Patent GB-893404-A (GB)
Title: Improvements in means for steering trailers
IPC: B62D13/00
Filed: 1960-07-25
Abstract: 893,404. Steering semi-trailers; articulated vehicles. FELBURN, J. P. July 25, 1960, No. 25809/60. Classes 79(3) and 79(5). [Also in Group XXXII] A steering mechanism for a trailer for use with a towing vehicle having a conventional fifth wheel coupling includes an automatic latching mechanism. The wheels of at least one axle of the trailer are steerable. The trailer bogey rear wheels 14 are supported by springs 20 mounted in shackles 22, 26,. the latter being attached to walking beams 28 pivoted at 32 to the trailer frame 10, 12, and the bogey front wheels are mounted upon an axle 46 connected to a plate 44 pivoted by a king pin to a plate 40 carried by the walking beam 28. The distance between the axle 46 and pivot 30 is half the distance between the pivot 30 and the shackle 26. The king pin 42 may be attached to either plate 40 or plate 44, the other being longitudinally slotted so as to allow pivotal and fore and aft relative movement therebetween, the wheels 16 being forwardly drawn by steering bars 140, 142. The king pin 42 is off-set forwardly to provide a castering action. At its forward end, the trailer comprises a slotted plate 110 (Fig. 5) attached to the frame members 10 and 12 and, pivoted thereto, a plate 80 (Fig. 7) having fast therewith a king pin 66 provided with annular slots 86 and 88, the plate 80 being retained in its pivotal connection with the plate 110 by engagement of a latch 120 with the slot 86. The tractor fifth wheel mounting comprises a plate 60 (Figs. 2 and 3) pivoted at 56 to a bracket 58 so that it normally tilts backwardly and, when the trailer is in position, is engaged by the king pin 66 which is retained in place by the engagement of a latch 68 with the annulus 88. A slot and throat portion 64, 62 of plate 60 are engaged by a block 92 and members 100 respectively, the former being rigid with plate 80 and the latter pivoted thereto by pivots 102 and urged apart by springs 104 connected to the members 100 and to a block 106 welded to plate 80. The plate 80 is connected by steering bars 140, 142 with the plate 44. When the tractor turns, the plate 80 is turned by the block 92 and members 100 thereby turning the bogey front wheels through steering bars 140, 142, the slotted connection between plates 40 and 44 allowing forward movement of the plate 44. The trailer bogey wheels may be readily detachable. The trailer may thus be disconnected from the tractor by withdrawing latch 68, or, by jacking up the vehicle and withdrawing the latch 120, the wheels and steering mechanism may be removed. In a modification, Fig. 9, a circular plate 190 is rigid with a king pin 194 and a lug 192 which seats within the throat of the member 60 of the tractor so that the plate 190 is stationary with respect to the tractor. The king pin is mounted for rotation within a transverse frame member 196, Fig. 11, and is rigid with a crank arm 200. A pivot 206 is mounted upon a transverse member 208 attached to vertical members 210 of a front temporary support and a linkage 202, 204, 216, 220 transmits steering movement to the steerable wheels, in this case pivoted at 236 behind the axle. The relative dimensions of the links can be varied to provide greater or lesser turning radii, and in another modification, Fig. 10, links 240, 260, 242 form a parallelogram system, the link 260 being connected to the steerable axis by links 262. The pivot pin 268 may operate within a longitudinal slot 266. In long trailers, the steerable wheels may be the rear wheels of the bogey as shown in Figs. 14 and 16 wherein the tractor fifth wheel connection 331 is as shown in Fig. 1 and is connected to the steerable axle 321 through crossing links 324, 326, cranks 340, 344, 348 and 342, 346, 348 and links 350. In an alternative system, Fig. 15, a link 360 is provided at one or each side of the vehicle and is connected to the steerable wheel through a lever 362 and link 366. In the embodiments of Figs. 14 and 15, the single fixed axle may be replaced by a dual axle.