GB459826A - Improved lubricating pumps and methods of operating the same - Google Patents

Abstract

459,826. Grease guns. TECALEMIT, Ltd., Great West Road, Brentford, Middlesex. March 31, 1936, No. 9548. Convention date, April 3, 1935. [Class 102 (i)] A grease gun comprises a pump plunger 11 connected to motor pistons 35, 41 by a rod 21 carrying a free follower piston 27, acting on grease in the chamber 1, and valve means for controlling air supply to the motor pistons. When an air hose is connected at 47 the air passes through a port 79 into the space between pistons 27 and 35 thereby moving the latter to the right, and withdrawing the plunger 11. The follower 27 is then pressed to the left and fills the pump cylinder. When grease discharge is required a trigger 65 is depressed to seat a valve 63 and open a valve 51, whereupon air passes through ports 59, Fig. 3, and 71, Fig. 1, to cylinder 33 and thence through a rod 37 to power cylinder 43. The pressure on piston 35 is thus balanced and pressure on piston 41 effects the discharge stroke. Upon release of the trigger the valve 51 closes and valve 63 opens to exhaust air in cylinders 33 and 43. The air pressure on piston 35 is thus unbalanced and it moves to the right and follower 27 primes the pump cylinder. The gun may be filled through a valve 19 or by removing the end caps.