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.

Date of Patent:
Mar. 31, 1992

Filed:

Apr. 02, 1991
Applicant:
Inventors:

Fusao Fushiya, Anjo, JP;

Takashi Yamazaki, Anjo, JP;

Yoshio Sugiyama, Anjo, JP;

Assignee:

Makita Corporation, Anjo, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B25D / ;
U.S. Cl.
CPC ...
173 17 ; 173200 ;
Abstract

An impact tool includes a body, a barrel mounted on the body and a cylinder disposed within the barrel and reciprocally moved by a drive mechanism. A communication groove is formed between the cylinder and the barrel and communicates with the outside. The cylinder includes a plurality of communication holes formed in a radial direction and spaced from each other in a longitudinal direction. A striker is reciprocally movable within the cylinder, and an air chamber is formed between the striker and the cylinder. The striker is positioned at a first position when the tool bit is not pressed on a work. The striker at the first position permits communication between the air chamber and the communication groove through any one of the communication holes so as to be prevented from idle impact. Further, the striker is movable to a second position rearward of the first position through the pressing operation of the tool bit on the work. The striker at a position rearwardly of the second position prevents communication between the air chamber and the communication groove so as to permit normal impact operation by the tool bit.


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