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:
Mar. 30, 1976
Filed:
Dec. 23, 1974
Jack D Nelmark, New Berlin, WI (US);
Bucyrus-Erie Company, South Milwaukee, WI (US);
Abstract
A shock absorber for dampening longitudinal and torsional vibrations in a drill is disposed intermediate a hollow drive shaft member and a hollow driven shaft member of a drill string. Resilient means are sandwiched between a drive plate attached to the drive shaft member and a driven plate secured to the driven shaft member. Additional resilient means are sandwiched between the driven plate and a pressure plate which surrounds the driven shaft member at a position beneath the driven plate. Pins project from the driven plate through the resilient means into vertically spaced openings formed in the drive plate and the pressure plate. Fastening means extend between the drive plate and the pressure plate to precompress the resilient means, and a shielding sleeve is connected to the drive shaft member for sliding movement within the driven shaft member. This sleeve forms a closed passage between the hollow shaft members for conveying compressed air, and for shielding the resilient means from dynamic air pressures.