US1429943A - Combustion-engine-valve mechanism - Google Patents

Description

w. HARPERJR. COMBUSTION ENGINE VALVE MECHANISM. APPLICATION FILED MAR. 7, 1918. 1,429,943.,

RENEWED FEB- 17, i922.

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COMBUSTION ENGINE VALVE MECHANISM.

APPLICATION FILED MAR. 7. 191a.

RENEWED FEB- 17. I922.

Patented Sept. 26, 1922.

2 SHEETS-SHEET 2.

INVENTOR A TI'OBNEY w Patented Sept. 26, 1922.

UNITED STATES 1,429,943 PATENT OFFICE.

WILLIAM HARPER, JR, OF NEW YORK, N. Y., ASSIGNOB, BY MESNE ASSIGNMENTS, TO GAS TURBINE CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELA- WARE COMBUSTION-ENGINE-VALVE MECHANISM.

Application filed March 7, 1918, Serial No. 220,949. Renewed February 17, 1922. Serial No. 537,860.

To all whom it concern:

Be it known that I, WILLIAM HARPER, J r.,

a citizen of the United States, and a resident of New York city, in the county of New York and State of New York, have invented certain new and useful Im rovements in Combustion-Engine-Valve echanism, of which the following is a specification.

This invention relates to combustion engines, and has especial reference to aviation engines of the rotary cylinder type.

he objects of the invention are to provide mechanical actuating meansfor all of the valves, whereby it is possible to increase both the ed and efliciency of this type of engine. eretofore, difiiculty has been encountered in operating these engines at high speeds owing to the inlet valve through t e piston not being mechanically actuated, which had the result in practice of being liable to stick and also varying in time of opening. At high speed, the unreliability of such a valve increases, owing to its inertia, with the result that the volumetric efiiciency of the engine rapidly decreases, because sufficient charge is not admitted nor are the exhaust gases completely discharged.

By this invention, the inlet valve is mechanically actuated by a cam which is itself moved by the connecting rod, through resilient connections such that the valve is held seated by the cylinder pressure during the working and compression strokes, but is positively and widely opened at the same point of travel in every cylinder for the admission of charge.

The exhaust valve mechanism is operated by external means including a compound levera e such that a relatively large force is applled to initially open the valve against the cylinder pressure with increased leverage for further movement of the valveso as to secure quick and wide opening. The

closing movement of the valve is at first re id and then slow so that it seats easily.

n the accompanying drawings,

Figure 1 is a. section showing parts 016 three cylinders of a nine cylinder rotary motor,

Figure 2 is an end elevation,

Figure 3 is a detail of the inlet valve, on an enlarged scale, and

Figure 4 is a detail of the exhaust valve, on an enlarged scale.

Referring to Figures 1 and. 2, 1 repreis reenforced by a casting 10 which forms the head 11 and carries the wrist pin. The casting 10 is provided with slots 13 through WhlCll the charge passes to inlet valve 12 from the carbureter connected to the cas ing 1.

The inlet valve 12 has a separable seat 14 and a hollow stem 15 which carries a collar .16. Between the collar 16 and the head 11 is placed a seating sprin 17 which normally holds the valve 12 seats ,Within the valve stem 15 is telescoping push rod 18 having a limiting shoulder 19 which engages the collar 16, and between the hollow rod 18 and t2l(1)e valve head is interposed another spring Pivoted at 21 on one of the webs of the piston is a rocker 22 which engages the push rod 18, and is itself operated by an oscillating cam 23 carried on the end of the connecting rods 6, 8. At the extreme ends of the piston stroke, the cam will be in such position that the valve 12 will be seated by the spring 17. I

Assuming the piston at its outer position ready to commence the suction stroke, the cam 23 will be under the rocker 22 and about to commence lifting the rocker as the piston moves in. The cam 23 acts on the rocker between the pivot 21 and the end of push rod 18, and consequently the actuating end of the rocker has a multiplied movement on the push rod. This multiplied movement while the piston is going inward towards the center quickly compresses the relatively stiff spring 20 to such extent that it overcomes spring 17 and opens the valve quickly.

