US742948A

US742948A - Steam-engine.

Info

Publication number: US742948A
Application number: US15262497A
Authority: US
Inventors: Charles C Worthington
Original assignee: Individual
Current assignee: Individual
Priority date: 1897-12-31
Filing date: 1897-12-31
Publication date: 1903-11-03
Anticipated expiration: 1920-11-03

Description

PATENT-ED NOV. 3, 19.0s.

C. G. WORTHINGTON.

STEAM ENGINE.

APPLICATION EILED mm. 31, 1897. RENEWED APR. 14. 1903.

3 SHEETS-SHEET 1.

N0 MODEL.

:Rs c0, PHOTL'LLITHOE. WXSMMGTDN, o. a

No. 742,948. PATENTED NOV. 3, 1903 O. U. WORTHINGTON. STEAM ENGINE.

APPLICATION PLILED DEC. 31, 1897. RENEWED APR. 14. 1903.

N0 MODEL. 3 SHEETS-SHEET 2.

UNITED STATES Patented November 3, 1903..

CHARLES C. WORTI-IINGTON, OF IRVINGTON, NEW YORK.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 742,948, dated November 3, 1903.

Application filed December 31, 1897. Renewed April 14, 1903. Serial No. 152.624. (No model.)

To all whom, it may concern:

Be it known that I, CHARLES C. WORTHING- TON, a citizen of the United States, residing at Irvington, county of Westchester, and State of New York, have invented certain new and useful Improvements in Steam-Engines, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

The object of the present invention is t provide means for controlling the length of the stroke in direct-acting engines operating at varying speeds, and especially to provide means for securing the full stroke of the pistons in such engines when the speed of the engine is reduced, although my invention may be applied also to prevent the engine making too long a stroke in case of excessive speed.

A further object is to provide means controlled by the speed of the engine for admitting steam to the expansion cylinder or cylinders of a multiple-expansion engine in addition to the exhaust from the high-pressure cylinder or cylinders to aid in starting the engine when stopped or, if desired, to aid in increasing the speed when the engine has slowed down to a low speed.

In crank and fiy-wheel engines the stroke of the piston or pistons is necessarily of the same length at whatever speed the engine is running; but in direct-acting engines, such as direct-acting pumping-engines, in which the motor-pistons are connected to .the rods which carry the corresponding pump-plungers in such manner that the piston and plunger are free to move in either direction in accordance with the pressures on opposite sides, the length of stroke of the engine may be reduced when the speed of the engine is lessened and may be increased in case of excessive speed, with the resulting danger of the piston striking the cylinder-head unless a considerable steam cushion be used. I avoid the short stroking of the engine by providing means for varying the pressure on one or both'sides of the piston or pistons during the latter part of the stroke, so as to increase the total effective pressure behind the piston or pistons as the speed of the engine falls in such a manner as to get a full stroke of the engine when running at low speed,

and by similarly decreasing the total effective pressure behind the piston or pistons as the speed of the engine rises I secure the same length of stroke at normal speed and prevent too long a stroke in case of excessive speed. While this feature of my invention is applicable to single engines, it is especially important in connection with that class of engines now well known as duplex direct-acting engines, in which the admission steamvalves on each side are operated from the other side of the engine and the two pistons are timed differently, so that each piston during the latter part of its stroke shifts the valves on the opposite-side, and thus any variation in the length of the stroke is liable to interfere materially with the proper action of the engine. The total efiective pressure upon the piston or pistons may be varied, by diflerent means so as to secure the desired result and either by varying the Working pressure behind the piston or by varying the cushioning-pressure in front of the piston, or by both; but in duplex engines I preferably use a cross-exhaust pipe between the opposite sides of the engine and control this so as to secure the result desired by the passage of exhaust-steam from the high-pressure cylinder of one side of the engine to the low-pressure cylinder of the other. This result may conveniently be secured by a valve controlling the cross-exhaust pipe and actuated or controlled by a speed-governor, so as to open the crossexhaust pipe as the speed of the engine falls and gradually close the cross-exhaust pipe as the speed rises. I may secure this result, however, by various other means- -as, for instance, in duplex engines by varying by the speedgovernor the point in the stroke at which the pistons close the valves on the opposite side of the engine or in single, duplex, or other engines employing cut-0d valves by connecting a speed-governor to the cut-off valves, so as to shift the point of cut-01f and continue to admit steam later in the stroke when the speed of the engine is low and to out off earlier as the speed rises. Instead of thus varying the pressure behind the piston,

as by shifting dash relief-valves controlling the steam-cushion employed to stop the piston at the end of its stroke or otherwise varying the cushion so as to reduce the amount of cushion when the speed of the engine falls and increase the amount of cushion as the speed of the engine rises.

