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. 07, 1998
Filed:
Jan. 31, 1996
Hitachi Koki Co., Ltd., Tokyo, JP;
Abstract
A power screw driver includes a clutch mechanism composed of a coiled clutch spring so designed as to entangle a drive shaft member and an output shaft member to connect them together, thereby enabling the drive and output shaft members to rotate in unison. By the use of the coiled clutch spring, the clutch engaging operation is achieved smoothly and silently without accompanying impact blow or shock, thereby securing reliable transmission of a torque from the drive shaft member to the output shaft member. The coiled clutch spring may be activated only when the drive shaft member is rotating in the forward direction, in which instance a one-way clutch is used to undertake transmission of the torque when the drive shaft member is rotating in the reverse direction. As an alternative, a single clutch spring may be used to undertake transmission of the torque in the forward and reverse rotational directions. Alternatively, two coiled clutch springs each provided for one rotational direction may be used.