Patent GB-1327600-A (GB)
Title: Transmission box
IPC: B60K17/36
Filed: 1970-12-30
Abstract: 1327600 Change-speed and differential gear ENGESA-ENGENHEIROS ESPECIALIZADOS SA 30 Dec 1970 61908/70 Heading F2D [Also in Division B7] A power transmitting unit, for driving the tandem rear axles and the front axle of a 6 x 6 road vehicle, comprises an. engine-driven input shaft 32, driving at two ratios through wheelpairs 60, 64 and 62, 66, selectively clutchable at 68, a layshaft 46, which drives through a clutchable wheel 70 and meshing wheels 74, 76, a differential gear 54, one output 56 of which drives one rear axle drive shaft 34 through a wheel pair 78, 80, whilst for differential interaxle drive, its other output 58 selectively drives the other rear axle drive shaft 38 through a wheel-pair 88, 86; and for non-differential drive a clutch 84 is engaged to lock to the axle shaft 38 a wheel 82, driven by the first differential output wheel 78, thus locking the differential, and at the same time a clutch 94 is engaged to drive the front axle drive shaft 42 from the shaft 38, so that all three axles are driven non- differentially. Rearwardly and forwardly extending power take-off shafts 48, 50 are selectively clutchable at 102, 106 to the layshaft-driven wheels 100, 104 and can be driven at either of the two speeds of the layshaft 46 irrespective as to whether or not the axles are driven. Selector mechanism for the various clutches is shown in Fig. 4. The two speed and neutral clutch 68, Fig. 2, is operated through a fork 120 on a three-position rod 132, movable axially between stops 132, 134 and positively locked in each of the two extreme positions by engagement of transverse rods 150, 152 in grooves 162, 164 on the selector rod 132, under control of a parallel lock-rod 142, connected to the selector rod 132 by a floating lever 140. To shift the selector rod 132 from its rightward low-ratio position shown, the centre point 172 of the floating lever 140 is moved leftwards, which first moves the lock-rod 142 left until the transverse lock-rod 150 enters a recess 168 in the lock-rod 142, thus freeing the selector rod 132 for movement to neutral, defined by ball detents 154, 156, whereafter further movement of the floating lever 140 takes the selector rod 132 to its extreme left, high-ratio, position, where it becomes locked by the second transverse lockrod 152 rising out of the lock-rod recess 168 to engage the selector rod recess 162. The differential driving clutch 72 is shifted by a fork 122 and shift-rod 174, having only two positions, the lock action being similar to that above, but controlled by a single transverse lock-rod 182. The differential lock clutch 84 and front axle drive clutch 94 are operated together only, their forks 124, 126 being connected by a common linkage, including toggle links 246, 248, straightened to move the clutch forks apart for engagement, position shown, and broken to bring them together for disengagement. The toggle is actuated by a bellcrank 236, 234, connected, at 232 to a selector rod 208, the two positions of which are resiliently set by a ball detent 228. Simple ball-located shift-rods 256, 274 engage the power take-off clutches 102, 106 through forks 128, 130.