I also provide means controlled by the speed of the engine so that high-pressure steam is admitted to the expansion cylinder or cylinders of an expansion-engine to aid in starting the engine when stopped and the admission of the high-pressure steam is-stopped when the engine is started or has reached a certain speed. This means may also be arranged so as to thus admit high-pressure steam when the speed .is slow to aid in increasing thespeed of the engine; but it is preferably used for starting the engine from a state of rest. This result may be secured conveniently and efficiently in any form of multipleexpansion engine by providing connections for admitting high-pressure steam directly to the expansion cylinder or cylinders and controlling this admission of steam by a valve operated or controlled by a speed-governor, so as to open the valve for the admission of the steam to the expansion-cylinders when the engine is stopped and the main throttle opened to start, and the valve is closed again to prevent this admission of steam after the engine. is started or as the speed rises; but in duplex engines I preferably admit this highpressu re steam to the cross-exhaust pipe of the engine and preferably combine this feature of the admissionof high-pressure steam to the expansion cylinders with the control of the cross-exhaust, as above described, so that when the throttle is opened the action of the expansion-cylinders is aided not only by the cross-exhaust from the opposite side of the engine, but also by the admission of highpressure steam to the cross-exhaust pipe, and 1 preferably arrange the valves controlling the admission of high-pressure steam and the cross-exhaust so that the former is open only when the engine is stopped or running at a very low rate of speed, while the latter is actuated gradually to stop or diminish the cross-exhaust as the engine attains a higher speed.

For a full understanding of the invention a detailed description of a construction embodying all the features of the same as applied in their preferred form in connection with a duplex direct-acting pumping-engine and of modified constructions for con trolling the stroke of a single or duplex engine by varying the point of cut-off and amount of cushion and of a duplex engine by varying the amount of lost motion in the connections for operating the admission-valves will now be given,in connection withthe accompanying drawings, forminga part of this specification, in which Figure 1 is a vertical section of a compound duplex direct-acting pumping-engine of a common form, the section being taken between the steam-cylinders on opposite sides I in different positions.

on the line 1 of Fig. 2. of a portion of the same, on an enlarged scale, with the steam-cylinders removed. Fig. 3 is a detail of the valve controlling the admission of high-pressure steam. Figs. 4 and 5 are details of the lever and lost motion link through which the speed -governor controls the cross-exhaust valve, the parts beingshown Fig. 6 is a side elevation of the steam end of an engine with a speed-governor applied to shift the point of cut-off for controlling the stroke of the piston. Fig. 7 is a detail vertical section through the steam -cylinder and valve-chamber. Fig. 8 is a plan view of a portion of the connections between the speed-governor and the cut-off lever. Fig. 9 is a view similar to Fig. 6, showing the speed-governor applied to actuate the dash relief-valves for varying the amount of cushion. Fig. 10 is a vertical detail section of the valvechamber and cylinder of Fig. 9. Fig. 11 is a detail section on the line ll of Fig. 9. Fig. 12 is a view similar to Fig. 9, showing a speed-governor applied to vary the lost motion in the operating connections to the main valve and to actuate the dash reliefvalves for varying the amount of cushion. Fig. 13 is a central vertical cross-section of the lost-motion connections, taken on the line 13 of Fig. 14. Fig. 14 is a detail side elevation. of the lost-motion connections. Fig. 15 is a section on the line 15' of Fig. 13. Fig. 16 is a similar view showing the parts in a different position.

Referring nowparticnlarly to Figs. 1 to 5, the invention is shown in these figures as applied to a duplex directacting pumping-engine of a well-known class, with high and low pressure steam cylinders A B and water-cylinders O on opposite sides, the high-pressure cylinders receiving steam from the general induction or-supply pipe D through branch pipes D"D and the high-pressure cylinders A on the opposite sides exhausting to the low-pressure cylinders through exhaust-pipes E E the low-pressure cylinders exhausting through the exhaust-pipes F to the suction or elsewhere, as desired, as usual in such constructions. The piston-rods a a on opposite sides of the engine are connected directly to the plungers through the cross-heads b b, as

Fig. 2 is a plan view usual in such constructions, and the valve movements for the high and low pressure cylinders are actuated from the respective crossheads through the levers m and crossover shafts n and links 0 (shown in dotted lines in in Fig. 1) or in any other suitable manner, the valve-chambersof the steam-cylinders being shown as below the cylinders, although it will be understood that this is not essential.

