Grease gun

A grease gun comprising a grease-containing cylinder having means for feeding grease therein toward one end of said cylinder;

• and a lever-operated piston pump assembly at said one end operative to pump grease fed thereto through a pump outlet passage;
• said assembly comprising a sheet metal head cap screwed onto said one end of said grease-containing cylinder and having a cylindrical side wall extending axially beyond said one end and terminating in a transverse end wall;
• a pump cylinder of circular cross-section secured in fluid tight relation in diametrically opposite holes in said side wall;
• said pump cylinder having an elongated central bore which is closed at one end of said pump cylinder and open through the other end;
• a piston inserted into the open end of said pump cylinder bore;
• a sheet metal clevis having a base secured by a welded area onto said end wall to extend diametrically thereacross in parallel relation to said pump cylinder and having upstanding portions providing a clevis pivot axially beyond said end wall;
• a link having one end pivotally connected to said clevis pivot;
• a lever pivotally connected at longitudinally spaced points thereof to the outer end portion of said piston and to the other end of said link;
• said pump cylinder having an inlet communicating the interior of said grease-containing cylinder with said bore when said piston uncovers said inlet during outward movement of said piston by swinging said lever away from said grease-containing cylinder;
• a check valve body having a cylindrical portion extending through aligned holes in said base and end wall remote from said welded area and extending through and secured in fluid tight relation in a cross bore of said pump cylinder adjacent the closed end thereof;
• said check valve body having shoulders at the ends of said cylindrical portion respectively engaging said base around the hole therein and said pump cylinder around said cross bore to retain said base against said end wall to prevent pulling apart of said base and end wall at said welded area upon application of large forces on said link as said lever is swung toward said grease-containing cylinder to move said piston inwardly toward said closed end to cover said inlet;
• said shoulder which engages said pump cylinder being defined by the radially outwardly deformed end of said cylindrical portion;
• said check valve body having a check valve therein through which grease is pumped to said pump outlet passage during movement of said piston toward the closed end of said pump cylinder.