How Rockford Systems Light Curtains Can Brighten Employee Safety in Your Plant

At first glance, a simple beam of infrared light would seem ineffective protection against fast-moving, dangerous industrial machinery. After all, isn’t that what heavy-duty steel guards are for? Yet, these beams of infrared light, when utilized as a component of “safety light curtains,” have prevented thousands of employee injuries and saved countless lives. Unlike other types of more bulky safeguards, such as physical barriers, light curtains make it easier to access equipment while performing maintenance or semi-automatic processes that require human interaction. Whether they are used to reduce exposure to point-of-operation hazards, or as a perimeter guarding device, being lightweight and compact makes light curtains ideal for machinery, robots or areas that require frequent access for purposes of material feeding, maintenance, repair, setup or the need to be adapted quickly to layout changes on a plant floor.

Light curtains are defined as being presence-sensing optoelectronic devices, and are often used as a component within an overall safety system in meeting nationally recognized safety regulations and standards, such as OSHA or ANSI (B11.19-2019). The most common application of light curtains is to detect people or objects passing through a perimeter boundary, or close to protect from direct contact with a machine’s point-of-operation. “Point of Operation” in this instance refers to where production material is being positioned for punching, bending, cutting, machining or where any type of hazardous motion is present. This is why light curtains are installed onto power presses and metal forming machines to protect the operator’s hands or fingers from crush injuries.

Transmitters and Receivers

Although light curtains come in a wide variety of designs, the two common features that make them alike are a transmitter and receiver. Transmitters units have a series of LEDs that emit an array of synchronized, parallel infrared light beams to a separate receiver unit on the other end. The receiver has a corresponding array of photo-diodes that automatically synchronize with the transmitter LEDs, in effect, “receiving” the pulses. Receiver circuitry is designed to detect only the specific pulse and frequency designated for it, preventing external light sources from being sensed. These systems can be mounted vertically, horizontally, or on any angle depending on the application. The only requirement is that the transmitter must align with the receiver when installed.

It is important to note that light curtains differ from other photoelectric sensors in that they have self-monitoring circuitry. When photoelectric cells from the transmitter are interrupted by an opaque object, this event triggers an output signal that is typically fed to a safety relay device delivering redundant protection. For example, if a person steps into a prohibited zone, this safety relay would signal to the machine to stop anywhere in its cycle or stroke to prevent a potentially catastrophic accident. Light curtains should only be used on machinery that can be quickly stopped anywhere within the machine’s cycle, and should never be used on any machine with a full-revolution clutch.

Once tripped, a conscious action is required on behalf of the operator to re-start the machine cycle after the source of the light curtain interruption is addressed. Prior Action Stations must be located outside yet within view of the protected area to prevent the inadvertent automatic or continuous resumption of the machine. Depending on the light curtain and its application, a separate enclosure may hold various diagnostic indicators, power supply, user controls and control logics that cannot be installed within the receiver.

Another light curtain design worth noting is an “active passive system” consisting of two unique devices. One both emits and receives beams while the other device essentially acts as a mirror to deflect the beams back to the receiver. While this approach minimizes overall costs and wiring, an active passive system reduces the intensity of the light beam and therefore normally has a much shorter operating range than a standard system. Mirrors will reduce the operating range of a light curtain by up to 18% per mirror, depending on the type of mirror installed.

Blanking & Muting

As mentioned earlier, light curtains come in a wide variety of resolutions and IP ratings. Other more advanced features have to do with minimizing the disruption to factory flow caused by machinery being completely shutdown when light beams detect an obstruction. Two worth noting are “blanking” and “muting” — two terms that are frequently used interchangeably yet incorrectly. Muting is the temporary automatic suspension of the entire curtain while a non-hazardous portion of the machine cycle is being performed, for example, during a press’s up stroke. Blanking is more complex. Instead of muting the entire sensing field, blanking is the bypassing of only a portion of it, leaving the rest of the light curtain active. Blanking finds utility when material is fed through the sensing field while the machine is in motion. Obviously, care must be taken to ensure the operators hands, fingers or arms cannot fit through the blanked portion.

Minimum Safety Distance 

When utilizing a light curtain as a point-of hazard safeguarding device, it is important to know and understand the stopping time of your machine.  Both OSHA, ANSI, and ISO all provide formulas to calculate the safe mounting distance of a light curtain based on the stopping time of your machine.  OSHA’s formula is the base requirement, while ANSI and ISO formulas represent best safety practice, and generally result in more than a 10% increase in safe mounting distance.

