US727558A - Steam-engine. - Google Patents

Description

.No.v727,558. PATENTED MAY 5, 1903- A. 0. SGHUMAN.

STEAM ENGINE.

APPLIOATION FILED DEC. 18, 1901.

I0 MODEL. 3 SHEETS-SHEET 1.

No.72 7,558'. PATENTED MAY-5,1903.

- A. 0. SGHUMAN.

STEAM ENGINE.

with STATES Patented May 5, 1903.

PATENT OFFICE.

ALEXANDER C. SCHUMAN, OF LOUISVILLE, KENTUCKY, ASSIGNOR TO SPALDING COLEMAN, OF LOUISVILLE, KENTUCKY.

\. STEAIVFENGINE.

SPECIFICATION forming part of Letters Patent No. 727,558, dated May 5, 1903.

Application filed December 18, 1901. Serial No. 86,439. (No model.)

To all whom, it may concern:

Be it known that I, ALEXANDER O. SCHU- MAN, a citizen of the United States, residing at Louisville, in the county of Jefferson and State of Kentucky, have invented a new and useful Steam-Engine, of which the following is a specification.

My invention relates to certain improvements in steam and similar engines operated by a fluid under pressure, and has for its principal object to provide an engine of sim-' ple and economical construction in which the expansive force of the steam will be fully utilized. l I

A further object of the invention is to provide an engine in which a plurality of cylinders will act successively to impart motion to a primary member common to all of the cylinders; and a still further object is to provide an improved form of valve operating mechanism in which the valve of each cylinder will be moved to operative or-inoperative position by the movement of the piston in the cylinder immediately preceding.

With these and other objects in view the invention consists in the novel construction and combination of parts hereinafter dea scribed,illustrated in the accompanying drawings, and particularly pointed out in the appended claims.

In the drawings, Figure l is an elevation, partially in section, illustrating an engine constructed and arranged in accordance with my invention, the cylinders herein shownbeing of the direct-acting high-pressure type. Fig. 2 is a sectional plan view of the same. Fig. 3 illustrates the preferred form of the engine, in which the cylinders are so connected as to utilize the expansive force of the steam. Fig. at is a detail of a portion of the same. Fig. 5 is a sectional elevation of an engine of somewhat-modified construction. Fig. (3 is a plan view of the engine illustrated in Fig. 5. Fig. 7 is an elevation illustrating a modification of the valve-operating mechanism shown in Fig. 4.

Similar nu merals of reference are employed to designate corresponding parts throughout the various figures of the drawings.

Referring first to the simpler form of the device, as illustrated in Figs. 1 and 2, 10 desjecting pin 21, said pins being each situated at an equal distance in a radial line from the center of rotation of its carrying-pinion and the pins beingso situated with respect to each other that if all were situated on the same pinion they would extend to an arc of one hundred and eighty degrees and located or spaced at intervals of forty-five degrees, or, in other words, if the pin of one pinion be situated in a vertical plane with the axis of rotation thereof the pin of the next succeeding pinion would be located at an angle of forty-fi ve degrees to the center of rotation of said succeeding pin, and the pin of the third pinion would brain the horizontal plane of rotation of said third pinion. On the side of the frame are mounted a number of cylinders equal to the number of pinions (four in the present instance) and each having a suitable source of steam-supply, the supply-pipe 22 being preferably connected to the various cylinders in the manner indicated in Fig. 1. To the piston of each cylinder is secured a rod 23,

connected at its outer end to a U-shaped frame 24, the parallel bars of such frame being dovetailed for the reception of bars or cross-head guides25, which serve to maintain the frames in proper position. The shorter member or bar of each frame terminates in-an abrupt shoulder 26, adapted to engage with the pin 21, and the longer bar is provided with an inwardly-projectinglug 27, to which is pivoted a finger 29, the inner or lower end of which is also adapted'for engagement with said pin 21, the shoulder 26 being adapted to engage \vithand move said pin in an outward direction, or away from the shaft 11, and the fingers 28 having an operative movement in the reverse direction. In

