US545709A - Gas engine - Google Patents

Description

2 Sheets-Sheet 1. F. S. MEAD. GAS ENGINE.

' (No Mode-1;)

Patented Sept. 3 1895- I WITNESSES: g/mafi A TTOHNEYS.

(No Model.) 2 Sheets-Sheet 2.

F. S. MEAD.

- GAS ENGINE. No. 545,709. I Patented Sept. 3,1895.

I 7/ JJ 1 INVENTOR- WITNESSES: I Q P g B) La g dfTTORNEYS. t

UNITED STATES PATENT OFFICE.

FRANK S. MEAD, OF MONTREAL, CANADA.

GAS-ENGINE.

$I-ECIFICATION forming part of Letters Patent No. 545,709, dated September 3, 1895.

Application filed August 2, 1894. Serial No. 519,288. (No model.)

To aZZ whom it may concern:

Be it known that I, FRANK S. MEAD, a citizen of the United States, at present residing in Montreal, Province of Quebec, and Dominion of Canada, have invented a new and Improved Gas-Engine, of which the following is a full, clear, and exact description.

The object of the invention is to provide a new and'improved gas-engine in which the speed is governed in a very economical and regular manner to insure a steady running of the engine, and without requiring omission of explosions in the working end of the cylinder, as is the case in the engines heretofor constructed. 7

The invention relates to that class of explosive-engines that is provided with a governor by which the time the exhaust is held open is varied to regulate the amount of air that is to be mixed with the gas or other combustible agent, and similarly the amount of gas admitted to the cylinder is varied, so as to insure the correct proportion of gas and air to always obtain an explosive mixture of substantially the same composition.

The invention also consists of certain parts and details, and combinations of the same, as will be fully described hereinafter, and then pointed out in the claims.

Reference is to be had to the accompanying drawings forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the figures.

Figure l is asectional side elevation of the improvement. Fig. 2 is an enlarged sectional side elevation of the mechanism for operating the exhaust-valve. Fig. 3 is a sectional face view of the centrifugal governor on the line 3 3 of Fig. 4:. Fig. 4. is a sectional side elevation of the same. Fig. 5 ma sectional face view of the eccentrics. Fig. 6 is a similar view of the same in a different position. Fig. 7 is a like view of a modified form of the same, and Fig. 8 is a sectional side elevation of a pump for pumping required fuel.

In gas-engines as heretofore constructed considerable difficulty is found in properly governing the speed of the engine in an economical and regular manner. Of the many designs for the purpose, that of omitting one or more explosions when the engine runs too fast is considered the most economical,but

the action of the engine is irregular and un steady.

In the improved gas-engine presently to be described in detail the regulating of the running of the engine is performed by changing the quantity of the explosive-charge, so as to increase the amount of expansion of the heated gases, both of which features tend greatly to increase the economy of the engine, and, as it gives an impulse regularly of more or less force, according to the needs of the workperforrned, the speed is very even and steady. l/Vhile this method of governing gasengines is shown in connection with an engine receiving an impulse at every revolution, it is equally applicable to any engine driven with explosive gas or vapor, and hence I do not limit myself to any particular form of engine.

The engine is provided with the usual cylinder A, in which reciprocates a piston B, connected by a pitman O with the crank-arm D of the main driving-shaft D. In the explosion or Working end of the cylinder A is arranged a port a, from which leads the supplyport I) and the exhaust-port c, the forme Joeing connected by a port I) with the cylinder E of the pump for admitting gas or other explosives into the upper or working end of the cylinder A. The exhaust-port 0 extends along the cylinder A to connect with the annular channel 0, and thence to the exhaust-pipe A A series of ports 0 lead from the interior of the cylinder A and connect with the exhaustpipe by way of the channel 0'. The ports 0 are adapted to be opened or closed by the piston B as the latter reciprocates in the cylinder A, and the ports b, previously described, are controlled by the piston-valve F reciproeating in the cylinder E and driven from the main driving-shaft D, as hereinafter more fully explained.

pressed on by a spring H held in a casing H secured to the cover for the cylinder A.