Light Curtain Resolution

The resolution of a safety light curtain is its detection capability measured as the amount of separation between its laser beams. Higher resolution light curtains improve the detection capability that can sometimes allow for the light curtain to be safely mounted closer to a hazard. While a 14mm resolution is ideal for finger detection and can be deployed closer to the source of hazardous motion, a lower 25-30mm resolution is all that is required for hand detection.

Rockford Systems strongly recommends a risk assessment prior to any light curtain installation.

Status Indicator Lights

Light curtains often feature status indicators clearly visible from a distance, preventing close proximity to dangerous machinery. Red, green, and yellow lights conveniently display operating status, configuration error codes, and blocked beams.

Questions to consider when selecting a light curtain:

  • What is the stopping time of the machine or equipment? Is it sufficient to even consider a presence sensing device?
  • How large is the area needing to be protected, and are there two corners or four corners?
  • What is the required height of the protection field?
  • What is the required operating range?
  • What is the required resolution, usually measured in millimeters? The tighter the required spacing, the higher the resolution.
  • What are your mounting requirements?
  • What Performance Level (PL) is required?
  • What environmental challenges will the light curtain face, including excessive temperatures, moisture exposure, and shock/vibration that can damage the equipment? This is often measured in IP ratings.
  • What cabling and wiring is needed?

Finally, with so much on the line, it is essential to overall employee safety that you consult with an experienced machine safeguarding expert when specifying and installing a light curtain. Contact Rockford Systems to ensure that your safety needs are fully met.

 

 

What the Wave of Retiring Machinists Means to Plant Safety

Within the next decade approximately 2.7 million “Baby Boomers” (b. 1946-1964) will retire, thereby ensuring that tens of thousands of skilled, well-paid positions will become available without a ready supply of American workers to fill them. Statistics paint an especially gloomy picture for the manufacturing sector, a widening of the skills gap, and a possible dilution of existing training programs.

Compared to the rest of the economy, the impact on manufacturing of this generational shift is oversized owing to two factors:

  • One, despite increased efforts by colleges and vocational schools to train new manufacturing workers, available jobs still outpace qualified employees.
  • And two, the existing manufacturing workforce is considerably older than the national employee average of 42 years. Currently, the average age of highly skilled manufacturing employees is 56, and nearly a third of all manufacturing professionals are over 50. As they retire, knowledge goes out the door with them.

What are the implications of these trends for your plant’s productivity? How will it impact employee safety? What can you do to transfer knowledge from one generation to the next?

Safety Knowledge Gap

Besides having less experience operating machinery correctly, workers new to the job are often unsure about their safety rights and responsibilities, or might feel uncomfortable speaking out about a potential hazard. They may also not have the proper training, so they underestimate the risks involved with operating high-speed machinery. A recent survey of machinists in North America exposed that 70% couldn’t recall receiving any formal training when they were first hired on.

Equally troubling, the Millennials (b. 1980-1996), who are replacing baby boomers, are more apt to job hop — 90 percent expect to stay in a job for less than three years — leaving manufacturers with heightened turnover and a badly depleted knowledge base, especially when it comes to safety. The so-called “Great Resignation,” the unprecedented mass exit from the workforce spurred on by Covid-19, also has reduced the pool for skilled labor.

Given all this, it probably comes as little surprise that employees under the age of 25 are twice as likely to visit the emergency room for an occupational injury than those over 25. The dangers facing younger workers underscore the critical importance of machine safeguarding. The lathe, press or saw on the plant floor considered “safe” solely on the basis of being accident-free for many years is no guarantee that modern safety regulations and standards are being met. A machine mistakenly perceived as “safe” may be the most dangerous in your maintenance shop, or on your production floor.

Safeguarding Assessment

Faced with the wave of Baby Boomer retirements, many manufacturers are trying to hold on to their older workers, persuade some to return after retirement, or recruit those retired from other companies. Unfortunately, these steps only postpone the inevitable. A more meaningful first step is to conduct a thorough machine safeguarding assessment on your machinery.

A machine safeguarding assessment draws on the expertise and experience of an outside company to identify and address machine hazards before they cause accidents. Over the course of a machine safeguarding assessment, detailed information is collected concerning each machine, how the operator interacts with the machine, and the process it is tied to. Hazardous areas are pinpointed on the machine and a hazard level assigned to each machine. Evaluating this hazard level helps determine which safeguarding methods should be applied to each machine to make it safe. If a risk is not tolerable, safeguarding measures need to be applied that will reduce the risk to an acceptable level that is in accordance with applicable regulations and standards. The assessor should also accurately identify all costs associated with the final project. After installing safeguards, a follow-up assessment will be conducted to verify that risk levels have either been eliminated, or reduced to a tolerable level.

