Patent GB-670959-A (GB)
Title: Electro-magnetically synchronized clutches and detents
IPC: F16D23/06
Filed: 1948-10-20
Abstract: 670,959. Synchronized claw-clutches; positive detents. DUYCK, G. Oct. 20, 1948, No. 27276/48. [A Specification was laid open to inspection under Sect. 91 of the Acts, April 22, 1949.] Classes 80 (ii) and 80 (iv). An electromagnetic positive clutch or detent, e.g. for use in a planetary change-speed gear, between coupled members 5, 3 (5 being shown as stationary), comprises a balk-member 2 having limited circumferential and axial freedom on the first member 5 and arranged so that, on energization of a magnet-winding 1, it is frictionally engaged with the second member 3 and thereby turned to balk-position until, on synchronism, springs return it to the unbalked position, permitting the magnet to attract both the second member 3 and balk-member 2 together towards the first member 5 to engage positive clutch-teeth 7, 8 on the members 3, 5. The friction synchronizing clutch 2, 3 operates with a smaller initial air-gap e than that e' of the positive clutch, so as to engage first. Fig. 21 uses double magnets and a single armature, whilst Figs. 1 and 15 use separate friction and positive clutch-armatures 3, 5 attracted by opposite sides of a single electromagnet 2. In Figs. 1 and 2 the prior engagement of the friction clutch 2, 3 turns the balk-member 2 on the member 5, in opposition to springs, (not shown), to an extent limited by a friction balk-device comprising friction-plates 15, Figs, 1, 2, axially located on the balk-member 2 and having axial slots 18 receiving shouldered tangential pins 13 secured at their ends in a flanged part 14 of the first member 5, and carrying also interleaved discs 12 incapable of axial movement. The drag-torque on the balk-member 2 on initial engagement of the friction clutch 2, 3 causes the shouldered pins 13 to clamp together all the balk-dises 12, 15, thus preventing axial movement of the balk-member 2, until attainment of synchronism releases the drag-torque and thus the balk-discs, permitting the member 2 to be attracted to the first member 5 in opposition to axial springs 11, taking with it the second member 3, closing the air-gap e<SP>1</SP> and causing final positive engagement of the clutch-teeth 7, 8. Fig. 15 replaces the friction balk-discs 12, 15 by positive balk-teeth 20, 21 on the outer periphery of the members 2, 5. Pairs of springs 22 centralise the parts in the unbalked position shown and additional single springs 23 also oppose movement from this position. Fig. 21 has a single armature integral with one toothed coupled member 3 and two simultaneously energized series magnet-windings 24, 1 associated respectively with the other toothed coupled member 25 and with the balk-member 2, which latter forms one member of the friction clutch and is connected to the coupled member 25 by a coil spring 28 attached at its ends 29, 30 to the parts 25, 2 respectively. Energizing the magnet 1 initially engages the friction-clutch 2, 3, dragging the balk-member 2 round on the member 25 and contracting the spring 28 to bind on the outer periphery of the member 2, preventing its further axial movement. Attainment of synchronism releases the drag-torque, permitting the spring 28 to expand and release the balk-member 2 for axial movement, together with the other coupled member 3 by the winding 24 to effect positive clutching of the teeth 7, 8.