Patent GB-1099029-A (GB)
Title: Improvements in or relating to double clutches
IPC: F16D21/06
Filed: 1965-05-17
Abstract: 1,099,029. Clutch control. ZAHNRADFABRIK FRIEDRICHSHAFEN A.G. May 17, 1965 [May 20, 1964], No. 20740/65. Headings F2D and F2L. In a double clutch arrangement having a release bearing 17a, see Figs. 1-5 and 9, movable axially in opposite directions from a neutral position for selectively engaging a clutch, both clutches are controlled by a single pedal 2 which, over a first portion a of its travel to a position 2<SP>1</SP> disengages the selected clutch, and over a second portion b of its travel from position 2<SP>1</SP> to 211 conditions the other clutch for engagement upon release of the pedal. The pedal is fast with a hub 1 engaging, through springs 3, with lugs 4a of a cam 4. During portion a of the pedal travel the lugs 4a are pressed by the springs against lugs la of the hub so that the cam 4 follows the movement of the hub and one of a pair of rollers 5 of the cam engages an edge 6a or 6b of a slotted plate 6 and pivots it about a pin 7 to its neutral position (shown in full lines) in which the other roller 5 engages the other edge 6b or 6a to lock the plate and the cam 4. The plate 6 engages by means of a slot with a pin 9a of an arm 9 of a shaft 11 which actuates the release bearing 17a through a member 17. The neutral position of the plate 6 corresponds to the neutral position of the release bearing and is determined by a pin 41 engaging a recess 44 in the member 17. Travel of the pedal in the portion b, from 2<SP>1</SP> to 2<SP>11</SP>, is permitted by compression of the springs 3, the lugs 1a leaving the lugs 4a of the cam, and an arm of the hub actuating, through a bolt 37 a link 18 which is pivotally mounted on the plate 6. Fig. 3 shows the position at the beginning of portion b of the pedal travel with one clutch selected, Fig. 4, the same position with the other clutch selected. With the position of Fig. 3 clockwise rotation of the link 18 by the bolt 37 causes a pawl 18a thereon to engage and pivot a locking member 25 about the pin 7, thus withdrawing a locking pin 39 from a recess in a lever 19 so that on release of the clutch pedal, and return of link 18 to its original position by a spring, the lever 19, which is fast with a shaft 22 and a rocker 24, is pivoted on the plate 6 by a spring 27, and the rocker 24 shifts from the position shown in Fig. 5 to its alternative position in which it releases the end of a spring 33 and engages the end of a spring 34. These springs, at their other ends are rotatably connected to supporting pins 35, 36 of the cam rollers 5 and at an intermediate point are wound around pins 29, 30 on the plate 6. On release of the clutch pedal the cam 4 is returned to its original position, and through the spring 34 or 35 which is held by the rocker displaces the plate 6 to one side or other of its neutral position so that the release bearing 17a is shifted accordingly. If the rocking mechanism is in the position of Fig. 4 when the pedal is depressed from position 2<SP>1</SP> to position 211, a nose 18b on the link 18 engages the lever 19 and returns it to the position shown in Fig. 3 where it is retained by the locking pin 39 of the locking member 25 which has been returned to its locking position by the pin 39 riding up the side of the lever 19. The pawl 18a of link 18 is depressed by the lower edge of the locking member 25 during return movement of the link 18. The spring 33 is thus held by the rocker. The release bearing 17a is shifted to one side or the other of its neutral position by movement of the plate 6 when the pedal is released, the bearing 17a then being subjected to the force of a spring-actuated toggle linkage 42 which provides the clutch engaging pressure. In a modification of the clutch selection mechanism (Figs. 7 and 8) the actuating cam 104 has the supporting pins 112, 113 of the cam rollers engageable by notches of lever 134, 134a which are pivoted to the plate 106 and are controlled by linkages having follower rollers 125, 125a contacting a selector cam 121 which is fast with a ratchet wheel 120 moved one step by depression of the clutch pedal from position 2<SP>1</SP> to position 2<SP>11</SP>. In the rest positions of the ratchet one follower roller engages a crest and one a trough of the cam so that one of the supporting pins 112, 113 is connected to the plate 106 by the lever 134 or 134a and the plate 106 is pivoted in the appropriate direction on release of the clutch pedal. On movement of the selector cam 121 the follower roller leaving a trough does so before the other roller leaves a crest so that both levers 134, 134a engage the support pins 112, 113 to ensure correct positioning of the cam 104. The double clutch may control forward and reverse in a vehicle having several forward and reverse speeds.