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:
May. 08, 2012
Filed:
Aug. 05, 2009
Chi Hong Ho, Kwai Chung, HK;
Chi Hong Ho, Kwai Chung, HK;
Techtronic Power Tools Technology Limited, Tortola, VG;
Abstract
A transmission assembly for a power tool comprises a first transmission path comprising a high speed transmission path and a second transmission path comprising a low speed transmission path. Driven gears of each transmission path are permanently driven during operation of the transmission. A controller is provided for engaging or disengaging the high speed transmission path in response to monitored operating current of an electric motor providing a driving torque to an input of the transmission. When disengaged, a driven gear of the high speed transmission path continues to be driven, but the driven gear is disengaged from an output of the transmission. Consequently, under these circumstances, the low speed transmission path is the 'active' transmission path providing a low speed, high torque drive to the transmission output. A clutch enables the low speed transmission path to operate at a lower speed than an output of the transmission assembly when the high speed transmission path is engaged and is providing a high speed, low torque drive to the transmission output.