Document Type and Number:
Japanese Patent JP3292969
PROBLEM TO BE SOLVED: To provide a lightweight hammer drill at a low cost by enabling prevention of idle strike of hammer drill without moving a cylinder fore and aft.
SOLUTION: A cylinder 15 of a hammer drill 1 is made of aluminum and grasped by and fixed to a crank housing 5, and on the front half thereof a slide sleeve 16 and tool holder 17 are fitted. The slide sleeve 16 is made cylinderically from synthetic resin, fitted loosely with movability fore and aft between the major diametric portion 20 of tool holder 17 and the cylinder 15, and energized forward together with a receptacle spring 28 by a compression spring 29 installed in the area to a bevel gear 23. Air holes 35, 35 blocked by the ring 28 in the position where the slide sleeve 16 and ring 28 are retreated are bored in the position of the air chamber 30 of cylinder 15, and slits 37, 38 are provided ahead of the slide sleeve 16 while a pluraility of through holes 39, 39 are provided in the major diametric portion 20.
More Like This:
April 05, 2002
August 18, 1995
B25D17/10; B23B45/16; B25C1/04; B25C7/00; B25D11/00; B25D16/00; B25D17/06; (IPC1-7): B25D17/10; B25D16/00