Transferring Tribal Knowledge

Retirees won’t leave behind every bit of knowledge they’ve gained over the years, but capturing a majority of the important operational details will be beneficial down the road. Your organization needs to find ways of both learning and sharing this “tribal” knowledge before experienced machinists retire.

One common way of doing so is implementing a structured training and mentoring program pairing young workers with senior people who are technically expert in complex machinery. Along with face-to-face training on the machinery, the experienced worker is there to answer questions about operating procedures, and to help the young worker learn how to operate the machinery correctly. Recognizing hazards and learning safe work practices must be a central part of training and mentoring programs so make sure they are given equal billing with productivity during conversations. Training and mentorship also play an important role in informing young workers about OSHA, every worker’s right to a safe workplace, as well as the right to refuse unsafe work. Once retired, the mentor can return on a part-time or as needed basis to continue training new hires.

Outside Training

While older machinists certainly have the experience and technical knowledge, they may not know how to teach because they aren’t professional trainers or they can’t communicate effectively with a younger generation. Others may feel that training is an additional obligation that has been hoisted upon them when they are already crunched for time.

Hiring an outside firm to teach your team about machine safety regulations and standards is another step toward overcoming dilution in training. Rockford Systems offers a variety of safety training courses, including Machine Safeguarding Seminars, Combustion Safety Training, NFPA 70E and other courses at its Training Center in Rockford, Illinois. The popular 2-day seminars combine classroom discussion with live demonstrations to give the hands-on experience that new employees need. Once the seminar is complete, the employee will be better able to interpret the OSHA 29 CRF and ANSI series standards as they relate to their specific machine applications and production requirements.

Can’t make it to Rockford? No problem. The seminars can be presented at your company and tailored to the types of machinery found at your plant.

Annual Audits

Rockford Systems also offers an Annual Verification Audit to verify that your properly safeguarded equipment is being used as intended to protect employees working in dangerous environments. Moreover, the audit ensures that your capital investment in providing a safe working environment is sustained and continues to be in compliance with OSHA regulation and ANSI B11 series standards, as well as meeting any internal safety policies that a company may have established.

The primary evaluation criteria for the audit are visual inspection and function testing of safeguarding, controls, disconnects, motor starters, and mechanical power transmission apparatus covers. Once an audit is completed, Rockford Systems identifies issues in a detailed report highlighting deficiencies or changes from the original project specifications and recommendations for corrective actions to bring the equipment back into compliance.

Final Thoughts

A perfect storm has formed, making it increasingly difficult for manufacturers to find and train labor. The retirement of tenured and experienced machinists only makes matters more challenging. To ensure plant productivity and safety needs are continuously met despite retirements, take proactive steps through working to develop and promote training and mentorship programs, properly safeguarding your machinery, and conducting annual verification audits to ensure that your safety program is being followed as intended.

For more information, visit www.rockfordsystems.com

 

Machine Risk Assessment vs. Safeguarding Assessment? Start 2021 off on the right safety foot.

When it comes to accidents, manufacturing ranks second highest of all industries. That comes despite OSHA regulations and American National Standards Institute (ANSI) standards. A key culprit is unguarded hazardous machinery.

Year after year, OSHA issues thousands of citations and levies millions of dollars in fines for machine safeguarding violations in an attempt to prevent injuries and save lives OSHA 1910.212(a)(1) is the most common section citation, whereby “one or more methods of machine guarding shall be provided to protect the operator and other employees in the machine area from hazards” followed by OSHA 1910.212(a)(3)(ii) whereby “the point of operation of machines whose operation exposes an employee to injury shall be guarded.

Why the disregard?

Why is this so? Often facility safety managers are lulled into a false sense of security because a serious accident has not yet occurred or because accidents are rare in their facility. Other managers might wrongly suppose that their newly purchased machinery arrives fully compliant, not realizing that OEMs are typically concerned with new machinery price competitiveness, not necessarily guarding compliance. Still other managers may wrongly assume that older machines are “grandfathered in” before OSHA was formed.

For whatever reason, approximately HALF of industrial machinery has not been properly safeguarded.

That is the bad news.

