A Semi-articulated SIX-WHEELER ATTACHMENT
Page 49
If you've noticed an error in this article please click here to report it so we can fix it.
First Particulars of an Interesting New. System Embodying a True Trailing Axle IN the Eureka Radial six-wheeler attachment which has been developed by Mr. George E. Duerden, of the Empire Engineering. Works, Brown Street, Burnley,the trailing, axle is permitted to live up to its name and to trail into the natural position when the Vehicle is cornering. Most six-wheeler attachments are so constructed that when considered in plan the four rear wheels always remain in the same position with relation to each other. When the vehicle is cornering this results in a certain amount of sideways sliding between some of the tyres and the road surface, a fact which is well recognised.
The Eureka Radial design allows a degree of lateral movement to the rear axle, which is connected to the main frame by a V-shaped radius member having a ball joint at its forward end. The frame is extended to overhang the additional axle and sliding surfaces are provided to carry the load. These, it may he mentioned, are faced with the Ferobestos bearing material which has already received mention in our columns.
The trailing axle is of straightforward design and the radius arm is pivoted to it. Its suspension system consists of compensating levers on both sides of the chassis frame, pivoted on the extended ends of a cross-member_ The forward ends of the levers are attached to the rear extremities of the leaf springs which connect the driving axle to the frame whilst the rear ends of the levers are connected indirectly to the trailing axle through the sliding surfaces already mentioned. In the lower member of each sliding bearing there is a curved slot, the radius of which is struck from the centre of the ball joint on the radius rod. The upper member carries a stud with a steel roller which fits into• this curved slot and serves both as a guide and as a limit to the amount of lateral movement which can take place. This is, however, sufficient to ensure a correct trailing position even when the vehicle is on full lock.
Trailing Axle is Not Steered.
There is no attempt to steer the trailing axle, which assumes the correct position automatically when the vehicle is moving forward. To assist the selfeentsing action when straightening up, two opposed springs are used, their action being to push the axle into its central position. When reversing there would presumably be a tendency for this axle to run off to one side or the other, and to prevent this a locking bolt is provided. It is spring-loaded and is normally held out of engagement by a lever in the driver's cab. When this control is released, the bolt moves back and locks the trailing axle in its central position so that the vehicle becomes a rigid six-wheeler.
Amongst the chassis to which the Eureka Radial conversion set has been applied are a Maudslay 8-tonner, a Reo anda.Morris-Commercial, •as well as a Morris-Oxford chassis, which has been fitted up for demonstration purposes and can be taken by arrangement to any part of the country for this purpose. It is understood that two of these machines have now covered well over 20,000 miles.
A reduction of the risk of skidding and an increase in tyre life are claimed as the main advantages of the design. The tyres on the trailing wheelsare said to last approximately as long as those on the front wheels, As regards cost, it is understood that for the conversion of 0-cwt. chassis the price will be competitive, and that for heavier vehicles a greater benefit is shown. An advantage in this connection is that the new parts necessary do not replace any of the existing coinPonen ts and. emiseouentiv, there is no wastage. The Eureka Radial system is, of course, riot limited to conversions and is capable of incorporation by the manufacturer in the original design.