CHAIN AND WORM DRIVEN COMMER CARS.
Page 12
Page 13
If you've noticed an error in this article please click here to report it so we can fix it.
ARANGE OF FOUR Comrner Car models will be shown on the stand of the established Luton company making these vehicles, three being chassis with carrying capacities of 2, 4, and 5 tons respectively, the other vehicle being a 30-seater motor coach.
The visitor who is on the look-out for the latest models will be particularly attracted by the new 5 ton chassis. This is a powerful and well-designed chassis built to carry a 5 ton net load in addition to the body and equipment of 1 ton. A 40 h.p. four-cylindered engine is used in this model, with a bore and stroke of 120 mm. lay 140 mm. respectively, and, in conformity with Commer Car practice, thermo-syphonic system of cooling is employed. Another highly satisfactory feature embodied in the engine is the method of automatic lubrication. A. very ingenious filter arrangement
should also be noted. When in position, the filter holds open a spring valve, allowing the oil to flow through it to the pump ; its withdrawal causes this valve to shut, so preventing any oil flowing from the crankcase When the filter is withdrawn for cleaning purposes. The Thomas four-speed gearbox is fitted in this chassis, and power is transmitted through it to the universally jointed shaft, thence to the hardened pinion and crown wheel, the final drive being by means of heavy roller chains. It should be mentioned that the engine, gearbox, and differential are all three point suspended. Points to notice on this chassis are the extra platform length, deep frame, wide springs, road wheels on large-diameter ball bearings, front axle drop forging, which is free from welding, and the strong rear axle.
For the visitor who is interested in anything mechanical, a gearbox specially arranged to show its construction and operation will be displayed on the stand. As the Thomas gearbox is fitted to all post-war Cornmer Car chassis' a short description will be of interest. The component consists of a mainshaft, layshaft, and reverse shaft, each running parallel with the other, and to this extent the lines of the conventiOnal sliding gear are followed. Instead, however, of the usual method. of sliding gear teeth into One another, all gear changes are obtained by means of dog clutches, and it is the successful application of this principle which enables many advantages to be claimed for the Thomas gearbox.
Exhibit No. 2 will be a 2 ton live axle chassis, which incorporates a 25 h.p. four-cylinder engine which is automatically lubricated. The vehicle is worm driven through an intermediate shaft and propeller shaft, the latter being enclosed in a substantial torque tube formed at its front end with a large ball-jointed socket, which also transmits the driving thrust to a substantial pressed steel cross-member, and thus obviates the need for the employment of radius rods. In this chassis the gearbox gives three speeds forward. A three-way tipping wagon mounted on a 4 ton chassis will constitute the third exhibit. This tipping body is arranged to tip by hydraulic rams to an angle of 40 degrees. • The chasSis to which this body is fitted is the -well. known R.C. chain-driven type, which embodies a 32 h.p. engine.
Those engaged in passenger-vehicle operation will be particularly interested in the 3P type Commer Car motor coach, which is similar to a number of chars-i. basics which have been very popUlar during the 1921 season. The model to be shown will he strikingly finished in crimson, with nickel-silver fittings, and it will be luxuriously upholstered. It is a typical example of the high standard of comfort which the modern motor coach provides, and in this connection it will be noted that interchangeable disc wheels shod with pneumatic tyres are fitted. The engine is four-cylindered, of 120 mm. bore and 140 mm, stroke, and, as in all other models, is three-point suspended. The Thomas patent four-speed gearbox is fitted. Final drive is by overtype worm working in a phosphor-bronze wheel. The propeller shaft is enclosed in a steel tube bolted at one end to the back axle, and this tube is provided at the forward end with a spherical enlargement, which acts as a combined radius and torque stay. The braking system on all motor coach chassis is particularly important, and it will.be noticed on the Commer Car passenger model that a wide margin of safety is allowed, the braking drums being of. particularly generous proportions, and all the connections being exceptionally strong.