US1966154A - Locomotive - Google Patents

Description

July 10, 1934.

A. J. TOWNSEND LOCOMOTIVE Filed Aug. 14, 1950 3 Sheets-Sheet l e 5/5 225 f? o 44 l/ d F L I 7; l7 V i If 35 2? as 29 46 f 44 3 v k 25 M A?) INVENTOR.

QZZM QW w BY WYW ATTORNEYS.

July 10, 1934.

A. J. TOWNSEND 1,966,154

LOCOMOTIYE Filed A g- 1930 5 Sheets-Sheet 2 z? 20 I9 as 2 42 I IN V EN TOR.

W f-Mwg A TTORNEYS.

July 10, 1934. A. J. TowNsENb LOCOMOTIVE 3 Sheets-Sheet 3 Filed Aug. 14, 1930 ID I Patented July 10, 1934 LOCOMOTIVE Albert J. Townsend, Lima, Ohio Application August 14, 1930, Serial No. 475,153

26 Claims.

This invention relates to locomotives and is more particularly concerned with a starting or auxiliary steam admission and control' mechanism therefor. The invention, furthermore, is especially adapted in its application to the well known limited cut-oif'type of. locomotive in which the point of cut-oli, even when in maximum cutoff position, is arranged to limit admission of steam for a portion only of each stroke.

The primary object of the invention is the-provision of an improved locomotive starting mechanism including starting steam passages and control means therefor which insures positive and automatic operation. In a limited cut-oii locomotive, particularly a two cylinder locomotive with the cranks 90 apart, it is possible for the engine to be in such a position, before starting, that one piston will be at or near the dead center and consequently the thrust of this piston cannot exert SLlfilClGnl] force to move the locomotive. At the same time it is possible for the other piston to be in such a position that the main steam port is closed to admission by the distribution valve in the steam chest. In such a case auxiliary steam admission must be supplied to the piston which is not on dead center in order to start the locomotive. After the first stroke this auxiliary admission is no longer necessary as there will always be steam in one of the cylinders tending to move the locomotive as long as the main throttle valve is open to permit steam from the boiler to enter the two steam chests.

The idea of auxiliary admission is not new, but

' such devices as previously used have depended on some form of throttling action to reduce the auxiliary admission as the speed of the locomotive increases, and thus the amount of auxiliary admission must be but a very small proportion of the total admission which results in slow starting or" the locomotive. It cannot be made a very large proportion as this will interfere with satisfactory operation of the locomotive at higher speed. The present invention has in View a means of positively closing the auxiliary admission after the first stroke of the piston and consequently the auxiliary admission may be made any desired amount in order togive quick starting.

Still further the present invention provides a control device which is very simple and rugged in construction as well as efiective in operation, numerous of the complicated mechanisms and elements heretofore employed having been elimi- F nated completely.

The general nature of the invention, as well as objects andadvantages in addition to those noted above will be more apparent from a con sideration of the following description taken with the accompanying drawings which illustrate the preferred embodiment of the invention, and in which- Figures 1 and 3 are fragmentary vertical sectional views of a portion of one cylinder of a locomotive with the associated valve mechanism therefor illustrated in different positions during the stroke, the cylinder, the valve mechanism, and various of the steam passages. being somewhat diagrammatically arranged and the starting steam control mechanism being illustrated in section between the cylinder and the associated valve.

Figures 2 and 4 are views similar to and corresponding, respectively, to Figures 1 and 3, it being noted that the invention is here illustrated as applied to a two-cylinder locomotive the lefthand cylinder of which appears in Figures 1 and 3 and the right-hand cylinder in Figures 2 and 4.

Figure 5 is a transverse vertical sectional view through one of the cylinders and the associated valve chest with the controlling mechanism of the present invention applied thereto.

Figure 6 is a View of the controlling mechanism taken in section as indicated by the line 66 in Fig. 8.

Figure 7 is a top view of the structure illustrated in Figure 6 with certain of the upper portions thereof broken away substantially as indicated by the line '7'7 in Figure 6, and

Figure 8 is a vertical sectional view taken substantially as indicated by the line 8-8 in Figure 6.

In considering the drawings, it should be noted that the invention is illustrated as applied to a two-cylinder limited cut-oil locomotive, the valve mechanisms for which are set for a 50% cut-off in maximum cut-oii position. In Figures 1 and 3, the left-hand cylinder is designated by the reference numeral 11 while in Figures 2 and 4, the right-hand cylinder is indicated by the reference character 12. Since the main steam supply as well as the auxiliary or starting steam passages are substantially the same for each cylinder, only one of these mechanisms will be described in detail.

