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:
Apr. 09, 1991
Filed:
Dec. 18, 1989
Yasumitsu Moriki, Tokyo, JP;
Hirotomo Numakura, Kawasaki, JP;
Maruma Jyusharyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A hydraulic shoe bolt wrench used to mount and remove shoe bolts which secure shoes to a track chain. The apparatus comprises a vertical cylinder stood upright on a frame moving on a work table, a main frame secured to a piston rod of the vertical cylinder, a wrench socket driving shaft vertically projected below the main frame, a low speed high torque motor and a reduction gear provided on the driving shaft. Pressure oil is supplied to the high speed low torque motor and high pressure oil is supplied to the low speed high torque motor. Switching of the high speed low torque motor to the low speed high torque motor is carried out by a pressure switch disposed in a low pressure hydraulic circuit.