GB358228A - Improvements in or relating to delayed-action electric switches - Google Patents

Abstract

358,228. Time switches ; snap-action switches. RHODES, Inc., M. H., 185, Church Street, New Haven, Connecticut, U.S.A. Sept. 8, 1930, No. 26840. Convention date, Sept. 6, 1929. [Class 38 (v).] A switch with time delay mechanism which may be used or not as required has two handles 3, 8. When the timing handle 8 is " off," operation of the switch handle 3 serves to move the switch rapidly on and off in a normal manner. When the handle 8 is " on," movement of the switch handle 3 into one position, say into its " on " position serves to close the switch rapidly, but the switch is then automatically latched and if the handle 3 is then returned to its " off position, the switch will only open after a predetermined time. The length of time may be increased by reciprocating the handle 3 a determined number of times before finally leaving it "off." With the handle 8 "off," operation of the handle or dolly 3 carries a compression spring 45, arranged between the lower end of the dolly and a member 4, over dead-centres, the member 4 then being driven about an axis 67 and its lower end, which moves in a slot 24 in a slide 61, hitting the end of the slot and driving the slide 61 and contacts 11 carried by it into or out of bridging engagement with fixed contacts 59, 60. When the handle 8 is " on," and the dolly 3 is moved " on," the member 4 is held latched in the position shown in Fig. 3 by a projection 72 on the member 4 engaging a latch 9 which has been moved into latching position by the handle 8 acting through an intermediate dead-centre spring 47. If the dolly 3 is now moved " off " the parts occupy the position shown in Fig. 3, and the arm 4 remains latched till after the time interval the latch 9 is moved out of position by a projection 84 on a wheel 13, Fig. 9. The wheel 13 is fixed to a ratchet wheel 18 and when the dolly 3 is reciprocated a spring- pressed pawl 7 on it engages and drives the ratchet wheel till the projection 84 has moved round through an angle dependent on the number of reciprocations. A spring is simultaneously wound up. The wheel 13 is prevented from return movement under the action of the spring by its fingers 77, Fig. 9, engaging holes 76 in a gear wheel 19, Fig. 8, which is prevented from rotating by being connected through a train of gearing with an escapement wheel 22 the anchor 82 of which is held fast by a spring-pressed bell crank lever 12 so long as the dolly 3 is "on." When the dolly 3 is moved " off " a portion 83 on it engages the bell crank 12 and releases the anchor so that the clockwork begins to run down and after the predetermined time the projection 84 on the wheel 13 releases the latch 9 and allows the arm 4 to move to open the switch. An indicating disc mounted on the same shaft as the wheel 13 shows the length of time still to run.