Patent GB-460664-A (GB)
Title: Improvements relating to clutches
IPC: F16D11/06
Filed: 1935-07-27
Abstract: 460,664. Clutches; operating clutches. SHEARMAN, C. H. HOWLAND-. July 27, 1935, No. 21427. Convention date, July 27, 1934. [Class 80 (ii)] A segmental clutch key 25 journalled in an outer driven member 26 and co-operating with arcuate recesses 23 in an inner driving member 21 carries pinions 28 meshing with a gear quadrant 29 pivoted in the member 26 and carrying a roller 31 co-operating with a plunger 49 slidable in a stationary guide 50, the oscillation of the quadrant being limited by cushion stops 34, 35. A rod 36 connected to the quadrant and slidable in a trunnion 37 supported in the member 26 has a notch co-operating with a spring-pressed latch 39 slidable in the member 26 and controlled by an arm 43 pivoted in the member 26 and carrying a roller 46. On depressing the plunger 49, the rod 36 remains locked by the latch 39 until the roller 46 is moved by the bevelled corner 47 of one of the recesses 23, whereupon the rod 36 is unlocked and a strong spring 38 acts to turn the key 25 into engagement with the following recess. Mechanism is provided whereby, when a hand lever 78 is held in a notch 102, as shown in Fig. 1, the clutch is inevitably disengaged at the end of one revolution. A pedal 63 is connected through an arm 61, link 60, bell-crank lever 58, and link 57 to a rod 55 slidable in the plunger 49, the operative head 51 of the latter being adjustable horizontally by means of a wedge 52. One arm of a lever 67 is weighted at 69, while the other arm is linked to a rod 98, which is urged upwards by a spring 99, and to a block 64 beneath the plunger 49. The rod 55 has a notch 56 co-operating with a spring-pressed latch 91 slidable horizontally in the plunger 49 and carrying a roller 96 engaging a vertical slot 97 in one arm of a bell-crank lever 84, the other arm of which has a horizontal slot engaging a pin on the lower end of a vertically-slidable rod 89, the upper end of which has an inclined head 90. Thus the spring 99 normally acts to hold the block 64, and thus the plunger 49, in raised position. Assuming the pedal 63 to be released, a spring 105 connected to the lever 58 acts to raise the rod 55 until it is locked to the plunger 49 by the latch 91. On now depressing the pedal, the rod 55 and plunger 49 are drawn down to free the roller 31, and clutch engagement results. As member 26 rotates, roller 31 engages and depresses rod 89 to swing the lever 84 and remove the latch 91 from the notch 66. The plunger is thus released and is forced upwards into the path of the roller 31 by the spring 99, whereby clutch disengagement and stoppage of the member 26 at the end of one revolution occurs, even if the pedal is held depressed. To re-engage the clutch, the pedal must be released and then depressed. By moving the lever 78 into engagement with a second notch 103, as shown in Fig. 7, the clutch remains in continuous engagement, irrespective of the position of the pedal For this purpose, an arm 72, which is pivoted on the same axis as the lever 67 and which is linked to the lever 78, has a projection co-operating with a projection on the lever 67 so that, when the lever 78 is moved to engage the notch 103, the block 64 is drawn down. If the pedal 63 has been released, the lever 67 acts on a shoulder 55<a> of the rod 55 to draw the latter, and with it the plunger 49, downwards, while if the pedal has not been released, the plunger 49 will fall by gravity. A spring-pressed latch 82 carried by a bell-crank lever 76, which is also linked to the lever 78, acts in these circumstances to maintain the head 90 clear of the roller 31. Specification 427,603 is referred to. The Specification as open to inspection under Sect. 91 states also that the members 25, 29 may be.replaced by the members 222, 228 and 230 shown in Fig. 17 of Specification 21432/35. This subject-matter does not appear in the Specification as accepted.