GB549333A - Improvements relating to pumps for hydraulic vehicle brake systems - Google Patents

Abstract

549,333. Hydraulic brake pumps. ROVER CO., Ltd., and IVERSEN, P. A. SCOTT-. April 11, 1941, Nos. 4854 and 16557. [Class 102 (i)] [Also in Group XXVI] A hydraulic brake pump comprises a hollow cylindrical or like body part a which is divided internally by a partition f to form a pump chamber g and a sealing chamber h, and which is mounted on a vehicle in an inclined position with the pump chamber at its lower end, and a plunger j extending completely through the sealing chamber and operated, against the action of a helical spring n in the sealing chamber, by hand or foot pressure applied to its outer end k. The pump is mounted in resilient bushes e and the plunger slides through glands m, the upper gland and the upper end of the plunger preferably being of non-circular crosssection to prevent relative rotation. The liquid in the sealing chamber is the same as that in the pump chamber, it serves to lubricate the plunger and spring, and it may be introduced through a side aperture s which may be connected to a supply reservoir. This liquid also may be utilized to replenish the pump chamber g, in which case the lower end of the plunger may be made hollow and provided with a side hole q. In the event of an undue pressure fall in the pump chamber, communication between the chambers g, h is re-established by means of a passage r and spring-loaded valve s within the plunger, as shown, or in the partition f. Alternatively, the pump chamber may be connected through a non-return valve to a separate supply reservoir. The plunger may consist of two parts which may be so interconnected as to allow limited axial relative movement.