The United Chassis.
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Capacities 2, 3_1T, and 5 Tons Net Load. Largest Size Not Yet Available.
Yet another name is to be added to the ever-increasing list of American assembled "propositions "—in other words commercial-vehicle chassis—on sale in this country. From the point of view of the man who must have means of transport, the news is good.
The existing "release " of 25 per cent. of British-made chassis from controlled establishments is hardly Sufficient for the needs of purchasers on Government contracts, notwithstanding the very strict interpretation which is placed upon the term. The products of other heavyvehicle makers, not tied to the War Department, are hardly sufficient to supply the present demand for chassis and to
give very early delivery as well. For these reasons we have pleasure in introducing to our readers an American chassis, new over here, but not in the country of its origin, where the United chassis, as it is named, is giving service in many different spheres.
Three Sizes Made.
it is made in three sizes, for net loads of 2, 3, and 5 tons. The first and second of these only are offered for sale in this country at present, and we recently availed ourselves of an opportunity to inspect the 3-tonner, of which the following is the first description to be published in this country. The two-ton chassis is similar in design.
Units Not Novel.
The units of which it is constructed are by no means new to our readers ; we have referred to them in connection with other chassis. IL may be observed, however, that, individually, they are soundly constructed, and all very largely used in the States in the construction of heavy vehicles. It must be admitted that, in order In stand up to the work expected of them "over there" their design, and the material of which they are made, must be above reproach. There are, moreover, in connection with the. chassis under review, one or two constructional features embodied, worthy of commendation. We shall refer to them in due course.
Wisconsin Engine.
The engine is a four-cylinder Wisconsin, of 44 in. by 5 in. bore and stroke respectively. It is a power unit specially designed for commercial work, the mannfactnrer having two sets of models—one • for touring cars and the other for heavy vehicles; the line of demarcation is very distinct.
In the latter type, pair-east, T-head cylinders are adopted. The cooling is by pump-circulated water, and the lubrication is by splash, ol being fed into troughs below the connecting rods, the latter are provided with scoops so that they may more readily collect and distribute the lubricant, which collects in trays above the main and camshaft hearings, The timing gears are oiled in a similar manner. The ignition is by high-tension magneto, driven in the usual manner by the timing gear, and we were pleased to observe that special attention had been paid to the method of carrying the highterii-on cables, with a vise to avoiding
any likelihood of electrostatic induction. The induction valves are ranged along the off side, the exhausts being on the near side. Each valve, with its spring and tappet, is enclosed and protected by an aluminium cover, cast in halves, and held in place by a spring clip. A feature of the valve gear is the use of disc-ended tappets so placed in relation to the Cams that a small rotational movement takes place at each stroke, thus ensuring that the cam dues not str.ke the same surface twice consecutively—a small point, but conducive to longer life of the parts in question. Another departure from accepted practice is noticeable in the method of attaching the gudgeon pins. These, instead of, as is more usual, being fa.stened in the piston, are secured to the connecting rods by bolts, and rotate in the piston bosses. The makers claim increased bearing surface and simplification of oiling. The crankcase is robust, and made from chrome-nickel steel. The bearings, both main and big-end, are bronze, lined with white-metal. The carburetter fitted is the Stromberg, one of the hest known of Americans. Its peculiarities are the use of a spring-controlled dashpot to regulate the amount of air supplied to the mixture, and, in th.s pa tieular model, the provision of a glass float chamber. The exact utility of the latter feature we are not able to determine, but mention it on account of its novelty. This component is fitted with a Kramer suction governor, so-called because it operates entirely in accordance with the engine suction, being quite independent of any mechanical drive whatever. It is alterable by hand, so that it can be set to come into effeot at a predetermined engine speed. Such alteration, however, can only be made at the will of the owner, who can then lock the governor up.
Unit Construction Adopted.
In this chassis the engine and gearbox bolt together to form one complete unit, which is three-point suspended from the main frame. The clutch is of the multiple-disc type, and is enclosed by the flywheel and the front end of the gearbox. Suits hie provision is made in the way of hand-holes, etc., 60 that this component is accessible for inspection and minor adjustments. It is disengaged in the usual manner by a foot pedal operating through a ball-thrust bearing.
The gearbox itself, a Brown-Lipe, provides three speeds forward and one reverse. It is of a type in which the gears slide endwise into mesh, and the sliding members are mounted on a squared shaft. Roller bearings similar to the Timken are used ; the la,yshaft is carried immediately underneath the main shaft, and a fair amount of attention seems to have been paid to the accessibility of the, principal components. The control is by means of a hand lever working in an open quadrant, the movements being similar to those associated with a gate change. This quadrant, and that for the hand brake, are carried by the large cover on the top of the box; it follows, therefore, that they occupy a position in the centre of the chassis width.
