EXECUTIVE INSIGHTS: RYAN EBENS

CRITICAL ISSUES
According to OSHA 29 CFR 1910.212, General Requirements for All Machines, one or more methods of machine safeguarding must be provided to protect the operator and other employees in the machine area from hazards. Unfortunately, it is an all-too-common occurrence to find operators bypassing, defeating, misadjusting, or turning off machine safeguards. This resistance to safeguards is likely the result of operators feeling that safeguards are intrusive, decrease productivity, and ultimately get in the way.

SAFETY TECHNOLOGIES
The misuse of machine safeguards can be corrected by the implementation of administrative controls and other protective measures such as training, supervision, and enforcement of use. More importantly, however, evaluations can be made to determine whether other safeguards would be more appropriate for each machine and application. Thanks to new technologies, several new and exciting machine safeguards have recently been developed.

New machine safeguards include camera systems, laser beams or bands, laser scanners, and capacitive detection systems. When applied properly, these new safeguarding devices and systems can prevent serious injuries or death by stopping hazardous motion (or preventing it from starting) when personnel are detected.

Two-dimensional camera systems are used mainly on press brakes and consist of a transmitter and receiver that visually monitor and detect intrusions into the hazard area by foreign objects such as fingers and hands and send a stop signal to the machine's control system.

Laser beams or bands are used in much the same way as two-dimensional camera systems: they consist of a transmitter and receiver and detect intrusions into the hazard area on press brakes and send a stop signal to the press brake's control system.

Three-dimensional camera systems are installed above areas to be safeguarded (such as industrial robot systems and other automatically operated machinery and equipment) and detect intrusions into a predefined zone that is set up and mapped out by the user through a PC. When an intrusion is detected, the camera system will send a stop signal to the control system of the machinery, robot, or equipment it is safeguarding.

Laser scanners are used to safeguard machine areas and access points on both stationary and moving equipment such as robot systems, areas around hazardous machinery, and the front and rear of automated guided vehicles or transfer carts. Laser scanners use a plane of pulsed laser light to scan the surrounding area and compare the scanned information to a predefined zone configured by a PC. If the scanner detects an intrusion into the predefined safety zone, it sends a stop signal to the control system of the machinery, robot, or equipment it is safeguarding.

Capacitive detection systems have been used for years in ergonomic palm buttons (which require no force to be actuated, thus reducing the risk of repetitive-motion injuries), but this technology has recently been applied to woodworking table saws to detect when an operator accidentally contacts the rotating saw blade and it retracts and stops in milliseconds.

This electronic detection system works by inducing an electrical signal onto the saw blade and monitoring that signal for changes. Wood has very little capacitance and conductivity, so the signal will not change during normal (safe) operation, but when an operator's finger or hand comes into contact with the blade, the high capacitance and conductivity of the human body will cause the signal to change and trigger the safety system to engage the fast-acting brake to stop the blade and retract it.

A SAFER WORKPLACE FOR ALL
In many cases, the implementation of these new safeguards can lead to increased productivity and improved safety for operators and other personnel by reducing any desire to subvert them. This will ultimately lead to a safer workplace for all employees.

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