Patent GB-855396-A (GB)
Title: Dirigible axle assemblies in vehicles
IPC: B60K17/30
Filed: 1958-09-01
Abstract: 855,396. Motor vehicles. ROCKWELLSTANDARD CORPORATION. Sept. 1, 1958 [Sept. 6, 1957], No. 27959/58. Classes 79(2) and 79(5). [Also in Group XXXII] A dirigible tandem axle assembly comprises two closely spaced axles supported at opposite ends by dirigible ground engaging wheels, a frame, longitudinally extending springs pivoted upon the frame and carrying the axles at their ends, a system of torque rods interconnecting the axles and the frames, and a steering mechanism by means of which simultaneous steering movement is imparted to the wheels. The vehicle has front and back pairs of axles, the axles of each pair being mounted at the ends of a pair of leaf springs which are centrally pivotally mounted upon a trunnion tube. In a front assembly, Figs. 2, 3, 5, the wheels are mounted upon stub axles 124 pivotable about king pins 106 carried at the ends of I section axle beams 38 and 40, the wheels in each pair being connected by steering arms 154, 155 and cross tubes 214, 216 respectively. The wheels are steered from a main drag link 200 pivotally connected to a pitman arm 178 pivoted at 180 to the vehicle frame 12, drag links 172 and 176 being pivotally connected to the pitman arm 178 and to the steering arms 150 and 152 respectively. The difference in distance between the centres of the knuckles 98 in each steered wheel and the pivotal connections 169 and 175 of the drag links 172 and 176, taken in conjunction with the different radii of the pivotal connections 186 and 202 of the drag links from the pivot centre 180 ensure that the wheels turn about the same turning centre. The ends of the leaf springs rest upon pillow blocks 64 and their centres are bolted to seats 70 pivotally mounted upon transverse trunnion tubes 72 which are carried in frame supports 28 attached to the vehicle frame. The axles 38 and 40 are connected to the frame supports 28 by upper and lower parallel torque rods 80 which act like a pantograph, allowing vertical but not rotational displacement of the axles. In a modification, Figs. 6, 7, the steerable wheels are driven and the upper torque rods 266 are connected to the axle beams via mounting arms 264. The steering mechanism comprises the members 380, 370, 378 and 376, and 352 and 354. Track rods 362, 366 are provided between the wheel mountings. A sway bar 280 is provided connected to the trunnion bracket assembly 284 and to a bracket 254<SP>1</SP> under the axle 220 which also provides a mounting for torque rods 266a. Each axle is provided with differential gears 240 and input assemblies 242. In a further modification, Figs. 9 and 9A, a trunnion tube 412 is mounted in a bracket 418 attached to the frame 12 and carries the leaf springs 406, at the ends of which are mounted the driven axles 402 and 404. Torque rods 420, 422, 424 and 426 extend between the axle housings and the bracket 418. Steering motion is effected from a steering wheel controlled pitman arm (not shown) pivoted at 444 to the frame 12 and -connected by a link 442 to a lever 446 pivoted at 448 upon a bracket 447. The lever 446 is connected by a link to a second pitman arm 452 pivoted at 454 from which the motion is further transmitted by drag links 460 and 466 and steering arms 458 and 464. The wheels of each pair are connected by the track rods 436 and 440 respectively. A brake actuating fluid motor 462 is mounted upon the steering arm 458. A sway bar is connected to the axle 402 and to the bracket 447 at 468. In another modification, Fig. 10, leaf springs 506 are held by a bracket 510 mounted upon a trunnion tube 508 and drive axles 502, 504 are mounted at the ends of the springs. A parallelogram system of torque rods 514, 516 is provided and the steering system comprises a main drag link 518, pitman arm 520, drag links 524 and 526, upper and lower steering arms 532, 534 and 536, 538 and cross tubes 540 and 542. A transverse stabilizing system is provided, comprising equalizer arms 546 mounted at right angles to brackets 548 and guide rods 550 and 552 extending between the vehicle frame 12 and the stabilizers and between the stabilizers and frame support brackets 512. In another modification, Fig. 12, a pair of drive axles 602, 604 are mounted upon pairs of springs 606, 608 which are pivotally mounted upon trunnions 614, system of torque rods 620; 622, 624, 626, 628 and 630 being provided. The wheels are steered through the system of links comprising a main drag link 642, a pitman arm 644, drag links 648, 650 and steering arms 634. A lateral stabilizing assembly is provided comprising equalizer arms 652 pivotally mounted about vertical axes upon studs 654 and guide rods 656, 658 mounted between brackets 662 and the equalizer arm, and the equalizer arm and the frame 12. This assembly provides free axial displacement and free tipping movement of the axles relative to the frame while preventing any relative lateral movement.