The valve-stem I of the valve I for the exhaust-channel c is pressed on by a spring I held in a casing 1 likewise secured to the cover for the cylinder A, as plainly shown in Figs. 1 and 2. The upper outer end of the valvestem 1 is pivotally connected with a lever J, (see Fig. 2,) fulcrumed at J to a bracket extending from the housing H and on the said lever J is fulcrumed a second lever J 2 at J the said second lever having an extension or foot-piece J adapted to raise normally a square shoulder J formed on the pivot end of the lever J. The spring J connects the foot-piece J with the lever J, so as to normally hold the levers J and J in alignment, as plainly illustrated in Fig. 2. The outer end of the lever J 2 is adapted to be engaged by a pin K, held on a gear-wheel K, journaled in a bracket extending from the housing H and the said gear-wheel is in mesh with a rack K secured on the piston or plunger F of the pump and extending through a suitable stufling-box in the upper end of the cylinder E. (See Fig. 1.)

Thelower end of the piston Bis formed with an exterior annular flange B, operating in the enlarged end A of the cylinder A, so as to compress air into the said enlarged end A for charging the upper or working end of the cylinder A with the necessary air. This enlarged cylinder A is provided with aspringpressed air-inlet valve A and with a springpressed air-outlet valve A leading into a chamber A adapted to connect by a springpressed valve A with a channel 01 opening into the upper end of the cylinder A.

The piston B is provided with a supplementary packing-ring B in engagement with an annular flange A forming part of the cylinder A and extendinginto the enlarged end A, as is plainly shown in Fig. 1, so that when the piston is in its lowermost position, as shown in the said figure, the said flange still engages the packing-ring B The plunger or piston F is pivotally connected with an eccentricrod F, held on an eccentric disk L, mounted on an eccentric disk L, secured on the main driving-shaft D. The eccentric disk L is pivotally connected by links N N with levers N and N respectively, fulcrumed at N on the rib of the fiy-wheel O, secured on the main driving-shaft D. Weights N are held on the free ends of the said levers N N and the weighted ends of the latter are connected by springs N so as to retard the outward swinging motion of the said levers caused by the centrifugal force when the engine is running above the normal rate of speed.

The operation of the engine is as follows: The normal position of the eccentric L is about ninety degrees in advance of the crank D, so that when the piston B is in its lowest position the pump piston or plunger F is one-half way up on its upstroke, as shown in Fig. 1. When the piston B rises, it cuts off or closes the cylinder exhaust-ports c and the rack K carried by the plunger F, turns the gear-wheel K, so as to cause the pin K to bear upon and press down the joint of the lever J to cause an up ward swinging of the lever J and a consequent raising of thevalve-stem I of the valve I, whereby the said port c is uncovered and opens into the port a. By this arrangement communication is established between the upper or working end of the cylinderA and the exhaust-pipe by way of the channels a and c. The exhaust-valve I is held open until the piston B is raised nearly one-half of its stroke, at which point the pin K in its circular motion has nearly reached the dotted position indicated in Fig. 2, so as to release the lever J to permit the valve I to suddenly close by the action of its spring I At this time the piston-valve F working in the-chamber E, is raised su'lficiently to begin uncovering the port I), to allow the gas or vapor which was previously compressed in the upper end of the cylinder E to enter the working end of the cylinder A by way of the ports I), I), and a, it being understood that the force of the gas is sufficient to raise the spring-pressed or check valve H. The gas on its way to the cylinder A strikes a perforated deflector A", (see Fig. 1,) and is then spread throughout the cylinder as the piston advances in an upward direction to now compress the mixed gas or vapor and the air in the cylinder, and

