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A NEW VALVE GEAR.

11th January 1921
Page 32
Page 32, 11th January 1921 — A NEW VALVE GEAR.
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A Resume of Recently Published Patents.

An engine of the four-stroke type without any timing gears is something of a novelty, and this fact lends particular interest to ,specification No. 154,358 by C. H. Ferrer, wherein is describedisuch a prime mover. The valves, valve pots and passages are formed within the _piston itself ; the seats for the valves are in the piston heads, and from them the ports run diagonally downward, terminating, one each aide of the piston, in a long slot in the wall or skirt of that component. The inlet for theexplosive mixture and the exit for the exhaust gases are holes in the cylinder wall situated nearer to the base of the cylinder than to its heed ; but, awing to the elongated shape a the ports in the wall of the piston, these ports are continuously open to the holes in the cylinder, so that for all positions pf the piston there is direct communication from the valves to the outside of the cylinder.

Valve guides of familiar type ' are formed in the piston coating, and the valves are held on their seats by the usual springs. The tappet rode are carried by the connecting rod, and slide in a dual guide which is secured to that member. In order that these tappets may be enabled to operate the valves for all positions of the connecting rod, in its angular movement, rocking levers are utilized, of curved formation. They in tervene between tappets and valves, being hinged to the bottom edge of the piston wall and curved to conform with the circumference of a circle, having its centre in the gudgeon pin.

The camshaft is also carried by the. connecting rod. It is hollow, and free to revolve on a pin which is secured to the rod at a point close to the big-end: it is operated by a four-pointed star piece, with which it is, to all intents and purposes, integral. The projecting portions of the star come into contactalternately with two projections fixed to the web of the crank, one on that part of the web remote from the crankshaft, the other between 864 and crankpin. It will be gathered that, as there are four points to the star and only two projections with which that star May engage, the camshaft makes half a revolution for each complete revolution of the crankshaft. In order to maintain the came in their correct positions, in betrifeen those times when the star is in engagement with the projections on the crank web, spring plungers are carried by the connecting rod, and these engage in suitable recesses formed, in the heel( of the star pie.

The principles of the operation of this Nvalve gear should_noW be clear. The inventor claims that with this construction Um valves are held open to the fullest extent for the whole period of the piston stroke, the number of working parts of the engine is substantially reduced, and, as there is no separate camshaft. or timing gear there are no external parts' required to operate the valves, and, finally, that the engine will develop greater h.p. than another of similar weight but of ordinary construction.

Other Patents of Interest.

An ingenious automatic air valve is the eubject 'of patent specification No. B26 154,424, by F. Burwell. The inventor points out that, in the ordinary way, an automatic air valve supplies air to the engine in 'proportion to its speed; the faster the engine runs the greater is the supply of extra air. This is a convenient arrangement so long as the car is travelling on a level or on a road which' is substantially level. It is not so advan

tageous, however, when the car happens to be climbing a hill with the engine turning over quickly. In such circumstances the demand for power may be considerable. His invention provides a simple means of achieving that desirable end. The principal portion of this automatic air valve is of quite familiar type, being a ported piston valve controlled by a spring, the teneAn of which is adjustable. This velve and ite mechanism is contained within a cylindrical casting, and the inlet to it 'emerges from a small cylinder disposed above the main-casting. With the car on a level road, this cylinder is not quite horizontal, but slopes downward fromthe passage which. leads into the body of the valve. In. the top of this cylinder, but near the end opposite to the .passage to the valve, is the air inlet primer. In the cylinder rolls e ball, which 4 almost completely

• blocks the passage through it. With the car on a level road the ball lies at the opposite end of the cylinder to the main air passage, and there is then free access for -air to the spring-controlled valve..

When the car bonunences to climb a hill, however; the cylinder assumes a position in which it is inclined in the contrary direction to the normal. The ball then rolls down and blocks the entrance to the spring-controlled valve, thus preventing ingress of extra air when the car is climbing a hill.

Crossley Motors, Ltd., describe in specification No. 154,420 a means of housing and supporting the ignition and throttle control levers on the steering wheel. A bored cylindrical casing accommodates these levers -which are each embraced by a cylindrical expanding spring, which fits the inside of the casing. Owing to the nature and arrangement of the spring, the control levers will stay in any position in which they are put, and are not liable to be dis turbed by vibration of the car. .

A magneto attachment which is clearly intended for a Fordson tractor is described in specification No. 154,320. A substantial castieg is bolted at four points to the crankcase and frame of the tractor. At its lower end this casting embodies a casing for the driving gear of the magneto; a tunnel rune thence towards the other end of the caste ing, which is shaped to serve as a. platform for the magneto itself. The patentee e are F. 'It. Simms and Simms Motor Units, Ltd.

C. E. Goodyear describes e construction of wheel rim in No. 154,357. It appears to be . particularly applicable to pressed-steel' wheels, the rim being formed in two parts, of which one may be contracted so as to allow. of the tyre being quickly fitted or removed. The specification is No. 154,357.

A peculiar type of final drive is described in specification No. 154,515, by A. -W. Griffith. A globular worm engages with internal worm wheel teeth cut in the interior of two spur wheels: the latter transmit the.drive in the usual way to a differential gear, whence it is taken to the road wheels of the vehicle.

A useful and practical type of liquid fuel burner for starting internal-combustion engines is described by Petters, Ltd., in specification No 154,387. 'It comprises a jet for liquid fuel, into which are turned converging jets of inert gas or air under pressure. Owing to the arrangement of air paasige.s, etc., in the valve, it is claimed that this burner will give an intense blue flame with the use of a minimum supply of compressed inert

gas or air.

In No. 154,346 is described a one-way motor plough, in which the lifting of one see of pleughs and the lowering of the i other s 'automatically effected when the tra,cter is reversed at the conclusion of each bout of the-field. The patentee is C. P. Backstrom.

Copies of complete specifications of each patent published on this page can be obtained from the Sales Branch, Patent Office, Chancery Lune, W.C, at a cost of ls. for each specification.

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