US1221114A - Internal-combustion engine. - Google Patents

Description

W. l. TWOMBLY.

INTERNAL COMBUSTION ENGINE. APPLICATION FILED NOV-29.1912.

1,291.1 1 Patented Apr. 3,1917.

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APPLICATION FILED NOV. 29, 1912.

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W. I. TWOMBLY.

INTERNAL COMBUSTION ENGINt.

APPLICATION man NOV. 29. 1912.

Patented. Apr. 3, 1917.

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iNTERNAL COMBUSTION ENGINE. APPLICATION FILEDANOV. 29, I9I2.

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WILLARD IRVING TWOMBLY, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGN- MENTS, T HENRY W. JESSUP, TRUSTEE, OF NEW YORK, N. Y.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented Apr. 3, 1917.

To all whom it may concern:

Be it known that I, WILLARD IRVING TWOMBLY, a citizen of the United States, residing in the borough of Manhattan, in the city, county, and State of New York, have invented new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

This invention relates to internal combustion engines, and it is the primary object of the invention to simplify 'the construction of engines of this type and at the same time increase the efficiency thereof.

One of the principal objects of the present invention is to provide the cylinder with a single port and. to control the charge of fuel to, and the exhaust of the burnt gases from, the cylinder through said port.

A further object of the invention is to provide improved valve mechanism to con trol the charge of fuel to, and the exhaust of the burnt gases from, the cylinder'through a single port. For this purpose I provide a valve chamber communicating with the source of fuel supply and with the cylinder port, said chamber also having a port through which to exhaust the burnt gases.

an improved cam to control the operation of the valve mechanism, said cam comprising a disk on the crank shaft having a raceway in one face thereof con isting of a pair of intersecting grooves. A shoe carried by a slidably mounted rod connected to the valve engages in said raceway to impart movevalve. In cams of this type as heretofore ment to the rod and thereby actuate the constructed it has been the usual practice to make the intersecting grooves of the same depth with the result that the shoe in crossing over the intersecting portion of one groove to the other groove is liable to engage with the wall of the intersecting portion of such other groove with the conse-.

quent result of making the engine inoperative. To overcome this difficulty I construct one of the grooves where it intersects with the other groove of less depth than the remaining portion of the raceway and also construct such portion of said groove in the form of a true are of a circle and to constitute an idle portion of the cam. The intersecting portion of the other groove which constitutes a working portion of the cam, being of greater depth the sides of said groove constitute a continuous wall at such intersecting 'portion. The cam-following shoe is so carried by the rod as' to have an axial as well as a rotative movement and is caused to engage at all times with the bottom of the raceway, with the result. that the said continuous wall of the intersecting portion of the latter groove will prevent any possibility of the intersecting portion of the one groove interfering with the travel of the shoe in the raceway.

Another object of this invention is to provide a port of large area, the opening and closing of which is controlled by a valve actuated by a cam that will give a quick opening and closing movement to said valve allowing the charge of fuel to enter, and the exhaust to escape, more freely than in engines as now constructed.

Another object of the invention is to -pro' vide a self-sealing valve that will automatically take up wear and be vself-balancing.

, Funther objects and advantages will hereinafter appear.

-As a preface to a description of the construction and operation of my improved engine, I wish to state that while I have illus-- trated and described the same in connection with an engine of the stationary type having a pair of opposed cylinders, it is to be understood that it will work as efliciently as a single cylinderengine, or a series of radially projecting cylinders may be employed and the actuation of the valve mechanism of all of the cylinders controlled by'a single cam; or that the crank shaft may be fixed and the cylinders and piston mechanism rotate about said shaft.

In the drawings accompanying and forming a part of this specification, Figure l is an end elevation of an engine having a pair. of opposed cylinders with my 1mprovements applied thereto.

Fig.

is a side elevation partly broken away to illustrate the piston and crank connect on. t

Fig. 3 is a perspective view of a removable Fig. at is a plan view and valve chamber.

