GB507015A - Improvements in engine starter drives - Google Patents

Abstract

507,015. Turning -gear. ECLIPSE MACHINE CO. Dec. 7, 1937, No. 33910. Convention date, Dec. 9,1936. [Class 7 (v)] In an engine starter drive comprising a pinion 11, slidably journalled on a power shaft 1 for movement into and out of mesh with an engine member 12, and a nut 7 having a threaded connection with the shaft 1, rotation and longitudinal .movement are transmitted from the nut to the pinion by means of a barrel member 13 and a cam connection between the barrel member and the pinion and operative to turn the pinion with respect to the barrel when the meshing movement of the pinion is interrupted. As shown, the nut 7 is threaded on a screwed sleeve 4, freely journalled on a sleeve 2 fixed on the shaft 1 and driven from the sleeve 2 through a torsion spring 5 having flattened convolutions. The barrel 13 is splined on the nut 7 and is connected to the pinion through cam members 15, 16 normally held in extended relation by a spring 26, the member 16 being fixed on the pinion and the member 15 splined in the barrel. Lock rings 19, 21 retain the members 16, 7 in the barrel and the movement of the nut 7 is limited by a thrust ring 8 and a stop on the sleeve 2. When the sleeve 4 is driven from the shaft 1, the axial movement of the nut is transmitted to the members 15, 16 and the pinion by thrust bars 23 fixed on the nut and engaging splines in the barrel. When the pinion meshes with the engine member 12 and a thrust ring 22 in the barrel abuts against the thrust ring 8, longitudinal movement of the barrel is stopped ; further longitudinal movement of the nut causes the cam member 15 to be forced into full engagement with the member 16 until the nut 7 engages the thrust ring 8, and the sleeve 4 then moves back against a thrust washer 29, compressing the drive spring, so that the parts are clamped together for rotation in unison. If the teeth of the pinion clash with those of the member 12, the continued advance of the nut 7 forces forward the cam member 15 and turns the member 16 and the pinion into meshing position by means of cam faces 24, 25 on the members 15, 16. The screwed sleeve 4 has a smooth portion adjacent to the idle position of the nut 7, to allow dissipation of the momentum of the nut when it runs off the screw threads, and a spring 28 ensures reengagement of the nut-with the threads.