GB715280A - Improvements in or relating to starting apparatus - Google Patents

Abstract

715,280. Turning-gear. NAPIER & SON,Ltd., D. Sept. 17, 1952 [Oct. 2, 1951], No. 22926/51. Class 7(5) In a two-directional engine - starting apparatus including two pairs of clutch elements 23, 28 and 24, 29, Fig. 1, one element 23, 24 of each pair being carried by a driving clutchmember, such as collar 22, and the other by a driven clutch - member 25 the arrangement being such that rotation of a driving shaft 2 tends to bring one or other pair of clutches into engagement by relative axial movement between members 22 and 25 whereas after starting the overrun causes disengagement of the appropriate pair of clutches, and a slip coupling, for example two or more centrifugally actuated levers 34, Fig. 2 which exert a frictional drag on the collar 22, Fig. 1, so that rotation of a shaft 11 in one direction or the other causes the collar to move in the corresponding direction due to the drag exerted by the levers 34, Fig. 2, there is provided a manually-controlled stopmechanism, such as a lock 44, having two operative positions in which it limits the relative axial movement of the members 22 and 25 in one direction or the other to prevent engagement, when the overrun occurs, of that pair of clutches which is arranged to transmit motion in the opposite direction to that in which the engine is being started. The shaft 1, which is driven by a starting motor, not shown, is connected by a worm 2 and a worm-wheel 3 or other reduction gearing to a hollow driven-shaft 4 in a stationary casing 7; within shaft 4 is the hollow starting-shaft 11, one end of which is connected by a multi-plate friction-clutch 14 to a flange 8 integral with the shaft 4. The collar 22 is connected by threads or helical splines 17 to the other end of starting-shaft 11 whilst the driven member 25 surrounds the collar 22 and is coupled to a turbine rotor 51; the levers 34, Fig. 2, are pivoted to the member 25 by bolts 33 and one end 35 of each lever is formed as a shoe to exert a frictional drag on collar 22 whilst the other end is acted upon by a spring 36; movement of the collar 22, due to the action of the levers 34, is limited either by a ring 18, Fig. 1, or the end 20 of a sleeve 21, whereupon one of the two sets of clutch teeth is engaged. The lock 44 may be moved into one of three positions by a lever 42 and a rod 37 to protrude through shaft 11 and prevent the movement of the collar from the central position or to enable it to be moved only to the left or right from the central position. A switch mechanism, not shown, controlling operation of the starter motor in either direction is conjointly locked or operated with the lever 42. The friction clutch 14 may be set to slip when maximum torque is being transmitted. The central position of rod 37, lock 44, and hence collar 22 may be dispensed with and more than one lock may be provided; the driven clutch-member may be axially slidable on a fixed driving clutch-member.