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:
Dec. 15, 1981
Filed:
Nov. 19, 1979
George W McCarty, Lutherville, MD (US);
Black & Decker Inc., Newark, DE (US);
Abstract
A bi-directional, self-tightening chuck for releasably gripping a tool bit such as a twist drill or the like includes a bit receiving nosepiece having a conical, internal opening formed therein. A control sleeve is rotatably mounted, through a thrust bearing, on the nosepiece and is adjustably connected to a chuck body to enable adjustment of the axial position of the nosepiece relative to the chuck body. Tapered gripping elements, which may take the form of cone-like gripping rollers or wedge-like jaws, are located in the internal opening of the nosepiece and are adapted to forcibly grip the stem portion of the tool bit in response to a hand-tightening adjustment of the control sleeve on the chuck body and further adapted to self-tighten in response to an axially directed thrust force applied to the gripping elements by a torque-responsive cam assembly. The cam assembly is located between the gripping elements and the chuck body and develops the axial thrust force in response to the torque applied through the tool bit to cause the gripping elements to self-tighten. In the preferred embodiment, the torque responsive cam assembly includes opposed, axial-face cams each having complementary sets of oppositely inclined ramp surfaces formed thereon with ball elements separating the cams. The torque applied through the tool bit causes the face cams to rotate relative one another to develop and apply the axially directed thrust force to the gripping elements to increase the gripping force.