when thus compressed the mixture is ignited by any well-known means. Then the expanding gas drives the piston'B downward, to give an impulse to the driving-shaft, until the upper end of the piston B uncovers the exhaust-port c to permit the burned gases to flow from the cylinder through the said ports c to the exhaust-pipe. During the time the piston B rises from its lowermost position to an uppermost position the annular flange B operates in the cylinder A and compresses, to some extent, the air within the compressed-air channel, the air passing through the valve A into the chamber A from which it passes through the springpressed valve A into the channel d leading to the upper end of the cylinder A. When the piston B is on the drownward stroke. then the air is drawn in through the valve A into the cylinder A, and this air is' again compressed on the upward stroke of the piston B, as above described. When the piston B has passed down sufliciently to uncover the cylinder exhaust-ports 0 then the burned gases flow into the exhaust-pipe, as previously mentioned, thus relieving the pressurein the cylinder A and allowing the compressed air in the chamber A to lift the check-valve A and to then flow into the upper end of the cylinder A and out through the exhaust-ports 0 thus cleaning the cylinder A of burned particles or residuum, and at the same time filling the cylinder with fresh pure air. In the meantime the piston F, on its down stroke, has drawn in a new charge of gas into the upper end of the cylinder E, and has already begun to compress it in rising to the position shown in Fig. 1. The momentum of the fly-wheel O carries the piston B on its upward stroke and the same sequence of operations takes place, thus giving an impulse or explosion at every revolution of the main drivingshaft A. As the pump piston or plunger F is on the down stroke it carries along the rack K so as to reverse the motion of the gear-Wheel K and that of the pin K, so that the latter passes to the left, and in rising lifts the end of the lever J 2 and passes out from under it to the dotted position shown in Fig. 2. The end of the lever is again brought into position by the spring J so that the downward stroke of the pumppiston F does not afiect the position of the valve 1, which consequently remains closed.

It will be seen from the operation of the engine above described that the longer the closing of the valve I is retarded during the upward stroke of the piston B theless' air will remain in the cylinder B, and therefore less gas will be required for a proper explosive proportion. The amount of compression will also be somewhat less, and these several matters all tend to reduce the amount of force exerted by the explosion and form the basis of my arrangement for regulating the 1 speed of the engine.

It will be seen that by the governor described and connected with the eccentric-rod F for the piston F the centrifugal force, acting on the weighted levers N and N will cause the latter to swing outward toward the rim of the fly-wheel O, to draw the eccentric L around back toward the crank by means of the links N and N. As illustrated in Fig. 6, the eccentric L is seen at about ninety degrees in advance of the crank D, and when acted on by the weighted levers, as above described, is rotated back to the position shown in Fig. 5 until the radius of the eccentric corresponds with that of the crank D. By this arrangement the faster the engine is running the more the weighted levers N and N pull back or retard the eccentric, and thereby retard the releasing and closing of the exhaustvalve I. The eccentric L, as previously described, does not turn directly on the shaft D, but on another small eccentric L, secured to the shaft D in such a manner that as the eccentric L is retarded, as above described, its radius or throw is greatly reduced, and consequently the stroke of the vapor-pump and the punger F is shortened and the opening of the port I) by the valve F is greatly reduced from full opening to no opening at all at the time the eccentrics are in the position shown in Fig. 5. By this means the amount of air in the cylinder and the amount of gas admitted are greatly reduced from a full charge to nothing, and the gas or vapor and air in the cylinder are always in the explosive proportions, and the force of the explosion is increased or diminished automatically by the action of the governor, which makes the speed of the engine very regular and smooth, at the same time avoiding racks and jumps, so common in the ordinary engines.

