GB752281A - Engine starter gearing - Google Patents

Abstract

752,281. Turning-gear. BENDIX AVIATION CORPORATION. June 25, 1954 [June 30, 1953], No. 18722/54. Addition to 702,978. Class 7(5) In a modification of the starter drive of the parent Specification centrifugally-actuated balls 47 disconnect and hold the driving clutch member 7 out of engagement with the driven clutch member 6 as long as the latter rotates above a given speed. Rotation of the power shaft 1 is transmitted through the sleeve 2, spring 17 and driving clutch ring 8 to the screw shaft 5, thereby causing traversal of the nut 21, barrel 24 and hence the pinion 18 into mesh with the engine gear 19, whereupon it abuts the ring 32; the screw shaft 5 moves to the left compressing the spring 17 until the clutch ring 8 is arrested by a thrust washer 11. The' clutch teeth 6, 7 are pressed together by the screw jack action of the screw shaft 5 and nut 21 and torque is applied to the pinion to crank the engine. When the latter fires, the pinion speed exceeds that of the engine so that the nut 21 threads back along the screw shaft until the latch 37 engages a shoulder thereon and the screw shaft overruns the clutch ring 8 and causes the balls 47 to move outwardly to engage an inclined surface 48, wedging the teeth 6, 7 apart against the action of the spring 35; the latch 37 is then centrifugally withdrawn to allow the parts to return to the idle position where they are yieldably maintained when the latch 37 engages another screw shaft shoulder 39. The balls 47 are contained within a housing comprising a disc 43 fixed to the ring 8 and a dish-shaped member 44 secured to the screw shaft, recesses 50 in the member 44 ensuring that the balls 47 rotate with the latter.