Patent GB-291879-A (GB)
Title: Improvements in clutch or coupling and other similar mechanisms
IPC: F16D19/00
Filed: 1927-03-11
Abstract: 291,879. Andrew, H. M. March 11, 1927. Locking rotary elements by positive detents.- Positive brake mechanism comprises two cylindrical, conical, or curved members co-operating peripherally, one being mounted either universally or tiltably on one shaft and the other mounted to be tiltable about a single axis on the second shaft, means being provided for moving the second member to, or retaining it in, its tilted position to cause absorption of power. Where the first member is universally mounted, means is provided for applying positive or successive resilient and positive resistance to its oscillation about one axis. The invention is described as applied to clutch mechanism. A block 5, Figs. 3 and 4, keyed to a driving-shaft 1, carries on pivots 7 a gimbal ring 8, to which is connected by pivots 9 the inner ring 10, cooperating with a flanged outer ring 11, carried on pivots 12 in a fork 13 keyed to the driven shaft 2. A collar 16, operable by a lever 19 adapted to be locked in the extreme positions by a pin 21, is connected by a link 18 to the ring 11, and by rods 27. to a collar 26, which serves to compress a spring 25 bearing against a collar 24 abutting on the flat or coned side of the gimbal ring 8. When the collar 16 is retracted, the rings 10, 11 are coaxial with the shafts and slip freely over one another. On advancing the collar, the rings are tilted and the spring 25 is simultaneously compressed progressively to resist motion of the ring 8 about its inner pivots 7, until either the spring closes up solid or the collars 24, 26 abut, or both, when positive drive ensues. In a modification, the inner ring 10 is movable about one axis only, and the parts 24 - - 27 are omitted, so that the clutch is engageable only when this axis is aligned with the pivots 34, Fig. 8, of the outer ring 45, and the drive is immediately positive. The collar 46 may carry a stop 44 to assist in maintaining the rings in the non-driving position. The ring 45 may be connected by links or a spring directly to the collar 46 or, as shown, by a link 47 to a bell-crank lever 48 pivoted on the collar. One arm of the lever 48 lies in a groove 87 of the fork member 88 and has an abutment 52 to support the rings when untilted. When the rings are fully tilted, the lever 48 drops into an inclined notch 53 and can be lifted therefrom only by return of the collar 46, so that the driving-rings are locked. In a further modification, the bell-crank lever is pivoted on the fork member and is pulled by a spring at its free, end into contact with a conical operating-collar, having at its greatest diameter a circumferential groove, into which a nose on the lever snaps to lock the rings tilted. The lever can be freed only by movement of the collar. The spring assists return of the rings. The link coupling the bellcrank lever to the outer ring may be replaced by a helical spring the turns of which are arranged to close up and give a non-yielding effect at or about completion of tilting. This control means may be employed in the gimbal type shown in Figs. 3 and 4. According to the first Provisional Specification, the controlling-sleeve may be axially moved by cam means. The second Provisional Specification mentions the use of flat or other springs in place of the helical spring 25.