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. 06, 1976
Filed:
Sep. 23, 1974
Masaaki Hiraoka, Yao, JA;
Hiromu Terada, Ikoma, JA;
Abstract
A pneumatic impact wrench. This device is characterized in the improvement of the torque controlling mechanism incorporated therein, said mechanism comprising a torsion bar, a spindle case, a fluid element, and valves, holes and passages all functioning in close linkage with each other thereby enabling execution of the torque control and even change of the torque control value precisely. In this mechanism, an air motor driving this device is brought to a halt automatically as the result of closing of a main valve in relation to the operation of said fluid element, said operation of said fluid element being available from air pressure change caused by the closing or narrowing of an air exhausting hole taking place in compliance with twisting of said torsion bar under its partially rolling effect at the rear portion thereof, said torsion bar fixing to said spindle case at their forward portions at this time being imparted with a rotation-suspending resistance thereto at their fixing portion. This invention is further advantageous in that conventionally used automated valves can be dispensed with besides simplification of circuits being available in the above-mentioned mechanism.