the steam-chest of each cylinderis a D-valve connected in suitable manner to a valve-rod 30. The inner end of the valve-rod of the piston mounted in operable relation to the shaft 12, and the prime mover of the series, is connected to one arm 31 of a bell-crank lever 32, and the inner ends of each of the remaining valve-rods is connected to a separate bell-crank lever 33, the three bell-crank levers 33 being similar iii-construction and mounted each in the same manner for operating its connected valve-rod. On each of the U-shaped frames is secured a pin 34,

' adapted to the longitudinal slot 35 of a rod lar movement of the latter through a distance equal to one-eighth of a revolution, or an angle of forty-five degrees, and as the diameter of said pinion is equal tothe one-fourth of the diameter of the gear-wheel 16 the latter is turned to the extent of one thirty-second of a revolution. During this movement the slot 35 of the connecting-rod 36 has been traversed by the pin 34, and as the piston nears the limit of its outward movement said pin comes into contact with the end of the slot and operates through the said rod 36 and bellcrank lever 33 upon the valve of the next succeeding cylinder- As each of the pins of the respective small pinions is disposed in the manner hereinbefore described, the partial revolution of the gear-wheel 16 has causeda movement of each of the gear- wheels 18, 19, and 20 for a distance corresponding to the movement of the initial pinion 17, or, in other Words, has advanced the impact-pin of each pinion to the extent of forty-five degrees. This movement has brought the impact-pin of the pinion 18 into position to be engaged by the shoulder 26 of the second engine on the outward movement of the piston and causes a movement of the large gear-Wheel to the extent of one thirty-second of a revolution and a second movement of each of the pinions for an eighth of a revolution, again advancing each of the impact-pins for an angular distance of forty-five degrees, the impactpin of the third pinion 19 being then in position to be operatively engaged on the outward movement of the piston of the third engine.

The operation of the valve of the third engineis accomplished'through the connecting-rod and bell-crank mechanism connecting the U- shaped frame of the second engine to the valve-rod of the third engine. This inter- :mittent movement is continued through all four of the cylinders until each engine has acted and each pinion has received four successive movements, each to the extent of forty-five degress, each pinion then having received a half-revolution and the impact-pin of the primary pinion 17 being then in position to .be engaged by the finger 28 of the first engine. To reverse the movements of each engine, the bell-crank lever 32 of the primary engine is arranged in a direction op-: posite to that of the remaining levers 33, so that on the outward movement of the fourth piston the valve of the first engine will be moved to such position as to permitsteam to enter between the outer end of the cylinder and the piston, causing an inward movement of the U-shaped frame, the finger 28 engaging the impact-pin of the pinion 17 and moving the same to the extent of oue-eighth.of a revolution. The movement of each of the second, third, and fourth engines then follows in proper order, imparting an eighthrevolution to each of the pinions, and when all have acted the pin 21 of the pinion 17 will be in the initial position to be again engaged by the shoulder 26 of the U-shaped frame of the first engine.