The good news is there is a way to determine compliance through an assessment of the machinery on the plant floor, as outlined by ANSI B11.0. There are two types of assessments that reign supreme: the Risk Assessment and the Safeguarding Assessment. This article will address both methods and how they help an organization better protect the people operating the machines and reduce the risk at the facility.

Risk assessments should be conducted annually, including whenever a new machine is installed or a major change to an existing machine or production line has taken place. Additionally, in an ideal world, a pre- and post-assessment would be done to verify that the hazards identified in the assessment were properly mitigated.

Risk assessment

What a risk assessment is comprised of is outlined in ANSI B11 Series Standards for Industrial Machinery, ANSI/RIA R15.06-2012 Safety Standards for Industrial Robots, and the National Fire Protection Association (NFPA) 79-2015 Electrical Standard for Industrial Machinery.

The overarching goal of a task-based risk assessment is to identify hazards associated with machinery or robots. This requires an on-site visit by a risk assessment professional who audits and assigns each machine a risk rating based on three considerations: Severity of Injury, Exposure Frequency, and Avoidance Likelihood, which produces a Risk Level. Today’s risk assessment specialists use software-based tools that can make the process quicker than working through a pen-and-paper risk assessment form.

In advance of the facility visit and based upon project scope, the risk assessment specialist will need to review a comprehensive machine list and potentially other documentation such as: corporate safety standards, lockout/tagout (LOTO) procedures, electrical and mechanical drawings, floor-plan layout and equipment manuals.

The scope of assessing a piece of machinery for risk begins with reviewing its operational states with functionality tests performed to help identify potential hazards during machine start-up, cycle, and stopping. The risk assessment specialist may perform a Stop-Time Measurement (STM) test to determine the machine’s reaction time after receiving a stop signal to ensure proper safety distance of safeguarding devices. The specialist will also establish if a passerby or other employees in the area could be hurt if an incident occurs, in addition to the operator.

Along with assessing the production risks of the machine, the risk assessment specialist must analyze the tasks performed by the machine operator as they relate to interacting with the machine, loading and unloading materials, planned and unplanned maintenance methods, frequency of tool changes, and general housekeeping.

During the risk assessment, the specialist will photograph machines and generate a final hazard report documenting their assessment findings and risk levels. The hazardous findings of each machine are broken down into the following ranked classifications:

Critical: There is an imminent life-threatening or dismemberment hazard and immediate action is needed to reduce risk and improve operator safety
Mandatory: There is an imminent hazard that creates potential for injury and action is required to reduce risk, improve operator safety and to comply with OSHA/ANSI standards
Compliant: There is not a recognized hazard that creates potential for injury and no action is required.

Safeguarding assessment

While a risk assessment helps to identify a problem, it does not provide specific safety solutions nor cost estimates. For that, a safeguarding assessment is needed.

During the safeguarding assessment, a specialist will visit the site and conduct an intensive audit of each machine and identify compliance in five guarding areas: safeguards, controls, disconnects, starters and covers. The safeguarding specialist may request copies of electrical, pneumatic or hydraulic schematics, operator manuals and ask for control panel access so that engineers can review the control circuit for electrical compatibility of any proposed safeguarding solutions and to verify reliability of the control circuit to determine the interfacing requirements of suggested equipment. Then the safeguarding specialist will focus on risk reduction using this basic methodology:

– Eliminate Access — A good safeguarding system eliminates the possibility of the operator or other workers placing parts of their bodies near hazardous moving parts.
Reduction in Exposure — A machine safeguard should not be able to be removed, bypassed or tampered with by the operator. To minimize risk exposure, all guards and devices must be securely mounted at the point-of-operation and durable enough to withstand industrial environments, vandalism and heavy usage.
– Create No New Hazards — A safeguard defeats its own purpose if it creates a hazard of its own such as a shear point, a jagged edge, or an unfinished surface which can cause a laceration. The edges of guards, for instance, should be rolled or bolted in such a way that they eliminate sharp edges.
– Create No Interference — Any safeguard which impedes a worker from performing a job quickly and comfortably might soon be overridden or disregarded. Proper safeguarding can actually enhance efficiency since it can relieve the worker’s apprehensions about injury.
– Allow Safe Lubrication — Locating oil reservoirs outside the guard, with a line leading to the lubrication point, will reduce the need for the worker to enter the hazardous area.
Administrative Controls — Without administrative oversight and supervisory control, a machine safeguarding program will fail. Training is key to establishing a safety culture. Operators need to trained to follow the Standard Operating Procedures provided by the machine manufacturer in order to reduce hazards and related risks.