Referring now to the features of the presentinvention as illustrated in connection with the engine generally described above, the cross-exhaust pipe G,.which is arranged to connect the exhaust-pipes E E on opposite sides of the engine and shown as arranged in the mannerusual in such duplex direct-acting engines, is provided with a valve-chamber 10, within which a valve 11 controls the cross-exhaust, this valve 11 being shown as a balanced piston-valve of common form. The stem 12 of this valve 11 moves in a bracket 13 on the valve-chamber and is pressed in a direction tending to close the valve by coilspring 1, acting on an enlargement 2 on the stem 12 and bearing against a cap on the head of the bracket 13, which is preferably a screwcap for the convenient renewal of the spring and adjustment of its tension. The outer end of the stem 12 is linked to a connecting-rod 14, which has at-its opposite end a lost-motion link 15, with an adjusting-screw 3, by which the amount of lost motion may be varied to secure the desired action of the valve 11. This lost-motion link 15 has a block connection with a slotted arm 16 on rock-shaft 17, which has another arm 18, so that the rockshaft and two arms form a bell-crank lever, the arm 18 being connected by link 19 to the weighted lever 20 of a speed-governor H, which is shown as of a common form fully described in United States Letters Patent No.

312,138 and well known under the name of the Mason pump-governor, as applied to control the speed of pumps by operating on the main throttle, the piston 21 of the pumpgovernor engaging the lever 20, so as to raise the latter against the resistance of the weight 22 when the engine is operating at normalspeed, and the operating-arms 23 on opposite sides of the governor being connected by links 24 to the respective cross-heads b b", so that the governor'is actuated by the pistons on both sides of the duplex engine, as usual in ,pipe D with the cross-exhaust pipe G, as

shown in full lines in Figs. 1 and 2, and is preferably provided with a throttle-valve 9, by which the amount of steam admitted. through this pipe may be regulated by hand or the pipe closed at any time,if desired. This pipe 26 is provided with avalve-chamber 27,

within which a valve 28, shown as similar to the valve 10, controls the passage of steam through the pipe 26 to the cross-exhaust pipe, the stem 29 of this valve being mounted and spring-actuated in the same manner as in the case of the valve 10 and as shown in detail in Fig. 3, with bracket 30 and spring 1 acting between enlargement 2 and the cap on the end of the bracket, as previously described, the stem 29 being linked to connecting-rod 31, having lostmotion link 32 and adjustingscrew 3, as in the case of the lost-motion link 15, and this lost-motion link 32 hasa block connection with a second slotted arm 33 on rock-shaft 17, the governor 11 thus actuating both the valves 10 28 through the rock-shaft 17 and connections previously described. This high-pressure-steam connection may be made with the cross-exhaust pipe G, as above described, or in any other suitable manner, so as to supply high-pressure steam to the lowpressure cylinders as desired; but the connection with the cross-exhaust pipe is preferably used and both the high-pressuresteam connection and cross-exhaust pipe controlled by the speed of the engine. In Fig. 2 I have shown in dotted lines the pipe 26 as connecting with a pipe 3i, which extends between the eXhaust-pipes E F. on opposite sides, but is provided with check-valves 4 at opposite sides of the connection with the pipe 26, each of these check-valves opening toward the exhaust-pipe next which it is placed, so that steam will pass from the pipe 26 to both the exhaust-pipes E E through these checkvalves, but no steam can pass backward from either of the exhaust-pipes through its adjacent check-valve, with'the result that there is no cross-exhaust through the pipe 34:.

The operation of the construction shown in Figs. 1 to 5 will be understood from a brief statement, in connection with the drawings and above description. The parts are shown in Figs. 1 to 4 in the position they'occupy when the engine is stopped or running at a low speed, at which itis desired that both the valves 11 28 shall be open, the weighted lever 20 of the pump-governor H having been rocked on the descent of the piston 21 as the engine slowed down, so as to move the link 19 upward, and thus through the arm 18, rock-shaft 17, and slotted arms 16 33 move the blocks carried thereby in the lost-motion links 15 32, so as to take up the lost motion and by engagement with the screws 3 move the connecting-rods 14 31 toward the right in the drawings, and thus open the respective valves 11 28 against the pressure of springs 1, which tend to close the valves. The parts are preferably arranged so that the cross-exhaust valve 11 opens to permit the cross-exhaust or to increase the cross-exhaust as the speed decreases and before the valve 28 opens, and the valve 28 is not opened until the engine is running at a quite low speed or practically stopped. It will be understood, however, that this action may readily be varied and will depend upon the running conditions of the engine and result desired. Assume now that the engine is stopped and the parts in the position shown in Figs. 1 to 4 and the engine is to be started. The steam is admitted to the high-pressure cylinders A through the general induction pipe D and branch pipes DD and the valve 11 being wide open full cross-exhaust is permitted from one side of the engine to the other, so that exhauststeam passes directly through the cross-exhaust pipe G to the low-pressure cylinder B on the opposite side of the engine as each of the high-pressure cylinders A exhausts,which is about two-thirds stroke of the piston in the low-pressure cylinder on the opposite side, so

