Patent GB-265688-A (GB)
Title: Improvements in or relating to motor propelled road vehicles
IPC: B62D55/02
Filed: 1925-11-10
Abstract: 265,688. Dawson, Sir A. T., and Buckham, Sir G., T. Nov. 10, 1925. Endless-track vehicles -In a motor vehicle of the kind having road wheels and endless-tracks for alternative use the front and rear road wheels and the track frames are moved upwards and downwards in opposite directions relatively to the vehicle chassis to convert the vehicle from one condition to the other. The road wheels and the track frames may be moved simultaneously or successively. In the construction shown in Fig. 1 the movements are effected simultaneously, the track frames C<2> being carried by arms G, G<1> which are pivoted to the chassis frame co-axially with the driving and idler wheels of the tracks and the road wheels B, B<1> being carried by springs Bx, B<1x>, and radius links b<4>, b<4x> connected to the arms G, G<1>. The arms are acted upon by the propelling engine through a friction clutch and reversing gear, longitudinal shafts G<1x>, G<2>, and screw-and-nut gearing g<1x>, g<3>. The road wheels are driven from the track driving-wheel shaft through chain gear and clutches which are automatically engaged and disengaged as the vehicle is converted to and from the wheeled state. The tracks are driven through epicyclic clutches and steered by releasing one clutch and applying a brake on the same side. In the construction shown in Figs. 13 and 13a the track frames C<2> are carried by arms H<1> pivoted on the chassis frame and the road wheels B, B<1> are carried by arms H independent of the arms H<1> but mounted on co-axial pivots. The arms H, H<1> can be rotated, through screw-and-nut-gear, by power-driven shafts h<6> carrying sun-wheels H<6> meshing with planet pinions h<4> which are mounted on a carrier H<5> and engage with a toothed annulus H'. The carrier H<5> and the annulus H<4> carry screwed shafts h<5>, H<2> which, when rotated, raise or lower the arms H, H<1>. The arms are normally locked by bolts H', H<8>, which can be withdrawn, one at a time, by a single hand lever H<9>. To convert the vehicle from the endless-track condition shown, the bolts H<7> are withdrawn and the shafts h<6> rotated. As the planet carriers H<5>, together with the arms H<1> are held locked by the bolts H<8> the sun wheels H<6> drive the annuli H<4> and lower the arms H until the road wheels reach the ground when the bolts H' engage with other locking holes h<x> and hold the arms H in position. The bolts H<8> are now withdrawn and the planet carriers consequently rotate and raise, the arms H<1>, carrying the endless tracks clear of the ground, the bolts H<8> finally engaging with other locking holes ho Specifications 265,898, 266,392 and 266,390 are referred to. According to the Provisional Specification (1) in constructions where the operating gear acts upon the track frames it may do so through laterally-arranged levers, (2) in constructions where hydraulic operating gear is employed, air chambers may be provided which serve as pneumatic cushions for the road wheels and take the place of the ordinary springs, and (3) two track frames pivoted together at their inner ends may be provided at each side of the vehicle.