GB837530A - - Google Patents

Abstract

837,530. Engine turning-gear. BOSCH G.m.b.H., R. Sept. 1, 1958 [Sept. 6, 1957], No. 27924/58. Class 7(5) [Also in Group XXXV] A starter for an internal combustion engine comprises a pinion 16 longitudinally displaceable on the driving shaft 11 of an electric starter motor and engageable with a flywheel gear rim 43 of the engine by means of a lever 30 formed by two lever arms and pivotable about a pivot point at or near its middle, one lever arm co-operating with the pinion 16 and the other lever arm being actuable to pivot the lever 30 to engage the pinion with the rim 43, and the pivot point being displaceable against a spring 34 Which is compressed if the pinion 16 encounters an obstacle during its motion of engagement. As shown, the shaft 11 is mounted in a bearing in an end plate 13 flanged on to the housing of the starter motor and is provided with a smooth portion 14 on which is located the pinion 16 integral with a sleeve 17 which forms the driven part of a free-wheel clutch 18 which is connected through, an annular disc 22 to a screw sleeve 21 located on a threaded portion 15 on the shaft 11. A helical spring 27 is arranged between the clutch 18 and the end plate 13. The lever 30 is longitudinally displaceably and pivotably mounted on a stud 33 parallel to the shaft 11 and on which the spring 34 is also located and is pivoted by an electromagnet 36 so that the forks forming one of the arms of the lever engage a flange 26 on the clutch 18. Operation: On exciting the electromagnet 36 the lever 30 is pivoted and pushes the pinion 16 and the clutch 18 along the shaft 11 against the spring 27 so that the pinion travels a distance b into engagement with the gear rim 43, the switches 38, 39 of the starting motor being then closed so that rotation of the shaft 11 causes the pinion to move to its final position at c by means of the thread 15 and the screw sleeve 21. At the end of the starting process the electromagnet 36 and the starter motor are de-energized and the pinion and the clutch are pushed back by the spring 27 to their position of rest. In normal engagement operation the spring 34 being stronger than the spring 27 is only slightly compressed. If on the engagement operation the pinion teeth bear against those of the gear rim 43, the lever 30 will be displaced against the pressure of the spring 34 which is subsequently released to push the pinion into mesh when the teeth of the latter are made to register with the grooves on the gear rim 43 by rotation of the starter motor.