Patent GB-795637-A (GB)
Title: Clutch-brake motor
IPC: H02K7/112
Filed: 1956-08-31
Abstract: 795,637. Gearing for starting and stopping machinery. SINGER MANUFACTURING CO. Aug. 31, 1956 [Sept. 26, 1955], No. 26650/56. Class 80 (2). In a clutch-brake motor having a lever pivotally mounted on the casing for actuating the clutch and brake, two solenoids are provided for moving the lever in opposite directions and electric holding means maintains one of the solenoids energized until the other solenoid is selectively energized. A clutch-brake motor 10 has a driving clutch face 20 and a fixed brake face 21 engageable by a disc 17 rigid with a driven shaft 15 which is axially movable by a sleeve 13 in which the shaft 15 is journalled. A lever 26 carries a pin 26<SP>1</SP> engaging in a groove 14 in the sleeve 13 and is pivoted on a fulcrum pin 25 carried in an adjusting fork 24 rigid with a pivot pin 23. The pin 23 is fixed to an adj usting lever 27 provided with thumbscrews 28 and 29 (not shown) which allow adjustment of the position of the fulcrum pin 25. A plate 32 rigid with the motor casing has slots 39 which in conjunction with blocks 38 and a plate 36 provides a slideway for two solenoids 30, 34. A strip of friction material is interposed between the plates 32 and 36. Frictional grip between the plates is provided by a cover 48 resting on the plate 36 and located thereon by tongue-andslot means, the cover being clamped by springs 52 and 57 (not shown) between an adjustable anchor plate 53 and clips 56 engaging the plate 32. The solenoids 30, 34, for brake and clutch engagement respectively, have armatures 44, 43 held together, with the interpositioning of a piece of resilient material 47, by hairpin springs 45, 46, the armatures being connected at 31 to the lever 26. The movable friction connection between the solenoids and the plate 32 ensures that the armatures bottom at substantially the same instant that the clutch or brake is engaged, since although the frictional force produced by the springs 52, 57 is sufficient to hold the solenoids in position under normal pull reaction, it is overcome by the hammer blow caused on release of one solenoid and engagement of the other. This hammerblow positions the solenoids such that the armatures bottom on full clutch or brake engagement. As the cover 48 moves with the plate 36, adjustment of the anchor plate 53 to one side or the other will allow the tension of the springs 52, 57 to be added or subtracted from the engaging face of the solenoids, to provide light or heavy clutch or brake engagement as desired. In a simplified embodiment of the invention, the solenoids are rigid with the plate 32, the armatures are rigidly connected and are urged to a brake engaged position by a spring. The electrical circuit of Fig. 7 provides a master switch A which can either provide for manual control or for cyclical control through two switches M1, M2 operated by cams from the motor spindle. The manual control has a start switch 5 which causes release of the brake and engagement of the clutch through brake and clutch solenoids BS and CS respectively and holding relays RC, RF controlling switches C1, C2, C3 and F1, F3, F4, F5, respectively. Stop switch D causes release of the clutch and engagement of the brake. Remote control of stop and start are provided by switches RD and RS respectively. Neutral switch N provides for release of both clutch and brake, and jogging switches J, J1 provide for alternate clutch and brake operation on pressing and releasing the jogging switch.