George O. Waring, MD, FACS, FRCOphth & Howard M. Lebowitz, MD, FACS
The primary function of all guarding is to prevent an operator or bystander from being injured by a potentially dangerous portion of a machine. Often the hazard involves moving parts with the potential to cut, crush or draw-in body parts, although barrier guards may also be necessary when electrical, thermal or chemical dangers are present. Guarding may be accomplished with simple physical shielding of machine parts, or more advanced techniques such as laser curtains. It is also often necessary to employ interlocks to disable power to the machine when a guard has been removed.
We have extensive experience evaluating proper machine guard design and methods including:
Damaged Pullback Hand Injury:
A machinist working on a press equipped with a pullback device suffered a crushed hand when it was caught in the point of operation. After inspecting the pullbacks, it was determined that one of the cable guide-tubes had been damaged. The damage allowed the pullback settings to be different for each hand. When the foreman set the pullbacks, he only tested the undamaged one. Thus, the damaged pullback permitted his other hand to remain at the point of operation and to be crushed by the ram.
Dr. Irving Ojalvo is Chairman of Technology Associates (www.technology-assoc.com), a forensic engineering firm with offices in New York City, Connecticut, and Florida. The firm's technical personnel, all of whom have advanced degrees, perform accident reconstruction involving issues of biomechanics, mechanical, traffic, and human factors engineering.