| 摘要 |
1,215,153. Rollers. KANGO ELECTRIC HAMMERS Ltd. 18 April, 1968 [24 April, 1967], No. 18868/67. Heading F2U. [Also in Division H2] An electric motor output shaft coupling comprises a second element 12, Fig. 2, spaced coaxially about a first element 10 secured to the shaft, one element having a sleeve portion encircling part of the other element and a third element 11 of electrical insulating material which is moulded about the sleeve portion to fill the gaps between the first two elements and transmits a rotary drive between the elements. The electric motor is in a portable percussive tool having a tool retaining device (20), Fig. 1 (not shown). The motor unit 21 is inserted in the main housing 24 spaced from the motor casing by ribs 25. The casing 26 is of an electrically-insulating material, e.g. glass filled nylon. The coupling element 10, Fig. 2, is press fitted on the splined portion of shaft 30 and its outer surface is knurled. Element 11, which is formed from an electrically-insulating material, e.g. glass-filed nylon, is moulded to elements 10 and 12, the free end portion of the latter being formed with gear teeth 16. A hardened steel sleeve 38 secured on portion 12a engages bearing rollers 37. An electrically insulating shroud 30a is fitted between the elements 10, 11 and the commutator 40. The opposite end of shaft 30 is supported by an electrically-insulating end member 33 and carries a fan 39. In a modification the element 12 is replaced by an element (46), Fig. 3 (not shown) having two rings of radial apertures (47) in its sleeve part and the element 11 is replaced by a moulded element which fills the apertures. The element portion (46a) which replaces portion 12a is bored to receive a gear stub shaft. In a further modification the latter part is formed with gear teeth. A coupling similar to that shown in Fig. 1 or modifications thereof may be fitted to the other end of shaft 30 in order to drive a shaft or other rotary member or where a metallic outer casing is in electrical contact with a metallic main housing. |