that this cross-exhaust acts on the piston in the low-pressure cylinder during the latter part of its stroke, and thus aids in securing full stroke of the pistons and plunger on that side of the engine, the action being the same on each side of the engine and the cross-ex- :o haust passing alternately in one direction or I5 is admitted through the pipe 26 to the crossexhaust pipe G, and thus to the exhaust-pipes E E and to the low-pressure cylinders, this admission being constant throughout the stroke,so that this high-pressu re steam aids in actuating the low-pressure pistons throughout the entire stroke,beiug aided in the latter part of the stroke by the cross-exhaust from the high-pressure cylinders, as above described. As the engine is started and its speed increases the weighted lever 20 of the speedgovernor H is raised by the piston 21 and through the link 19, arm 18, and rock-shaft 17 moves the slotted arm 16 33 to the left in the figures, so as to move the blocks carried 0 by these arms to the left in the figures, and

thus permit the connecting-rods 14 31 and valve-stems 12 29 to be moved to the left by the springs -1, and thus gradually close the valves 11 28, the parts preferably being con- 5 structed and adjusted so that the valve 28 closes immediately after the engine starts to shut ofi the high-pressure steam, while the valve 11 closes later and gradually to out off or decrease the amount of cross-exhaust, al-

0 though it will be understood that the valves may be arranged to act otherwise, if desired. By so arranging the cross-exhaust valve 11 that it shall be partially open and permit some cr0ss-exhaust at the normal speed of 5 the engine the stroke may be controlled so as to prevent the piston making too long a stroke in case of excessive speed, the speed governor then operating through the valve 11 to further. reduce or entirely stop the crossexhaust, so that the pressure behind the pistons during the latter part of the stroke is reduced and overstroke of the pistons prevented. As shown in Figs. 4 and 5, the arm 16 moves to the left after the valve 11 is closed, so that the block carried by the slotted arm 16 moves away from the screw 3, securing lost motion between the block and screw on the return movement of the arm 16 as the engine again slows down, so that the connecting-rod 14 and valve 11 are not actuated by the engagement of the block on arm 16 with the screw 3 until after this lost motion has been taken up. By the adjustment of the screw3 the amount of lost motion may be varied, so that the valve 11 will be opened wide and closed wholly or partially at any desired-speed of the engine as the speed of the latter is decreased or increased. The same action and adjustment of the lost-motion link exist in connection with the two valves except that, as above stated, the valve 28 preferably closes at once on starting the engine or at a very slow speed, while the Valve 11 may be arranged so as to en'tirely close the crossexhaust at normal speed or simply to decrease and increase the crossexhaust.

The action of the construction is exactly the same as above described when the pipe 26 is connected as shown in dotted lines in Fig. 2, except that the high-pressure steam does not enter the,low-pressure cylinders through the cross-exhaust pipe G.

Referring now to Figs.6 to 8, in which means are shown for controlling the stroke of the engine by varying the point of cut olf in accordance with the speed of the engine, the invention is shown as applied in connection with a single steam-cylinder of a direct-acting engine, which is shown as the steam-cylinder on one side of'a duplex engine, but which maybe a duplex direct-acting pump- .ing-engiue, such as shown in Figs. 1 and 2, or

of any other suitable construction of directacting engine, either single or duplex and either a high-pressure orexpansiou cylinder. In this construction the steam-cylinder A is provided with an oscillating induction-valve c and oscillating cut-01f valves d, controlling the admission of steam from the inductionpipe D through theinduction-ports c,the valve 0 controlling also the exhaust from the cylinder A through the exhaust-ports f and exhaust-cove g. The parts are shown in the position they occupy, with the steam-piston it just about to commence its stroke to the right, the induction-valve c and cut-off valve d being in position to open the induction-port e at the left of the cylinder. The valve 0 is shown as actuated through the usual crank 35 on the stem, link 36, and arm 37 of the crossovershaft 38, and the cut-off valves through cranks 39, links 40, lever 41, and link 42, connecting the lever 41 to the cross-head 43 on piston-rod a, so that the induction-valves are operated by the opposite side of the engine and the cut-0E valves by their own side, as usual in such constructions. The construction shown and above described is well known and may be varied as desired, being selected only as a convenient construction for illustrating the application of the present invention.

Referring now to the features embodying the present invention, the lever 41, through which the cut-off valves are actuated, has a vertically-movable pivot, being mounted in a block 44, sliding vertically in guides 45 on the cylinder A, and this block 44 is connected by a link 46 to one arm of a bell-crank lever 47, the other arm of which is connected by a link 48 to the bell-crank lever 49 of a Mason pumpgovernor H, the weighted arm of this speedgovernor forming one arm of the bell-crank lever 49 and being raised by the piston of the speed-governor as the speed of the engine increases and lowered by the weight as the piston of the speed-governor falls as the engine slows down. The operating-arm 51 of the speed-governor H is shown as actuated from the lever 41 through a link 52.

