Facilitating the Man-handling of Trailers
Page 54
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A Re:sun-1i of Patent Specifications that Have Recently Been Published
THE bearing surfaces of trailer turnJ. tables are usually large enough to create sufficient friction for the prevention of "snaking," but this friction is a disadvantage when the trailer is required to be moved by man-power. A scheme to relieve the friction by the movement of a hand lever is shown in patent No. 457,898 by J. Brockhouse and Co., Ltd., and A. T. Dear, both of Victoria Works, Hill Top, West Bromwich.
In the drawing the upper and lower turntable plates (1 and 2) are centred on a common king-pin, and are normally in frictional contact. The lower end of the king-pin is screwed with a coarse thread, or may be formed as a face-cam. In either case a lever (3) is provided, movement of which separates the plates, and permits easy swivelling of the turntable.
Combining Endless Tracks With Wheels.
A VEHICLE giving the choice of endless tracks or wheels for the driving system is shown in patent No. 457,573 by Steyr-Daimler-Puch A.G., Steyr, Austria. The novelty of the design lies in the means used for avoiding excessive overall width, a failing to which previous schemes have been subject.
In the drawing the vehicle is shown in the wheeled state, with the track drive lifted clear of the ground. To change the system the rear wheels are removed, thus letting the tracks down on to the ground, whilst the front axle, also with wheels removed, is folded up to the position shown by the dotted lines. A feature of the scheme is that the front wheels may be left in action when the tracks are used; this is said to be an advantage on uneven ground, as it prevents any tendency to "-nosedive."
A New Laminated Piston Ring.
DESCRIBED as an attempt to proLduce a metallic ring having the characteristics crf rubber, a novel scheme is disclosed in patent No. 457,612 by W. P. (Lymington), Ltd., and J. W. Howlett, both of Radial Works, Lymington, Hants. The groove in the
a36 piston is filled with a number of thin steel rings, each being .032 in. thick and bevelled at the outer edges to a thickness of .020 in. The composite ring thus formed is then backed by a wavy spring-steel band, to supply the expansive force. The relative hardness of the rings and the expander is a matter of some importance, the former being 40 to 55 Scleroscope units, whilst the latter should have a value of from two to three times as much.
The specification is most interesting to read, describing as it does the results of many experiments, successful and otherwise; moreover, it is written in plain English, an unusual and refreshing feature in these publications. Two additional patents No. 457,639 and No. 457,640, by the same patentees, also deal with piston-ring developments.
A Pneumatic Road-rail Wheel.
I NTENDED for vehicles which travel on rail to a given point and then complete the journey by road, a special type of wheel is shown in patent No. 457,586 by Steyr-Daimler-Puch A.G., Steyr, Austria. The object is to retain the pneumatic cushioning effect even when the vehicle is used on rails. To this end the tyred wheel is, for rail use, enclosed in a flanged steel shell (2). This shell is attached to the wheel rim by a series of ball-jointed links (1), so that it is restrained in only an endwise direction, and is quite free to oscillate as the tyre flexes. The outer shell is made quickly detachable, and is removed when the vehicle is to be used on the road.
A Safety Device for Injection Pumps.
I N the conventional rack-rod-operated injection pump, if one of the pinions should become jammed, as may sometimes happen, the whole control system becomes immovable. If this should occur while the pump is set for full delivery it is then impossible to stop the engine, and serious consequences may result. In patent No. 457,322, Scintilla, Ltd., Soleure, Switzerland, describes a novel construction of pump control, designed so that the above circumstances cannot arise.
In this scheme, the rack-rod (1) has its teeth cut at an angle with the axis, and the pinions (2) are provided with corresponding helical teeth. By this means, should one of the pinions be prevented from turning by seizure, return movement of the rack-rod merely alters the height of the pinion relative to the rack, the only contrary force being the pressure of the return spring.