Fig. 5 is a sectional .e cylinder head and valve the cylinders.

of a cylinder head nd elevation of the chamber taken substantially midway through Fig. 3.

Fig.6 is'an end elevation of the valve. Fig. 7 is a side elevation of the valve.

Fig. 8 1s a side elevation of the cylinder head and valve chamber.

Figs. 9 to 12, inclusive, are VIEWS. of the valve mechanism,

. mechanism and cam to il positions of the same of operation.

Fig. 13 is a Fig. it is a sectional ortion of the cam, the line AA of Fig. 1

lower mechanism, illustrating the diagrammatic the piston lustrate the relative during the four cycles face view of the cam.

side elevation of a taken substantially on 3, and the cam folcam follower engaging in the shallow-portion of the cam raceway at the point of intersection of said raceway.

, Fi 15 is a sectional plan view taken on the line B B of Fig. 14.

Fig. 16 is a view similar to Fig it, but

illustrating the cam follower engaging in the cam raceway of greatest depth at the point of intersection of the raceway.

Fig; 17 is a perspective view of the cam follower shoe; and

Fig.

taken substantially on .Fig. 13.

Similar characters of 18 is a sectional view of the cam the line (3-6 of reference designate like parts throughout the different views of the drawings.

In the drawings I have illustrated an embodiment of my inven crank case 19 in whichis journaled a single tlOll, comprising it throw crank shaft .20. a pair ofcylinders 21,

21 being fixed to said case in opposed relation. Pistons '22 to work in the cylinders are connected by rods 23 to The charge of fuel to,

the burnt gases from the trolled through a single the crank shaft 20. and the exhaust of cylinders are conport :24: in the cylinders, in the present instance located in a removable head '25 secured to the cylinders by tie rods 26 which also cylinders to the crank case. cylinders consist of cylindrical sleeves the serve to fix the As shown. the

ends of which engage in annular recesses and to make a gas-tightand heads 1 provide a suitable packing, as at 27, which may inders through the ports consist of a ring of asbestos covered with of fuel to, and the ases from, the cyl- Ql I provide valves 28 to engage int-he bores of valve chambers 29 constructed inte 'ral with the cylinder heads and spaced tierefrom, as shown at 20, to isolate the valve chambers from the cylinder heads and facilitate the cooling thereof. The valve chambers communicate with the portion 24 and are closed at one end by caps 30,- and at the other ends are connected through couplings 31 and pipes 32 to a fuel-distributing chamber 33 in one end of the crank case, said latter chamber having a removable cover 34' and connected therethrough, as at 35, with the source of fuel supply, such as a carbureter (not shown). Each valve chamber is also provided with a port 36 to exhaust the burnt gases from the cylinder-through the cylinder port 24 and the valve chamber.

The valves 28 consist of a tubular sleeve mounted to oscillate in the valve chamber, said sleeve closed at one end by a cap .37 and open at the other end to communicate with the source of fuel supply, a port 38 in the-side wall of the sleeve being adapted to communicate with the cylinder port 24 to control the charge of fuel to the cylinder. The sleeve is also provided with a recessed portion 39 in the peripheral wall thereof adapted to connect the cylinder port 24: with the port 36 in the valve chamber to control.

the exhaust of the burnt gases from the cylinder.

The valves are actuated by a cam on the of the crank case, having a removable cover 42, through which the shaft projects, to permit of easy access to the cam. Cain-follower shoes i3 engaging carried at one end of rods t4 slidably mount ed in guides lfffixed within the portion 41 of the crank case and in sleeves 45 having screw threaded engagement with the portion 41 of the crank case. Said rods are pivotally connected at the other ends to arms 47 fixed to shanks l8 integral with the valve caps 37 and journaled in a hub portion of the closure cap 30 for the valve chamber.

