GB653183A - Direct cranking engine starter - Google Patents

Abstract

653,183. Turning-gear. BENDIX AVIATION CORPORATION. April 23, 1948, No. 11258. Convention date, April 30, 1947. [Class 7(v)] In a direct cranking engine starter comprising in combination an axially stationary hollow nut 32, driving means for rotatively driving the nut and a starter jaw member 44 including a screw shaft portion 40 having a long-lead thread connection with the nut, the member 44 being capable of axial movement relative to the nut 32 into engagement with an element 46 to be driven thereby and of rotation with the nut upon engagement with the element, there is provided holding means. such as spring-loaded balls 80 operable to positively engage the member 44 and restrain it against rotation with the nut 32 and thereby faciliate the axial movement as well as to release the member 44 for rotation with the nut upon engagement with the element 46. The drive to the member 44 is taken through sun and planetary gearing, a multiplate friction clutch 34, nut 32 and screw shaft 40, the latter being splined to the jaw 44 and provided with a flange 58 engaging a corresponding flange 56 on a mesh rod secured to the member 44, a spring 62 being interposed between a collar in the interior bore of the shaft 40 and the rear face of flange 56. The member 44 is provided with a shank 45 that embodies twelve spiral surface grooves 70, with a pitch that is of reversed hand compared to that of the screw shaft, the grooves opening into a depression 72. In order to positively hold the member 44 until it is engaged with the element 46, the. starter cover 16 incorporates twelve radially arranged pockets 76 housing spring-loaded balls 80, each of which engage in one of the grooves 70. When the balls have dropped into the depression 72 the jaw member is free to rotate. The nut 32 is engaged by a sealing ring 84 of neoprene or like substance that may be vulcanized to the starter casing. Tn a modification, the grooves are straight and disposed parallel to the axis of jaw member whilst a spring is located inside the main engaging spring, its inner end abutting the collar within the screw shaft and its outer end engaging a cup secured to a spindle held in the boss in which the sun gear is formed. The spring is compressed by the engaging movement of the jaw member and assists in returning it, after the starting operation, to the retracted position.