroke.
4. The minimum distance the light curtains can be located to the pinch point must be known.
5. The light curtains must be control reliable.
6. The machine stop circuit with which the light curtains are interfaced, must be control reliable.
7. The light curtains must be self checking for proper operation on each stroke.
8. There should be no easy way to disable the safety system without special tools.
9. If the safety system is disabled there should be a clear indication that it is disabled.
10. The operator and setup person should be properly trained in the operation of the safety system.

LASER FOCUSED ON SAFETY
The newest entry into the press brake safety category is probably its most revolutionary, the Laser Active Optic Protective Device, more commonly referred to as the AOPD. Four manufacturers now make AOPD systems including LazerSafe™ a partner of Rockford Systems. Inclusion of Laser AOPD technology in the B11.3 is a welcome addition to the standard that now gives press brake manufacturers, dealers and users a clear guideline to implementing this technology safely. (B11.3 sub-clause 8.8.7 – Close Proximity Point of Operation AOPD Safeguarding Device)

The biggest advantage of AODP is that operators can hand-hold piece parts up close to the dies, while using a foot-switch to actuate the machine-cycle, which is almost impossible to safely accomplish using a light curtain. Another advantage is for larger piece parts with tall side-legs that would be difficult when using a vertically mounted light curtain for safeguarding. For those familiar with using light curtains, those two situations often require excessive “Channel Blanking” which “yes” allows for production of those parts, but often lets the hands and fingers to reach too close to the dies.

LIGHT CURTAINS or AODP?
Laser AOPD protects the point of hazard whereas light curtain systems restrict operator access to the point of hazard. Operators can hand-hold piece parts up close to the dies with AOPD, while using a foot-switch to actuate the machine-cycle. This is virtually impossible to safely accomplish using a Light Curtain. But that doesn’t make AODP perfect for every application. AOPD systems are well suited for applications such as box bending, bending with flanges, or where light curtain effectiveness is diminished due to excessive blanking or muting.

There are advantages and drawbacks to both systems. And we would stress that it is not an “either-or” situation between light curtains and AODP. The two can be used, and often are, on the same machine. Light curtains provide for die configurations that the AODP won’t handle like compound bends, for instance. This is done to ensure that safeguarding is provided for all die setups. For die setups where neither light curtains or AOPD can offer effective safeguarding, but the part can be fixture in place, that is it does not require hand-support, a two-hand control can be used for safeguarding.

The diagram below sums up the two systems.

The Alternative Universe of Lockout/Tagout

On the surface, at least, machine lockout/tagout (LOTO) appears simple: Identify and isolate energy sources, lock and tag, and perform the procedure that needs to get done.

Simple, right? Wrong.

When energy is required to complete machine diagnostics or set-up work, or when a minor maintenance job is going to throw production hours behind schedule, LOTO becomes something far more complex than a textbook explanation.

Once you understand its intricacies, it is understandable why LOTO, as outlined in OSHA standard 29 CFR 1910.147 ”The Control of Hazardous Energy (Lockout/Tagout), has become an everyday struggle for many safety personnel. And why LOTO ranks among OSHA’s top ten violations, year after year. It is also understandable why industry is fast embracing the concept of “Alternative Measures”.

OSHA REQUIREMENTS
OSHA 29 CFR 1910.147 requires employees to remove power sources to a machine that could otherwise result in personal injury if energy were unintentionally released during maintenance or service. It clearly states facilities are responsible for establishing a written program covering how required safety measures will be applied. This includes provisions for developing machine-specific energy control procedures, training authorized workers to protect themselves with lockout/tagout, and for periodic inspections of the adequacy of the written procedures, along with the performance of personnel applying them.

As comprehensive as LOTO may be, it can be very time-intensive, often requiring longer than is required to finish the actual maintenance task on the machine. Production comes to a halt, resulting in the day’s production numbers potentially being missed. This becomes even more frustrating when the maintenance task is one that must be implemented several times a day. Loss of time and profits create a strong incentive to bypass LOTO to carry out repetitive machine tasks. However, it still violates OSHA requirements and puts workers in serious danger.

Thankfully, OSHA 29 CFR 1910.147 also outlines “Alternative Protection Measure” (APM) procedures that can result in increased efficiency without compromising the safety of the operation. This exception is also referred to as the “minor servicing exception”. Designed for machine tasks that demand frequent repetitive access, i.e., clearing a jam on a conveyor or a minor tool change, Alternative Measures do not require that power sources be completely cut off. Examples of Alternative Methods technology may include key-controlled locks, control switches, interlocked guards, remote devices and disconnects. It can also mean locking out just a section of a piece of equipment, rather than the entire machine.

