GB648741A - Improvements in or relating to automotive vehicle driving system - Google Patents

Abstract

648,741. Change-speed gear. STEVENS, A. H. (Eaton Manufacturing Co.). Sept. 6, 1945, No. 22970. [Class 80(ii)] [Also in Group XXXIV] The vacuum or electric selector-control of a two-speed rear axle 18 on a motorvehicle operates also a corresponding twospeed gear 46 driving the vehicle speedometer so that the latter reads correctly with either axle-ratio effective. The vacuum shift, Fig. 2, has a push-pull manual selector-knob 28, mounted on the conventional shift-lever 34 of the main change-speed gear, and operating, through Bowden wire 30, a simple valve 8, which in the raised position of the selector-knob 28, applies manifold-depression from ar inlet 6 simultaneously to two single-acting diaphragm-motors, one, 10, operating ar axle-ratio shift-lever 22 to select high ratio the other 16 operating a speedometer-ratic shift-lever 46. In the depressed position of the selector-knob the valve 8 vents bott motors, and springs return the axle anc speedometer shift-levers 22, 46 to low-ratio A non-return valve in the valve deliveryline 12, prevents unintentional shift from high to low in the case of a temporary reduction of manifold depression. A preselected upshift is effected by momentary release of the accelerator-pedal 60, to un load drive-torque, and downshift is by a full depression of the accelerator-pedal for the same purpose but affected in this case by short circuiting the engine ignitiondistributer 56<SP>1</SP>, by an accelerator-operated switch 50, wired in series with two other switches one 54 opened by the axle ratic shift-motor 10 to restore the ignition after the axle control reaches neutral position tc permit the downshift to synchronize another 52 which is closed when the manual selector-valve 8 is moved into the low-ratio position only. A preselected downshift may alternatively be effected by releasing the usual main clutch or, as for upshift, by momentarily releasing the accelerator-pedal. The manually-controlled all-electric shift shown in Figs. 7 and 8 comprises a reversible electric motor 160 (not further shown) operating the axle-ratio shift-level 104 in either direction through a screw. and-nut (not shown) and a torsion spring 130 which is preselectively stressed and effects a shift when drive-torque is removed as by accelerator-release. In its extreme positions the motor-operated shift-member 124, which turns about, the spring-axis 116 operates, through a pin 142, a bow-spring 140, which breaks appropriate switch-con. tacts 136, 138, to cut off current at the enc of a shift, and also coacts with a pair of change-over contact-bars 164, 166 in the manual selector-switch 152 to reverse the current through the motor-armature 160 but not its series field 162, at the succeeding selection. The ratio shift-lever 168 of the speedometer-drive 166' is operated by a solenoid 174, wired directly to the battery 156 through a main key-switch 158, its circuit being completed through a contact 176 earthed by movement of the axle-shift lever 104 to the high-ratio position, the speedometer shift-solenoid being thereafter energized continuously until the axledrive is shifted back to the low ratio. The direct and underdrive planetary axle shown in Figs. 9 and 10 has a ducted lubrication system, its gearing being of conventional form and comprising a driving internal ring-gear 268, secured to the main driving bevel ring-gear 206; planets 266 carried by the differential-spider 272, and a reaction sun 264, slidable for clutching the carrier at 270 for direct-drive, and the fixed casing at 350 for reduced drive. A stationary lubricant-scoop 228 is pressed by a spring 238 into contact with a pick-up flange 202, secured to the driving bevelwheel 206, and has two partitioned ducts 244, 246, which supply collected oil respectively to the bearing 224 of the main driving bevel-pinion 220, and to the right-hand side bearing 214 of a drum 210 carrying the driving bevel-wheel 206, and thence to the interior of the drum 210 and, through channels 274, 276, 278, 280 in the planetspindles and planets, to the interior of the differential-spider. The direct- and under-drive speedometer drive shown in Fig. 12 comprises aligned driving and driven shafts 310, 316, carrying respectively a ring-gear 314 and planets 320. For direct-drive a spring 336 clutches a freely-mounted reaction-sun 324 to the carrier by sliding a sleeve 330, slidably keyed to the sun at 344, and having axial clutch-pins 338 engaging the carrier. In the under-drive position shown, the sleeve 330 is retracted and frictionally held by a stationary electromagnet 326. Specifica- 616,533 is referred to. Reference has been directed by the Comptroller to Specification 598,377.