Made in America / Established 1989

How A Press Brake Operator Is Kept Safe With Laser Sentry

How A Press Brake Operator Is Kept Safe With Laser Sentry

The Laser Sentry provides press brake safety for the press brake operator by eliminating the hazard in a similar manner as do elevator and subway doors eliminate the hazard of the doors closing and crushing someone. In the event the doors are blocked, the doors retract automatically. Thus, eliminating the hazard! They use pressure sensitive switches to detect the presence of an object or the press brake operator. When the sensor is activated the doors retract.

press brake operator laser sentry safety

Interruption of the Laser Beams

The Laser Sentry uses the interruption of lasers beam to sense objects. If any object breaks any of the three beams, press brake operator or otherwise the ram instantly retracts.

To permit the bending process the Laser Sentry determines when it is safe for the laser beam to be broken. That is, when the hazard is less than 1/4 inch.

To determine just exactly where that “safe” point is, a precision digital absolute position transducer is used. The transducer provides the rams position within .0025 inches of repeat ability.

Press Brake Operator Teaches the Laser Sentry

The press brake operator “teaches” the Laser Sentry. The press brake operator teaches the exact position of the surface part to be formed when it is resting on the lower die. This position is used by the Laser Sentry to determine the safe area of ram travel.

However the laser is not “muted” at 1/4 inch above the material as with the use of light curtains, it is muted .100 above the surface of the part being formed!

The beam is scanned between 3/16 and 1/4 of an inch under the die. This distance is determined by the reversing capabilities of the machine. The Laser Sentry tests the reversing time and this time of ram travel distance is used to determine just how far below the die the beam can be placed.

As the ram travels down or up in the case of an up-acting press and any of the beams are broken before the die reaches to within .100 of the part to be formed, the ram will retract immediately.

Slow Speed for Press Brake Operator Safety

The machine’s slow speed function is used to reduce the risk of pinching even further. As the ram approaches to within a minimum of 1/4 inch above the part, the Laser Sentry forces the machine into slow speed. In slow speed the reaction time of stopping and reversing the machine is considerably reduced. Thus, allowing a greater margin of safety as the die closes.

High Speed, Pulsed Lasers

To provide as near fail-safe operation as possible, the laser beam is pulsed at very high speed. A separate microprocessor monitors the laser pulse. It will detect any malfunction in the laser transmitter or receiver and shut down the machine.

Safety Relays

Two safety relays that are crosschecked by both processors are provided to control the ram motion valves.

An input from the machines’ control circuit that signals the ram to move is monitored. When activated the Laser Sentry knows that ram motion is to begin and be maintained until the signal is de-activated. The Laser Sentry uses this information to monitor the output of the position transducer. Should it fail, the system will be shut down immediately.

Control reliability is provided by two microprocessors to maintain the transducer and the control the Laser Sentry’s operation. All, while cross checking each other for proper operation.

Metal Tech Controls Corp

Metal Tech Controls Corp.’s Laser Sentry meets all OSHA Standards. For more information, contact us any time and we will be sure to answer any questions you may have. For more information on press brake safety visit pressbrakesafety.info.