US760920A - Admission-valve for internal-combustion engines. - Google Patents

Description

No. 760,920. PATENTBD MAY 24. 1904.

l H. POWER. ADMISSIONVALVE FOR INTERNAL GOMBUSTION 'ENGINES APPLIoA'rIon Imm JULY e. 1901. no 101m..

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UNITED STATES Patented May 24, 1904.

PATENT OFFICE.

HENRY POWER, OF MONTOLAIR, NEW JERSEY.

SPECIFICATION forming part of Letters Patent No. 760,920, dated May 21, 1904. Application filed July 6,1901. Serial No. 67,286. (No model.)

those which are opened and closed positively `by mechanism operated from the cam-shaft.

With suction inlet-valves the valve does not open until there is a suiiicient difference in pressure upon its two faces to permit the tension of its closing-spring, as wellas its iner- In consequence the charge admitted to thel cylinder is not proportional to the capacity of the latter, and as a result the engine at no timel operates with its theoretical maximum efficiency. With suction-valves whichr are mechanically opened and closed the valve is opened at the commencement of the suction-stroke and closed at the end of that stroke, so that a maximum charge is drawn into the cylinder. When, however, engines equipped with these valves are operating at a high speed, a complete exhaustion of the products of combustion does not take place on the exhaust-stroke, so that when the admission-Valve is opened at the commencement of the suction-stroke the high pressure of the remaining exhausted products of combustion permits the latter to pass the inlet-Valve back to the carbureter. This destroys the mixture, and in consequence the engine will miss explosions and its efciency will be reduced.

My object is to provide an improved type of inlet-valve for internal-combustion engines which will not have the disadvantages of either type of valve now employed, and to this end the invention in its broadest aspect contemplates the employment of mechanism by means of which the inlet-valve will be opened and closed with an elastic pressure.

In another aspect the invention consists in the interposition between the inlet-valve and suitable opening and closing mechanism therefor, of a flexible connection by which the valve will be elastically opened and closed. The advantages of such a construction will be appreciated when the method of operation is explained.

In order that the invention may be better understood, attention is directed to the accompanying drawings, forming part of this specification, and in which- Figure 1 shows a conventionaltype of internal-combustion engine illustrating an in let-valve therefor embodying my present improvements, and Fig. 2 is a side View of the admission-valve cam and rod coperating therewith.

In both of the above views corresponding parts are represented by the same numerals of reference.

The engine is provided with a cylinder 1, which is usually water-jacketed or provided with other cooling means and connected with a crank-case 2 at its lower end. The shaft 34 vis mounted in bearings in the crank-case and is provided with a crank 4, with which the rod 5 of the piston 6 connects. On the crankshaft 3, outside of the crank-case, is a pinion 7, meshing with a spur-gear 8 of double its size, said spur-gear being mounted on a stubshaft 9, secured to the side of the crank-case. Rotating with the gear 8 is an exhaust-valve vcam 1() of usual form, which operates a rod 11 of an exhaust-valve 12 to open the latter during the exhaust-stroke of the engine. The exhaust-valve coperates with the proper seat in a valve-chamber 13 and alternately opens and closes communication to a suitable exhaust-pipe 14.

Carried with the exhaust-valve cam 10 is a two-.part admission-valve cam composed of sections 15 and 16. The'section 15 is formed with a raised part 17, occupying three-fourths of its circumference, and with .a depressed part 18, occupying the remaining quarter. The section 16 of the inlet-valve cam is provided with a raised portion 19, occupying onefourth of its circumference, and with a depressed portion 20, occupying the remaining three -fourths of its circumference. The raised portion 19 of the section 16 corresponds with and is opposite tothe depressed portion 18 of the section 15. Cooperating with the section 15 of the inlet-valve cam is a roller 22, and cooperating with the section 16 of the cam is a roller 21. These rollers are carried on a valve-operating rod 23, working in .bearings in the casing 24 and in bearings 25 at the side of the valve-casing.

Mounted within the valve-chamber 13 is an inlet-valve 26, which cooperates with the proper seat and which opens and closes communication between an admission-pipe 27 and the cylinder, the admission-pipe being connected to a carbureter of the desired type to supply a suitable mixture to the engine.

Intel-posed between the valve-operating rod 23 and the admission-valve 26 is a flexible connection which permits the admission-valve to be opened and closed with an elastic pressure. For the sake of convenience I illustrate acommon leaf, spring 28, connecting the upper end of the operating-rod 23 with the stem of the admission-valve 26.

In operation the exhaust valve will be opened at the commencement of the exhauststroke and closed by the spring 29 at the end of that stroke in the usual way. At the commencement of the suction-stroke or at the extreme end of the exhaust-stroke the raised portion 19 of the inlet-valve cam begins to depress the roller 21, the depressed portion 18 of that cam coming into position beneath the roller 22. The operating-rod 28 will be thus moved downward and will be held downward until the completion of the suctionstroke. If the exhaust from the engine is complete and no pressure exists in the cylinder, the inlet-valve will open without resistance, so that the charge will enter the cylinder at the very commencement of the suctionstroke instead of at a later moment` as with suction inlet-valves as'now used. If, however, all the vexhausted gases have not been expelled from the cylinder and pressure in consequence exists therein, such pressure will hold the admission-valve closed against the tension of the spring 28, and the admission-valve will therefore not open until practically all the exhausted gases have been expelled. It will therefore be seen that in its opening operation my improved valve overcomes the objections already explained as existing with admissionvalves as now constructed. With suction inlet-valves when the piston approaches the end of the suctiosn-stroke and is moving very slowly, so that the suction effect is slight, the excess of pressure on the top of the admission-valve is not suicient to overcome the closing effect of the operating-spring therefor, and in consequence the admission-valve will close before the end ofthe suction-stroke, so that the charge admitted to the cylinder will be reduced at both ends of the suction-stroke. With my improved inlet-valve the valve-operating rod 23 is not moved upward untilv the very end of the suction-stroke, so that the admission-valve in consequence remains open during the entire suction-stroke. In this way I secure the same maximum charge as that which will be obtained with positively-operated admission-valves under theoretically-perfect conditions.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is as follows:

1. The combination with the cylinder and crank-shaft of an internal-combustion engine, of an admission-valve therefor, avalve-rod, means operated by the crank-shaft for moving said valve-rod in both directions, in definite relation to the engine-cycle, and a spring, which forms the sole connection between said valve-rod and admission-valve, whereby` the valve will be` positively opened and positively closed with an elastic pressure, substantially as set forth.

2. rI`he combination with a cylinder of an internal-combustion engine, of an admissionvalve therefor, a valve-operating rod movable parallel with said valve, bearings carried by said rod, a double cam engaging with said bearings and a leaf-spring connecting said rod with the stem of said valve for opening and closing the latter, substantially as set forth.

rlhiis specification signed and witnessed this 17th day of June, 1901.

HENRY POWER.

Witnesses:

FRANK L. DYER, JNO. R. TAYLOR.

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