GB897601A - Improvements in or relating to central lubricating system - Google Patents

Abstract

897,601. Force-feed lubricating. SATZGER, E. July 21, 1960 [Aug. 3, 1959], No. 25416/60. Class 12 (3). In a lubrication system having a manuallyoperated pump, a relief-valve automatically opens as the pressure of the lubricant rises after completion of the lubrication operation, through metering elements (not shown), so that a delivery pipe is relieved of pressure. In an embodiment a piston 2, in a casing 1, is hand-actuated by a lever 7, through a lever 5 having a ball-shaped end 4 engaging a recess 3 of the piston. The relief-valve comprises a plunger 17 in a bore 24 of a spring-urged piston 20, the plunger having a head 16 engageable with a surface 21 of the piston 20. By moving the lever 7 into a position A, Fig. 1, the piston moves to the left so that lubricant enters a chamber 10 via a bore 9 connected to a reservoir 8; by moving the lever into a position B the piston moves to the right and the lubricant is forced out of the chamber 10 through a non- return ball valve 11 to an outlet 12 connected to the delivery-pipe 13. When the metering elements have completed the lubricating operation the pressurized lubricant returns via bores 14, 15 and opens the relief-valve so that its head 16 moves from its seating to expose an aperture 28, through which lubricant flows and impinges on the surface 21 of the piston 20 and causes it to move, along with the plunger 17, against the spring 19. The lubricant returns to the reservoir when the surface 21, of the piston 20, coincides with a bore 23 in the casing 1. The plunger 17, having a button 18 thereon, is forced by hand against the seating prior to re-commencement of the lubricating operation, and lubricant displaced by the head 16 flows via an axial bore 27 and an annular bore 26 of the piston, through a slit, defined by the bore 26 and the bore 23 to the reservoir. This allows the piston 20 to be urged by the spring 19 into engagement with the plunger 17. The slit disappears when the piston 20 is displaced by the pressurized lubricant. Lubricant received by the passage 24, in the piston 20, returns to the reservoir via a bore 25 in the casing 1.