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:
Aug. 27, 2024
Filed:
Nov. 08, 2021
Furukawa Rock Drill Co., Ltd., Tokyo, JP;
Tsutomu Kaneko, Takasaki, JP;
Susumu Murakami, Takasaki, JP;
Isao Kobayashi, Takasaki, JP;
Atsushi Shioda, Takasaki, JP;
Shinsuke Nagano, Takasaki, JP;
Furukawa Rock Drill Co., Ltd., Tokyo, JP;
Abstract
A hydraulic hammering device enables an auto-stroke mode and an idle strike prevention mode to coexist with a simple circuit configuration. The device includes a first control valve to control advancing and retracting movements of a piston, an auto-stroke mode and an idle strike prevention mode, and a second control valve to select either of the auto-stroke mode or the idle strike prevention mode. To the second control valve, a shared spool is slidably fitted and a mode selection means is disposed. When the mode selection means allows supply of pressurized oil to an auto-stroke setting portion of the shared spool and prohibits discharge of pressurized oil from an idle strike prevention setting portion, the auto-stroke mode is selected. When prohibiting supply of pressurized oil to the auto-stroke setting portion and allowing discharge of pressurized oil from the idle strike prevention setting portion, the idle strike prevention mode is selected.