GB671460A - Improvements in or relating to operating systems for motor vehicle accessories - Google Patents

Abstract

671,460. Rotary pumps. TRICO PRODUCTS CORPORATION. July 26, 1948 [July 26, 1947], No. 15784/51. Divided out of 671,462 [Group XXVIII]. Class 110(ii) [Also in Group XXXVII] The pump is driven by an electric motor having an electric switch connected in circuit with the motor and having a magnet to attract the switch to its circuit-closing position, and pressure-responsive means for opening the switch against the action of the magnetic force. The pump provides a source of suction which may be used for operating an accessory on a motor vehicle when the manifold suction is insufficient. In the Figure the pump is of the outwardlysliding vane type having an inlet 18 and delivery port 19. The driving motor circuit is connected by wires 21 to a suctionresponsive switch with fixed and movable contacts 24, 25. The space below a plunger 30 leads, by way of a pipe 10, to a source of reduced pressure, e.g. an engine intake manifold. A spring-pressed valve 35 closes a shunt passage 34 when the pump is operating and suction, through the pump inlet 18, is caused in a pipe 10<SP>1</SP> leading to the accessory to be actuated. If, however, the suction pressure in 10 is sufficiently reduced, the plunger 30 is drawn downwards and the connection between the contacts 24, 25 is broken, the pump then stopping. In order to avoid arcing between the contacts 24, 25, there is provided a permanent horseshoe magnet 56 to hold up an arm 26 until the pull by the plunger dominates to snap the contact 25 away from the contact 24.