The operation of the construction is as follows: Assuming that the engine is running at normal speed, as shown in the drawings, as the speed of the engine decreases the piston of the speed-governor H is lowered, thus permitting the weighted arm of the bellcrank lever 49 to fall, which, through the link 48, bell crank lever 47, and link 46, moves the block 44 downward in the guides 45, and thus lowers the lever 41. This lowering of the lever 41, through the links 40, swings the crank-arms 39 of the cut-off valves d of the cylinder A so as to move the cut-off valves d into a position in which the steam will be cut ofi later in the stroke by the action of the lever 41, operated from cross-head 43 through link 42, with the result that the steam is admitted later in the stroke and a full stroke of the piston still secured as the speed of the engine decreases. If the engine is stopped, the weighted lever 49 holds the block 44 in its lower position, so that the cut-0E valves will operate to cut off late in the stroke when the engine is again started, or, if de sired, the parts may be constructed and arranged so that there will be no cut-oft on starting and the cut-0E secured only as the speed of the engine increases. When the speed of the engine again rises, the piston of the speed-governor H is raised and lifts the weighted arm of the bell-crank lever 49, and thus, through the link 48, bell-crank lever 47, and link 46, raises the block 44 in guides 45, so as to move the lever 41 upward, which movement of the lever 41, through the links 40, swings the crank-arms 39 and moves the cut-off valves d into position to secure an earlier cut 05, the point of cut off being arranged as desired by the construction or adjustment of' the parts and the lever 41 being held in position for the desired out 01f in accordance with the speed of the engine by the piston of the speed'governor H holding the weighted arm of the bell-crank lever 49. The proper stroke at normal or excessive speed is thus secured.

In Figs. 9 to 11 I have shown a construction in which a speed-governor is applied to secure the desired result of a full stroke at low speed by decreasing the pressure on the forward side of the steam-piston at the end of the stroke and to prevent an overstroke by increasing this pressure instead of increasing and decreasing the pressure behind the piston, this result being secured by shitting the dash relief-valves, so as to vary the steam-cushion in accordance with the speed of the engine. The construction and arrangement of the steam-cylinder, its main valve and valve movement are substantially the same as shown in Figs. 6 to 8, except that the valve is at the upper side instead of the lower side of the steam-cylinder, and the valve-movement levers are varied accordingly. The same references will therefore be used in Figs. 9 to 11 for parts corresponding to those shown in Figs. 6 to 8. The parts in Figs. 9 to 11 are shown in slightly-difierent position from that shown in Figs. 6 to 8 for the purpose of illustrating the action of the dash relief-valves, the valves being shown in the position they occupy just as the piston h is completing its stroke and before the induction-valve c is shifted to reverse the stroke. In this construction the usual relief-ports i are used, connecting the induction and exhaust ports 6 f at opposite ends of the cylinder, so that the gradual passage of the steam from the cushion through the inner end of the induction-port e to the exhaust-port f, and thus to exhaust through the cove g, will be permitted at the end of the stroke after the piston it has closed the inner end of the exhaust-port for cushioning the piston by the steam retained between the inner end of the exhaust-port and the head of the cylinder. The dash relief-valves k are shown as plugvalves, controlling the ports t and provided at their outer ends with slots 5, entered by one arm of bell-crank levers 6, mounted at the top of the cylinder, the other arms of which bell-crank levers outside the valvechamber are connected by links 53 to the bell-crank lever 49, one arm of which is the weighted arm of the speed-governor H. The operating-arm 51 of the speed-governor H in this construction is connected by link 52 to arm 54 on one of the crossover-shafts of the valve-motion, so as to be actuated thereby. The operation of this construction is as follows: With the pump running at normal speed, as shown in the drawings, the weighted arm of the bell-crank lever 49 is held in its raised position by the piston of the speedgovernor H, and through the link 53 and bellcrank levers 6 has moved the dash reliefvalves is inward and now holds them in position to close or nearly close the relief-ports i, so that the normal cushion desired and for which the parts are constructed or adjusted is secured. As the speed of the engine decreases the weighted arm of the bell-crank lever 49 falls, as permitted by the descent of the piston of the speed-governor H, and thus moves the link 53 to the right in the drawings and through the bell-crank levers 6 draws the valves outward, so as to open the relief-ports i, and thus permit the steam in front of the piston at the end of the stroke to IIO pass more freely through the relief-ports t,

and thus decrease to the extent desired the cushioning of the piston, so that the full stroke of the piston will be secured at slow speed without increasing the pressure behind the piston, and the closing of the relief-ports by excessive speed will prevent overstroke.