The valve stays openuntil the cam moves when the cam 23 is out of contact with the rocker, thus bringing the piston back to its outer position with the charge compressed ready for firing. During the explosion stroke. the pressure in the cylinder prevents the valve from opening even though the cam 23 is compressing spring 20. The exhaust occurs during the succeeding outward stroke of the piston while the cam is below the rocker. thus completing the cycle. Engines of this type are ordinarily lubricated by a spray within the cylinders, which will necessarily reach all the moving parts within the cylinders including the rocker, valve stem, etc. Also, the mechanism is such that the valve is seated gently although operating at very high speed. The valve seat 14 is threaded into the piston head 11 and is so arranged that the valve can be removed as a unit through the cylinder head.

This mechanism will positively and quickly actuate the inlet valve at the same point inthe stroke of each cylinder, and the valve can be of suflicient area to enable the full volumetric efiiciency of the engine to be obtained at high speeds.

The head exhaust valve mechanism shown in Figures 3 and 4 provides quick opening and easy seating of the valve, with ample area, and enables the full advantages of the inlet mechanism to be realized. 25 is the exhaust valve cooperating with a removable seat 26 of larger diameter than the inlet valve mechanism, before described, so as to permit removal of both valves as units through the cylinder head. 27 is a push rod operated by a cam within the casing and connected to a link 28 which is connected to a lever 29 pivoted at 30 on an arm 31 carried by a casting 32 seating on valve seat 26 and having slots for passage of the gases. The valve stem 33 carries a collar 34 to hold the seatin spring 35. Pivot/ed on an arm 36 is a roc er lever 37 having a circularly milled slot 38 in which is seated a block 39 having its shank 4O slidably engagin lever 29, as through pins 11. The lower sur ace of the block 39 is flat and rests on the rounded end of valve stem 33. Beyond the slot 38, the lever 37 extends to an actuating end 42 which is engaged by lever 29 to initiall open the exhaust valve against the cylin er pressure, at which time the lever 29 is relatively short and acts on lever 37 with greater force. After the valve has opened and the pressure has been relieved, the extreme end 44 of lever 29 engages with the intermediate portion of lever 37 thereby increasin the throw of lever 37 so as to give a wide opening of the valve. By providing the movable block 39 between the 1 ,azaoie valve stem and the lever 37, lateral ressure on the valve stem guide 45 is avoided, because the tendency of lever 29 rocking on center 30 to produce lateral pressure on one side is neutralized through the block by the lever 37 rocking on its center on the opposite side, so that the resultant force on valve stem 33 is always in an axial direction. This exhaust valve mechanism does not objectionably increase the total diameter of the engine, and it applies a powerful force to initially open the valve against the cylinder pressure and then a less force through a greater distance to secure wide and quick valve opening. At the same time, this system of compound leverage operates in the reverse direction to gently seat the valve.

The invention is applicable to various purposes and other types of engines than that herein illustrated, but is of particular advantage in the rotary cylinder type of engine by reason of permittin ample valve areas at high speeds, with positive actuation, and also insurin easy seating of the valves. The gases also have practically a straight path through the cylinder, which is essential in high speed engines. By this invention the speed, power and flexibility of a given size of engine will be largely increased, which is of extreme importance in aviation.

What is claimed, is:

1. A combustion engine having a cylinder, crank shaft and connecting rod, a valve in the piston, valve actuating means operated by the connecting rod, and means for multip ying the movement between the actuating means and the valve.

2. A combustion engine having a cylinder, crank shaft and connecting rod, a valve in the piston, valve actuating means carried by the connecting rod, a resilient actuating connection between the valve and the actuating means, and means for multiplying the movement between the actuating means and the valve.

3. A four cycle rotary cylinder combustion engine having a mechanically actuated valve in the piston head held seated against its actuated means by cylinder pressure during alternate like strokes, actuating means including a cam operated by the connecting rod, an opening spring, and a rocker engaged by the cam, a valve in the cylinder head, and external valve actuating means moving the valve at a varying rate during each movement.

Signed at New I ork city, in the county of New York, and State of New York, this 5th day of March A. D. 1918.

WILLIAM HARPER, JR.

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