Patent Number: 8,028,760

Title: Hammer drill

Abstract: The invention is to provide a hammer drill which is to be capable of restricting rotation of a bit in a hammer mode, and improve usability. A hammer drill includes a lock plate 51 in a housing 2, and the lock plate 51 engages with a second gear 31 so as to lock rotation of the second gear. The lock plate 51 is provided to be slidable between an engaging position with the second gear 31 and a non-engaging position, and is biased to the engaging position by a coil spring. The hammer drill further includes a restriction part 50 on an outer peripheral side of a holding tube 46 in a mode switching knob 44. The restriction part 50 abuts the lock plate 51 in one of two phases for engaging a clutch 37 with only a boss sleeve 32 so as to hold the lock plate 51 at the non-engaging position, and cancels the abutment with the lock plate 51 in the other phase to slide the lock plate 51 to the engaging position. In a hammer mode, a user can select a state for making rotation of a tool holder 3 free in one phase or a state for restricting the rotation of the tool holder 3 in the other phase.

Inventors: Yoshikane; Kiyonobu (Anjo, JP)

Assignee: Makita Corporation

International Classification: E02B 7/02 (20060101)

Expiration Date: 2019-10-04 0:00:00