US1249418A - Internal-combustion engine. - Google Patents

Description

E, F. KIMBALL.-

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INTERNAL COMBUSTION ENGINE APPLICATION FILED APR. I8, |916.

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Be it known that I, EARL E. KIMBALL, a citizen of the United States, residing at Brookline, county of Norfolk, Sta-te of Massachusetts, have invented anlmpr ovement in Internal-Combustion Engines, of which the following description, in connection with the accompanying drawings, isa specification,'like characters on the drawings representing like parts. 1

This invention relates tointernal combustion engines and has for itsobject to provide an engine with a slow-rotating cam shaft. constructed. to provide the desirable quick-openimg` and closing of the valves notwithstanding the relatively-slow rotary movement thereof. l L

The ordinary founcycle internal combus tion engine is provided `with a cam shaft by which the valves are opened and closed and which is geared to the `crank shaft by a twoto-one gearing sothat the cam shaft moves at one-half the speed of the crank shaft. The cam shaft `is provided with cams so constructed that each rotation of the cam shaft will open each valve once. It is desirable that the valves should open and close with a quick movement and the cams that are used on the cam shaft for operating the valves are shaped to give as quick an opening and closing movement as possible, but when the engine is running very rapidly and the cam shaft has a correspondingly rapid speedof rotation,the more or less abrupt cams on the cam shaft are apt to cause the valves to jumpvwhich results in an uneven operation of the engine. 1 obviate this by providing a multiple cam for each valve which is constructed to secure the opening and closing of the valve a plurality of times during each rotation of the cam and l interpose a train of gearing between the crank shaft and the cam shaft by which the cam shaft will be rotated at a very much slower speed than the crank shaft. By this means a slow-moving cam is provided which nevertheless will give the requisite quick-opening and closing movement to the valve.

ln order to give an understanding of my invention, l have illustrated in the drawings a selected embodiment thereof which will now be described, after which the novel features will be pointed out in the appended claim.

Figure 1 of the drawings is a vertical sectional view through an internal combustion Specification of Letters Patent.

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Application le. April 18, 1916. SeralNo. 92,005.

engine embodying kmy inventionwith a por-` tion of the crank casing shown in elevation; .Eiga 2 is a section on the line linei2-2, Eig- 1;

Fig. is a valve stem.

Fig. 4 is a section on the line 4, Fig. 3. j IV have shown at 1 an internal combustion engine having the cylinder 2 in which `opcrates the piston 3, saidpiston being connected by a connecting rod 4 to the crank 6 ofthe crank shaft 5. The cranks operate in the usual crank casing 7. 8 is one of the valves (either the inlet valveorthe outlet valve) controlling the port 41 tothe cylinder. This valve is herein shown as a piston valve provided with communication is established between `the manifold 43 and the port 41.` The valve is` for each cylinder are actuated from a cam shaft 10 by suitable cam mechanism which embodies my invention. The cams which l have herein illustrated for the `valves are shown at 11 and these are in the nature of multiple cams, that is, each cam is provided with a plurality o-f cam projections 12, each one of which acts on the valve stem to open the valve as the cam is rotated. ln the illustrated embodiment of my invention the cam 11 has twelve such cam projections 12 so that upon each rotation of the cam the valve 8 will be operated twelve times. Each cam projection is provided with the abrupt cam face 13 which acts on the toe or dog' 14 at the end of the valve stem thereby to raise the valve as the cam rotates anti-clockwise Fig. 1. Each cam projection is also provided with the radially-extending face 15 so that as soon as the cam projection has passed the toe 14, the valve can close quickly.

Any suitable gearing may be employed to rotate the cam shaft 10 at the proper speed relative to that of the crank shaft which is necessary to secure the correct timing of the valve action. Where the cam member 12 has twelve cam projections, then it will be necessary to rotate the cam shaft once only during each twenty-four rotations of the crank shaft. The gearing herein shown for connecting the crank shaftto the cam shaft comprises a bevel gear 16 fast on daan `View of the and vor the a port 42 by which.`

construction and form no Vpart of my present invention The valves toV turn lbackwardly 4in the fork 23.

they cani shaftl meshing suitable bearings 19 carried by the crank casing 7. This shaft 18 has a Vworm wheel 20 thereon which meshes withl a worm 21 fast yon the end of the crank shaftl 5. This worin gearing provides a simple device for ldriving the cam shaft from the crank shaft at the proper reduced speed. The toe 14 willvbe pref the lvalve stein!)V so as topermit the cam 1l whenv in the position shown in Fig. 1 without injuring the valve rod in case the engine back lires.' yThe lower end of the valve stem 9 is shown as forked,

as at 23, and the toe 14 is provided with an extension 24 that is received between the arrnsof the fork 23. l This toe memberv 14 is secured to a pin 22 which is journaled in thearms of the fork 24 and said toe Inemer is provided with the inclined face '25 which engages an inclined face 26 formed A spring-27 acts to hold the toe member yiel with the 'gear 17 Y Afast on a cross shaft 18 ythat is journaled in erably.V veldinglyl connected toA 14 will keep the inclined face 25 against the inclined face 26 so that the toe and valve stem will actasa rigid member in opening the valve. If, however, the engine should backre and the cam should be rotated backwardly, the toe 14 will yield, thus preventing any damage from occurring. By means of this construction it is possible to use a slow-moving cam shaft which will eliminate any possibility of the valve jumping and yet it is possible to have the valves opened and closed quickly.

y improved engine is especially useful in operating automobiles, air ships and other devices where a high speed is desirable.

I claim:

In an internal combustion combination with a cylinder, of a piston therein, a crank shaft to which the piston is connected, a valve having a valve stern, a'vtoe pivoted to the valvey stem and'capable of swinging backwardly about its pivot, a cam shaft, a cam element thereon having a plurality of projections to engage said toe, and thereby actuate said valve, a worm on the crank shaft, and a countershaft geared to the cam shaft and having a Worm wheel thereon ymeshing with said worm.

In testimony whereof, l have signed my name to this specification.

EARL F. KIMBALL.

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Gopies of this patientrmay `be obtained for five cents each, by addressing the Commissioner of Patents.

- y v f Washington, D. C.

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