Two Injectors Give Improved Starting
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A COMBUSTION system for oil i—tengines-forms the subject of patent No. 625,946, from H. Ricardo and G. Holt, Bridge Works, Shoreham-bySea. According to the specification, whilst downstream injection gives the best running characteristics, starting is better served by upstream injection. The patent shows a scheme in which, the
best is obtained from a combination of both systems.
The main principle involved is the provision of two fuel jets, one upstrearn and the other down. Both jets are in use together,but are arranged so that one or the other, performs the major part, according to whether a full-power or an idling . charge is being delivered.
The drawing shows a.
practical method employ .
ing two injectors, although two nozzles in the same injector can be used... The starting nozzle (I) delivers its fuel upstream and the main nozzle (2) downstream, with respect to the adr-flow as indicated by the arrows.
Both injectors are supplied from the same inlet (3) but the smaller nozzle_ has a small plain orifice, and the larger one a pirate. Also, the needle-valve of the small one is loaded to a less degree than that of the large one, so that at low loads it delivers all the fuel, With an increase in delivery, the small jet cannot handle it all, the pressure goes up, and the main jet comes into action. A screw-down valve (4) may be provided to cut off the starting injector.
ACCELERATOR PEDAL LINKAGE
THE first few degrees of movement of an accelerator pedal have a considerable effect on the engine speed, but once past the . midway position the pedal • movement becomes increasingly ineffective. An attempt to obtain a more uniform action in this respect is shown in patent No. 624,290, by Humber, Ltd., A. Miller and G. Berry, all of Ryton on Dunsmore, Coventry.
In the drawing, 1 is the accelerator pedal which pivots about its shaft (2). At the end of its arms, it carries a' pin (3) which slides in a slotted arm (4) attached to the butterfly spindle, or some part linked thereto. By this means, initial pedal action is mostly spent in sliding along the slot and gives only a slight turning motion to the thTottle. Further movement gives an increasing ratio, and the parts can be proportioned so as to give any desired degree of variable coupling.
A HAND-OPERATED CLUTCH WHEN an operator is VT hitching an implement to a tractor, it is convenient to be able to inch back the tractor from behind, and a handoperated clutch is often fitted for this purpose. But it is rather important that the "let-go," position of the hand-lever, should disengage and not engage the clutch, and a scheme to ensure this forms the subject of patent No. 626,07-8 from J. Elliot, "Goldielands," Hawick, Scotland.
The drawing shows a Fordson tractor fitted with a clutch hand-lever (1) which normally has to be / pushed forward 'to disengage the clutch. In the present scheme, it is fitted With a strong spring (2) which overcomes the clutch springs so that it has to be pulled to the rear to cause engagement. A locking catch (3) is provided for use when permanent engagement is needed. A lost-motion link (4) enables the normal pedal to override the action of the lever. The -handle need be moved through only 35 degrees, as against 95 degrees with known mechanisms. TUNGSTEN-CARBIDE SEATINGS
TWO of the chief requirements of a valve-seat insert are resistance to. erosion and good heat-conductivity. Unfortunately, these . two properties seem to run counter, to each other when. the choice of material has to be made, and an attempt to solve the problem, forms the subject of patent No: 625,394; which comes from Mallory Metallurgical Products, Ltd., 78,• Hatton Garden, London, E.C.1.
Tungsten-carbide is a material which has already proved its hardness and durability for cutting tools, and it is proposed to use this as the basis of the new material. Its low thermal conductivity is improved by t he addition of silver, both in the mix and as a separate layer in the seating, although the latter is optional.
The drawing shows a typical example in which the seat (1) and the facing (2) are made from a sintered mixture of tungsten-carbide 65 per cent., silver 35 per cent. and cobalt 2 per cent. In the sintering, 2 per cent, of silver is lost.
The outer ring (3) is made of silver or an alloy thereof, and is either brazed to the seating or bonded to it in the sintering.
A TRACTOR HOIST
PATENT No. 624,460, which comes from Harry Ferguson Incorporated, Detroit, Michigan, U.S.A., shows still another attachment for use with the Ford-Ferguson tractor. The device shown is a high-lifting jib that can be used as a means for loading, or, as
illustrated, to carry a `pulpit for the use of fruit-picking from tall trees.
The outfit is arranged to snit the Ford-Ferguson hydraulic iniplementlift, in which links (1) are pulled by arms (2) operated by hydraulic cylinders (not shown). The jib is doubly pivoted at fop and bottom, so as to maintain the pulpit (3) always in the vertical position.