New Riden Overdrive Gear
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ATWO-SPEED electrically operated overdrive gear is now available on Eoden goods chassis. In the case of four-wheeled chassis the overdrive section is effective on all four ratios of the main gearbox, but on sixand eight-wheelers it is used in conjunction with third and top gears only.
The overdrive unit, which is bolted directly to the rear face of the main gearbox, has sliding-gear engagement of direct and overdrive ratios. The gear is moved by a 12v. electric motor which actuates the selector fork through a screw linkage. This arrangement is similar to that employed in Eaton two-speed axles which incorporate electric shifts.
An overdrive ratio of 0.78 to 1 is given, the lower ratio being direct. It raises the maximum road speed of a Foden-engined vehicle with a 6.25-to-1 axle and 9.00-20-in, tyres from 36.7 m.p.h. to 47 m.p.h., or from 31.2 m.p.h. to 39.8 m.p.h. in the case of a Gardner-engined chassis with similar 'axle and tyres.