Uncovering gaps in protection

Unlike a risk assessment, a safeguarding assessment recognizes both the problem and the solution. A final compliance report and safeguarding project proposal is issued to facility management which identifies deficiencies or gaps where each machine is not in compliance with current or specified regulations and standards. When not in compliance, the proposal offers standard and customized safeguarding solutions, along with associated costs and timelines to help bring machines into compliance and reduce risk. Each proposed solution is carefully weighed against factors such as risk-reduction benefit, productivity, technological feasibility, economic impact, and maintainability.

In this way, a machine safeguarding assessment follows the OSHA/ANSI approach to controlling machine hazards: eliminate the hazard by design; or control the hazard by guarding, posted warnings, personal protective equipment, and employee training.

Risk reduction strategies

When evaluating risk reduction solutions to address identified hazards, consider each machine and its unique risks. Three basic methods are available.
– Eliminating or reducing risks to a “tolerable” level by installing a new, inherently safe machine. Please note that what constitutes “tolerable” to one company is not necessarily tolerable to another.
– Installing the necessary safeguarding equipment on an existing machine to minimize risks that cannot be eliminated. Fixed enclosing guards, protective devices such as light curtains, palm buttons or presence sensing mats, and training on the safe working methods of the machine are all necessary to reduce injury risks.
– Changing the production process to eliminate the hazard. Perhaps the operator performs actions that increase his exposure to serious hazards? Or recent changes upstream have created a more dangerous environment? Even a small change in procedures can make for a safer, more efficient operation.

Conclusion

Both risk assessments and/or the safeguarding assessments are critical first steps in any machine or robot safeguarding project as outlined in ANSI B11 Series Standards for Metalworking, OSHA 1910.212 General Requirements, ANSI/RIA R15.06-2012 Safety Standards for Industrial Robots and NFPA 79. These standards pave the way for risk-reduction measures that are both effective and economical. Machine risk assessments provide a comprehensive hazard analysis with a risk ranking; machine safeguarding assessments identify safeguarding solutions and provide cost estimates for implementation. Which one is right for an organization depends upon the specific needs of the organization, the organization’s objectives, desired outputs and risk levels.

Related Blogs:

Machine Risk Assessment Process

Machine Safeguarding Assessment

Machine Risk Assessment

Machine Risk Assessment – Inquiry Confirmation

Remote Safeguarding Assessment

Safeguarding Mechanical Power Presses

Mechanical power presses (a.k.a. punch presses, stamping presses, flywheel presses), have existed in the U.S. since 1857. They were originally designed as either full-revolution, or part- revolution, both of which still exist, although the latter currently represents an estimated 90 percent of the roughly 300,000 mechanical power presses being used in the United States today.

This blog will address part-revolution presses only. These are often referred to as “air clutch” presses, made by dozens of manufacturers. The idea of safety for these machines has existed since 1922, when the first ANSI B11.1 Safety Standard was developed. The latest version, ANSI B11.1-2009 is the 10th update of that standard. This is generally considered to contain the “Best Safety Practices” for press users.

In the early 1970’s, OSHA promulgated a “machine specific regulation” for mechanical power presses, their CFR SubPart O, 1910.217. Very few changes have been made to that regulation since then. Keep in mind that OSHA’s 1910.217 Regulation was taken from ANSI B11.1 using a version that was freshly updated for OSHA in 1971. ANSI has updated their B11.1 four times since that time. Every update adds new, more stringent requirements than the previous version.

Although many companies have long since met the basic OSHA requirements for their presses, a significant number of those shops have yet to make updates to meet the latest ANSI B11.1 Standard. When OSHA regulations came 46 years ago, press control systems were primarily relay-logic systems, designed to meet OSHA’s initial requirement for “Control Reliability” and “Brake Monitoring.”

Press control systems manufactured in the mid 1980’s and beyond have been mostly solid-state, designed to meet the ANSI Standard concept for the “Performance of Safety Related Functions.” One of the advantages to solid-state controls are the features built-into them. Two of these are a: built-in “Stopping Performance Monitor” and built-in “Stop Time Measurement,” which prevents users from having to use a portable device to determine “Safety Distance” when applying Light Curtain and Two-hand Control devices.

Mechanical Power Presses require some combination of guards and/or devices to reduce or eliminate exposure to hazards at the “point of operation” where the dies close. Safeguarding alternatives include: Point-of-Operation Guards, Awareness Barriers, Light Curtains, and Two-Hand Controls.

