GB678631A - Improvements relating to mechanically-released electrical switch devices - Google Patents

Abstract

678,631. Switches held set and freed mechanically. NEWMAN, J. B., and PORTER, C. I. April 4, 1951. [April 4,1950] No. 8441/50. Class 38 (v). A switch which is arranged to be operated in response to a slight abnormal relative displacement of two parts of a machine, e.g. a press, comprises a slidable contact 5 normally held in bridging engagement with two fixed contacts (not shown) against the action of a spring 9 by a locking element 19 on the longer limb 16 of an L-shaped lever, the shorter limb 17 of which is pivoted at 18, 15 to members 1, 12, respectively connected to the two parts of the machine. The member 1 carries the fixed contacts and lugs 7, 8 in which slides a rod 6 on which the contact 5 is mounted. The part 12 is threaded into a nut 13 having two parts held together by screws 13<SP>1</SP> and holding between them the enlarged head 11 of a member 10 fixed to one of the machine parts, rotation of the nut 13 causing vertical adjustment of the member 12. Relative movement apart of the machine parts tilts the lever 16 counterclockwise to move the element 19 from latching engagement with an element 20 on the rod 6 so that the contacts span. The switch parts may be reset by depressing the rod 6, the faces of elements 19, 20 being bevelled to permit them to slide over one another.