Grease cup

Claim 1

A lubricating device for automatically feeding lubricant from a reservoir to an element such as a bearing or the like, comprising: a. a hollow housing having a one-way lubricant injection fitting positioned in a wall thereof; having connection means for connecting said housing with said element, said connection means defining an axial lubricant discharge passageway communicating with the interior of said housing; said housing including an axial cylindrical internally threaded wall merging inwardly into an annular sealing shoulder; b. a distensible elastic diaphragm element formed of a nonmetallic, lubricant-resistant material terminating in a peripheral sealing flange seated on said annular sealing shoulder; said annular sealing shoulder incorporating anti-slip means to aid in retaining in place said sealing flange on said diaphragm element; c. annular threaded ring threadedly engaging said internal threaded wall and affecting compression retention of said peripheral sealing flange intermediate said annular threaded ring and said annular sealing shoulder, said annular threaded ring having torqueing means for screwing said annular ring inwardly to increase the compression on said peripheral sealing flange independently of any guard element; d. an annular washer interposed intermediate said peripheral sealing flange of said diaphragm element and said annular threaded ring to alleviate problems of distortion and wearing of said peripheral sealing flange responsive to simultaneous compressive and rotaTional forces of said annular threaded ring; and e. a rigid guard element disposed about said diaphragm element and extending outwardly from said housing a distance sufficient to enclose, at least laterally, and protect said diaphragm element even when the latter is fully distended under the pressure of contained lubricant.