As already stated, the cam 40 comprises a disk having a two-way cam groove in one face thereof, that is a raceway comprising a pair of intersecting grooves a, b in which the cam followin shoes -13 engage. In cams of this type as heretofore constructed the raceway has been of the same depth throughout, with the result that the cam shoe as it engages in one of the grooves as a and crosses over the other cam groove 5, the shoe was liable to engage with the intersecting portion of said latter cam groove 6 at the point c with the result that the cam shoe would be broken and the engine made inoperative.

in the cam raceway are The same thing was liable to hap- 130 pen when the cam shoe was engaging in the groove 6 1n crossing over the groove a. To

overcome this disadvantage I construct the cam groove 6 from substantially the point d to the point e in the form of a true are of a circle to constitute an idle portion of the cam, and construct the said portion of this groove between the points d, e of less depth than the remaining portion of said groove and the groove a with the result that the groove a at the point of intersection with the groove, and which constitutes a'working portion of the cam, is provided with opposite continuous walls. Furthermore, the cam following shoe is so mounted as to have axial as well as rotative movement and is caused at all times to contact and follow the bottom of the raceway. For this purpose the shoe is provided with a shank 49 engaging in a hollow arm 50 projecting laterally from the rod all, a spring 51 seated at one end in a hollow in the shank 49 and the other end seated in a cap abutting against a pin 53 extending transversely through the hollow arm, the spring tending constantly to force the shank outward .and the shoe into the cam groove. The shoe is substantially flat at the bottom, as at 54, and curved at the top, as at 55, with the face at the ends slightly curved, as at 56, to facilitate the travel of said shoe in the cam raceway. Furthermore, it will be noted thatthe shoe carrying end of the rod 44: is rectangular in cross sections and engages between the guide 45 and face of the cam to have reciprocating movement therebetween with the result that there will be no tendency of any .rotative movement imparted to the rod id and a consequent liability of the shoe jumping out of the cam raceway.

In Figs. 9 to 12 I have shown in adiagrammatic manner the relative positions of the valve mechanism, the piston mechanism and cam duringfour cycles of operations. In Fig. 9 the piston 22 has completed its exhaust stroke and is commencing its suction stroke. In this position of the piston the cam-follower shoe 43 is engaging in a working portion of the outer cam groove 6, indicated by the radial line g, (Fig. 13,) and with the valve port 38 in communication with the cylinder port 24, connecting the cylinder with the source of fuel supply through the hollow valve and valve chamber; The valve will remain open for the greater portion of the suction stroke of the piston, or until the cam shoe reaches the position indicated by the radial line Z, when the valve will commence to oscillate and the intake port will begin to close and will be'entirely closed when the shoe reaches the point indicated by the line 71., and as the pisthe parts will be in the positions indicated in Fig. 4 with the cylinder port 24 fully closed. During the succeeding 180 degrees of revolution of the cam, or during the fuel compression stroke of the piston, the shoe will engage in an idle portion of the cam groove and the valve remain closed. During the 180 degrees of the succeeding revolution of the cam, or during the power stroke of the piston, theshoe will cross overinto the inner cam groove and engage in an idle portion thereof and the valve remain closed, as

shown in Fig. 11. Just previous to the piston reaching the end of its power stroke or when the shoe approaches the point indicated by the line 2' in said cam groove motion-will be imparted to the valve and the recessed portion therein will begin to approach the cylinder port 24:. The port 24:

