The Vulcan Lorry Chassis)
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A New American Production which will Carry a Total Imposed Load of 75 cwt., Including the Body and Fittings.
We have pleasure in placing before our readers particulars of another American chassis, described az the Vulcan. This machine is of particular interest, inasmuch as in the important details of its construction it bears remarkable evidence of its design having been based on that of one of the foremost British manufac
turers. It bears, in fact, a noteworthy resemblance to the wellknown Commerear. It should be remarked, however, that Comraer
cial Cars, Ltd., is in no way responsible with regard to its construction or exploitation. The chassis is built up on a stiff frame of pressed steel, an unusual feature of which is the addition of reinforcing plates underneath the top flanges of the main side mem
bers. The cross-members of the frame are well .placed and gusseted. The engine is a 32 h.p., with four cylinders, cast in pairs, well water-jacketed, and is no ram. by 140 mm. bore and stroke. The lubrication system is described as automatic, the oil being pumped into troughs beneath each connect_ ing rod, from an oil pump situated in the base chamber of the engine ; a suitable indicator is placed on the dash. The valves, which are interchangeable. are ranged along the near side of the engine, being operated by one camshaft ; the whole of the valve gear is enclosed by readily-detachable cover plates. The cooling water is circulated on the thermo-syphon system, the pipes for which are unusually large. The ignition is by high. tension magneto and coil: A ReMY
magneto is fitted and is placed on the near side of the engine, well back, being driven from the timing gears through the medium of a long shaft with flexible leather Joints at each end. The carburetter fitted as a standard is the Stromberg. The engine itself is supported from the main frame at three points. The front end takes bearing in the trunnion bracket on the foremost cross-member, and the rear end is carried on a special girder bolted to the side frame. The radiator is a departure from modern practice, in that it is of the cellular or honeycomb type, but has detachable cast top and bottom headers. The reversion to this type of cooler in view of the well-established fact of its unsuitability for heavy commercial vehicles on solid-rubber tires is unfortunate. The cooling is assisted by means of a belt-driven fan. We noticed also that suitable provision h,ei been made for the adjustment of the tension of the fan belt.
The three speed and reverse gearbox is set well back in the frame, so that the differential gear and cross-shafts for the chain drive can be included in the same casing. Between the engine and gearbox come the customary clutch and doubly-articulated cardan shaft. The clutch itself is of the Ferodolined cone type, and of suitable diameter for the power which it has to transmit. The gearbox, of course, is not of the Commercar patented form. An ordinary type of gear-change mechanism. has been incorporated in the design of this chassis, with gears which slide endwise into mesh, and with the more .customary gate type of operating gear, the change-speed lever being at the right-hand side of the chassis.
The suspension of the gearbox is interesting, the rear portion is extended right and left so as to enclose the differential crossshafts. These extensions are carried, at theii-Louter ends, in bearings attached to the main-frame side-members. At the front end of the box a spherical portion is formed integral with the casting. This takes a bearing in a part casried, after the manner of gimbals, on horizontal pins which are fitted in a bracket riveted to the cross-member. The whole arrangement strikes one as being admirably adapted to prevent any harm coming to the gearbox owing to writhing of the frame when under load.
The ends of the cross-shafts carry chain sprockets, from which the final drive is by the usual side roller chains to chain wheels bolted to the brake drums on the rear road wheels. No provision is made to enclose these chains. Their tension is adjustable, however, by means of the radius rods. These latter are stampings of girder section. They bear at their front ends cm spherical portions of the cross-shaft brackets, and as to their rear on vertical pivots situated behind the rear axle. The springing is ample, both front and rear springs being of good length, width and depth. The steering is by the usual type of worm and segment, and is irreversible. The front axle is an H-section forging, and the wheels are carried on Timken roller bearings. This type of bearing is also used for the rear road wheels.
The braking system is indicative of the American origin of the chassis, as the foot brake takes effect on two drums bolted outside the front chain sprockets, . They are external contracting, Fend° lined, with ample provision for
adjustment, but without there being any means of compensating for unequal tensions in the operating rods, The side brakes are internal expanding, taking effect, as is usual, in the drums on the rear road wheels.
The control of the engine is by means of a throttle lever on the steering wheel, the ignition lever, being placed on the dash. No accelerator pedal is provided on the standard chassis, although we understand that if required this can be fitted as an extra.
The makers have had the foresight to arrange for British sizes of tires to be fitted for this market. These are 920 mm. by 100 mm., twins on the rear wheels and singles on the front. The price of the chassis, with the present unusual high freight rates, is 2725. We believe that prompt deliveries are possible. The sole concessionnaire for the United Kingdom is the Scottish Commercial Cars Co., Ltd., of Glasgow. The agency for the South of England has been secured by Mr. W. Binman.