GREASE GUN WITH AN OBSERVATION WINDOW
A grease gun with an observation window is provided with a metal outer barrel, a plastic transparent inner barrel received in the outer barrel, and an operating end cover and a piston end cover screwed at two ends of the outer barrel. The observation window is formed on the outer barrel, and the two end covers define an oil storage space with respect to the inner barrel, and the interior of the oil storage space can be seen through the observation window of the outer barrel and the transparent inner barrel.
1 . A grease gun with an observation window comprising:
an outer barrel made of metal and including a front open end and a rear open end, a direction extending from the front end to the rear open end being defined as a direction X, and the outer barrel being formed on the outer surface thereof with an observation window extending in the direction X;
an inner barrel including a transparent plastic barrel body with a first end and a second end and being received in the outer barrel in such a manner that the front and rear open ends of the outer barrel are aligned to the first and second ends of the inner barrel, respectively, and the barrel body of the inner barrel is viewable through the observation window of the outer barrel;
an operating end cover made of metal and provided with a front end cover, on the front end cover being provided a nozzle and a lever, the front end cover being screwed with the front open end of the outer barrel to abut the first end of the inner barrel; and
a piston end cover made of metal and provided with a rear end cover and a piston inserted through the rear end cover, the rear end cover being screwed with the rear open end of the outer barrel to abut against the second end of the inner barrel, the front end cover and the rear end cover define an oil storage space with respect to the inner barrel, and interior of the oil storage space is viewable through the observation window of the outer barrel and the barrel body of the inner barrel.
2 . The grease gun with an observation window as claimed in claim 1 , wherein the piston of the piston end cover includes a push handle at one end thereof and a piston head at another end thereof, the piston head is received in the oil storage space, so that, when the piston moves in the direction X within the oil storage space, the movement of the piston head will be viewable through the observation window of the outer barrel and the barrel body of the inner barrel.
3 . The grease gun with an observation window as claimed in claim 1 , wherein the piston of the piston end cover includes a rod portion, and a push handle and a piston head at two ends of the rod portion, a spiral spring is sleeved on the rod portion with two ends pushed against the rear end cover and the piston head respectively.
4 . The grease gun with an observation window as claimed in claim 1 , wherein the piston of the piston end cover includes a piston head at one thereof, a grease bar which consists of a grease barrel filled with grease, is filled into the oil storage space of the grease gun, the piston head of the piston is received in the grease barrel of the grease bar to push the grease out of the nozzle of the operating end cover, the grease bar is viewable through the observation window.
5 . The grease gun with an observation window as claimed in claim 1 , wherein the piston of the piston end cover includes a piston head at one thereof, and the piston head is received in the oil storage space, the grease is stuffed between the piston head and the front end cover, and the piston head pushes the grease toward the operating end cover.