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:
Jan. 10, 2012
Filed:
Jul. 07, 2009
Makoto Kosuge, Tokyo, JP;
Masaki Haruta, Tokyo, JP;
Makoto Kosuge, Tokyo, JP;
Masaki Haruta, Tokyo, JP;
Max Co., Ltd., Tokyo, JP;
Abstract
A pneumatic screw driver includes: a tool body; a nose portion; a main air chamber; a hammering cylinder; a driver bit integrally combined with a hammering piston in the hammering cylinder; an air motor; a valve housing provided in an air passage between the main air chamber and the air motor; a stop valve piston provided in the valve housing; a stop valve stem coaxially provided with the stop valve piston; a timer chamber connected to the hammering cylinder; a first pipeline and a second pipeline respectively formed at upper and lower positions in a lower portion of the stop valve stem; and a upper end proximal portion of a contact member provided slidably in a driving direction. The upper end proximal portion of the contact member is provided engageably with the stop valve stem. The first pipeline and the second pipeline are arranged so as to close the first pipeline after closing the second pipeline by moving the stop valve stem upward from a bottom dead center.