Patent GB-595695-A (GB)
Title: Improvements in motor driven trucks
IPC: B60K1/04
Filed: 1945-04-23
Abstract: 595,695. Electrically -propelled vehicles. HARBOROUGH AIRCRAFT CONSTRUCTION CO., Ltd., and LLOYD, F. W. April 23, 1945, No. 10194. [Classes 79 (ii), 79 (iii), 79 (iv) and 79 (v)] In an electrically driven truck, preferably a battery driven vehicle of the walk-type with tiller arm for controlling steering, driving and braking, the power unit comprising a motor, reduction gearing and driving axle is suspended below the chassis frame to permit of limited swinging movement about a horizontal axis. By withdrawing the trunnion member about which the power unit swings, the latter may be removed from the vehicle. Frame construction. The vehicle, Figs. 1 and 2 comprises two longitudinal tubular members 1, 2, connected by transverse plates 3, 4, 5, 6. To the front plate 3 is attached the switch box 72, the plate 4 carries the front axle 7 and the rear plates 5, 6 carry the trunnion member 41 about which the power unit swings. Controlling and steering. The tiller arm 10, Figs. 1 and 2 can be moved about the pivot 47 rearwardly to apply brake to the two rear wheels or forwardly to control the electric motor. Rearward movement of the arm 10 against the tension spring 79 pulls rod 52 and chain 52a to rotate the cross shaft 55 and so pull rod 57 which turns lever 58 about its adjustable central pivot to operate balance rod 59 which applies brakes 45 to both wheels. A hand parking brake comprises a bell-crank lever 92, 90 with ratchet 93, which on depression pulls a rod attached at 91 to the brake cross shaft 55. Initial forward movement of the rod 52 during braking moves a switch 74 to disconnect the motor circuit. Forward movement of the handle 10 operates the motor switch 74 and continual forward movement may be arranged to give an increased speed, or different motor windings may be brought into circuit to give an increased speed after a time lag. During forward movements of the handle 10 the chain connection 52a goes slack so that the brakes are unaffected. A reversing switch 87 may be provided adjacent the motor 19, operated manually by a knob 80 projecting from the tube 1. The handle 10 is held in neutral position by a spring loaded plunger 82 which engages a notch in the bottom of the sector plate 49, and a catch 85 may be provided to lock the handle 10 in such neutral position Steering is effected by lateral movements of the handle 10, the pivot 47 and sector plates 48, 49 being integral with the horizontal rod 11 which is rotatably mounted in bushes 12 and 13 carried by the frame plates 3 and 4. Depending from the rear end of the rod 11 is an arm 14 connected to drag link 15 and steering arm 16, which is connected to the other steering arm 17 by a track rod 18. Motor mounting; transmission gear. The motor 19, Fig. 4, together with flexible coupling 26 and reduction gear unit 25, shown in section in Fig. 5, which carries the rear side 33 are all hung by lugs 36, 37, and bearings 40 from the horizontal trunnion -member 41 which is detachably mounted in frame plates 5, 6 by means of bolts 43 passing through frame plate 6 and a flange 42 integral with the trunnion member. Upon removal of bolts 43 the trunnion member 41 can be withdrawn and the motor, reduction gear and rear axle with wheels detached. Angular movement of the motor and transmission assembly about the trunnion member 41 is limited by stops 43 b, Fig. 5a, secured to the frame plate 6 by the bolts 43. The reduction gear unit 23, Fig. 5, comprises an input shaft 25 coupled direct to the motor armature, which drives a worm and wheel 27, 28, and spur reduction gears 31, 32 to the rear axle 33, to which both rear wheels are secured. Alternatively, one wheel only may be driven. The gear 32 runs in oil and an oil tray 45a is arranged to lubricate the worm and worm wheel. Batteries, mounting. The batteries 61, 62, Fig. 2, are mounted on either side of the chassis frame so that they can be pulled out to the position shown in dotted lines, for servicing. The mounting comprise a pair of brackets each comprising two arms 64, Fig. 7, which hang from the main tubular members 1, 2 and which carry a cross tube 67a. The ends 68, 69 of such cross tube are cut away to leave a semi-cylindrical position shown in dotted lines, for servicing. are channel members 70, Fig. 9. Slidably engage with channel members 70 are other channel sections 71 which carry the batteries.