US621111A - Governing device for gas-engines - Google Patents

Description

No. 62I,III. Patented Mar. '14, I899.

a. w. LEWIS.

GOVERNING DEVICE FOR GAS ENGINES.

(Application filed Jim 21, 1594. Renewal! se t. 14, 1895.)

(No Model.)

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I jaw/72252" 2 W QM wa ww f 5 No. 62l,l|l. 'Patented Mar. l4, I899- G. W. LEWIS. GOVERNING DEVICE FOR GAS ENGINES.

(Application filed June 21, 1894. Renewed Sept. 14, 1898.)

' 2 Sheets-Sheet 2.

(No Model.)

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UNITED STATES PATENT Onricn.

GEORGE IV. LEWIS, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE J. THOMPSON & SONS MANUFACTURING COMPANY, OF BELOIT, WISCONSIN.

GOVERNING DEVICE FOR GAS-ENGINES.

SPECIFICATION forming part of Letters Patent No. 621,111, dated March 14, 1899.

Application filed June 21, 1894.. Renewed September 14, 1898. Serial No. 690,985. (No model.)

T0 at whom it may concern:

Be it known that I, GEORGE W. Lnwrs, of Chicago, in the county of Cook-and State of Illinois, have invented certain new and useful Improvements in Governing Devices for Engines; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to speed-governing devices for engines,-adapted more especially for explosive gas or vapor engines, but some parts of which are adapted for use in connection with other engines.

The invention consists in the matters hereinafter described, and pointed out in the appended clailns. Certain features of the present invention constitute improvements on an engine of the general character set forth in a prior application, Serial No. 482,343, filed by me August 4:, 1893, embracing a construction by which an explosion is made at each alternate stroke of the piston.

The invention may be better understood by reference to the accompanying drawings, in which Figure 1 is a view in rear elevation of a gasengine containing the improvements constituting myinvention. Fig. 2 is a plan section of the parts more directly concerned in governing the engine, taken on line 2 2 of Fig. 1. Fig. 3 is a detail section taken on line 3 3 of Fig. 2. Figs. 4 and 5 are detail views of a wedge which forms part of the governing deprovided with two chests B B arranged on opposite sides of the closed end of said cylinder,the first-named chest,B,containing a sup ply-valve, of which the valve-stem B only is shown, and the last-named chest, B containment of the valve-stems B and B crank-shaft.

ing the exhaust-valve, which is attached to the stem 13. v

B is a supply-pipe for gas or vapor and air, leading to the chest B from a suitable mixing-chamber or other source of supply, and B is an exhaust-pipe leading from the chest B to any suitable point of discharge. The valves within the said valve-chests are constructed and operate in the same manner as those described in said prior application for patent, both of said valves being inwardlyopening valves operated by endwise move- The inlet-valve is opened automatically to admit the admixture of air and gas to the cylinder by the suction of the piston in its forward or outward movement in the cylinder, it being of course understood that in this type of engine the explosion takes place at every other forward stroke of the engine and that the charge of air and gas is drawn into the cylinder in the forward strokes of the piston preceding each explosion, as fully set forth in said prior application.

For the control of the exhaust-valve of the engine in the regular operation thereof devices are provided as follows: G is a shaft mounted in suitable bearings at the side of the machine and provided with a worm-wheel g, which is engaged by a worm g on the The said shaft G carries a cam H, which is adapted to act upon one end of a centrally-pivoted lever I, which bears upwardly at its opposite end againstthe shoulder 29 on the downwardly-directed valve-stem B of the exhaust-valve. A spring J, attached to the valve-stem and to the machine-frame, serves to draw the valve toward its seat. Said spring is provided with suitable devices by which its tension may be adjusted. The same is herein shown as consisting of an adjusting-bolt j, which passes through a log ct on the frame and is provided below said lug with a nut j, which may be turned on the bolt to draw it downwardly or permit it to rise for the purpose of varying the tension or strength of the spring J.

