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:
Jul. 07, 1998
Filed:
Aug. 14, 1996
Yasutoshi Shinma, Anjo, JP;
Makita Corporation, Anjo, JP;
Abstract
A hammer drill has an aluminum cylinder non-rotatably mounted in a crank housing, a synthetic resin slide sleeve, and a tool holder. The latter two members are coaxially fitted over the front part of the cylinder. The slide sleeve is a cylindrical member slidably mounted between a large bore portion of the tool holder and the cylinder. A steel ring is mounted at the rear of the slide sleeve. The slide sleeve and the steel ring are urged in the forward direction by a compression spring interposed between a bevel gear and the steel ring. A first air chamber which is formed in the cylinder includes a plurality of air ports which are covered by the steel ring when the slide sleeve and steel ring are pushed in their respective rear positions by pressing a tool bit attached to the hammer against a work piece. A plurality of wide and narrow slits are formed in the front portion of the slide sleeve while a plurality of air passage holes are also formed in the large bore portion of the tool holder.