Patent GB-744362-A (GB)
Title: Improvements in or relating to electro-magnetic clutch
IPC: F16D48/06
Filed: 1952-10-09
Abstract: 744,362. Friction clutches. SOC. D'ETUDES DE TRANSMISSIONS ELECTRO-MECANIQUES, S.E.T.E.M. Oct. 9, 1952 [Feb. 20, 1952; April 19, 1952], No. 25371/52. Class 80(2) In an electromagnet disc clutch for motor vehicles in which the magnet and its armature rotate with the engine shaft, the clutch is engaged, upon energization of the magnet, under pressure exerted by spring means. In the form shown in Fig. 1, the armature 17 is slidably mounted on screws 18 secured to a flywheel 11 on the engine shaft 12 and is urged against the flywheel by springs 19. The magnet 26 carries pins 24 slidable in holes in the armature 17 and is urged away from the latter by springs 29. A clutch disc 8 splined on the driven shaft 5 lies between the flywheel 11 and a presser plate 23 within the armature 17. The parts are shown in the clutch disengaged position, the magnet being de-energized. On energizing the magnet 26, it moves to the left against the action of the springs 29 and the pins 24 push the presser plate 23 to the left for initial engagement of the clutch parts, the armature 17 then moving to the right against the reaction of the springs 19 which thus provide the clutch loading pressure. In a modification of this form, the magnet is in the flywheel, the armature is slidable and has secured thereto the presser plate, and there is a spring-loaded back plate. In the form shown in Fig. 8, the magnet winding 82 is in the flywheel 11, and rods 130 secured to the presser plate 23 pass through the flywheel 11 and armature 17, which latter is urged by springs 125 towards adjustable nuts 134 on the rods. In the de-energized condition shown, the springs 125 press the armature and, through the rods 130, the presser plate 23 to the left. On energization of the magnet the armature moves to the right_ to allow springs 118 to move the presser plate to the right so as to engage the clutch. In the form shown in Fig. 2, the armature 17 is fixed to but spaced from the flywheel 11, and the movable magnet 26 applies pressure to the presser plate 23, on energization, through s'prings 42. In a modification of this form, the flywheel itself forms the armature, in other modifications the magnet is in the flywheel 11 and the movable armature applies pressure to the presser plate through helical or blade springs, while in Fig. 11 the magnet is in the flywheel 11 and the movable armature 17 applies pressure through springs 177 to levers 171 connected to a back plate 166 between which and the the armature the driven disc 8 is gripped. The magnet 26 is energized from the engine-driven dynamo 52, Fig. 4, either through a switch 58, which is closed when the gear lever is in second or higher gear position, or through a resistance 62 and a switch 60 which is closed whenever the accelerator is depressed. The dynamo 52 also feeds the battery 57, through a voltage regulator 54. The circuit from the dynamo to the magnet 26 is normally completed by an arm 74 bridging between contacts 65, 66 in a rheostat 64 which has resistance contacts 67, 67a, 67b connected to the battery 57, so, that, if the dynamo fails the arm 74 may be moved to use the rheostat for energizing the magnet 26.