Patent GB-450748-A (GB)
Title: Improvements in motor vehicles having endless tracks and road wheels
IPC: B62D55/02
Filed: 1935-11-18
Abstract: 450,748. Endless - track vehicles. KEGRESSE, A., 48, Rue du Theatre, Paris. Nov. 18, 1935, No. 31936. Convention date, Nov. 19, 1934. [Class 79 (i)] In a motor vehicle having steering and driving road wheels which are always in contact with the ground, and endless tracks which can be driven and lowered on to the ground for simultaneous use with the driving wheels, the endless tracks are raised and lowered by deformation of their central portions between front driving and rear idle pulleys mounted on fixed axes, and the bringing into use of the track driving-gear simultaneously, causes the driving road wheels to be driven at a lower speed. In the construction shown, endless tracks 6 pass over driving pulleys 17 and idle pulleys 18 mounted on the chassis frame. Load-supporting rollers 12 are connected in pairs by equalizing beams 13 which are connected together by springs 14 pivoted at 10 on a crank 8 formed on a shaft 5 mounted in bearings on the chassis. Other rollers 55, engaging the upper run of each track, are carried by a lever 54 pivoted at 56 to arms 53 mounted on the crank pin 10. Thus when the shaft 5 is rotated the cranks 8 move from the position shown in Fig. 1, and in which the tracks are clear of the ground, to the position shown in Fig. 3, in which the tracks bear on the ground with a pressure which may be varied by varying the angular position of the shaft 5. Other crank arms 9 on the shaft 5 are connected by shackles 16 to the forward ends of the main springs 15. The shaft 5 may be rotated by hydraulic or mechanical power or, as shown, by an electric motor 21, Fig. 7, which drives the shaft through worm gearing 20, 19, an indicator (not shown), being provided on the dash and connected by a cable to an arm on the shaft 5 so that the driver is always aware of the position of the tracks. A reversing switch 44 is provided for the motor 21 and is operated from the dash by one or two tension members 48. The track driving pulleys 17 are driven from the main driving shaft 30 through a clutch 32, Fig. 6, worm gearing 22, differential gear 24, and differential shafts 25, the shaft 30 having an extension which passes freely through the worm 22 and its shaft. The clutch 32 comprises a slidable gear-wheel 31 controlled by a hand lever 43 and having clutch teeth 32, 41. In the position shown in Fig. 6, in which the clutch 32 is engaged and the track pulleys are driven, the gear 31 is in mesh with a gear 33 on a countershaft 34 which is geared to the propeller shaft 3 of the rear road wheels through gears 35, 36, so that the shaft 3 is driven at a lower speed than the shaft 30. When the tracks are not to be driven the lever 43 is operated to move the sliding gear 31 to disengage the clutch 32 and to engage the clutch 41 with the gear 36 so that the shaft 3 is now driven directly by the shaft 30. The motor 21 may be controlled by contacts on the track-controlling lever 43, and the motor circuit may be automatically broken at predetermined positions. The load rollers 12 may be mounted so as to slide vertically instead of being carried by the shaft 5.