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:
Feb. 04, 1992
Filed:
Jan. 08, 1991
Kenzi Mukoyama, Anjo, JP;
Makita Electric Works, Ltd., Anjo, JP;
Abstract
A pneumatic percussion tool includes a head valve device including first and second head valves disposed in the body and movable in response to the pressure variation in the head valve chamber. The first and second head valves are positioned at a first position for preventing communication between the main air chamber and the percussion piston chamber while permitting communication between the percussion piston chamber and the outside of the body and preventing communication between the head valve chamber and the outside of the body when the compressed air is introduced into the head valve chamber through the change-over valve. The first and second head valves are movable from the first position to a second position for permitting communication between the main air chamber and the percussion piston chamber while preventing communication between the percussion piston chamber and the outside of the body and between the head valve chamber and the outside of the body when the compressed air has been discharged to the outside through the change-over valve. The first and second head valves are movable relative to each other for permitting communication between the head valve chamber and the outside of the body and for preventing communication between the percussion piston chamber and the outside of the body during the movement from the first position to the second position.