Patent ID: 7168595
Filing Date: 2007-01-30
Classification: F16N

Abstract:
1. An improved pneumatic grease gun, comprising: a hilt having a hollow sleeve on a front end, an air intake nozzle on a tail end, a channel in the interior bridging the sleeve and the air intake nozzle, and a trigger to control air entering; a coupling duct fastened to a front end of the sleeve through a plurality of bolts having a front end thereof to couple with a dispensing tube and a lower end which has a cap, the cap having a passage communicating with the interior of the coupling duct; a storage barrel for containing grease being fastened to the cap and having a handle on a bottom end to squeeze grease; and a thrust assembly located between the coupling duct and the storage barrel including a cylinder which has an aperture in the center of the cylinder bottom, and a first piston set and a second piston set located respectively on a front side and a rear side of the cylinder, the first and the second piston sets having respectively a first piston and a second piston that are run through respectively by a first strut and a second strut to form an integrated body, the struts being hollow and having a front end to couple with a compression spring; wherein the sleeve and the first piston set form a first compressed air chamber and the sleeve and the second piston set form a second compressed air chamber, compressed air being delivered to the first compressed air chamber and the second compressed air chamber to double compression and increase thrust force to replenish grease.