DESIGNING FOR LOW MAINTENANCE COST.
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Details of a New 50-cwt. Lacre of Particularly Interesting Design Affording Remarkable Accessibility.
MHE modern commercial chassis has reached a very high standard of design. The materials incorporated in its construction are usually first-class, even in the cheaper models, and, in the opinion of some builders, progress must, in future, be comparatively slow. We, however; do not think this is correct. There are other things to be looked for than a long wearing life, and, of these, improved accessibility is one of the most important, for there are still far toe many chassis which, whilst being eminently satisfactory in other respects, are deficient in this. Particularly is this the case when the body is fitted and when this body is loaded. Replacements in the event of breakdown on the road should be almost as easily effected as those in the workshop.
In producing its new _2i-ton chassis, the Leers Motor Car Co., Ltd., 78, York Road, London, N.1, with works at Letchworth, Harts, has taken these points into consideration, and in no hesitating manner, for it is so arranged that the engine-clutchgearbox unit, complete with radiator, petrol tank and silencer, can be withdrawn in a few minutes from the rest of the chassis, and this without interfering in any way with the body. Apart from this, the gearbox is so designed that by removing its upper half the shafts can be lifted out and the gears examined or renewed with the box in situ, a trapdoor being provided in the body floor.
The new model is driven by an overhead enveloping-type worm in lieu of the chains employed in the earlier model, of which £1,000,000 have been sold, and which, of course, can still be supplied.
The appearance of the new Laere is unconventional, but by no means unsightly. It is of the side-driven type, but it does not present that lack of balance which so detracts c40
from the appearance of some chassis, as a second seat is provided in a similar position at the off side of the vehicle, so making the whole front symmetrical. The inner panels Of the seats are provided with handles and can be removed by sliding them upwards so that accessibility is readily obtainable to the carburetter, magneto, dynamo, etc., without removing the unit, and this is further facilitated by the bonnet over the engine, this bonnet being provided with a large hinged lid of cast aluminium, which is raised to give access to the petrol-tank filler.
Mudguards are parts which usually become damaged more rapidly than others, and each eau be entirely removed by undoing two nuts only and sliding the guard off the two horizontally projecting brackets by which it is supported.
The clutch adjustment, in many instances, means the removal of the floorboards and labour involving an hour or more. In this chassis, more or less compression can be put upon the single clutch .spring by rotating a worm through the medium of a cranked rod easily operated from the off side of the chassis.
To render the operation of the gears as simple as possible and to give them a long life, engagement for the four speeds and reverse is by dog clutches, and silence is afforded by cutting all the gears with double helical teeth. Both brakes act on the rear-wheel drums, which are of steel, the shoes being internally expanding, faced with friction fabric and operating side by side.
Special attention has ,bs...en paid to the matter of suspension, and in a short trial run in which we participated the suspension proved to be d1 that Was claimed for it. The springs are of the semi-elliptic type, bag and with a large number of thin leaves, some of the leaves being turned up over the spring eyes to add to their strength.
The lubricators for the spring pins, etc., should never escape the notice of -the driver, for each is of unusual size, holding a D. a grease and being equipped with a handle. An important feature in the construction of the radiator, which is of the built-up cast aluminium type, is that half of the tubes can be blanked off in cold weather by a concealed plate valve controlled by a small lever at the front of the bottom tank. The plate seats itself against a portion of the rubber joint for the tube plate. Half-way up the inner side of the radiator bracket is a handle controlling a combined choke and flooding device.
The scuttle dash of the driver's seat contains an instrument board with engine switch and C.A.V. switch panel for the 12-volt lighting and starting equipment and Watford speedometer. Incidentally, the controls are at the sight.
• The engine is a four-cylindered monobloc of 24.8 11.A.C. rating. The lubricant is force-fed to the main bearings
and the water circulated by a centrifugal pump driven by a separate link belt from a double Jralley, which also drives the fan. The oil filter is conveniently situated above the cylinders, being bolted to the water outlet connection.
The clutch is of the cone type, leather-faced and with two fabric-faced clutch stops. There are two laminated-steel flexible joints of the link type on the clutch shaft.
Roller races and ball thrusts are employed throughout the gearbox. Roller races are also employed for the cardanshaft joints, which have no gaiters or built-rip covers, and require greasing approximately twice a year.
The eardan shaft has splines and compression-spring inserts at each end.
A pot-type axle is employed. The axle shafts are fully floating and the steel disc wheels ruu on phosphor-bronze bushes.
The frame is of angle steel, parallel in all planes, whilst the sub-frame forms the detachable portion. This is secured to each side member by six bolts siassing through the webs and engaging nuts secured to cross members of the sub-frame. Each side member carries two rollers, these being on eccentric pins, so that they can be raised to bear on the sub-frame, and this, with the bolts removed, can roll along the main frame after three taper pins have been lifted nut of the selector-rod links. With the sub-frame part of the way out, a pair of castor wheels on a trussed frame is secured at the front, and as the removal continuos a further pair is mounted at the seats The whole sub-frame with its units can then be slid free, the cardan shaft, of course, dropping clear. The operation can easly be effected in from 15 mine, to 20 rains., and we saw the assembly replaced in position in 2 mills., this latter time, of course, not including the bolting op. Incidentally, it is not essential to lower the rollers, providing the bolt holes are in correct alignment.
The following chassis details will be of interest: gross capacity, 3 tons 5 cwt.-' average net load, 2 tons 10 cwt.; wheelbase, 9 ft. 9 ins., 10 ft. 6 ins., or 12 ft., as desired ; track, 4 ft. 11 ins.; frame length (behind engine), 10 ft. to 15 ft.. ; height of frame, 2 ft. 6 ins.; ground clearance, 9 ins.; overall length of 9 ft. 9 ins., wheelbase model, 14 ft. 6 ins., as compared with the 17 ft. 9 ins, of the bonneted type to take the same size body. (In packing and freight there is
the big saving of 140 Cu. ft. or 3i shipping tons:) The overall width is 6 ft. 5 ins. The tyres axe 100,mm. solid for 720 rims, or 110 mm. air cushier, Quotations can be given for ordinary or giant pneurdatius.
The gear ratios are: 7 to 1; 11.34 to 1; 19.6 to 1; 36 to
1; reverse, 28.9 to 1. If required the axle ratio can be reduced to 6 to 1.
The price of the chassis with solid tyreis is £595.