In Figs. 12 to 16 I have shown a construction in which the connections for operating the main valve on opposite sides of the pump are controlled by a speed-governor, so that; the amount of lost motion between the piston on one side and the valve on the opposite 1 side is varied in accordance with the speed; of the pump, this construction being shown as employing also means by which the dash relief-valves are shifted by the speed-governor, as illustrated in Figs. 9 to 11 and described above, although it will be understood that the means for varying the amount of lost motion in the connections to the main valve may be used alone, if desired. The lost-motion device thus controlled by the speed-governor may be of any suitable form; but that illustrated, with the connections thereto, is as follows: The link 36 between the crank 35 of valve 0 and the arm 37 on crossover rock-shaft 38 is broken and the two parts pivotally connected to a lever 55,

which is pivoted on a block 7, mounted to:

slide horizontally in a frame 56, rising from the engine-cradle. The frame 56 is divided longitudinally of the line of movement of the block 7, and between the two parts of the frame and mounted to slide vertically therein is a stop-block 57, formed on its under side into forks 8 with inclined surfaces, which providean opening enlarging gradually downward and positioned to act as stops to engage the stud 9 in block 7, which forms the pivot of lever 55, and thus limit the movement of the block 7 and pivot of lever. 55 in either direction, more or less horizontal i movement of the block 7 being permitted, according to the vertical position of the stopblock 57. a link 68 to a bell-crank lever 69, which is connected by a link 70 to the weighted bellcrank lever 49 of the speed-governor H, and i this bell-crank lever 49 carries also another arm 71, which is connected by a link 72 to a tween the piston A on one side and the valve 0 on the opposite side of the engine are less, and

the parts may be so arranged that there is no lost motion at this time; but preferably a small amount of lost motion is used at this normal high speed, so that by the reduction of this lost motion the stroke of the engine may be controlled and an overstroke prevented by reducing somewhat the amount of lost motion. As illustrated in the drawings, the engine is operating at high speed with no lost motion in the connections between the arm 37 and the valve 0, the stop-block 57 being in its The stop-block 57 is connected by 1 lower position, as shownin Figs. 13 to 15, so that the stud 9 is at the upper end of the ta pering recess between the forks 8' and the block 7 and held by such engagement against horizontal movement, the block 57 having been moved into and being held in this lowered position by the raising of the weighted arm of bell-crank lever 49 by the piston of the speedgovernor H. The pivot of lever 55, therefore, does not move horizontally, as the arm 37 acts upon it through link 36; but the movement of arm 37 is transmitted directly to crank 35 of valve 0 by links 36 and lever 55 as though the latter were mounted on a permanently-fixed pivot. In this position of the parts the bell-crank lever 49 has also moved the dash relief-valves h inward, so as to close or nearly close the dash reliefports 2' and maintain a large cushion in the cylinder A. If new the speed of the engine decreases and the steam-valves c on opposite sides are operated at thesame point in the stroke of the piston on the opposite side to close the valves and shut 0d the steam from behind the pistons hand the same large steamcushion is maintained, the stroke of the engine is liable to be shortened. This shortening of the'stroke as the speed of the engine decreases is avoided, as illustrated in this construction, first, by causing or increasing lost motion betweenthe pistons and steamvalves operated thereby, so as to close the valves and shut off the steam behind the pistons later in the stroke, thus increasing the pressure behind the pistons during the latter part of the stroke, and, second, by reducing the amount of cushion in front of the pistons by withdrawing the dash relief-valves k to open the relief-ports 1} and permit a freer escape of the steam from the cushion. These results are secured as follows: As the piston of speed-governor H is lowered as the speed of the engine decreases the weighted arm of bell-crank lever 49 falls, and thus through the link 70, bell-crank lever69, and link 68 gradually raises the stop-block 57 from the position shown in Figs. 1 2 to 15, so as to increase the width of the opening between the forks 8 opposite the stud 9 and permit the block 7 to move horizontallyrmore and more as the stop-block 57is raised. In the position of the stop-block 57, as shown in Fig. 16, a considerable amount of lost motion is secured, the first action of the arm 37 as it moves in either direction operating to shift the block 7 sidewise in the frame 56 before the movement of the arm 37 is transmitted through the lever 55 to the crank 35, crank 35 and valve 0 being actuated only after the block 7 has been stopped by the engagement of the stud 9 with one or the other of the arms 8. The position shown in Fig. 16 is that in which the block 7 has been moved to the left by the movement of the arm 37, to the right in Fig. 12, the lost motion having been taken up, so that the valve 0 is about to be shifted. This movement of the bell-crank lever 49 as its weighted It is obvious that all of the means above described for varying the relative pressures on the opposite sides of the piston to control the stroke of the engine by its speed may be used in a single construction, except that means for varying the lost motion in the connections to the main valve will not be used on a cylinder with separate cut-off, as in the construction shown in Figs. 6 to-8. \Vith this exception, however, all the means above described may be combined in a single engine and with advantage under some circumstances, and, of course, the means for ad mitting high-pressure steam to the low-pressure cylinders for starting or increasing the speed of the engine may be used in such a construction. Instead of using all the means above described any two or more can be combined,

and the various combinations of such means require no further illustration in view of the combinations shown in Figs. 1 to 5 and Fig. 12, from which suitable connections for any combination of means desired may readily be devised by those skilled in the art, employing either a single speed-governor or a plurality of speed-governors, as may be found most convenient. In the case of duplex engines a single speed-governor may be used for operating the admission, cut-off, or dash relief valves of both sides or a speed-governor for each side.