A difficulty with heavy-vehicle chassis, where unit construction is adopted for the power plant, is the extreme length of propeller shaft involved. This necessitates either a tubular shaft of large diameter or a division of the component, if trouble due to its whirling at high speeds is to be avoided. In the United the latter method has been adopted. A
short shaft runs from a universal joint immediately behind the gearbox, and is carried at rear end in ball bearings supported from a cross member of the Came. Connection between this and the vac axle is then established by means of a propeller shaft of the usual form, °filled at each end. It is worthy of note
that all the universal joint .employed arc entirely enclosed, and carry a fair of lubricant.
Sheldon Semi-floating Axle.
The axles are Sheldons, made by one of the two principal makers of heavyvehicle igsles in the States. That at the rear is worm driven, the worm being earl ied above the wheel, it is of the senii-flieitieg type. The makers claim tn have discovered special materials both for the alloy steel of which the worm is made and for the bronze of the wheel; the formulm for these are secret. The live axles, which in this construction CSrI y also the weight of lorry and load, are of chrome-nickel steel, and tapered from outer to inner ends, se as to present at any point of their lengths, a section as nearly as possible proportioned to the work it is to perform.
'Die construction of the main body of this unit is somewhat interesting. The housieg for tho worm and gear is of
east steel. Into this, forced into place hydraulically, is pressed at each end a substantial steel tube, which is then further secured by rivets. On the outer ends of these tubes, pushed into place by the same means, and also additionally secured in a similar manner, are the cast-steel spring seats and brake spiders.
The method is quite a good one, and should produce a strong axle of reasonably light weight. It is noticeable that tie-rods are not deemed eecessary.
Brake and Steering Gear.
A wide drum of good diameter on each wheel accommodates the service and emergency brakes. Both are of the band type, hut expanding. A special toggle movement provides for positive operation and release: it is also designed to allow of simple and effective adjustment. As may have been gathered from its construction, no radius or torque rods arc used with this axle, the top laps of the rear springs being utilized for both thrust and driving torque, the springs themselves being held at their front ends in brackets attached to the frame, and shackled only at the rear.
There is nothing of especial interest about the steerieg gear. It operates by worm and wheel, the Litter being riallt plete, and not a segment. Ball-thrust bearings are provided for the worm, and the 'wheel spindle is carried in bushes. The hand wheel is 20 ins, diameter, and the column is placed vertically on the footboards. Underneath it are mounted the hand levers for operating the engine throttle. No other means of control is pr old ed.
Frame. Minor Points. Price
' A description of this chassis would lka be complete without special reference to the frame. This is very strongly made of rolled-steel channels of heavy gauge. It Is pmvided with cross members, themselves well proportioned to match the exceptional strength of the main frame. Minor points of note, interesting inasmuch as they denote attention to detail, are the provision of screw-down grease cups for the brake pins; an arrangement whereby it is possible to swing the starting handle imdeeneath the frame out of harm's way, when not required; the fitting of an undershield and of nice curved front wings with valances. We wish to comment favourably on the bonnet fittings, these being of exceptionally substantial nature, and, in the case of the handles. are something to get hold of. The radiator is a honeycomb, mounted on the main frame bCt'A'ePTI rubber blocks. NO doubt later deliveries will carry the tubular type.
A Test Run.
We had the pleasure of a short run on a hare chassis, and although we prefer, as is rule, to test a commercial vehiclt under full load, this trial was very useful, insomuch as we are thereby enabled to testify to the ease of steering, which is all that can he desired, the progressive and sweet action of the clutch, and the very effective manner in which the
Kramer governor controls the speed of the engine. We hope to have the opportunity,: to try thie chassis under load on some future occasion.
The Sole Agents.
The sole agents for the United Kiugdem, The 'Royal Garage Co., of 48a, Gillingham Street, S.W.; of whom the priiicli?al directors are Messrs. Lord and _Halsa.i, who have, as it were, grown up with the motor industry, wish to lay stress on the fact that spare parts sufficient in quantity for 100 chassis are on their way to this country, so that no trouble need be anticipated on the score of replacements. Another point of interest is that, owing to the COILS'alidi.011 of the frame, any reasonable requirements in the matter of length of wheelbaue can be met. The limits set are 12 ft. and 23 ft. respectively, Actually, 14 ft. is the standard, with 14 ft. 1 in. length of frame behind deiver's seat. Over this length a small extra charge is made. The prices ruling at present for chassis with tires are £.575 and £.775 for the two and three-and-a-half tanners respectively.