The speed-governing mechanism herein shown embraces a centrifugally-actin g speedgovernor, which is constructed as follows: K

is an arm or rod which is constructed to oscillate about a suitable center of rotation, said rod being herein shown as secured in a sleeve is, which engages a stationary pin or stud I, attached to a bracket L on the machine-frame. The said pin L is shown as arranged horizontally, and the arm K, thus mounted,swings in a vertical plane; but this feature of construction is not essential. Oscillatory move ment is given to the arm K by means of an eccentric M on the shaft G, which eccentric is connected with the crank-arm on the sleeve 7t by means of an eccentric-rod M. N is a weight arranged to move freely on the arm K and which is connected, by means of a rod 0, with a horizontally-arranged sliding wedge P, which is adapted for contact with a shoulder or projection b on the stem 13 of the inlet-valve. In the particular construction illustrated the wedge P is mounted to slide in the bracket L by means of lateral flanges 17 on the wedge, adapted to engage guide-grooves Z in the bracket, and said wedge is slotted longitudinally and so arranged that the stem B which passes through and is guided in the bracket L, passes also through the slot in the wedge. The shoulder b of the valvestem is shown as being formed by means of nuts engaging the screw-threaded end portion of the stem, this construction enabling the position of the shoulder to be adjusted as desired. The nuts, arranged as described, strike the lower or inclined surface of the wedge when the valve is lifted to admit the admixture of air and gas in the forward stroke of the piston, thereby limiting the upward movement of the valve according to the position occupied by the wedge. The arm K being arranged so as to oscillate in either direction from a horizontal position and the wedge being arranged to slide horizontally, the connecting-rod will obviously serve to transmit motion continuously from the weight to the wedge, so that the latter will be moved forwardly or backwardly as the weight moves outwardly or inwardly on the said arm. The outward movement of the weight on the arm is produced by centrifugal action arising from the oscillatory movement of the arm, and in order to draw the weight inwardly on the arm a spring K is applied in a manner suitable for the purpose, said spring being shown as of coiled form and connected with the arm and the weight. As a convenient construction said spring is herein shown as coiled around the arm for a part of its length and as being attached at its outer end to the weight N and at its inner end to a collar k which is adjustably secured to the arm in order to enable the tension of the spring to be adjusted as desired. Stops or shoulders at n on the rod K serve to lim it the inward and outward movement of the said weight N. While said weight may be made to slide on the arm or rod K and may have antifriction-rollers or other antifriction devices to insure its moving freely on the rod, yet, as a further improvement, I

' propose to make the aperture in the weight through which the arm passes larger than the arm in the direction of the plane of oscillation of the arm and preferably slightly larger also in a plane at right angles to the plane of oscillation. By making said aperture wider than the arm in the direction of the oscillation of the arm the weight moves on the arm with an intermittent or step-by-step movement, this arising from the fact that the weight is caused to move sidewise relatively to the arm at each stroke of the latter, the arm being brought against first one side then the other side of the aperture as the arm reaches the extreme limit of its throw in either direction. When the aperture in the weight is thus made larger than the arm, the advance or shifting movement of the weight on the arm takes place during the time when the weight is free from contact with the arm, or, in other words, during the period between the time the arm leaves contact with one side of the aperture and comes in contact with the opposite side thereof. The weight when thus made is of course free from frictional contact with the arm during the period of such motion relatively to the arm, and outward or inward movement of the weight on the arm takes place at such time, because there is then little or no frictional engagement between the weight and the arm. In practice the weight, when made as described, is found to move on the arm not uniformly or continuously, but with a step-by-step movement, as above described, the same being shifted steadily and gradually inward and outward, according to the speed at which the arm is oscillated, an increase in speed suliicient to make the centrifugal action of the weight overcome the spring resulting in the weight moving outwardly on the arm and a decrease in speed having the reverse effect.

In order to avoid noise or jar, which would otherwise be produced to a greater or less extent by the lateral movement of the weight on the arm, I propose to provide the opening or aperture n of the weightN with a lining a of leather or the like, as clearly seen in Fig. 7.

In operation of the governing devices thus constructed oscillatory movement will be given to the arm K through the medium of the shaft G and eccentric M continuously during the operation of the engine. 13y such oscillatory movement of the shaft the weight N will be moved inwardly oroutwardly thereon in the manner hereinbefore described and by its movement will shift the wedge P inwardly or outwardly. hen the wedge is shifted to bring its thicker part opposite the valve-stem B, the valve attached thereto will be lifted only slightly, and under the suction produced by the forward movement of the piston the admixture of air and gas in small quantity only will enter the cylinder from the supplypipe B When, on the contrary, the weight is moved inwardly upon a decrease in speed of the engine, the thin part of the wedge will come opposite the valve-stem and the valve will be afforded a greater degree of movement, thereby admitting a greater quantity of the admixture ofair and gas and giving greater power to the engine.

