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Securing safety

Rockford Systems educates robotic welding users on safety standards and designs safety solutions to meet those standards

Despite the high price of robotic welders, some manufacturers don’t provide the safety equipment that would keep the machine in compliance with OSHA regulations and American National Standards Institute (ANSI) standards. ANSI writes industry specific safety standards for how different types of machines, including robotic welders, should be safeguarded. While some robotic welder manufacturers do include the safety devices as part of the package, they aren’t required to do so in the United States.

Fortunately, companies like Rockford Systems LLC educate manufacturers on OSHA, ANSI and National Fire Protection Association (NFPA) regulations. More importantly, Rockford designs customized and engineered safeguarding solutions for customers.

Matt Brenner, vice president of sales, says Rockford Systems is one of the original safeguarding companies. Its core business, he explains, involves sending representatives to customers’ plants, conducting surveys of their machines and helping them understand what safety standards and regulations pertain to their machines. Rockford can then offer a solution with a custom design that keeps the machines in compliance, yet also allows them to retain a high level of productivity.

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Rockford Systems’ pressure sensitive perimeter safety mats come in a variety of sizes to safeguard workers in hazardous areas.

Rule changes

While OSHA regulations regarding safeguarding machinery have only changed a handful of times since the early 1970s, ANSI standards evolve every few years. For instance, the ANSI robotic standard used to allow for a 12-in. sweep, which is the maximum amount of space allowed between the floor and the bottom of a perimeter guard typically located around a robotic workcell.

Perimeter guards are designed to keep machine operators and other plant employees out of the robotic welding cell and safe from the hazards it creates. However, a rash of serious injuries and fatalities prompted a change in the ANSI standard, reducing the sweep of a perimeter guard from 12 in. to 6 in.

Machine guarding violations are one of the top 10 violations cited by OSHA in the industrial environment (ranking No. 9 as of January 2016). Because moving machine parts can create hazards in the workplace and because injury and death can occur, guarding the machines, including robotic welders, becomes necessary. In response, ANSI created a guide, or what they call performance criteria, that educates manufacturers on acceptable methods for safeguarding all types of machines and provides information on how to do it. 

Rockford not only advises customers of changes that occur in ANSI and NFPA 79 standards and regulations, the company has representatives that sit on different ANSI committees, which means they are well informed on changes throughout the metal fabricating industry.

“We do a lot of retrofitting projects with machines that are already sitting in a customer’s plant,” Brenner says. “We also assist customers with safeguarding new machines when the manufacturer was not able to provide the appropriate equipment.”

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Rockford Systems’ safety light curtains come in 14-mm and 30-mm resolutions covering a range from 11.8 in to 70.9 in. They meet industry OSHA, ANSI, UL, IEC, and EN safety standards.

Applying the standard

OSHA is unable to issue citations to manufacturers for violating ANSI standards.  OSHA can issue citations for robotic welding cells that are unguarded or improperly guarded for not meeting 29 CFR 1910.212, also known as the “general duty clause.”

“To paraphrase it,” Brenner begins, “it says you have to provide protection for machine operators and other employees from known machine hazards. That’s a pretty vague statement.”

Many end users are then unsure what course of action to take after being cited under a general duty clause for a lack of machine guarding. They wonder, “what do we do, what are our options?” Brenner says. The answer is that they should turn to ANSI B11 series consensus standards that identify industry-accepted options for safeguarding different types of machines.

When Rockford approaches a project for a robotic welding cell, it refers to the robotic standard, which is ANSI RIA R15.06, last updated in 2012.

“ANSI RIA R15.06 provides information on the hazards associated with the robot and offers acceptable methods for safeguarding it,” Brenner says. “Customers’ needs are different and the standard provides different options they can choose from. Thoroughly understanding the options and then applying them to the robot can be a very challenging project for our customers to take on themselves.”

To understand how to apply these concepts, Rockford uses the ANSI B11.19 standard, Performance Criteria for Safeguarding. It’s a guideline that provides criteria for how different types of safety devices should be used in different circumstances.

“It’s kind of a roadmap,” Brenner notes. “If you know which safety device you want to use, this standard tells you how to do it properly.”

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The perimeter light beam system is built to meet the safety standards for one-side or multi-sided hazardous area and access protection.

Rockford’s method

Brenner explains that Rockford’s solutions for safeguarding robotic welding cells are customized and they may include individual or a combination of electrically interlocked perimeter guards, safety light curtains, safety laser scanners and pressure sensitive safety mats.

“We offer custom interfaces with all of our safety devices that monitor and electrically tie-in the device to the robots existing control circuit,” he says.

Rockford works with a variety of customers in many different industries. They range from modest projects with small companies to multi-year projects with Fortune 500 companies.

“We have a systems approach to safeguarding,” Brenner says. “While we carry standard products, most of our customers demand specialized and integrated systems to meet their unique needs. During a site visit, which we call a machine safeguarding survey, our specialists analyze the workspace, understand the machine’s use and discuss the customer’s needs to develop a fully customized safeguarding system.”

Sometimes compromises have to be made in the interest of safety. Brenner says there is some give and take with safeguarding, but the goal is to maintain a high level of productivity for the customer. However, every safeguarding project is different and presents its own set of unique challenges.

“Sometimes machines are located too close to one another,” he says, “or there is an overhead hoist or some other obstruction that might prevent us from using one method of safeguarding. We try to present all options, discuss the pros and cons, and let the customer decide which method works best for them.”

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Rockford Systems’ S3000 safety laser scanner has a programmable feature that eliminates the need to reprogram every time the work area undergoes changes. The minimum response time is 60 milliseconds.

Common safeguards

Rockford employs a number of solutions to keep workers safe around welding equipment. The S3000 safety laser scanner is a common safeguard installed around robotic welders. It comes in three models – standard, advanced and professional, and it meets OSHA, ANSI and other organizations’ safety standards. The S3000 is a fully programmable device, which utilizes an infrared laser to scan its surroundings. It can be set up to scan on a horizontal or vertical plane. Should a person or object come into contact with the infrared beam, hazardous machine motion stops.

A safety light curtain system is another common safeguard used with robotic welding equipment. Rockford’s EZ-Screen system includes a transmitter that emits infrared light to the receiver. The transmitter and receiver can be installed top to bottom (vertical protection field) or side to side (horizontal protection field). Should an object or the operator interrupt an infrared beam, hazardous machine motion stops.

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Available in short range or long range, the perimeter light beam system consists of a transmitter and receiver. The infrared beam is invisible, but when interrupted, it can shut down the machinery it surrounds.

Pressure sensitive safety mats are another option for safeguarding robotic welding equipment. They can be used around the perimeter of machines, but more commonly they’re used as a secondary safety device located inside of perimeter guarding systems. They are constructed with a heavy-duty molded vinyl encasing two metal plates. When someone stands on the mat, the metal plates make contact and hazardous machine motion stops.

No matter the chosen solution, Rockford’s primary goal is to educate its customers on the steps to increase on-site safety. Considering the sometimes difficult-to-navigate landscape of OSHA, ANSI and other regulatory bodies, the company’s guidance is readily welcomed.

Rockford Systems LLC