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. 23, 1999
Filed:
Mar. 27, 1997
Takuo Arakawa, Anjo, JP;
Masaki Sakuragi, Anjo, JP;
Makita Corporation, Aichi, JP;
Abstract
A percussive tool generates a reduced impact at the start of percussive operation following idling operation. The percussive tool has a cylinder containing a piston, an air chamber in front of the piston, and a striker disposed in front of the air chamber. A slide sleeve and a rimmed ring at the rear end thereof are fitted around the cylinder. The cylinder has formed therein an exhaust port and auxiliary ports in front of the exhaust port for placing the air chamber in communication with the atmosphere. When the slide sleeve is retracted, the exhaust port is closed by the rimmed ring. During percussive operation of the percussive tool, the auxiliary ports are always closed by the reciprocating striker and therefore not open to the air chamber. During idling operation, the striker takes an advanced position and opens the auxiliary ports, thereby placing the air chamber in communication with the atmosphere. The distance between the rear end of the striker and the auxiliary ports is set slightly shorter than the distance between the rear end of the ring and the exhaust port in normal operation, so that the auxiliary ports are opened prior to the exhaust port.