A NEW 35-CWT. UNIC CHASSIS.
Page 14
Page 15
If you've noticed an error in this article please click here to report it so we can fix it.
An Interesting Machine which Incorporates a Double Reduction Rear Axle and a Laminated Spring Torque Member.
COMMERGIAL VEHICLES of Unic manufacture have enjoyed wellmerited popularity in this country, as 'well as in France—the country of their origin—for some considerable time. Apart from their well-known toxi chassis, the company specialize in two pneumatic-tyred, fast delivery vett chassis, the smaller of which is designed to carry 'a total load, including the body, ot 30 cwt.,. and the larger mode', a total load of 2 tons -4 cwt., which gives a useful load capacity of, apoproximately, 35 cwt. It is with this 35 cwt. chassis that we propose to deal in this article. The latest examples a this machine are already being sold in thi,s country by Unic Motors, Ltd., 18, Brewer Street, Buckingham Palace Road, &W.1.
The' chassis embodies several new ana interesting features, amongst which are a double reduction rear axle, and a lambmated spring torque member. A channel section pressed steel frame is employed. This frame tapers to each end, the taper being both in the web and in the• flanges. It is provided with a sub-frame,which is held at the front end by a strong cross-member. This frame sepports both the engine and the gearbox. .The•engine is a four-cylindered monobloc with all the valves on the near The• bore and stroke are 80 mm. and 130 mm. respectively. Its normal speed is in the neighbourhood of 1,200 r.p.m., but it can be. accelerated to 1,500 r.p.rn., when it develops 24 h.p. It. is rated by the manufacturers as a 13-24 hp. A centrifugal governor, situated on the timing gearease,, controls an li auxiliary throttle, and mits the speed of the 'vehicle to 20 m.p.h.. . The fuel is vaporized in a carburetter of Uric make, which incorporates a giyeerine-dashpot air valve. It is also provided with a hot-air muffle round the exhaust pipe through which the necessary air supply is drawn.
The rater circulation is by-pump, the latter being situated in front of the timing case at the offside. At the back of the timing case, in a line with the pump, is an S.E.V. magneto, which, incidentally, is a very neat and compact job.
The engine has an exceptionally heavy flywheel, which assists m maintaining an' even torque. The drive is taken through a leather cone clutch and double rubber fabric disc universal joints to the four-speed-and-reverse gearbox, which is situated amidships. The changespeed quadrant and brake ratchet are bolted to the offside frame side member.
Behind the gearbox is situated a neat footbrake with internal expanding shoes.
The carda.n shaft is of the 'tubular type, and is provided at its front end with a univessal joint of the sliding block type,, and at the rear end with a startype joint provided with four steel bushes.
Perhaps the most, interesting point about the new model lies in the back axle. This incorporates a double reduction gear, the first reduction being through a spur gear to an internally toothed pinion. The latter drives a bevel 'pinion. To the bevel wheel is attached the ordinary type of differ= ential gear.
The rear axle casing is a mild steel casting split vertically. At each side of this is bolted a flanged coupling carrying a rear axle tube, to which the coupling_is securely riveted.
The first reduction *ear is contained in a separate easing, which is bolted to the front of the main casing, and is supported additionally by a bracket extending from the torque member. The latter is a steel pressing firmly bolted to the axle at one end and provided with a laminated spring at the
other. The eye of this spring is supported in a shackle bolted to a frame cross-member. This allows a certain amount of flexibility, and permits the
drive to be taken up more smoothly. It also takes the braking stresses from the hand-brake, which operates on'ciruma bolted to the -rear wheels. The handbrake shoes are also of the internal -expanding type, and a compensator is provided.
All the wheels are. built up from pressed steel discs riveted to the rime. The wheels at the rear are provided with twin pneumatic tyre,. whilst .single pneumatics are fitted to those at the front.
Careful attention has been paid to the exclusion of. dirt and water frOm the working parts, and in this connection the rear brakes are totally enclosed, The chassis is exceptionallr;,7 well sprung. The rear springs are long, and are shackled at their rear ends only, as they have to aetaa radius rods: Considerable protection is afforded the driver by a pressed and welded steel -scuttle dash. In this dash is contained a large petrol tank, and also an oilpressure indicator for the engine. Steering is of the worm and quadrant type, the tie-bar being situated in front of the axle,, and provided with pin joints. The stub axles are forked, whilst the front axle itself is a solid equareforging. We have • not yet mentidned the radiator. This is of the gilled tubular type, the tank being constructed of stout sheet brass. The front of the radiator forms an obtuse angle, and with the sloping bonnet andscuttle dash gives the machine a good appearance. In the hollow formed by the angle of the radiator is contained a two-bladed cast aluminiumfan.
This ride chassis is said to be very economical, and the makers claim a consumption of 12 miles per gallon of petrol.
The main dimensions are: overall length, 15: ft. 10i ins.; wheelbase, 11 ft.. 7 ins.; dashboard to end of frame, 11 ft. 1011 ins. ; tyres, 895 mm. by 135 ram.
The price without tyres is £890.