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An Epicyclic-cum-hydraulic Transmission

22nd August 1952, Page 58
22nd August 1952
Page 58
Page 58, 22nd August 1952 — An Epicyclic-cum-hydraulic Transmission
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DATENT No. 674,525, comes from t h e Borg-Warner Corporation, Chicago, Illinois, U.S.A., and shows the latest suggestions for transmissions employing a torque-converter in conjunction with an epicyclic gearbox. Such arrangements usually include a multi-plate clutch for giving a direct drive, but this type of-clutch is not the best for providing a free disengaging action.

As neither the torque-converter nor the epicyclic gear will give complete disengagement, it would be possible, with cold sticky oil, for a really free neutral not to be obtainable. To remedy this is the aim of the invention.

The drawing shows the general layout of the hydraulic and epicyclic units which follow well-known principles. The novel feature is the addition of an extra cone-clutch (1) which can break the main drive to the planetary gears and so give a free neutral.

The clutch is operated hydraulically by a piston (2) which is supplied with fluid via a port (3) and a central bore (4) in the shaft. ?he direct-drive clutch (5) is also hydraulically operated, but its working fluid is supplied via a separate path formed outside tube 6 in the central bore.

A COMBUSTION HEAD FOR OIL ENGINES

pATENT No. 674,713 discusses in some detail the comparative advantages of placing the combustion chamber of an oil engine in either the cylinder-head or the piston. There is more space available in the piston, but heat-expansion can cause trouble, and whilst the water-cooled head avoids overheating, it is difficult to find the space, especially if four salves per cylinder are used. The patentee, K. Maybach, Friedrichshafea, Germany, proceeds to describe a novel scheme in which lack of space in the head is overcome by ingenuity in layout.

The essence of the scheme is to use a large number of small valves, spaced round the cylinder so as to leave a' large central space to accommodate the combustion chamber': In the exarhple shown in ' the drawing, six A40

valves (three inlets and three exhausts) are used, and the combustion chamber can be made to hold more than half of the total compression volume, up to 90 per cent, being possible.

Each of the six valves is operated by its own cant, the lightness of which gives quick action. The piston is provided with a nose-piece which enters the combustion chamber and imparts a swirl.

The scheme is claimed to present new and far-reaching possibilities in high-speed oil engines for road vehicles, 'giving a power output and degree of smooth running not hitherto obtainable.

THE UNPUNCTURABLE TYRE AT LAST?

THE unpuncturable tyre once excited the imagination of almost every inventor, and in one year in the late 1800s patents on this subject outnumbered all others. However, in spite of this, the ordinary pneumatic tyre is still with us, but at any time the wide variety of new materials constantly appearing may bring forth a practicable solution. A move in this direction is shown in patent No. 672,372, which comes from the Expanded Rubber Co., Ltd., 675, Mitcham Road, Croydon.

One of the chief drawbacks to the production of a filled tyre is the difficulty of assembly on the rim, unless special ones are used, and the present patent shows si practicable method of using a standard outer cover and a special inner tube, both of which can be assembled in the ordinary way. Heat treatment is, however, required after assembly.

The drawing shows the three stages in the assembly. A small thick-walled inner tube (1), surrounded by a layer of partly-vulcanized expanded subber (2) is placed in the cover in the normal

manner. Inflation then blows the tube out to meet the outer cover as shown at 3. Next, heating fluid is circulated through the air-space; to do this, two valves have to be provided, the only departure from standard practice.

The heat completes the vulcanization of the rubber, and at the same time releases gassing agents incorporated in the mixture. The gas then expands the rubber filling until it occupies all the space in the cover. The inner tube is by this time completely collapsed into position 4, but in the event of violent damage to the tyre could be inflated as an emergency measure.

SLIDING DOORS FOR VANS

TOgive clear and unobstructed access without external projections, is the object of a design of sliding door shown in patent No. 673,412. The patentee is Normand, Ltd., Cumberland Avenue, London, N.W.10.

The door consists of a number of vertical slats connected by hinges along their vertical edges. The drawing shows one of the slats (1); they are made of light alloy, filled with wood along their edges. Each slat is fitted with a U-bracket which carries a V-shaped roller to run on a guide-rail, the latter member being fixed to the body as shown at 3. The lower ends of the slats are provided with plain rollers (4) running in a guide channel (5). A second channel (6) receives only the roller of the last slat, and directs it in a different direction so as to conform more nearly to the body outline. le the open position, the door, which is divided in the middle, lies inside the body alongside the walls thereof. The foregoing represents an alternative means for supporting and guiding a sliding • door of the type covered in patent No. 653,463.

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