GB969007A - Rotary hammer device - Google Patents

Abstract

969,007. Percussive tools. SKIL CORPORATION. Dec. 19, 1960 [March 30, 1960; April 4, 1960; May 18, 1960; May 31, 1960; June 1, 1960], No. 43550/60. Heading B4C. In a rotary and percussive hammer the drive for the tool includes a rotary cylinder and a striker reciprocating within the cylinder. The cylinder 26 (Fig. 1) is rotatable in a body 12 having a handle 15 and carrying an electric motor 70. The cylinder is driven from the motor by gearing 77, 78, 86, 87, 92, 24, the gear 77 carrying a pin 82 joined by a connecting rod 65 to a piston 64. A tool adapter 46, formed at 50 to carry the tool, has an octagonal shank cooperating with an octagonal bore 33 in a drive member 32 rotating with the cylinder, and extending into the cylinder to the zone of movement of a striker 58 which is reciprocated by movement of the piston 64. Leakage of air past the striker from the space between the piston and striker is compensated by air entering the space through a bore 100. Air is delivered to and exhausted from the space in front of the striker through ports 95, 98 and a duct 97. when the tool is not in contact with the work the adapter is held in extended position by the engagement of its shoulder 49 with an internal taper 55 in a nose 52 fixed to the body, and the striker moving beyond holes 124 is not reciprocated. The hammer may be adapted for percussive tool movement only by fitting an adapter with a circular shank. In the construction shown in Fig. 3 the hammer carries a chuck 120, which is rotated only, the chuck being screwed into the member 32 which is rotated by the cylinder, and its shank being too short to be struck by the striker. In a modification (Fig. 10, not shown) a spring is interposed between the piston and striker. The shanks of tools adapted for non-rotary operation may have squared portions or apertures so that the tools may be turned by a wrench or handle. Specifications 969,008, 969,009 and 969,010 are referred to.