Operators and other employees are exposed to point-of-operation hazards if they enter the backside area of press brakes, shears or other machines. This cable and push-button e-stop assembly can be used to warn them of the exposure. The switch that interlocks the cable is arranged so that if someone either pulls on the cable or removes the cable from the hook, the machine becomes inoperable. The switch must be electrically interfaced with the cycle control of the machine.
The switch has a unique cam operation of the contact mechanism to give rapid, positive operation of the contacts. This mechanism also provides a failure to the safe condition if the cable goes slack or is cut, but is immune to nuisance tripping due to machine vibration. Should the cable be pulled, the contacts are opened, isolating machine power, and the latch engages. The machine cannot restart until the hazard has been corrected and the switch is reset. The switch is reset by turning the blue reset dial from the off position to the run position. This switch also incorporates a cable-tension indicator. This indicator assists in installation and maintenance of the switch. A red mushroom-head emergency-stop button is provided on each switch.
A cable tension kit, which includes thimbles, cable clamps and a turnbuckle, is included with this cable and push button e-stop assembly. When installing this switch on cable runs over 12 feet, one switch should be installed at both ends of the cable. The cables should be supported by eye bolts every 6 1/2 to 10 feet (2 to 3 m) along its length. They should also be used about one foot from each switch to ensure that all emergency-pull movement is transmitted to both units in a linear fashion. If this cable and push-button e-stop assembly is to go around a corner, a free-moving pulley should be used. Please consult the factory if this is required.