ANSI REQUIREMENTS
The newest ANSI standard, ANSI/ASSE Z244.1 (2016) The Control of Hazardous Energy – Lockout, Tagout and Alternative Methods, agrees with OSHA in that workers should be protected from injury due to unexpected equipment startup or release of potentially hazardous energy. However, the ANSI committee did not try to align fully with every historic OSHA compliance requirement. Instead, the new standard gives expanded guidance beyond OSHA’s regulatory limitation to tasks that are “routine, repetitive and integral to production operations”.

ANSI makes it very clear that LOTO shall be used unless the user can demonstrate that a well-established alternative method will provide effective protection. In situations where the task is not well understood or risk assessed, lockout shall be the default protective measure applied to control machinery or processes. Section 8.2.1 of ANSI/ASSE Z244.1 (2016) specifies that alternative methods shall only be used after hazards have been assessed and documented through the application of a Practicability (or Justification) Study to determine that the techniques used will result in a negligible risk or no risk for sudden start up. Following the Hierarchy of Control model, ANSI/ASSE Z244.1 (2016) provides detailed guidance on if, when, and how a range of alternative control methods can be applied to result in equal or improved protection for people performing specific tasks. In addition, alternative risk reduction methodology is covered in detail specific to a number of new technologies including the Packaging, Pharmaceutical, Plastics, Printing, and Steel Industries; Semiconductor and Robotic Applications and others challenged by the current regulatory limitations.

Since the two standards are somewhat conflicting it is best to review ANSI first to help identify discrepancies that may not meet federal minimum regulations.

At this point, it would be appropriate to underscore that LOTO provides the greatest level of protection and, whenever possible, it should be utilized to protect employees from hazardous energy. In other words, inconvenience alone is not an acceptable excuse to use alternative measures. In addition, CFR 1910.147 clearly states that an allowable alternative measure must provide the same or greater level of protection as LOTO. Otherwise, it is considered noncompliant and therefore insufficient to replace LOTO.

By using standard safety-rated devices, such as interlock gates and e-stop buttons, a plant manager can achieve safe, reliable machine access that replaces standard LOTO procedures without violating OSHA requirements. Implementing alternative procedures to ensure equivalent protection for specific tasks can enhance productivity without endangering employees. But those procedures — and their benefits — come with strings attached, requiring a thorough understanding of the latest OSHA and ANSI standards.

Detect-A-Finger® Prevents Welding and Riveting Injuries

According to the Bureau of Labor Statistics, more than 5,000 American manufacturing workers suffer injuries involving amputation or limb loss every single year. In all, amputations rank in OSHA’s top three serious workplace injuries. The Detect-A-Finger® drop-probe device is designed to prevent a riveter, welder or other small machine from cycling if it encounters fingers in the point-of-operation area, therefore preventing contact between the operator and dangerous moving parts.

Simplicity is the key to Detect-A-Finger’s success. Whenever an operator initiates a machine cycle, typically through an electric foot switch, the Detect-A-Finger sensing probe is automatically released, ensuring that safeguarding can not be deactivated or overlooked by the operator. If the probe detects anything more than the material thickness, it halts the machine from cycling. However, if an operator’s fingers or hands have not entered the point-of-operation area, the sensing probe will drop into its preset position, and the Detect-A-Finger’s control unit will allow the machine to cycle to maintain ongoing machine productivity and performance.

With its compact design, Detect-A-Finger easily mounts on most machines, regardless of brand, providing fabricators with an invaluable way to enhance both safety and productivity. Depending on space and preference, the drop probe assembly can be mounted on either the left or right side of a machine, while the head and control unit are normally mounted on the machine frame or custom-fabricated brackets. The aluminum probe rod is shaped to fit around the tooling, allowing parts to be formed safely at high speed to achieve maximum output.

Protection For Most Machinery
Accidents occur on all types of manufacturing equipment, which is why Rockford Systems offers its proven Detect-A-Finger system to safeguard virtually every machine found on a plant floor.

The RKC-000 Detect-A-Finger model is for smaller machines, including riveters, eye letters, stalkers, staplers, crimpers, and fastening and assembly machines. Available now online for $868.00 (USD), this version is ideal for retrofitting machines to meet new safety standards.

The RKC-500 Detect-A-Finger model is exclusively for welders. The unique design of its sensing probe module allows it to be attached to a welder arm, whether it is fixed or moving. Depending on the type of welder, a single-stage or a two-stage foot switch may be required. It may also be applied to mechanical foot pedal-type welders, although the mechanical pedal must be removed and replaced with an air cylinder. The RKC-500 is available for $1,053.00 (USD).

The DAF-100 Detect-A Finger model is the premium version for both riveters and welders. Featuring an adjustable stroke up to four-inches, it comes with the control box, drop-probe assembly, aluminum sensing probes, and other necessary components. The DAF-100 is available for $1,998.00 (USD).

All Rockford Systems Detect-A-Finger versions are designed for compliance with OSHA 29 CFR, Subpart 0, 1910.212 general requirements for all machines.