It is expressly understood that the principle of my governing apparatus consists in holding open the exhaust, while the piston is returning toward the explosion end of the cylinder, until the proper time comes to open the gas-inlet valve, at which time the exhaustport is closed and an amount of gas forced into the cylinder which is in proportion to the amount of air remaining there. In this manner the explosive-charge, though reduced or increased in quantity, is supplied always in proper proportion for ignition, and as gas or vapor is always introduced before compression takes place in the cylinder, it is always properly mixed, and hence there is no waste. By the construction of the eccentrics which control the action of the gas-inlet and exhaustvalves not only is the exhaust held open longer when the engine is inclined to gobeyond regular speed, thus reducing the amount of air in the cylinder, but the stroke of the gas-inlet valve is also shortened, thus simultaneously reducing the quantity of the gas introduced,

and both actions are automatically controlled 5 by the weighted arms N and N of the centrifugal governor.

In order to be able to pump solid oil or naphtha I provideapump, (shown in detail in Fig. 8,) so that oil or naphtha may be directly pumped into the cylinder instead of first evaporating the fuel and then pumping vapor into the cylinder. This pump is provided with a cylinder E, in which operates a rod F held on the stem F connected with the eccentric-rod F, and on this stem F is held loosely the piston F pressed on its under side by a spring F coiled on the stem and supported on a pin thereon. The upper end of the cylinder E is provided with a suction-pipe G having a check-valve G and in the plunger end of the cylinder is arranged the port 12 adapted to connect with the port b. When the pumpstem F moves downward, then the plungerrod F engages the.piston F whereby the lat- 'ter moves downward and the air is drawn within the suction-pipe G it being understood that the area of the piston 15 is considerably larger than that of the rod F On the upward stroke of the stem F the spring F is compressed in proportion as it moves slower than the pump-rod. When, however, the pump-rod has nearly reached the end of its upstroke, then the port I) is uncovered by the rod F and the force of the compressed spring F immediately pushes the piston F up to and against the rod F thus quickly forcing out all the oil or naphtha contained in the upper end of the cylinder E. It will beseen, however, that when attached to the engine having the governor, as previously described, the discharge of the pump will be delayed and the cording to the requirements of the work performed by the engine. By enlarging this pump it may be readily used for pumping gas or vapors if desired.

It will be seen that by the use of the supplementary packing-ring, as previously explained, communication between the cylinder exhaust-ports c and the enlarged cylinder A and leaking of air thereby isprevented and at the same time an increase of the length of the engine is avoided by providing the inter nal flange A to hold the packing-ring B in place at the time the piston moves into the lowermost postion.

In Fig. 7 is shown an arrangement whereby both eccentrics, if desired, may be made movable, so as to change the radius of the main eccentric L more readily, and for this purpose I provide a segmental rack P in mesh with a pinion P, attached to the balancewheel or any other part fastened to the shaft, the said rack P being likewise in mesh with gear-teeth L on the periphery of the eccenric L. By this arrangement any rotative movement of the eccentric L causes the pinion P' to revolve, and by means of the segment P to rotate the eccentric L in the opposite direction.

Having thus fully described my invention, I claim as new and desire to secure by Letters Patent-- 1. In an explosive engine, the combination with the working cylinder of the pump for feeding the fuel to the cylinder, means for driving the pump, an exhaust valve for the escape of the products of explosion, and connections operated by the pump and extending therefrom to the exhaust valve to actuate the latter, substantially as described.

2. The combination, in an explosive engine, with the working cylinder, the piston and the drive shaft operated thereby, of a governor operatively connected with the said shaft, a pump for feeding the combustible agent to the cylinder, operative means, controlled. by the said governor, for driving the said pump, and exhaust valve for the escape products of explosion, and connections operated by the pump and extending therefrom to the exhaust valve to actuate the latter, substantially as described.

3. The combination,in an explosive engine, with the working cylinder, the piston and the drive shaft operated thereby, of a governor operatively connected with the said shaft, a pump for feeding the combustible agent to the cylinder, operative means, controlled by the said governor, for driving the said pump, an extension on the plunger of the pump, an exhaust valve for the escape of the products of explosion, and means operated by the said extension to hold the exhaust valve temporarily open, as and for the purpose set forth.

