GB348278A - Electric time switch - Google Patents

Abstract

348,278. Retractive switches. FRIEDINGER, A., F³rstenfeldbruck, near Munich, and MONHEIT, H., 29, Balanstrasse, Munich, Germany. March 11, 1930, No. 7888. [Class 38 (v).] Retarding. -A switch, adapted to close a circuit for a predetermined short time, comprises a pivoted contact 15 adapted to be pressed by a spring into engagement with a fixed contact 14 but normally held out of engagement b y the collar 5 of a weighted head 4 of a piston 2 pressing upon a lug 17 of the contact 15. To operate the switch the piston is raised a predetermined distance by a handle and then allowed to fall, the rate of fall being determined by the weight of the piston and the clearance between it and the walls of the cylinder 1. One from of handle is shown in Fig. 2 and comprises a longitudinally-moving slider 19 the forked end of which embraces the collar 5 and which may be moved into any predetermined position on a scale, carrying the piston with it, and either left there, if it is desired to leave the contacts 14, 15 permanently engaged, or moved back again to its lowest position the piston then following slowly. The handle may also comprise a spring-controlled pushbutton or lever (Fig. 7, not shown), or a rotatable cam (Fig. 8, not shown). The cylinder 1 may have longitudinal grooves 25, 26, 27 arranged at its ends and at intermediate points corresponding to the various setting positions of the piston, to prevent the piston springing back when it is set, the piston having grooves 28 co-operating with the other grooves to allow air to slip by at these positions.