Patent GB-743415-A (GB)
Title: Improvements in or relating to endless tracks for vehicles
Inventor: DOWELL PETER THOMAS GEORGE
IPC: B62D55/12
Filed: 1953-01-21
Abstract: 743,415. Endless tracks for vehicles. DUNLOP RUBBER CO., Ltd. Jan. 7, 1954 [Jan. 21, 1953; Oct. 30, 1953], Nos. 1700/53 and 29999/53. Class 79 (1). In a flexible plate 1 for a vehicle track a pair of parallel spaced-apart rigid members 2 are connected by a flexible inextensible member formed by a layer of parallel strands of wire cable 3a, each rigid member 2 being enclosed in an end unit formed by two cooperating metal clamps 6a, and the flexible plate also including vulcanized rubber composition 10 enclosing the flexible members and bonded to the clamps. As also shown in Figs. 1, 2 and 3, the endless track comprises a series of the flexible plates 1 interconnected by studs 19 on three straps 18, the studs passing through a rigid plate 14 and being secured in position by nuts 20. The plate 14 is formed with a hard rubber grouser 16, the outside and centre straps 18 carry guiding teeth 21 and a driving dog 22 for engagement with the sprocket and track bogie wheels of the vehicle. Each flexible plate 1 comprises two pairs of coaxial rigid members 2 formed as bars, the spaced pairs of the bars being each encircled by a spiral 3 of rubber-covered metal cable and the bars having rubber fillets 4. The webs 3a of cable between the bars are each wrapped in a sheet of weftless cord fabric 9, the cords of the fabric being at right angles to the direction of the cable. Each pair of co-operating clamps 6a are connected together by screws 12 and are provided with holes 13 for the passage of the studs 19. In another form of the flexible plate, Figs. 4 to 6 (not shown), the pairs of coaxial bars are each replaced by a single hollow bar and the screws interconnecting the co-operating clamps pass through the bars. In another form of track, Figs. 7 and 8, each flexible plate comprises four pairs of steel bars 40 interconnected by lengths of wire cable 41, the portion of the lengths between the bars being reinforced by a layer 42 of fabric ply or metal cable on each side, the warps or strands running transversely of the plate. The clamps 43 are arranged on both sides at each end of the plate with a filling of vulcanized rubber 47. The vulcanized rubber 45 encloses the middle portions of the cable 41. Adjacent abutting flexible plates are interconnected by rigid steel plates 49 one on each side of the plates overlapping and mating with the clamps 43, and the plates 49 are interconnected by bolts 51. The plates 49 on the outside of the track have bonded thereto hard rubber grouser bars 55. The plates 49 on the inside of the track are formed with depressions 56 mating with projections 70 on driving dogs 54 which are bolted to the plates. Each dog is provided with a slot 59 to engage a central disc of the sprocket and position the track centrally. The faces of the plates 49 on the inside of the track are provided with vulcanized rubber coverings 52. The interface between each dog and the corresponding plates may have a layer of packing or jointing material such as a viscous rubber solution or a rust provoking material. Alternatively a thin vulcanized rubber film may be moulded over the contacting face of the plate. In a modified form of track, Fig. 10, two spaced-apart series of the flexible plates 50 are provided, each plate having two pairs of rigid bars 40 joined by webs 41 of steel cable. Adjacent plates of each series are connected by the plates 49 which interconnect the two series of plates. The inside plates 49 carry the upstanding dogs 54 for engagement with the driving sprocket to laterally locate the track. Between each pair of plates is a rubber moulding 68, mating projections being provided. Each moulding has on its fore and aft faces plates 63 secured to the moulding by dowels 64. In a modification, Fig. 12 (not shown), the plates 63 and dowels are replaced by U-shaped members. The plates 63, or the bases of the U- shaped members, form driving connections with teeth on a driving sprocket (not shown). Other modifications are described: (a) the spiral of metal cable may be replaced by a sheet of parallel lengths of cable, the end portions of the sheet being wrapped round the bars within the clamps; (b) each flexible plate may have the bars formed wholly of vulcanized rubber, the clamps of reinforced plastic material and the web reinforcement formed of a pair of layers of parallel lengths of metal cable instead of the fabric ply; (c) the grousers on the rigid connecting members may be replaced by similar ground-engaging portions contiguous with the vulcanized rubber coverings of the flexible plates; and (d) rubber plates for engagement with the track supporting wheels may be provided on the vulcanized rubber coverings of the flexible plates. The rubber may be of a natural or synthetic composition.