GB496943A - Improvements in or relating to electrically operated engine starters - Google Patents

Abstract

496,943. Turning-gear. SPERRY GYROSCOPE CO., Ltd., and CLOUSTON, C. E. June 3, 1937, No. 15438. [Class 7 (v)] In an engine starter comprising an electric motor 45, the armature 46 of which is normally displaced axially of the field windings by a spring 32 and on energization is moved axially to effect the engagement of starter clutch members 1, 1<1>, the clutch member 1 is arranged to follow up the member 1<1> if and when the engine overruns the motor. As shown in Fig. 1, the clutch member 1 is mounted on a shaft 62 and has ratchet teeth 26 held in engagement with similar teeth on a member 25 by a spring 35. The member 25 is splined in a sleeve 221 driven from the armature shaft 47 of the motor through splined sleeves 48, 49 and the reduction gearing described in Specification 494,119 with reference to Fig. 3 of the drawings. When the engine starts and overruns the motor, the shaft 62 and the clutch member 1 are driven directly from the armature shaft 46 through a friction clutch 70 which normally slips during the starting operation. The clutch comprises a plate 71 fixed on the shaft 62 and a sliding plate 72 held by a spring 73 in engagement with an interposed cup-shaped member 75 secured to a disc 69 on the shaft 47. In a modification, Fig. 2, the clutch 1 is normally held out of engagement by a detent 76 pivoted at 77 on the motor housing and urged by a spring 78 against an inclined face 79 on the clutch housing 80. The spring 78 yields when the motor is energized and does not tend to throw the clutch 1 out of engagement if the endwise magnetic pull on the motor armature is weakened during the starting operation. The friction clutch 70 comprises metal plates 81 splined on the shaft 62 and gripped between plates 82 splined in the housing 80, which has a screwed end plate 84 forming an abutment for the spring 83. The member 25 of the clutch 1 is journalled in an antifriction bearing 91 and the spring 35 bears against a thrust block 92 in the member 25.