David P Sutton

US Patent:

6241027, Jun 5, 2001

Filed:

Jul 21, 1999

Appl. No.:

9/358639

Inventors:

Reimund Beck - Hunfelden, DE
Stefan Blickhan - Darmstadt, DE
Rainer Herting - Langenhahn, DE
Ernst Staas - Limburg, DE
David L. Sutton - Easton MD

Assignee:

Black & Decker Inc. - Newark DE

International Classification:

B23D 4904

US Classification:

173216

Abstract:

A hand-operated electric tool, especially a jigsaw, has a motor unit provided in the tool housing. The motor unit contains in a motor housing the stator and the rotor. One end of the rotor shaft projects from the motor housing and is mounted in two bearings fixed in the motor housing. A countershaft forms an extension of the rotor shaft and carries a toothed arrangement. The countershaft is coupled to the rotor shaft and is rotatably mounted in a bearing. The rotor shaft and countershaft engage axially with radial play and are coupled non-rotatably by co-operating radial projections and recesses receiving the projections. In the region of the overlapping portions of rotor shaft and countershaft, one of the shafts has an annular portion extending at least over a part of the circumference. The annular portion is substantially in line contact with an adjacent circumferential surface of the other shaft. The line contact permits misalignment of the rotor shaft and countershaft but reduces noise.