The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 18, 1990
Filed:
Apr. 24, 1989
Ward D Morrison, Claremont, NH (US);
Arthur A Michaud, Claremont, NH (US);
Cannon Industries, Inc., Claremont, NH (US);
Abstract
A pneumatic rock drill which has a pneumatic percussion unit with a piston which slidably engages the cylinder in which it reciprocates. Preferably clearances of less than less than about 0.00125 inches per inch of piston diameter and greater than about 0.00075 inches where clearances are diameter are maintained to assure a fluid film between the piston and the cylinder wall. The clearances are based on diameters. The piston of the pneumatic drill has at least one stem section which slidably engages a distributor. The rock drill has a pneumatic motor connected to the percussion unit and engages a distributor of the percussion unit. An air motor gear in the pneumatic motor is rotatably mounted on the distributor. The exhaust is employed to lubricate the bearings and gearing which turn the striker bar.