"While I have illustrated the preferred methods of varying the total effective pressure on the piston in carrying out my invention, it will be understood that my invention, considered broadly, is not to be limited to constructions for carrying out my invention by any of thesemethods, but that I may apply the invention in connection with other means for varying the total effective pressure on the piston to control the stroke of the engine. I preferably use a speed-governor and connections of the form shown, especially in connection with duplex engines; but it will be understood that other means may be used for securing the desired control of the valves or other moving parts through which the pressure on the piston is controlled.

While the two features of varying the pres-- sure on the piston to control the stroke by the speed is preferably combined with the feature of admitting high-pressure steam to the low-pressure cylinder or cylinders to aid in starting the engine or in running at low speeds, it will be understood that these features may be used separately and in themselves form parts of the invention, although the invention includes also certain combinations of. parts in constructions embodying both these features.

The feature of admitting high-pressure steam to the low-pressure cylinder or cylinders to aid in starting the engine or running at low speeds and controlling the admission of high-pressure steam by the speed of the engine may be applied to engines of other classes than direct-acting engines, and such constructions are included within this feature of the invention, considered broadly.

What I claim is- 1. The combination with a direct-acting engine and devices for varying the total effective pressure behind the piston during the stroke, of means for controlling the action of said devices by the speed of the engine to control the length of the stroke, substantially as described.

2. The combination with adirect-acting engine and devices for varying the total effect ive pressure behind the piston during the stroke, of a speed-governor operated by the engine and connections for controlling the action of said devices by the speed-governor to control the length of the stroke, substantially as described.

3. The combination with a direct-acting engine and devices for varying the pressure on one. or both sides of the piston during the stroke, of a speed-governor and connections for controlling said devices to vary the pressure on one or both sides of the piston at the end of the stroke to control the length of the stroke, substantially as described.

4. The combination with a direct-acting engine and devices for varying the total effective pressure behind the piston during the stroke, of means for controlling the action of said devices by the speed of the engine in such a manner as to obtain a higher total effective pressure behind the piston when the engine is running at low speeds to secure the full stroke of the piston, substantially as described.

5. The combination with two direct-acting cylinders, and means for actuating the valves ofeach cylinder from the piston of the other cylinder, of devices for varying the total effective pressure behind the pistons during the stroke, and means for controlling the action of said devices by the speed of the engine to control the length of the stroke, substantially as described.

6. The combination with two direct-acting cylinders, and means for actuating the valves of each cylinder from the piston of the other cylinder, of devices for varying the total effective pressure behind the pistons during the pistons during the stroke, and means for controlling the action of said devices by the speed of the engine to control the length of the stroke, substantially as described.

8. The combination with a duplex directacting engine having means for reversing the valves on each side of the engine by the piston of the opposite side during the'latter part of the stroke of said piston, of devices for varying the total effective pressure behind the pistons during the stroke, and means for controlling the action of said devices by the speed of the engine in such a manner as to obtain a higher total effective pressure behind the pistons when the engine is running at low speeds to secure the full stroke of the pistons, substantially as described. I

9. The combination with a duplex directacting multiple-expansion engine, of crossexhaust connections between the opposite sides of the engine, and means for controlling the cross-exhaust connections by the speed of the engine to open the cross-exhaust as the speed of the engine falls and open the cross-exhaust as the speed of the engine rises, substantially as described.

10. The combination with a direct-acting multiple-expansion duplex-engine, of a crossexhaust pipe connecting the opposite sides of the engine, a valve controlling the cross-exhaust and means controlled by the speed of the engine for controlling said valve to open the cross-exhaust as the speed of the engine falls and close the cross-exhaust as the speed of the engine rises, substantially as described.

11. The combination with a multiple-ex'pansion direct-acting duplex engine, of a crossexhaust pipe connecting the opposite sides of the engine, a valve controlling the cross-exhaust, a speed-governor operated by the engine, and adjustable connections between said speed-governor and the valve for opening the valve at the desired point as the speed of the engine falls and closing the valve at the desired point as the speed of the engine rises substantially as described.

12. The combination with a m ultiple-expansion direct-acting duplex engine, of a crossexhaust pipe connecting the opposite sides of the engine, a valve controlling the cross-ex haust, a spring tending to close said valve, a speed-governor operated by the engine, and

lost-motion connections between said speedgovernor and valve for opening the valve against the spring-pressure as the speed of the engine falls and permitting the spring to close the valve as the speed of the engine rises, substantially as described.