1) Point-of-Operation Guards
Point-Of-Operation Guards are typically used for continuous operations where coil-stock feeds into the press as it operates in an uninterrupted mode of operation.

By OSHA’s definition, a guard must prevent people from reaching over, under, through, or around it. (OUTA is an acronym easy to remember; This guard keeps you “OUTA” here.) 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.

To discourage misuse, hinged or sliding guard sections are often electrically interlocked, so that they remain in position (closed) during press operations. Without interlocks, movable sections can easily be left open, whether intentional or not, leaving Operators and others in the area unprotected.

Guard Interlocks are attached to hinged or moving guard sections, since access to the point-of-operation is most often made through those openings. Interlock attachment is best accomplished with tamper-resistant fasteners to discourage cheating the switch.

Many older guards use simple lever-arm or push-button switches. Not only are these switches easy to cheat with tape or wire, they are also spring-operated, leaving them subject to failure it the spring breaks. Newer switches are free of springs, and use actuators with a unique geometry, making them much more difficult to defeat.

2) Awareness Barriers (for low-level hazards only)
Another common method of safeguarding on coil-fed presses is an “Awareness Barrier” (A/B). They should completely surround press auxiliary equipment with railings, chains, or cables, suspended on floor stations. Although they don’t provide the same level protection as a guard, they do help to limit access to hazards on auxiliary equipment like coil-payoffs, feeds, straighteners, etc.

Awareness Barriers are considered superior to just a yellow line on the floor, because to get beyond the A/B requires an intentional act and some physical contact with them. This means the person is well aware that they are entering a hazard area, contrary to their safety training. Auxiliary equipment may also require that ingoing rolls are covered to prevent entanglement with long hair or loose clothing.

Awareness barriers should also have several Danger or Warning signs attached to them specifying what the hazards are in going beyond the A/Bs. Examples of sign verbiage might include: moving coil stock, ingoing pinch points, sharp edges, tripping hazard, etc.

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

One of the reasons that presses make a good application for light curtains is that they can be stopped mid-cycle very quickly. Light curtains can be used for either single or continuous applications. The only thing that light curtains don’t provide is “impact protection” should something break in the point of operation and be ejected in the operator’s direction. Where that’s an issue, poly carbonate shields or guards may be appropriate.

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.

4) Two-Hand Controls
Two-Hand Controls are considered a safer means of cycling a press than a foot-switch because both hands must be in a safe position to use them. When cycling a press with a foot switch, hands can be anywhere. When operating a press in the single-cycle mode of operation, it’s possible to use a two-hand control as a safeguarding device as well. This requires that they meet a list of rules in both OSHA and ANSI.

Ten of the basic requirements for a two-hand control being used as a safeguarding device (in the single-cycle mode of operation) include:
1) protection from unintended operation
2) located to require the use of both hands (no elbow & finger tips)
3) concurrently operated (actuation within half-second of each other)
4) holding-time during the downstroke (hazardous portion of cycle)
5) anti-repeat (push and release both actuators for each single cycle)
6) interrupted stroke protection (for all operating stations)
7) separate set of two-hand controls for each operator
8) mounted at a calculated “Safety Distance” from nearest hazard
9) control system to meet “Performance of Safety Related Functions”
10) Stopping Performance Monitor is also required

When running high-production operations, don’t forget to consider ergonomics when choosing and installing two-hand controls. Several manufacturers of low-force and no-force actuators are on the market.

Also required by OSHA on Mechanical Power Presses is an electrically interlocked “Safety Block” whenever dies are being adjusting or repaired while they are in the press. The interlock is required because safety blocks are very seldom designed to hold the full working-force of the press (please refer to our Die Safety Blocks blog for additional information).

Mechanical Power Presses require two types of OSHA inspections:
1) Periodic and regular (typically quarterly) inspections of the press parts, auxiliary equipment, and safeguards . . . (don’t forget to document)
2) Weekly inspections of; clutch/brake mechanism, anti-repeat feature . . . along with other items (don’t forget to document)

OSHA requires training (in 1910.217) for anyone who cares for, inspects, maintains, or operates mechanical power presses.

ANSI B11.1-2009, requires training for “all (people) associated with press production systems, including operators, die setters, maintenance personnel, supervisors, which must also include (OSHA) 1910.147 Lockout/Tagout.”

Please call 1-800-922-7533 or visit rockfordsystems.com for more information.