GB510228A - Improvements in impact wrenches - Google Patents

Abstract

510,228. Screwing-up nuts etc.; clutches. MOSS, E. W. (Ingersoll-Rand Co.). Feb. 16, 1939, No. 5102. [Class 83 (iii)] [Also in Group XXIV] In a machine for screwing-up or unscrewing nuts, screws &c. having a rotary anvil normally connected to a rotary hammer by clutch teeth, the hammer is connected to its driving member by balls lying in V-shaped grooves in the two members so that when the nut &c. is set the balls will ride along the slots to separate the clutch teeth and deliver rotational blows to the anvil. The anvil 25 carrying a socket 33 for driving a nut 41 has segmental clutch teeth 23 co-acting with teeth 21 on the hammer 19 which is driven by balls 73 engaging V-shoulders 65 on the hammer and lying in V-grooves 57 in a sleeve 17 attached to a polygonal portion 15 of the driving shaft 9 rotated by a motor in the casing 5. The V-angle of the grooves and shoulders is considerably less than 90 degrees. A spring 53 seats against the base of the hammer 19 and against a ball-bearing 51 in the sleeve 17 to maintain the clutch 21, 23 in engagement for driving a nut. The balls 73 normally lie at the apices 63 of the grooves 57 so that when rotation of the nut stops, the balls will ride up the grooves 57, thereby raising the hammer 19 against the spring 53 until the clutch teeth have cleared each other, as shown in Fig. 3. The compression of the spring 53 will then cause the hammer to be rotated forward rapidly in restoring the balls to their normal positions in the slots, whereby the hammer will deliver a rotational blow to the anvil, the clutch teeth 23 being widely spaced to allow the teeth 21 to enter. These blows will be delivered repeatedly to set the nut until the motor is stopped. The rotating parts of the device are maintained in alignment by a central member 47 rotatable on a spigot 45 on the driving shaft 9 and engaging a bore 49 in the anvil 25, this member also preventing endwise movement of the anvil. Axial movement of the driving shaft is prevented by a collar 13 thereon.