Two stage delivery valve for hydraulic pump - has two coaxial valves held by strong and weak springs respectively

摘要

The two stage delivery valve (2) is for a piston type hydraulic pump. It has a main body, blocking the delivery pipe (1) by a very strong spring (3). Through this is an opening (5) in which is an auxiliary valve (6), held by a weak spring (7). The two springs are co-axial and held in position by a single part (4). The contact faces of the auxiliary valve and the rear of the main valve body are flat. The spring retainer has a cylindrical skirt, with slight play, around the outer wall of the main valve. The wall is partly spherical.