| 摘要 |
The present invention provides an apparatus for limiting deflection of the armature shaft 38, 38f, 103 of an electrically powered tool, such as a hand held saw 10 or drill 91. In saw 10, the armature shaft 38, 381 extends as a cantilever from the motor 14 and has a geared connection 58, 60 to an arbor 44 for driving the saw blade 18. An arrangement for limiting the deflection of the armature shaft 38, 38' comprises a pilot member 72, 84 and a socket 68, 82 associated, respectively, with one and the other of the armature shaft and a motor housing supported wall. The socket 68, 82 is larger in cross-section than that of the pilot member 72, 84 and limits transverse deflection of the armature shaft 38, 38' away from its axis of rotation A. If the saw 10 stalls in the material being cut, force is transmitted from the geared connection 58, 60 to the armature shaft 38, 38'. The socket 68, 82 and pilot member 72, 84 permit the armature shaft 38, 38' to deflect a predetermined amount to counteract torques resulting from the geared connection 58, 60. In one embodiment, the pilot 72 extends from the armature shaft 38 to be received in an aperture 68 formed in the housing wall 66. In another embodiment, the pilot 84 extends from the housing wall 66' to be received in a bore 82 formed in the armature shaft 38'. According to a third embodiment, in drill 91, the shaft deflection limiter is constituted by an armature shaft pilot 111 disposed in a roller bearing aperture 117. <IMAGE> |
