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. 16, 1989
Filed:
Oct. 05, 1987
Applicant:
Inventor:
Robert S Carlson, Portland, OR (US);
Assignee:
Other;
Primary Examiner:
Int. Cl.
CPC ...
B23B / ;
U.S. Cl.
CPC ...
408 / ; 408 87 ; 408102 ; 408112 ; 408137 ; 4082 / ;
Abstract
A drilling tool for removing spot welds includes a central shaft having a threaded portion which extends through a center nut and washer assembly. A pair of oppositely opposed compression springs bear on the center nut and washer assembly to maintain it in a fixed position. Stops located on the shaft engage the center nut and washer assembly to limit the forward travel of the drill bit. This ensures that the drill bit has a predetermined stroke length. The springs provide compression for the drill bit as the shaft rotates thus forcing the drill bit into the workpiece, but with some resilience so that the drill does not bind up.