From inspection of Figures 1 to 4. inclusive, it will be seen that each of the cylinders has an associated steam chest indicated, in general, by the reference character 13. The steam chest is adapted to house the valve 14 which reciprocates 110 therein, the valve illustrated being of the usual piston type. Live steam is conducted into the chamber in the steam chest through the pipe 16 at the center of the latter while exhaust from the cylinders is provided at the ends 17 and 18 of the valve chamber in the customary manner. The steam supply passages 19 and 20 are the conventional arrangement for connecting the steam chest to the cylinder. Live steam is admitted through each passage to the cylinder for the power stroke, and during the exhaust stroke the steam is released through the same passage and out through the end of the steam chest. The auxiliary or starting steam passages 21 and 22 communicate with the cylinders through ports 23 and 24 which are spaced between the main steam ports 19 and 20. The usual type of piston 25, of course, is arranged to reciprocate within each cylinder.

At each end of each valve chest, auxiliary steam controlling ports are provided and so positioned in the main valve mechanism as to provide a cut-off later than that of the main steam ports and as to permit uncovering or opening thereof by the valve to the central or live steam chamber 15 only, the ports being so arranged for reasons which will appear more fully hereinafter. These ports are indicated in the drawings by the reference characters 26 and 27 and are shown as being coupled with the auxiliary steam controlling mechanism to be described herebelow by means of pipes or passages 28 and 29.

In Figures 1 to 4 inclusive the starting steam supply and controlling mechanism is indicated in general by the reference character 30 and from inspection of the figures noted, it will be seen that in addition to communication with the passages 28 and 29, the device or mechanism 30 communicates or is connected with the auxiliary steam supply passages 21 and 22.

Referring now more particularly to Figures 5 to 8 inclusive, it will be noted that the device 30 includes a body member 31 providing a cavity or chamber 32 which is coupled with the live steam chamber 15 of the valve chest 13 by means of the connection 33 (see Figs. 5 to 8 inclusive). This connection is shown only diagrammatically in Figs. 1 to 4. The starting steam passages 21 and 22 communicate with the chamber 33 through valve seats 34 and 35 on which poppet valves 36 and 37 are adapted to seat and thus cut off communication between the chamber 32 and the passage 21 and 22. It might be observed, at this point, that the poppet valves 36 and 37 are arranged or positioned in such manner as to close under the influence of steam pressure in the chamber 32 so that the only actuating mechanism which must be provided is that necessary to open the valves at the desired points during the stroke.

The actuating mechanism takes the form of a piston device having a shaft 38 positioned within the chamber 32 and carrying piston heads 39 and 40 at the ends thereof. The heads 39 and 40 work in cylindrical cavities 41 and 42 which extend laterally from each end of the chamber 32. The piston heads, therefore, serve to complete the enclosure of the chamber 32 and are thus exposed at one side to the steam pressur in the chamber. The operating connection between the shaft 38 and the valves 36 and 37 includes a double bell crank or rocker member having an upwardly extending and bifurcated arm or lever 43 (see Fi s. 6 and 8) embracing the shaft 38. The rocker member is pivoted on a shaft 4.4 at

the sides of which the forked bell crank levers 45 and 16 extend. An operative connection between the arm 43 and the shaft 38 is provided by means of a pair of stop members or shoulders 47, one arranged at each side or" the arm 43. The connections between the arms 45 and 46 and the valves 36 and 37 include valve stems 48 and 49 carrying heads 50 and 51 the underside of which, in each instance, is engaged by one of the levers 45 or '46. From inspection of Fig. 6 it will be apparent that a movement of the shaft 38 with the pistons 39 and 10 to the left will rock the bell crank device in such manner as to raise the valve 37 from its seat. A movement of the shaft 38 in the opposite direction, obviously, provides an opening movement of the valve 36.

Control of the movements of the shaft 38 and thus of the valves 36 and 37 is effected by the admission of fluid pressure to the outer faces of the piston heads 39 and 40.

This pressure is applied to the outer faces of the piston heads through the pipes or passages 28 and 29 which communicate with the cylindrical cavities 41 and 42, respectively, it being noted that at their other ends the passages 28 and 29 are coupled with the ports 26 and 27 in the main steam chest.

A summary of the operation is as follows, reference being had primarily to Figs. 1 to 4 inclusive in which the direction of movement of the valves 14 and the pistons 25 for each of the cylinders is indicated by the arrows. Figs. 1 and 3 as previously mentioned represent the left hand cylinder and Figs. 2 and 4 the right hand cylinder, with the positions of the parts shown in Figs. 1 and 3 corresponding, respectively, to the positions of the parts shown in Figs. 2 and 4.

