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Centralized Heat Flow From Piston Crown

2nd April 1943, Page 34
2nd April 1943
Page 34
Page 34, 2nd April 1943 — Centralized Heat Flow From Piston Crown
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Which of the following most accurately describes the problem?

A Rama of Patent Specifications That Have Recently Been Published

I N engines having comblistion chambers off set from the • pistons,.

trouble has arisen through the latter distorting, owing to unevenly distri buted heat causing expansion on one

side more than the other. To remedy this is the Ibbject of a scheme proposed

by F. H. Clayton, 71, Jersey. Road, Hounslow, and the London Passenger Transport Board, 55, Broadway, London, S.W.1, in patent No. 550,832.

Each piston has a crown (1) made as a separate portion and insulated for the most part from the body by an air space (3) or a non-conducting packing. At the centre; the crown makes direct contact with the body so that if the upper part be heated more on one side than the other, the lower part still receives its heat at the centre and, therefore, there will be an equal flow to the portion carrying the piston rings, which will be maintained at a temperature that is constant all the way around.

One construction is shown in an accompanying sketch and seems to require. no written explanation, part 2 being merely a locking dowel. Others are mentioned in the spedification.

It will be observed that the crown makes contact with the body at certain points (4) besides the central boss. These may be chosen according to requirements. Also, the boss may be off set, if desired, in a direction away from the hot zone to render the device even more effective in respect of its object. .

NEW IDEA IN TWO-LEADINGSHOE BRAKE VIRTUALLY a new _principle is cov,ered in patent No. 550,878, from the Rover Co., Ltd., and P. A. ScottIversen, Chesford Grange, Kenilworth, Warwick, which details numerous embodiments of it in brake-shoe assemblies. One of these, of a basic 'nature, we illustrate; others employ as shoe anchorages pins in slots instead of links, and instead of # lower pivot a floating adjuster.

The brake functions on the two leading-shoe system and, as sketched, in either direction. By omitting one of the links (3 and 7) it becomes unidirectional. to operate the brake there is an expander (I) of known type, and the ends of the shoes are joined by a pivot, but this joint pin is not fixed to the back plate. It is anchored by a link (5). The other links (3 and 7) are also anchored to .the back plate and the pins at the other ends work in slots (2 and 9) in the shoes.

When the drum is turning in a clock wise direction, shoe 4 moves, for a short angular distance, with it,. being able to do so because of the slot (2) at its upper end. Link 5 then swings to the left and, the upper left-hand link (7) does likewise. allowing shoe 6 to move bodily towards the drum, pin 8 taking the thrust. HIGH-REED FUEL INJECTION ON NOVEL PRINCIPLE A N unusual type of injector is shown in patent No. 550,476, by G. A. Bell, 642, West Elk Street, Glendale, Cal., U.S.A. It is claimed to be suitable for small high-speed engines, 7,000 r.p.m. being mentioned as a practicable operating speed. The device is also a pumping unit, but it does not meter the fuel, this function being performed by throttling the Nei before it reaches the injector.

, A' spindle (I) projects from the top of the body and carries an arm, which must be reciprocated by mechanical means so as to impart about 60 degree§ of angular movement to the spindle. Farther down on the spindle is a recessed ring (3), which, in combination with a similar stationary ring (2), houses a number of short,. ball-ended push rods (9). When the ring (3) is turned by its spindle these rods impart an approximately helical' motion to it, which is rapid at the beginning but slows as the rods approach dead centre. The motion is transmitted to the pressure plunger (4), which thus descends with a helical motion of diminishing pitch. Splined to the plunger is a cone-valv& (5) carrying a coarsethreaded end (7), which screws into a sleeve on the needle-valve (8).

In operation, metered. fuel arrives via the inlet (10) and passes down a central clearance, eventually reaching the pressure space (6) via the cone-valve (5). When ring 3 and scfew 7 start to move, plunker 4 gains on its seating, owing to the initial higher speed, and finally closes valve 5. Further movement of the plunger raises the pressure of the fuel in space 6. At this time the plunger descends at the same rate as the screw enters' its sleel".e, but near the end of the stroke the plunger speed diminishes te less than that of the screw, so that the needle-valve sleeve is lifted by the differential action to permit injection of the fuel.

TORQUE DISTRIBUTOR FOR MULTI-WHEEL DRIVE

PROPORTIONING of torque to the axles of all-wheel-drive vehicles is tlie subject of patent 1lo.'549,514, from the Four Wheel Drive Auto Co., Clintonville, Wisconsin, U.S.A. It is pointed out in the specification that the power distributed should be primarily proportional to the number of tyres on the front and rear wheels respectively.

As an example, a six-wheeler with twins on all four bogie wheels is chosen. In this case one-fifth of the total torque should go to the two tyres on the front wheels and four-fifths to the eight tyres on the bogie wheels, and the essence of the patent is a distribution gear, which is depicted in an accompanying sketch.

A chain conveys power from the gearbox-driven shaft (1) to a sleeve (8) carrying a spider (2). This holds a cross-shaft carrying planet wheels (3 and 6). From wheel 3 drive is conveyed, via gear 4, tO shaft 5, and from wheel 6, via gear 7, to shaft 9. Shaft 5 transmits torque to the rear bogie, and shaft 9 passes it to the front axle. There ,are further differentials subdividing the power between the two bogie axles and between, each wheel of each pair.

The ratio of the gears 7 and 6 is 1 to 2, and of the gears 4.and 3 is. 2 to I. Accordingly, the ratio between shafts 5 and 9 is 4 to I.

A clutch (10) is provided so that shaft 9 can be locked to sleeve 8 in the event of loss of traction at either end.


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