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:
May. 07, 1991
Filed:
Oct. 06, 1989
Llewellan Anderson, Renton, WA (US);
The Robbins Company, Seattle, WA (US);
Abstract
Drive head apparatus for driving the drill string of a rock boring machine, such apparatus comprising one or two drill string connectors (28) (30) having resilient means such as a coil spring (66) acting therebetween, with respective floating bearings (62) (64) separably secured thereto and with each bearing arrangement comprising respective cooperating, axially fixed bearing seating surfaces (68) (86). Each floating bearing (62) (64) is in the form of a softer metal insert replaceable on the associated connector (28) (30) without replacement of the drill string connector (28) (30). A splined cylindrical drive insert (88) rotatably drives the drill string connector and is separable from the drive body (58) in which it is seated and is axially reversible to swap wear ends or is readily replaceable without need for replacement of the entire drive body (58).