A Mass-produced Rear-engined Van
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F:HIBITED for the first time at the Paris Show, last month, the
Renault 4-cwt. rear-engined van is already in the mass-production stage. It is basically the Renault 4 C.V. car, with minor modifications to the bodywork, so that tooling and other manufacturing costs are relatively low. It is, indeed, one of the lowest-priced vans produced on the Continent.
Its outward appearance closely resembles that of a conventional car, the battery and spare wheel being housed in the scuttle, whilst the integral engine and transmission unit is sufficiently compact to be accommodated within the sweep of the rear panel.
Body and Chassis a Unit
Structurally, the framework of the body and chassis is fabricated as a steel unit. Box-section side members are linked by cross-members, in conventional fashion, and braced by the integral steel floor.
Tapered extensions of the scuttle structure provide mountings for the independent front-wheel suspension, whilst at the rear, extensions braced to the roof bearers, carry the power unit, transmission and driving-axle assembly. Each front wheel has a double suspension wishbone, the lower member of each being constructed to carry the pad for the coil spring; the upper members serve as the operating arms of the horizontal hydraulic shock absorbers. These units are notable for their sturdiness and simplicity, and, for the manner in which the springs are positioned to support the weight of the vehicle.
Rear suspension is on the dividedaxle principle, the final drive being carried on the sprung structure and taking effect on the wheels through a pair of universally jointed shafts. Each of these shafts is enclosed in a fixed tubular half-axle member, which is attached to the differential casing so that it can swing in a vertical plane. A single ball bearing transmits road-wheel reactions to each tubular member.
The van is supported, at the rear, on coil springs interposed between the axle tubes and a tubular member, which is clamped across the final-drive casing. Spring action is controlled by hydraulic shock absorbers. Acceleration and braking torque reaction is transmitted to the body structure through needleroller bearings, on which each axle tube pivots. This dispenses with the need for radius arms.
On each side, at the front, the brake drum, hub and wheel-carrying plate are riveted together as a unit, and the detachable portion of the tyre and wheel assembly is little more than a rim with a five-hole fixing, Each rear hub assembly has a flange formed on the extremity of the axle shaft, to which is riveted the brake drum and wheel carrier.
The 760 c.c. four-cylinclered over
head-valve engine develops 19 b.h.p. at 4,000. r.p.m. It embodies an integral crankcase and cylinder-block casting. Push-fit wet cylinder liners are used. The fully counterbalanced crankshaft is supported by three main bearings.
The cast aluminium-alloy head has scat inserts for the inlet and exhaust valves, which are carried vertically and are operated from a high camshaft through short push-rods and rocker gear. A skew gear, cut from the boss forming the centre camshaft-bearing journal, drives the oil pump and distributor shaft The fan and water pump are belt-driven from a pulley attached to the front of the camshaft. Air for combustion is drawn through a large filter box positioned alongside the power unit.
No Direct Drive
Drive from the single-dry-plate clutch is by a shaft above the differential assembly, to the three-speed gearbox. After passing through the gears, a lower shaft in the gearbox transmits power to the crown wheel. In effect, there is no direct drive, each forward speed being engaged through a pair of gears linking the input and output shafts. Helical constant-mesh gears with synchronized dog-clutch engagement are used for the two upper ratios. A remote control, at the side of the driver, is linked by a long universally jointed shaft to the gear-selector forks.
In the Lockheed braking system, operating cylinders of larger diameter are used for the frontwheel units than for those at • the rear. This method affords the required distribution of braking effort.
The radiatOr, pump and fan are positioned above the clutch housing, the two air intakes provided for the radiator being formed in the leading edge of each of the rear mudguards. A roller blind is mounted in front of the radiator, and it may be adjusted to give the required degree of blanking in cold weather.
ANUMBER of trailers and roundsmen's vehicles, including new battery-electric models, equipped with milk-float and ice-cream sales bodies, was exhibited, last week, at the Dairy Show at Olympia, London.
An entirely new four-wheeled pedestrian -controlled battery electric vehicle was shown by T. U. Lewis. Ltd., Watford. Fitted with a coachbuilt milk-float body, the new model can . carry 90 gallons of milk in 36 crates, which is equal to a I-ton payload. As a pedestrian-controlled vehicle, it is subject to £3 road tax. Its main feature is that the front and rear track are the same, affording high stability under adverse conditions. Care has been taken in design to simplify maintenance, and the body, hinged at the rear, may be lifted and retained in the open position by a builtin prop, exposing the whole of the chassis and batteries for normal attention.
The controller has been specially developed to provide automatic threespeed acceleration, thus eliminating heavy currents in the battery and motor, and preventing high torque stresses in the transmission when starting from rest. This system also assists rnanceuvring in confined spaces, The controller, operated by a finger switch on the tiller grip, is interconnected to the braking system, so that the contactor gear is
automatically cut out when the brakes are applied. Full use is made of carbon contactor tips to prevent welding or burning, no circuit being made or broken through metal-to-metal contact.
A special arrangement on the control panel operates the contacts at a predetermined interval, ensuring that a minimum of current passes through the resistances and reducing the losses of the battery potential capacity. A relatively high-powered 24-volt motor. developed by the Electro Dynamic Construction Co., Ltd., Birmingham, is employed.
It is claimed that the Electruk model E.B.. as it is known, can climb a gradient of I in 4 when fully laden. Tudor 24-volt traction batteries of 108-amp.-hr. or 135-amp.-hr. capacity arc used, affording a range of 9-12 miles under average conditions. For normal operation, the speed is controlled to 3-4 m.p.h.
Girling-pattern brat:.es on the rear wheels are automatically applied when