The preferred form of engine is that illustrated in Figs. 3 and 4, Fig. 3 being partly in diagram in order to more clearly illustrate the connections betweenthe cylinders. In Figs. 3 and 4, 40, 41, 42, and 43 represent, respectively, the cylinders of the first, second, third, and fourth engines, and in each cylinder is a wide piston 44, connected by a suitable piston-rod 44 to the U -shaped frames previously described with reference to Figs. 1 and 2. The pistons operate to open and close ports 45 and 46, leading, respectively, from opposite sides of the longitudinal center of the first cylinder to the opposite ends of the second cylinder and in similar manner from the central portions of the cylinders 41 and 42 to the end por tions of the cylinders 42 and 43, respectively. The primary cylinder is provided at its opposite ends with steam-inlet ports 47 48, and the admission of steam through such ports is governed by suitable valves 49 50, each of which is provided with two arms pivotally connected thereto. The arms 51 52 of the valve 49 are arranged on opposite sides of a fixed pin 53 and are normally held in position by small springs 54. The arms 55 56 of the valve 50 are pivoted on opposite sides of a pin 57 and are held therea-gainst by small springs 58. The piston-rod 44 of the final cylinder 43 carries a frame 59, having two arms 60 61, adapted to operate on the arms 51 and 55, respectively, and on the piston-rod of the primary cylinder are two pins 62 63, adapted to operate on levers 64 65, pivoted to the fixed frame and connected to rods 66 67, arranged in operative relation to the arms 52 and 56. With the various pistons in the position illustrated in Fig. 3 the valve 49 will admit steam to the cylinder, causing a movement of the piston of the primary cylinder in the direction of the arrow, said piston being moved outwardly and completing its stroke when it has reached the position indicated in dotted lines. The pin 62 of the piston-rod will then engage the lever 64 and through the rod 66 and arm 52 effect the closing of the valve 47, cutting off the supply of steam to the cylinder. The outward movement of the piston has opened the port 45, and steam will flow therethrough to the outer or lower end of the cylinder 41, causing an inward movement of said piston from the point indicated indotted lines in the cylinder atl and opening the port 46, permitting the steam to flow therethrough and enter the inner end of the cylinder 42. The steam in expanding will cause an outward movement of the piston in the cylinder 42 and open the port 45, thereby placing said cylinder in communication with the upper or outer end of the final cylinder The action of the steam will cause an inward movement of the piston in the cylinder 43, the latter traveling downward and opening an exhaust-port 68 in said final cylinder, through which the steam in all of the cylinders may be exhausted. If the boiler-pressure in the first cylinder be one hundred pounds and all of the cylinders of equal size, the steam in expanding to the second cylinder will exert therein a pressure of fifty pounds and in the third cylinder a pressure of about thirty-three pounds and in the final cylinder a pressure of about twentyfive pounds, the entire expansive force of the steam being utilized before being finally exhausted. Owing to the movements of the pistons in closing the centrally-disposed ports 45 and a6, a portion of the steam will remain in the ends of the cylinder and in order to exhaust the steam without reducing the effective pressure of the steam I place at the end of each cylinder a small outlet-valve 70, having a spindle 71, the outer end of said spindle being provided with a toothed wheel 72. On each piston-rod are secured two rack-bars 7e 75, which engage with the teeth of the wheels and open the valves, the valves receiving a complete rotation, being opened momentarily and finally closed just before the piston has reached the end of its stroke in order that a suitable cushion may be formed to prevent contact between the piston and the cylinder-head. The rackbars are so constructed as to operate in one direction only and may, if desired, be of the construction illustrated in Fig.7, each bar 74 being provided with a series of pivoted pawls 78, adapted to engage with the teeth of the wheels 72 when moving in one direction and to yield on the return movement. Each pawl is supported in operative position by a pin 79. The downward movement of the piston of the cylinder 43 effects a corresponding movement of the frame 59, the arm coming into contact with the arm 51 without, however, effecting any movement of the valve, the spring yielding and permitting the free downward movement of said arms. The arm 61 comes into operative contact without the arm 55 of the valve 50 and moves said valve to the open position, steam entering the cylinder through the ports 48 and the movement of the piston being reversed. As the piston completes its stroke the pin 63 makes contact with the lever 65 and through the connecting-rod 67 and arm 56 moves the valve to the closed position. These movements are continuous, and on the next operation a pin 60' on the end of the arm 60 will lift the arm 51 and open the valve 49, said valve being closed on the completion of its stroke by the contact of the pin 62 with the lever 6st, as previously described.