13. The combination with ,a direct-acting engine and avalve controlling the admission .Of the motor fluid, of means for closing said valve before the piston has reached the end of itsstroke and controlled by the speed of the engine to vary the point in the stroke at which the valve is closed to control the length of the stroke, substantially as described.

14. The combination with a direct-acting engine and a valve for con trolling the motor fluid, of means including lost-motion connections for actuating said valve, and meansfor varying the amount of lost motion in accordance With the speed of the engine, substantially as described.

15. The combination with two direct-acting cylindersand connections for operating the valve of each cylinder by the piston of the other cylinder, of means controlled by the speed of the engine for varying the point of the stroke at which the valves are closed, substantially as described.

16. The combination with two direct-acting cylinders and lost-motion connections for actuating the valve of each cylinder from the piston of the other cylinder, of means controlled by the speed of the engine for varying the amount of lost motion, substantially as described.

17. The combination with a duplex directacting engine and its lost-motion connections for operating the valves of ,each side from the piston on the opposite side, of a speedgovernor operated by the engine, and connections controlled by said speed-governor for increasing the amount of lost motion as the speed of the engine falls and decreasing the amount of lost motion as the speed of the engine rises, substantially as described.

18. The combination with a direct-acting engine, its admission and separate cut-off valves, of means controlled by the speed of the engine for varying the point of cut-ofi to control the length of the stroke, substantially as described.

19. The combination with two direct-acting cylinders and their valves, and connections for operating the valves of each for admission by the piston of the other cylinder and for cut-off by the piston of their own cylinder, of means controlled by the speed of the engine for varying the point of cut-off to control the length of the stroke, substantially as described.

20. The combination with a direct-acting engine, and its steam-cushioned piston, of means controlled by the speed of the engine to control the length of the stroke for varying the amount of cushion, substantially as described.

21. The combination with a direct-acting engine and its steam-cushioned piston, of means controlled by the speed of the engine for decreasing the cushion as the speed of the engine falls and increasing the cushion as the speed of the engine rises to control the length of the stroke, substantially as described.

22. The combination with .a direct-acting engine and its dash relief-valves, of a speedgovernor operated by the engine, and connections for controlling said dash relief-valves by the speed-governor to decrease the cushion as the speed of the engine falls and increase the cushion as the speed of the engine rises, substantially as described.

23. The combination with a multiple-expansion direct-acting engine and devices for varying the total efiective pressure behind the piston during the stroke, of means for controlling the action of said devices by the speed of the engine to control the length of the stroke, connections for supplying highpressure steam to the lower-pressure cylinder or cylinders, and means for controlling said connections by the speed of the engine to admit the high-pressure steam to the lowerpressure cylinder or cylinders to aid in starting the engine or running at a low speed and shut ofl said high-pressure steam when the speed of the engine reaches a certain point, substantially as described.

24. The combination with a duplex dire'ctacting multiple-expansion engine, of crossexhaust connections between the opposite sides of the engine, means for controlling the cross-exhaust by the speed of the engine to increase the cross-exhaust as the speed of the engine falls and decrease the cross-exhaust as the speed of the engine rises, connections for supplying high -.-pressure steam to the lower-pressure cylinders, and means for controlling said connections by the speed of the engine to admit such steam as the speed of the engine falls and shut off such steam as the speed of the engine rises, substantially as described.

25. The combination with a duplex directacting multiple-expansion engine, of crossexhaust connections between the opposite sides of the engine, means for controlling the cross-exhaust by the speed of the engine to increase the cross-exhaust as the speed of the engine falls and decrease the cross-exhaust asthe speed of the engine rises, connections for supplying high-pressure steam to the crossexhaust connections, and means for controlling said connections by the speed of the engineto admit such steam to the cross-exhaust connections as the speed of the engine falls and shut off such steam as the speed of the engine rises, substantially as described.

26. The combination with a multiple-expansion engine,of connections for supplying highpressure steam to the lower-pressure cylinder or cylinders, and means for controlling said high-pressure steam by the speed of the engine to admit the steam to the lower-pressure cylinder or cylinders in starting the engine and shutting ofi said high-pressure steam when the speed of the engine reaches a certain point, substantially as described.

27. The combination with a multiple-expansion engine, of a pipe for admitting high-pres sure steam to the lower-pressure cylinder or cylinders, a valve controlling the passage of the high-pressure steam through said pipe, a speed-governor operated by the engine, and means controlled by said speed-governor for opening said valve as the speed of the engine falls and closing said valve as the speed of the engine rises, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

CHARLES C. WORTHINGTON. Witnesses:

LOUIS R. ALBERGER, B. W. PIERSON.