| 摘要 |
1,060,652. Percussive tools. M. A. STU TZ. May 4, 1964 [May 10, 1963], No. 18613/63. Heading B4C. A percussive tool, such as a power hammer or vibratory power drill, comprises a striker 18 arranged to be reciprocated by rotary flyweights 34, 44 mounted for rotation in opposite senses on opposite sides of the striker, each flyweight being balanced by another flyweight 38, 42 rigidly connected to it and arranged so that the two connected flyweights lie one on each side of the striker. The striker is formed with arms 22 which are bored for slidable engagement on guide rods 26 extending between lower and upper parts 56, 58 of a casing 10. The lower part 56 supports a drill 14 and a transmitting rod 62, and the upper part supports a bearing for the shaft 16 of an electric motor 12 in a housing formed with a handle 52 and carrying a switch 54 for the motor. The shaft 16 carries a rotatable block 50 which has a splined connection with a shaft 48 secured to a bevel pinion 46 mounted in the striker 18. The pinion meshes on one side with a bevel gear 40 which is mounted on a shaft 30 carrying at its ends the flyweights 42, 44. The other side of the pinion meshes with a bevel gear 32 which is integral with or secured to the flyweight 34 and is mounted on one end of a sleeve 28 rotatable on the shaft 30 and carrying at its other end the flyweight 38. The arrangement is such that all the flyweights reach their highest and lowest positions at the same time, the flyweights 34, 38 rotating in the opposite direction to the flyweights 42, 44 to reduce any tendency of the tool yawing. The lower position of the striker is cushioned by a spring 64 coaxial with the rod 62 or by springs on the guide rods. The upper position of the striker is cushioned by a spring 66 and additional springs 68 on the guide rods are operated momentarily when the striker is in its upper position to impart additional impetus to the striker. |
