An Auxiliary Low-gear for Tractors
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A Resume of Recently Published Patent Specifications
WHEN using a tractor for some VV special purpose it may render desirable the use of a specially low gear, and patent No. 560,085 shows how this may be accomplished without calling for structural alterations to the transmission. The patentees are A. Howard and Rotary Hoes, Ltd., Station Road, East Hornchurch, Essex.
The drawing shows the worm-drive axle of a standard Fordson tractor with the addition of the extra reduction gear. Normally, the worm is fast on the drive shaft but, in the present scheme, the one-piece worm and shaft are replaced by a longer shaft upon which is joumalled a free sleeve .(3) carrying the worm. The shaft and the sleeve are extended into a two-speed gearbox (1) bolted on to the end-face of the casing. The gearbox provides either a normal straight-through drive or an additional reduction as required. The drawbar attachment plate (2) is fitted on the back end of the gearbox.
AN IMPROVED FORM OF HOT-SPOT
A DEVICE for preheating the ingoing mixture forms the subject of patent No, 659,862, from S. Clowes, The Atlas Garage, Birmingham, 9. The
main object is to provide an increased heating area in the induction pipe. The drawing shows a part-section view of the heat-exchanging device in the manifold. It consists of a screwedin cane (I) fitted with heat-transferring fins on the outside where the incoming mixture impinges upon it. Internally, the exhaust gas is guided by a deflector (2), so that some of it is directed up into the bore of the cone, returning down the other side of the deflector. The device is said considerably to shorten the warming-up period when the choke has to be used.
Although the' warming-up period may be shortened by heating the in.going mixture, loss of volumetric efficiency may be experienced under normal running conditions unless the mixture-heating factor be controlled. POWER-ASSISTED STEERING MECHANISM
I NTENDED, principally, for heavy commercial vehicles, a design for a power-assisted steering gear is shown in patent No. 560,144, by Clayton Dewandre Co., Ltd., and J. Rodway, both of Titanic Works, Lincoln. The scheme is claimed to provide a powerful action without detracting from the driver's delicacy of control.
The drawing • shows the scheme diagrammatically, the actual construction being in a more suitable form. The power cylinder contains a piston (5) which, in the "straight-ahead " position, occupies the middle of the cylinder, as shown. The piston is directly connected to an extension of the usual drop-arm (3). Both ends of the cylinder are piped, via control valves (2 and 4), to a supply of compressed air. Movement of the handwheel is transmitted, via a reduction gear, to a stud (1) which moves right or left to open one of the valves and vent the other to the atmosphere, thus applying power to the piston. By means of mechanism, not shown, the moving piston tends to cut off its air supply and so equilibrium is established at any set position.
BALANCING THE INLET VALVE IN SUPERCHARGED UNITS
SUPERCHARGENG an engine brings with it the problem of the tendency of the feed pressure to force open the inlet valve at the wrong time. To
prevent this without resorting to excessively strong valve springs is the object of a scheme disclosed in patent No. 539,980, by A. Sanders, 1, Park Crescent, Roundhay, Leeds.
The end is achieved. by balancir out the applied pressure by causing it to exert an equal and opposite force on the valve. The spring is enclosed in a cylinder of a diameter equal to that of the valve head, the sliding motion being permitted by .the use of a piston-like disc (3), which also ,performs the duty of enclosing the usual split collars (4).. , The boost pressure is led to this cylinder via a port (2) from the induction pipe and a ring of ports, (1) through the flange of the valve guide. An equal force is thus created in both the up and down directions, the net effect being zero.
PERMITTING AXLE FLOAT IN MULTI-WHEELERS
ik VEHICLE with more than Pi two axles is at a disadvantage when cornering, owing to the fact that all the axles should direct their axes towards a common point of intersection. A design in which this action can occur forms the subject of patent No. 560,080, from A. Ayers, of Oakland, California: 1.3 .S. A .
The drawing shows a plan view, of a dual-axle semi-trailer arranged according to the invention. The first axle is fixed to the frame in the usual manner and calls for no comment. The second axle is, however, attached by means of sliding shoes (1) which are embraced by curved runways on the frame so that, during cornering, the axle is permitted a slight change of angle coupled with a small lateral shift.
The metribers 1 are also curved in an up-and-down direction, so. that a slight tilting effect is also obtained on corners. This action shifts the centre of gravity and helps to maintain stability. A locking device is incorporated foh use -during reversing as, in these circumstances, it is not desirable that the axle should float.