The steam at one stroke will exhaust through the port 68 and at the next stroke through the port 69 of the cylinder 43, or a single wide port may be employed, if desired. The structure may be somewhat simplified by dispensing with the gear-wheel and the connected pinions and placing on the shaft 11 a series of disks 80, each having a tappetpin 21, adapted to be engaged successively by the various arms of U-shaped frames 24, each carried at the inner end of a piston-rod 23, extending in a radial line from the center of the shaft, and where this construction is followed the expense may be materially reduced and the engine rendered much more compact and suitable for launches or othersmall work.

In the construction illustrated in Figs. 5 and 6 the valve-rods S1 of the various cylinders are provided with rollers 82, adapted to be reciprocated by grooved cam-disks 83 on the shaft 11, or any other suitable valve-operating mechanism may be employed for the purpose.

While the construction herein described presents the preferred form of the device, it is obvious that many changes in the form, proportions, size, and minor details of construction may be made within the scope of the claims without departing from the spirit or sacrificing any of the advantages of my invention.

It will be understood that in operation each of the actuating elements, consisting of the cylinder and its cooperating piston, produces its effect independently of the other elements and while the other elements remain at rest, so that the operation of the several elements is successive, and obviously each operating element performs only its percentage of the entire function of the apparatus, the percentage which it performs being proportionate to the entire number of the operating elements employed in the mechanism.

Having thus described my invention, what I claim is-- 1. In a steam-engine, the combination with a driving-shaft, of a series of cylinders, ports connecting the central portions of each cylinder to the opposite ends of the next succeeding cylinder, pistons adapted to open and close said ports, means for controlling an initial supply of steam to the first cylinder of the series, each of said pistons having an op-v erative connection with the driven shaft and adapted to operate successivelyv to impart motion thereto.

2. In a steam-engine, the combination with a driving-shaft, of a series of connected cylinders, means for supplying a predetermined quantity of steam to the first cylinder of the series, each of said pistons operating to open communication between the steam side of its cylinder and the next succeeding cylinder, thereby to permit the steam to expand, with gradually-reducing pressure throughout the series of cylinders.

3. In asteam-engine, the combination with a series of cylinders, of ports or passages leading from the central portion of each cylinder to the ends of the next succeeding cylinder, means for supplying steam for the initial movement of the first piston and for cutting oflr' such supply on the completion of the stroke, each of said pistons governing the communication between its steam side and the next succeedingcylinder thereby permitting the steam to act expansively on each piston in succession.

4. The combination with a driving-shaft, of a revoluble member operably connected to the shaft and having a series of pins, a series of cylinders, U-shaped frames connected to the pistons of said cylinders and adapted to operate successively to impart a step-by-step rotative movement to said pins, substantially as specified.

5. The combination in a steam-engine, of a driving-shaft, a revoluble member operatively connected to the shaft and having a series of pins, a series of cylinders, U -shaped frames connected to the pistons of the cylinders and adapted to operate successively on the revoluble member, and valve-operating mechanisms connecting the movable frame of one piston to the governing-valve of the next succeeding cylinder, substantially as specified.

6. The combination in a steam-engine, of a series of cylinders, pistons disposed in said cylinders and adapted to be operated upon inder, and mechanism connecting the recip- I rocat-ing frame of one piston to the valve-opcrating mechanism of the succeeding cylinder, substantially as specified.

8. The combination with a steam-engine, of

the cylinder having an inlet-port, a piston in said cylinder, means for controlling the admission of steam to said engine, and an exhaust-valve-operating mechanism comprising a toothed wheel mounted on the valvespindle, and a toothed rack connected to the piston-rod of the engine and adapted to engage said wheel for operation in one direction only, substantially as specified.

9. The combination with a cylinder, of a piston, a piston-rod connected thereto, rotary valves disposed at each end of the cylinder, spindles secured to or formed integral with the valve, a toothed wheel carried by each of the spindles, and rack bars carried by the piston-rods and adapted for operative engagement with said toothed wheels, substantially as specified.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses.

ALEXANDER O. SCHUMAN.

Witnesses:

E. E. DOYLE, FRANK S. APPIZEMAN.

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