A New Petrol Chassis.
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Messrs. the Yorkshire Stearn Wagon Co. Enter the Field of Petrol-vehicle Manufacture with a 25-30 cwt. Chassis.
Messrs the Yorkshire Patent Steam Wagon Co., as we announced some weeks ago, have definitely decided to manufacture petrol engined commercial vehicles, and their first effort in that direction, a 25-30 cwt. chassis, was exhibited at the Royal Show at Norwich, and, more recently still, at the Royal Lancashire Show at Bury. We illustrated the chassis, in course of our report on the Norwich Show. The Yorkshire Co.'s steam wagons have long enjoyed a reputation for original and practical design, coupled with sound construction, and, in the hands of users all over the world, wagons of this make continue to create satisfactory records, which redound to the credit of their builders. Yorkshire petrol chassis promise to carve out for themselves a position comparable in importance to that of their steam-driven shopmates. During the interval between the Norwich Show and the Royal Lancashire Show, one of our representatives was afforded an opportunity to examine the new chassis in detail, and the photographs from which the accompanying illustrations have been prepared were specially taken for this article.
In general appearance, there is nothing particularly remarkable about this new model : it closely conforms to present-day practice. The only unusual feature which ar rests the eye is the manner in which the steering pivots are housed within the enlarged hubs of the leading wheels. We shall refer to this detail later in this article. The Yorkshire Co. have been well advised to select an engine of proved merit, rather than to experiment in the manufacture of this class of power unit in their own shops, at Hunslet. They have chosen a 15.9 h.p. four-cylinder lArhite and Poppe engine, with the four cylinders cast in pairs, each cylinder being 80 mm. in diameter, and with a piston-stroke of 130 mm. The engine is complete with a. White and Poppe carburetter and Bosch high-tension magneto. Cooling may be effected by natural circulation, as the inlet and outlet pipes are of very large diameter, and the gilled-tubular radiator is of ample size to insure efficient working for long periods without the aid of a fan, although the. periphery of the flywheel is provided with diagonally-placed paddles, by the action of which a continuous current. of air is induced to pass through the radiator and bonnet. The clutch is of the inverted-cone type, and is leather faced, and between this unit and the three-speedand-reverse gearbox there is a flexible coupling to allow for any "out of alignment." The gearbox itself is of particularly-neat design ; it has very short shafts, and a completely-enclosed system of striking gear, by which the gear wheels, which are of the sliding type, are operated. The design is such that there can practically be no leakage of oil from the gearbox. The gears provide for forward speeds of 6.25, 11.9 and 16.1 miles an hour, and a reverse speed of 4.9 miles an hour, the top speed being a direct drive from the engine to the worm-driven live back axle. The gear ratio of the worm and worm wheel is 1 : 6.2 ; it will be noted from the illustrations that. the worm is placed below the worm wheel, and that the propeller shaft, gearbox, clutch and engine are all inclined so as to avoid want of alignment of more than a few degrees at any time between any of the parts. Throughout the whole transmission system stub-toothed gearing is employed, the angle of pressure being 20 degrees, thus giving a form of tooth which is at once capable of resisting the maximum stresses which will be imposed upon them at any time, coupled with smooth and silent running. A reference to the chassis views will show that the two radius rods from the axle are anchored at their forward ends to brackets, the transverse axes of the anchoring pins being almost coincident with that of the forward universal coupling. A couple of torque rods, anchored at their forward ends by spring-loaded ball joints, resist all tendency for the axle casing to rotate about the axle.
The universal joint for the propeller shaft is completely enclosed by a grease-retaining cover, and, surrounding the joint, there is the foot-brake drum. The blocks for this brake are cam-operated : they are provided with an extremelyeasy means of adjustment, and all the wearing portions may readily be renewed as required. The sidelever brakes are of the internalexpanding type, the drums being fixed direct to the rear-wheel hubs. Another point which should be noticed from the illustrations is that the spring-suspension system has been carefully thought out. The back springs are very long, and, therefore, should insure very easy riding for the load, whilst the front springs have been mounted in a manner which is directly opposed to the method of most manufacturers, although the Yorkshire Co. cannot claim originality in this respect, because the method has long been in use by the de Dion Co. ; we refer to the method of shackling the springs. In the Yorkshire chassis, the springs are anchored at their rear ends and shackled at their forward ends, the result of their arrangement being that the objectionable " wobble" of the front wheels, so often noticeable when a vehicle is being driven over it bumpy road, is eliminated.
The front axle, it should be noted, is of stamped steel, with forked ends, and the pivots for the stub axles are so set that lines passing through their vertical axes intersect, at the ground line, the vertical axes of the steering wheels. An enlarged detail of this stub-axle arrangement is also reproduced, and the latter view more clearly shows the details of the arrangement.
The principal dimensions of this small chassis are as follow : wheelbase, 9 ft. 2 in. ; wheel track, 4 ft. 8 in. ; diameter of all wheels, 34 in., size of tires used (front wheels single and back wheels twin), 877 mm. by 75 mm. ; overall length of chassis, 13 ft. 7 in. ; overall width, 5 ft. 81 in. ; outside width of frame,
ft. 2 in, ; length of frame behind dashboard, 10 ft. 2i in. ; length of frame available for body behind driver's seat, 8 ft. 7 in. The weight of the chassis, as illustrated, is 26 cwt. Although the available space on the chassis for the body is given as 8 ft. 7 in., the body may, of course, be made considerably longer than that, provided the overhang from the centre of the back axle does not exceed the distance from the centre of the back axle to the back of the driver's seat.
At the time of our representative's visit, the selling price of the chassis had not been determined, but there is no doubt that, when fixed, it will compare favourably with the prices of other manufacturers for chassis of similar capacity. Further models are at pre sent under consideration, and, ultimately, the company will build three sizes of chassis, the back axles of all of which will be worm driven. The present model, as already stated, is for loads of from 25 cwt. to 30 cwt. The next in size will be designed to take imposed loads up to 50 cwt., and the largest model lor imposed loads of 70 cwt. At the present time, t h e company has only decided to make the three models named, but it is quite probable that at some future time they may consider the
designing a n d building of a
stillheavier vehicle, for loads up to five or six tons ; as to whether such a nioclek will be worm driven,
the company is at present hot prepared to make any definite statement. The management is at the present time collecting information, and observing the working of other makes of five-tonners in regular service, both in this country and. abroad, before they determine which type of final drive they will ultimately adopt for their proposed five-ton model, should they decide to built such a type ; much will depend upon the development, or probable development, of heavy petroleugined wagons as may be indicated during the next twelve months. Whatever type or types the Yorkshire Co. decide to turn out, purchasers may rely upon their obtaining machines of undoubted reliability, sound construction, and excellent materials. Yorkshire steamers, from the driver's point of view, are amongst the handiest of steam wagons: the same good quality will be a feature of all petrol vehicles that are built in the same works. The small chassis here illustrated is typical of what may be expected in that direction : all its controlling levers are most conveniently arranged, whilst its dashboard is a model of simplicity and neatness.
We hope, in the near future, that we shall have an opportunity of submitting the 25-30 cwt. model to a severe road test.