Safety blocks prevent damage to equipment or personnel by stopping the ram and die of a press from closing whenever dies are being repaired or adjusted. The use of safety blocks in die presses is required by the U.S. Occupational Safety Hazard Administration (OSHA) to protect press operators.
Safety blocks are placed between the die punch and the press bed when the machine is in the up position. Safety blocks are rated to handle a stationary load that includes the weight of the press ram, the upper dies, and any other ram components or assemblies such as arms or connection rods. In some machines, more than one safety block may be required. Since a ram press is usually adjustable, a press safety block may also come with additional wedges or a screw device. An adjustable screw device is added to a die safety block to prevent any space between the block and the die punch. Safety wedges may also be used to close up the space between the safety blocks and the press ram.
Safety blocks may be available as part of an electrical power cutoff system that includes safety switches. The safety block has an interlocking safety switching element attached to it by a short chain. The press will only operate when the interlock is interfaced with the control system. When the machine is running, the interlock is in place with the safety block standing next to it. To place the safety block between the die and the press, the interlock must be unplugged from the control system, shutting the machine down.
Other safety devices used in conjunction with safety blocks include safety sensing equipment. Safety sensors use photoelectric devices that detect when an object or person passes through a light barrier. A safety sensor can shut down a component or an entire machine. A safety sensing element may also include an optoelectronic device to produce an infrared beam of light that senses when the beam is broken.