Patent GB-694739-A (GB)
Title: Improved friction clutch
IPC: F16D67/02
Filed: 1950-10-10
Abstract: 694,739. Operating clutches. KNOCHL, L. Oct. 10, 1950 [Oct. 10, 1949], No. 24724/50. Class 80 (ii). A radially-acting friction clutch of the kind which is directly mounted on a crank-shaft or eccentric shaft and in which the coupled or driven shaft is braked on uncoupling, includes a spring force storage means adapted to be loaded on uncoupling by the energy of the masses to be brought to rest and which is of a magnitude sufficient to close the clutch for transmission-of full torque after disengagement of a catch for the force-storage means. In the arrangement shown, a hub 2 of a driving wheel is mounted concentrically of a driven shaft 5 and together with a cover end plate 2<SP>1</SP>, which is mounted on a hub 6 of a coupling body 7 keyed to the shaft 5, constitutes a clutch housing. A friction ring 8 is supported at one end against a snout 11, Fig. 1, in the coupling body and at the other end is acted on by an expanding lever 12 pivoted to the coupling body. The lever 12 engages, through a roller 15, with a lever 17 which is mounted on a shaft 18 in the coupling body and is connected to one end of a tension spring 19. The spring 19 is disposed in a groove 20 on the coupling body end is anchored to the latter. An oil-filled stationary control housing 27, Fig. 2, is mounted adjacent the housing 2, 2' and also encloses the shaft 5. The shaft 18 projects into the housing 27 and carries at that end a lever 22, Fig. 1, one end of which forms a stop co-operating with the shaft 5 and the other end of which, bears, through a roller 23, on a pivotally mounted cam lever 25, Fig. 3. Spring loaded friction discs 48, 49, Fig. 2, bear on each side of the lever 25. The latter is supported on a toggle lever arrangement 30, 30', 34, Fig. 3, mounted on a shaft 31 the arm 30' of which bears on an arm 35 of a movable support consisting of arms 35, 37, 39. The arm 39 is spring biased towards a stop 40. A catch 42 which is pivoted about one end of a bell crank lever 44, 44' engages the arm 35 and an engaging rod 47 is pivoted about the other end of the lever 44, 44<SP>1</SP> which is movable between fixed stops 46, 46'. An extension 42' of the catch 42 carries a push rod 65 and a spring 64, Fig. 4, which urges the catch into engagement with .the arm 35. In the declutched position the lever 44, 44<SP>1</SP> is retained in the position shown in Fig. 3 by a restoring spring (not shown). A cam 53, Fig. 4, fixed to the shaft 5 co-operates with a roller 54 on a pivoted two-armed lever 55, 55<SP>1</SP>. One end 73 of the lever co-operates with a connecting member 58, controlled by a spring 60. A lever 69, 69' which is movable through a worm and rod 71, 70 to change the operation of the clutch from single stroke to continuous operation, is pivoted about a bolt 82 to move a rod 67, slidable on a guide 68. The rod 67 is connected through pin and slot connections to the push rod 65 and to a push rod 78 pivoted on the arm 39 of the support 35, 37, 39. The rod 78 co-operates with a stop 77 on a guide 75 pivotally mounted on the member 58, a bent over portion 59 of which is retained against the arm 55' by the spring 60. The guide 75 is guided on the arm 55' by a bolt 76 therein. In the clutch disengaged position shown in Fig. 4, for single stroke operation, depression of rod 47, releases the toggle lever 30, 34 and under the tension of spring 19, the shaft 18 rocks the lever 22 and thus the lever 25 until a shock and sound absorbing pad 24 on the lever 22. strikes the shaft 5 and the arm 30<SP>1</SP> strikes a similar pad 52. Release of the shaft 18, expands the ring 8 to engage the hub 2. For each revolution of shaft 5, the cam 53 rocks the lever 55, 55<SP>1</SP> and the member 58 and the latter strikes the lever 63 to move it from the clutched position to the full-line position shown in Fig. 4. Consequent rotation of shaft 31 restores the toggle lever 30, 34 levers 25 and 22 to the position shown in Fig. 3 in which the brake is applied through the rod 29. For engagement of the clutch for continuous running, the rod and worm 71, 70 is adjusted to move the rod 67 to the right on Fig. 4. This prevents the push rod 65 from being engaged by the stop 73 and the catch 42 remains in engagement to prevent the arm 35 returning to the position supporting the toggle lever 30, 34 so long as the rod 47 is depressed. Displacement of rod 67 also rocks the rod 78 which latter lifts the guide 75 to rock the member 58. The member 58 is therefore moved clear of the cam lever 63 which is then unaffected by the rocking movement of lever 55 effected by the cam 53. The clutch is disengaged by releasing the rod 47, which returns the parts to their positions shown in Figs. 3 and 4. The friction brake for the lever 25 may be replaced by blades offering resistance to movement on oil, or by spring, oil or air buffers.