GB847395A - Improvements in friction clutches or brakes - Google Patents

Abstract

847,395. Friction clutches; clutch-brake combinations. HEINE, A. Sept. 11, 1957, No. 28632/57. Class 80 (2). [Also in Groups XXXIV and XXXV] A friction clutch or brake is engaged by a permanent magnet causing one clutch &c. member to move axially into engagement with another clutch &c. member, control of the clutch &c. being effected by moving either the permanent magnet or a magnetic shunt perpendicularly to the lines of force. In one form, a radially magnetized ring 12, Fig. 1, is moved to the right from between soft-iron pole-rings 9, 10 when it is desired to disengage friction clutch members 3, 7. The soft-iron pole-rings 9, 10, which rotate with the clutch member 7, co-operate and engage with a soft-iron channelshaped pole-ring 6 in the clutch member 3. Axially directed pins (not shown) carried by the permanent magnet ring 12 are connected to the inner race of a bearing having its outer race fast in an axially-movable control fork or the like. Disengagement of the clutch members 3, 7 may be assisted by weak springs. In one modification, a permanently-magnetized ring 112, Fig. 2, is secured between soft-iron pole-rings 109, 110 carried by a clutch member 107 and co-operating with similar soft-iron pole-rings 118, 119 carried by a clutch-member 103. The clutch may be disengaged by one or other of two methods. Either a soft-iron ring 121, acting as a magnetic shunt, may be moved leftwards from between the two pole-rings 118, 119, thus breaking the magnetic circuit, or alternatively a soft-iron shunt-ring 116 may be slidden leftwards into position between the two pole-rings 109, 110, thus short-circuiting the ring magnet 112. If desired, both of the soft-iron rings 121, 116 may be moved simultaneously. In a further modification, the device is applied to a clutchbrake combination having a first clutch disc 203, Fig. 3, a second clutch disc 207 and a brake disc 303. The clutch disc 207 carries a permanently-magnetized ring 212 and control of the clutch-brake is effected by a pair of axially slidable soft-iron shunt-rings 221, 321. In the position shown, the shunt-ring 321 has been moved leftwards to lie between its associated pole rings 318, 319 and complete the flux path of the permanent magnet ring 212. The clutch disc 207 is accordingly engaged with the brake disc 303, the shunt-ring 221 having also been slidden leftwards to break the flux path through the soft-iron pole-rings 218, 219. By sliding the two shunt-rings 221, 321'to the right; the flux path through the pole-rings 318, 319 is broken, to disengage the clutch disc 207 from the brake disc 303, and simultaneously the flux path through the pole rings 218, 219 is completed, to engage the clutch disc 207 with the clutch disc 203. The device may also be applied to multiplate friction clutches. The permanentlymagnetized rings are preferably made from a ceramic material including poly-oxides of iron, barium and other materials.