4. In a gas or oil engine, a shifting eccentric operatively connected with a gas, vapor or oil pump, and a governor consisting of one or more weighted arms actuated by centrifugal force derived from the speed of the engine and arranged to both retard and diminish the throw of the said eccentric, substantially as shown and described.

5. In a gas or oil engine, the combination of a working cylinder and piston, and a pump for gas, oil or vapor, said pump being driven from an eccentric arranged to be rotated upon another eccentric as a center, substantially as shown and described.

6. In a gas or oil engine, the combination of a gas or vapor pump cylinder, a plunger or piston working therein, and an annular piston valve attached to and worked by said pump piston and controlling the exit port of said pump, substantially as shown and described.

7. In a gas or oil engine, an exhaust valve normally closed, and a gas, vapor or oil pump whose piston or piston rod or an attachment thereto is arranged to open and suddenly release the said exhaust valve, substantially as shown and described.

8. In a gas or oil engine, the mechanism for working the exhaust valve from an extension of the gas, vapor or oil pump piston or piston rod, consisting of a rack a rotating pin, a jointed lever, and a spring or equivalent for seating the valve when released, substantially as shown and described.

9. In a gas or oil engine, a pump for injecting oil or naphtha having its piston arranged to slide on the piston rod, substantially as shown and described.

10. In a gas or oil engine, a pump for injecting oil or naphtha, having its piston arranged to slide on the piston rod and the said piston rod arranged to operate the discharge port of the pump, substantially as shown and described.

11. In a gas or oil engine having concentric cylinders of different diameters, the extension or lip whereby the small cylinder is extended into the larger one, substantially as shown and described.

12. In a gas or oil engine having a working cylinder, an annular compression cylinder, and exhaust ports in the wall of the working cylinder, the combination of the extension or lip and the packing ring, as and for the purpose herein set forth.

13. In a gas or oil engine, the combination of a gas or oil inlet valve whose time of action is variable relative to the main crank of the engine, an exhaust valve, and a connecting mechanism operated by one of the valves and extending therefrom to the other valve to actuate the latter, said mechanism being so timed that the exhaust valve is closed before the inlet valve is opened, substantially as shown and described.

14.. In a gas or oil engine, the combination of a gas, vapor or oil pump, an eccentric rod controlling the action of said pump, an eccentric revoluble on another eccentric as a center and a governor for turning the revoluble eccentric, substantially as shown and described.

15. In a gas or oil engine, the combination IIO of an eccentric of variable circumferential position on the shaft which drives it, a pump, and a gas, vapor or oil inlet valve operating within the compression chamber of the pump, and controlled by said eccentric,.substantially as shown and described.

16. In a gas or oil engine, the combination of an eccentric of variable circumferential position on the shaft which drives it, an ex haust valve and an inlet valve both operated by said eccentric, and a passage, connecting the port of said inlet valve and the explosion chamber of the engine, substantially as shown and described.

17. In a gas or oil engine, an automaticgovernor consisting of one or more weighted arms actuated by centrifugal force derived from the speed of the engine, an eccentric mounted to turn upon another eccentric as a center and operatively connected to said governor, and a gas, vapor or oil pump whose plunger is provided with a cross passage for controlling the exhaust of the engine and is operated by said variable eccentric, substantially as shown and described.

18. In a gas or oil engine, an automatic governor having one or more weighted arms actuated by centrifugal force derived from the speed of the engine, and a gas, oil or vapor pump whose plunger is provided with a cross passage for controlling the exhaust, so arranged that the stroke of the pump plunger is advanced or retarded relative to the main crank, by the action of said governor, substantially as shown and described.

- 19. In a gas or oil engine, the combination of a movable eccentric whose circumferential position on its driving shaft is automatically controlled, a gas, oil or vapor pump and an exhaust valve both governed in their action by said eccentric, substantially as shown and described.

FRANK S. MEAD. Witnesses:

LEWIS P. MEAD, FRANK E. MEAD.

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