I propose, in connection with a speed-governor of the kind shown or any other form of speed-governor which variably controls or limits the extent of opening of the inlet-valve, to make the spring J, which holds the exhaustvalve closed, of such strength or to place it under such tension that said exhaust-valve will open automatically in the outstroke of the piston, so as to admit air to the cylinder at the same time that air and gas is admitted through the inlet-valve. Said spring for this purpose is made to act on the exhaust-valve with a pressure less than that coming on the said exhaust-valve by reason of the suction of the piston in its advance movement. By so constructing the spring J that it will allow the exhaust-valve to open automatically durin g the forward stroke of the piston I provide means for supplying air to the cylinder, in addition to the admixture of air and gas drawn into the cylinder through the inlet-valve, sufficient tofill the cylinder, it being obvious that in the operation of the device when thus made if the inlet-valve be opened to a small extent onlya large quantity of air will be drawn inwardly through the exhaust-valve, but if the inlet-valve be opened nearly or quite to its fullest extent little or no air will be drawn in through the exhaust-valve. By reason of the improved action resulting from the making of the spring of such strength as to permit the exhaust-valve to open during the time that the inlet-valve is partly closed this construction is of great importance and is claimed herein as part'of my invention. The adjusting device for changing the tension of the said spring is also of importance, because it enables the spring to be easily adjusted in strength to open as soon as the necessary external pressure is brought thereon.

In Fig. 6. I have shown a governing device embodying the same general principles of con struction present in the device illustrated in the figures before referred to, but diifering therefrom in its details. In this instance the arm or rod K, which carries the governingweight N, is mounted on a pivot q, attached to a bracket Q in such manner that said arm swings at either side of a vertical line when oscillated. The weight in this instance tends to move outwardly by gravity, as well as by centrifugal force, and a spring R, which is applied to retract the weight, is made ofsuch strength as to overcome the. gravity of the same when the arm is not in motion. Oscillatory movement is given to the arm K in this instance by means of a double cam S on the shaft G, against which a rigid arm K attached to the arm K, is held by means of a contractile spring T. A bell-crank lever U is pivoted to the bracket Q, and one of its arms depends from said bracket and is attached to the sliding wedge P. The other arm to of said lever is connected with the weight N by means of a connecting-rod U. The spring R is in this instance shown as a coiled spring of contractile form and as connected with the arm to of the bell-crank lever U and a stationary part of the machine-frame. An adjusting device for said spring is herein shown, the same consisting of a screw-bolt R, which passes through a bracket 1 on the engine-frame and on which is placed a nut r, which bears against the bracket and which may be turned on the bolt to increase or decrease the tension of the spring.

I claim as my invention 1. The combination with a valve, of a speedgovernor .comprising an oscillating arm, a weight applied to move freely on the arm, meansacting yieldingly on the weight and tending to draw it inwardly on the arm and connecting mechanism between the weight and the valve, whereby the action of the valve will be controlled by the movement of the weight on the arm, substantially as described.

2. The combination with avalve, of aspeedgovernor comprising an oscillating arm, a Weight applied to move freely on the arm, means acting yieldingly on the weight and tending to draw it inwardly on the arm and connecting mechanism between the weight and the valve, said weight having an opening for the passage of the armwhich opening is larger than the arm, substantially as described.

3. The combination with an oscillating arm, of a governor-weight applied to move on the arm, said weight having an aperture for the arm, which aperture is larger than the arm and is provided with a lining of leather or the like, substantially as described.

4. The combination with an inlet-valve for the explosive mixture, of a speed-governor comprising an oscillating arm, a governorweight mounted to move freely endwise of the arm, means acting yieldingly on the weight tending to move it inwardly on the arm and connecting mechanism between said weight and the valve, whereby the opening of the same will be variably limited, substantially as described.

5. The combination with an inlet-valve for the explosive mixture, of a speed-governor comprising an oscillating arm, a governorweight mounted to .move freely endwise of the arm, a spring applied to the weight and tending to draw the same inwardly on the arm, and connecting mechanism between said weight and the valve, whereby the opening of the same will be variably limited, substantially as described.

6. A speed-governor comprising an oscillating arm, a weight mounted to move freely endwise of the arm, and a sliding wedge connected with the weight and receiving motion from the latter, substantially as described.

7. The combination with an inlet-valve for the explosive mixture, of a speed-governor vIOO ment of the inlet-valve, a connecting mechanism between said weight and the wedge by which the latter is actuated, and a spring applied to draw the weight inwardly on the arm, substantially as described.

In testimony that I claim the foregoing as my invention I affix my signature in pres- 20 ence of two witnesses.

GEORGE \V. LEWIS.

WV itnesses:

0. CLARENCE PooLE, WM. L. HALL.

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