GB832770A - A timer control device for controlling the sequential operation of control members formed by fluid control valves or electric switches - Google Patents

Abstract

832,770. Retractive switches. ROBERTSHAW-FULTON CONTROLS CO. May 28, 1956 [Oct. 7, 1955], No. 16438/56. Class 38 (5). [Also in Group XXIX] A timer control device for operating two switches 164, 190, Fig. 9, in timed sequence includes manual setting means for closing the switch 190 and opening the switch 164 and clockwork actuating means for subsequently closing the switch 164 after a first delay period and opening the switch 190 after a second delay period. The setting and actuating mechanism comprises a housing 56, Fig. 7, of insulating material and a spindle 52 passing therethrough, the outer end of the spindle having an actuating knob 72, Fig. 5, and the inner end being connected to a spring-loaded plunger 172, Fig. 7. The plunger 172 controls a toggle mechanism which actuates the switch 164 and has a flange 182 which controls the switch 190. Fixed to the spindle 52 within the housing 56 is a plate 86, Fig. 6, having two extending fingers 88, 90 which co-operate with helical surfaces 94, 98 of a cam 92 and which may engage in slots 96, 100 of serial cam. Attached to the cam 92 is a second plate 102 having fingers 104, 106 which co-operate with helical surfaces 118, 120 of a cam 108 carried by a sleeve 126, the outer end 'of which has a setting knob 128, Fig. 5. The clockwork drives the spindle 52 through a friction clutch which permits of rotation of the knobs 72, 128 to preset the two delay periods. The arrangement is such that the setting results in downward movement of the spindle 52 and closing of the switch 190 and opening of switch 164. The spindle 52 is then rotated by the mainspring and the above described cam and follower arrangement allows the spindle to return axially to the starting position in two stages, the switch 164 being closed at the first stage and the switch 190 being opened at the second stage. In another embodiment (see Group XXIX) the device controls two valves disposed serially in a fluid flow path. Reference has been directed by the Comptroller to Specification 799,828.