Abstract: A pneumatic grease gun includes a handle, a storage container, a coupling tube and a cylinder assembly. The handle has a grip and a bushing. The grip is located at one side of the bushing. The cylinder assembly has two ends connected respectively to the bushing and coupling tube. The coupling tube holds a feeding tube which has one side communicating with the storage container. The feeding tube has a tubular wall coupled with a protrusive O-ring close to the cylinder assembly. The cylinder assembly includes a feeding rod running through the feeding tube and surrounded by the O-ring to prevent grease held in the storage container from flowing back to the cylinder assembly, thus increases the lifespan thereof. The grip is positioned at an adequate location to save user's effort in holding, hence can better meet use requirements.

Abstract: A pneumatic grease gun has a first compressed air chamber formed between a sleeve and a first piston set, and a second compressed air chamber formed between the sleeve and a second piston set so that the pressure of compressed air is double to increase the thrust force to push grease therefore make replenishment of fresh grease more effective. Moreover, grease is blocked by the two piston sets and the sleeve so that grease is prevented from returning and clogging the air vane and the life span of the pneumatic grease gun increases.

Abstract: A pneumatic grease gun has a first compressed air chamber formed between a sleeve and a first piston set, and a second compressed air chamber formed between the sleeve and a second piston set so that the pressure of compressed air is double to increase the thrust force to push grease therefore make replenishment of fresh grease more effective. Moreover, grease is blocked by the two piston sets and the sleeve so that grease is prevented from returning and clogging the air vane and the life span of the pneumatic grease gun increases.