Patent GB-478723-A (GB)
Title: Improvements in or relating to continuous or progressive change speed gearing
IPC: F16H9/24
Filed: 1935-04-14
Abstract: 478,723. Expanding-wheel chain-gearing. JANESCH. R. April 14, 1936, Nos. 10749, 10750, and 10751. Void. Convention dates, April 11, 1935, Feb. 18, 1936, and Feb. 18, 1936. [Classes 80 (i) and 80 (ii)] [Also in Group XXV] In expanding - wheel chain-gearing, the teeth of the chain or of the wheels are formed by juxtaposed slats 1, which yield to adapt themselves to the teeth of the engaging member as the pitch varies with different working diameters. The slats may yield pivotally or slidably against centrifugal, spring, rubber, pneumatic or magnetic force. In Figs. 1 and 6, the chain comprises a series of pivotally - connected chambers 2, in which the slats 1 are supported on longitudinal pivots 9, and are pressed into contact with teeth 3 on the sprocket-wheels, by centrifugal tails 1a, extending laterally in alternate bundles on either side of the chain. The sprocket-teeth 3 are formed on transverse members 31 sliding in radial slots in wheelflanges 4 and formed with nuts 30 engaging screw-threaded radial shafts 28 which are all geared together by bevel-wheels 29, so as to be simultaneously rotatable for adjusting the radial position of the sprocket-teeth 3. Alternating with the tooth-carrying members 31 are idling rollers 22, and by means of a separate control-lever 26, the toothed members 31 can be allowed to move independently radially inwards to an extent sufficient to disengage them from the chain, which then rides idly on the rollers 22. This control-lever 26 acts through a rod 23 to operate an expansible eccentric 24, tracked by rollers 27 on the shafts 28 of the toothed members only. The eccentric serves also to hold the teeth radially inwards until they reach a desired point in the arc of contact, thus improving the meshing action. The working diameter of the wheel is adjusted by turning the screwed-shafts 28, either by synchronous motors acting oppositely on driving and driven sprockets, or by a mechanical servo acting as follows. One of the screwedshafts 28 is carried diametrally through a recess in the main-shaft 33, accommodating a ratchetwheel 34, Fig. 6, secured to the shaft 28, and adapted to be selectively engaged, for stepwise rotation in one or other direction, by one of a pair of pawls 35, 36, Fig. 11, pivoted on a slide 50, carried in a groove in the main-shaft 33 and constantly reciprocated by means of a lug 55 engaging a sinuous groove 54, Fig. 1, in a fixed ring 53. The pawls 35, 36 are selectively allowed to engage the wheel 34 under control of a cam-bar, sliding by the side of the member 50, and operating on pins 39 on the pawls. A sliding collar 42 controls the cam-bar, and, in the extreme outward position of the sprocket-teeth, is moved to a neutral position, by a projection 46, acting on a bellcrank lever 48. As shown in Fig. 6, the rear faces of the sprocket-teeth 3 are bevelled, to allow the driven wheel to overrun the chain. In a modification, the screwed-shafts 28 are turned by braking toothed wheels, engaging. pinions on the outer ends of the shafts. The modification shown in Fig. 45 utilizes a similar chain to that shown in Figs. 1 to 6. The members 85 carrying the sprocket-teeth 3, and the idling rollers 77, are provided at their ends with pins which project axially through radial slots 75 in the sprocket-flanges 73, into spiral grooves 76 in adjacent discs 74, which, for adjusting the working-diameter of the sprocket, are turned relatively to the flanges by pawls 80, turning ratchets 79, secured to worms 78, carried by the flanges 73 and engaging worm-teeth projecting from the discs 74. In order to provide for complete disengagement of the sprocket-teeth 3 from the chain, for idling, and also for regulating the time of mesh, the toothed member 3 has an inclined pin-and-slot connection with its carrier 85, which latter has a guided axial movement controlled by plates 87, 88, the former of which can be moved axially by a hand-lever to retract the teeth 3 inwards. In the modification shown in Figs. 54 and 57, the slats 106 are carried by the sprocket-wheels instead of by the chain 102, and are radially slidable in frames 114, secured to members 108, which are radially movable and correspond to the tooth-carrying member 3 in Fig. 45, in that they have inclined pin-and-slot 111 engagement with radially-adjusted and axiallyguided carriers 109, which correspond to the carriers 85, Fig. 45. The slats 106 are urged radially outwards by centrifugal force, magnetism or mechanical means. A pin 105, on the frame 114, limits their outward movement, so that they are unable to rise above pairs of lateral driving teeth 103 on the chain 102. until the carrying frame 109 has been moved. axially in the manner described with reference to Fig. 45. Such movement causes radial movement of the members 108 and the frames 114. The slats are thus freed for outward radial movement and are urged outwards into driving engagement with the chain-teeth 103, as shown in Fig. 57. A centrifugal lever 113 packs the slats 106 together in the frame 114. The chain-links 102 run on rollers 107 on members 112 supported directly on the carriers 109. The edges of the chain-teeth 103 and slats 106 are stepped as shown, and the slats may have thickened ribs to produce line contact with each other for reducing friction In some forms, the positive driving teeth on the chain or wheels make contact with the slats through semi-cylindrical rollers, recessed into their faces, and in forms in which the chain carries the slats, these 1, Fig. 18, may be radially slidable in the chambers 2 of the chain, and are inwardly pressed by means such as a pressure-filled tube 11, by integral spring- tongues 10, by surrounding rubber yokes, by magnets combined with springs, or by tongued resilient backings, Figs. 19 to 21 respectively (not shown). In Fig. 31 (not shown), the chain-slats are attracted radially inwards by magnets carried by the sprocket-wheel adjacent its teeth. In Fig. 61 (not shown), the chainslats are packed closely together whilst the chain is on the sprocket, by cams carried by the link-pivots of the chain. The gear may be used in a motor vehicle in place of the usual clutch, change-speed transmission and freewheeling unit, and may be controlled by a ring 122, Fig. 66, mounted inside the steering- wheel 121, on a control-rod passing through the steering-column. The ring 122 is pressed down to reduce speed or bring the gearing to a standstill.