Inventors:
Robert D. White - Akron OH
Assignee:
Scovill Inc. - Waterbury CT
International Classification:
F16P 322
Abstract:
A mechanism for controlling either momentary or maintained, continuous operation of devices such as valves, presses, machines and other devices which require simultaneous use of two hands by an operator to prevent accidents and injury. The mechanism includes a moveable linkage formed from rigid links pivotally connected in a closed polygon, preferably a parallelogram. A pair of hand-controlled plungers, which are biased to return the linkage to its rest position when released, enable movement of the linkage to momentarily or continuously operate an electrical switch, pneumatic valve or other contact control device only when both plungers are depressed simultaneously. A raised surface for guiding movement of the linkage is included to prevent unintended or single-handed operation. Constant depression of one plunger with intermittent operation of the other, or sequential operation of the plungers, will not engage the contact or control device.