, will continue to be uncovered until the shoe reaches the-point indicated by line j, when the piston will be at the commencement of its exhaust stroke and the port 24 will be entirely uncovered and communicating with indicated by the line m, motion will commence to be imparted to the valve and the port 24 will commence to be closed, and this motion of the valve will continue until the shoe reaches the point indicated by line 70 when the port will be entirely closed for the remainder of said 180 degrees of revolution. The parts are now again in the positions shown in Fig. 9. It will be noted that motion is still being imparted to the valve. During the commencement of the suction stroke of the piston, and as the cam shoe reaches the position indicated by line f the valve ,port 38 ,will commence to be placed in conimunication withthe cylinder port 24 andvsaid latter port will be entirely uncovcredfwhen the shoe reaches the point indi cated by the line g. One of the essential featurcs is the quick covering and uncovering of thecylinder port to permit the charge of fuel to enter, and the exhaust to escape more freelfv.. For instance, the exhaust will be shutofl" as the shoe travels from the line at to line la, the intake port of the valve will be placed in communication with the port 24; during the travel of the shoe from the line f to line g, the fuel intake will be entirely shut off as the shoe travels from the line Z to the line It, and the exhaust will be opened during the travel of the shoe from the line 2' to the line To counterbalance the pressures on the valve through the cylinder port 24 during the fuel compression and power strokes of the piston and thereby preventing'leakaga'l I provide the cylinderwith' a second port 57,

in the present instance also located in the cylinder head, said port being somewhat larger than the port 24 with the result that the said pressures in the cylinderwill exert a greater force on the side of the valve oppo- I air cooled type, and for this purpose the cylinder head has integral cooling ribs or.

fins The cylinders are provided with movable fins 59, consisting of a plurality of superposed annular sheet metal members, preferably of copper, said members having an annular flange portion to engage with the cylinder and which serves to space the fins apart. The lowermost fin rests upon an annular flange or shoulder on the outer surface of the cylinder, and the fins are clamped in superposed position as the head is secured to the cylinder and the latter to the crank case, the tie rods 26 passing through openings in the fins preventing rotative displacement thereof on the cylinder. The fins are preferably crimped or corrugated, as clearly shown in Fig. 3, to provide a greater cooling surface.

The compressed charge in the cylinder is fired in the usual manner by a spark plug 58 having screw threaded connection with the cylinder head with the sparking points pro jecting into the port 24, whereby a fresh charge of fuel mixture at the sparking points and the igniting of the charge will be assured.

Variations may be resorted to within the scope of my invention, and portions of the improvements may be used without others.

Having thus described my invention, 1 claim: I s l 1. In a four-cycle gas engine, the combination with a crank-shaft, of a cylinder,a single valve chamber, a transverse rotary valve to control the fuel intake and the exhaust, walls at the head of said cylinder defining two ports extending from the cylinder proper respectively to substantially I said valve.

diametrically opposite sides of said valves, for the purpose described and a cam operated by said crank-shaft rotatable at the same .speed thereof and means to connect the valve" to be actuated by said cam.

2. In an internal combustion engiriefthe combination with the cylinder, a. head on said cylinder, a transverse cylindrical valve in said head, an inlet at one end of said cylindrical valve, two ports laterally in said valve, one of-said ports adapted to admit fuel from the interior of the valve into said cylinder and'the other of said orts constitutmg' a bypa$ on one side 0' said valve,

a valve seat in said head, an opening in one side of said seat to permit incoming and outgoing gases from and-past 'said valve,

walls in said cylinder head on the opposite side of said valve seat defining a port,

whereby the pressure of gases within said cylinder is effective on substantially diametrically opposite sides of said valve, for the purpose described, and means for actuating 3. In an internal combustion engine, a

cylinder, a separable cylinder head, a cylindrical transverse aperture in said head adapted for the reception of a valve, a tubular valve in said seat open at one end and a fuel supply duct communicating with said open end, a lateral opening in said valve and a lateral opening in said valve seat 7 adapted to register therewith upon the oscillation of the valve, a. lateral depressed wall on said tubular valve out of. contact with the valve seat on part of its circumference and adapted to register with the transverse opening in the valve seat to permit the passage of exhaust gases, and an exhaust openmg from said head to permit.

ultimate exit of said gases, a cooling jacket surrounding a section of the'valve seat fac ing the cylinder proper, and a lateral aperture in the valve seat substantially diametrically opposite to the lateral aperture for gases, and means for osclllatingsaid' valve. WILLARD IRVING TWOMBLY.

Witnesses I LAURA I E. SMITH, JonN 0. Snrrnnr.

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