GB1429132A - /neumatic timing device particularly for time-delay relay - Google Patents

Abstract

1429132 Adjusting pneumatic dashpot timers; toothed gearing METZENAUER & JUNG GmbH 2 April 1974 [3 May 1973] 14598/74 Headings F2S and F2Q [Also in Division H1] A pneumatic dashpot timer has a timing passage 27 adjustable by a rotatable adjusting spindle 28, 35, the spindle co-operates with a toothed wheel 40 carrying a dial 46 to indicate the number of complete rotations of the adjusting spindle, the spindle carries a dial, Fig. 4, not shown, to indicate its angular position, and the co-operation between the spindle and the toothed wheel is such that a complete rotation of the spindle indexes the toothed wheel one tooth. The spindle has a single tooth 38. The toothed wheel 40 is locked between indexing movement by spring-pressed balls 43, Fig. 2. The indexing tooth 38 is formed on a detachable actuating head 35 of the adjusting spindle. To calibrate the timer this head is removed and the spindle is rotated so that a frusto-conical valve head on the spindle reduces the size of the timing passage to give a mean time delay value. The positions of the two dials corresponding to such a value are found from a table, Fig. 6, not shown, and the actuating head 35 is placed on the spindle with the dials in these positions. The timer is used to provide a time lag between the actuation of an electromagnet 12 and a microswitch 14. When the electromagnet 12 retracts a lever 11, a member 8 is permitted to move down and actuate the microswitch 14 at a rate determined by the flow of air (arrowed) into a bellows chamber. When the timing stroke is over, a spring 10 forces the member 8 quickly back to its original position, air being exhausted from the bellows chamber past a valve member 6.