Machine Design

Unguarded press brake crushes fingers

Editor: Jessica Shapiro

A worker was reaching into the operating area of a press brake to clean the die when he depressed the foot pedal that cycled the machine. The ram descended, crushing four of his fingers.

The machine carried one prominent placard warning against reaching into the die area. The dual-foot-pedal control also had a warning at floor level.

The worker’s supervisor had taught him to use a hook at the end of the ram to turn the die out of the operating area for cleaning without reaching into the operating area. However, he was cleaning the die in its operational position when the accident happened.

Company officials knew safety features on the machine, which was used for bending sheet metal, were not up to date. A voluntary OSHA walkthrough about a year before the accident had noted the press brake lacked safety devices or guards.

Clear plastic guards for the press brake would have interfered with some of the sheet-metal parts. And two-hand palm buttons wouldn’t have worked for 25% of workpieces which needed operators to support them during bending.

Eight months after the OSHA visit, the company chose a light curtain that could be programmed to work with the variety of parts. The equipment took two months to arrive on site. Shortly thereafter, the safety coordinator alerted OSHA that the light curtain was in use and avoided having to request a sixth correction-date extension.

In reality, maintenance personnel tried intermittently for another month to install the light curtain without success. Nor could a third-party company hired for the task set up the device so it wouldn’t shut down the machine each cycle.

During this year, workers were still operating the press brake without modifications. Safety staff had shown workers a video about the dangers of reaching into energized equipment and occasionally reminded them during staff meetings. A formal training process where workers signed off on what they were taught was still in development.

After the accident, the third-party lightcurtain installers took a full week of work to get the device running properly, but the effort came too late to save the injured worker from going through two surgeries and losing movement in his hand.

This month’s safety violation comes from the files of Lanny Berke, a registered professional engineer and Certified Safety Professional involved in forensic engineering since 1972. Got a safety violation to share? Send your images and explanations to [email protected].

© 2011 Penton Media, Inc.

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