In Figs. 1 and 2 it is to be assumed that the locomotive is just beginning to move after steam from the throttle has entered the passage 16 and the chamber 15. The righ hand cylinder shown in Fig. 2 will be the working cylinder. Inasmuch as the main passage 20 for the right hand cylinder is closed by the main valve, the necessary steam will have to be supplied through the starting passage 22.

The steam in chamber 15 will enter the port 27 and pass through the pipe 29 to the right hand piston head 40 in the chamber 12, thereby moving the motor device to the left so as to raise the poppet valve 37 and allow steam to flow in from the chamber 32, through the starting passage 22 and into the cylinder 12 through the'port 2 1.

Under the influence of this steam the locomotive will begin to move and very shortly thereafter main port 20 in Fig. 1 will be sutliciently uncovered so that live steam can be admitted to the working face of the piston 25 in cylinder 11.

Figs. 3 and 4 r present the positions of the parts at a somewhat later stage in the same stroke. In Fig. 3 the valve 14:, after having traveled to its extreme right hand position, is already moving back toward the left and beginning to close the main port 20 inasmuch as cut-oif must be effected at 50% of the piston stroke in accordance with the present disclosure.

In Fig. 4. piston 25 of the ri ht hand cylinder 12 has moved pretty nearly to the end of its stroke and the valve 14 has just uncovered the port 26 so that live steam pressure can flow through the pipe 28 to the chamber 41 at the left of the piston head 39. This pressure just balances the pressure previously introduced to the chamber 42 at the right of piston 49 so that the pressure of the live steam in the chamber 32 acting upon the upper face-of the :poppet valve 37 will cause this valve to move downwardly-and close the passage 22. Starting steam, *thereforais cut off at'this 'moment to the right hand face of the piston 25 in Fig. 4. The steam, however, will be working'ex- .pansively'until such time as thevalve 14 opens the mainpassage 20 to theexhaust at '18. However, at=the same time, the piston in cylinder '11 shown in Fig.3 'is creating torque because the -main:passage 29 in Fig.3 is open to live steam from the chamber 15. Fig. 4 represents the.:position which the parts of the starting device will assumeand hold during normal running of the locomotive 'justafter a start has beenmade.

The action wouldbe exactly'similar-to the' fore- 'goingat theother 'end'of the cylinder, but in the reverse direction so it need not be described again. It shouldbe -noted,however,in connection with the actuation of the various .parts in the mechanism just described that when either one of the valves 36 or 37 is moved to provide "communication between the steam chamber 32 and the auxiliary or starting steam passages 21 and 22, such opening movement is effected only during the first reciprocation of each piston 25 in the cylinders when the engine is started. This condition is brought about by virtue of the fact that the control ports '26 and 2'7 in the valve mecha- 'nism are never opened to exhaustby the valve '14 but at'all points in the cycle'are either closed by the main valve or are opened for communication with'thelive steam-cha'mber15 of -the chest. This action will be clear from inspection of Figure 2, for example, assuming that the locomotive has stopped or come to rest with the piston 25 at 'the :point of cut-off. In starting from this point, as noted above, starting steam is admitted through the passage 22 by virtue of the fact thatthecontrol port 27 is open -to receive live steam from the chamber 15 in the valve chest and thus effect 'a movement of the double headed piston device in the control 'mec'hanism'to the left. Asthe stroke proceeds the valve 14 moves to the left as indicatedby the arrow and 'uncoversthe control .port 26, at which time'steam pressure 'ilowsthere'in and counteracts the efit'ect of the pressure admitted through the other control port and thus creates what might be termed a balanced condition. That is, equal pressures are now applied to the outer faces of both'of the piston heads 39 and 40. Under these circumstances, the pressure in the chamber 32 acts to return the shaft 38 with its piston heads 39 and 40 to the central or mid position (see Fig. 6). This last mentioned action is produced in view of the eifect of the pressure in chamber 32 on the upper side 'of the valve '37, the force exerted in this way being 'sumc'ient to return the shaft 38 to the mid or central position. This central and balanced position of the auxiliary steam controlling mechanism is maintained at all times in the operation of the locomotive, with the exception of the first stroke in starting, for the reason that with each stroke of the main valve, the control ports 26 and 2'7 are opened to receive live steam from the chamber 15 in the steam chest, with the result that the equal pressures are retained at a constant value immediately after the starting stroke.

The mechanism for the control of auxiliary 'or starting steam disclosed in this application, therefore, provides for positive, as well as entirely automatic closing of the starting steam passages irnmediately after the first or initial movements or the locomotive. In this way, wastage of steam through the starting passages at times when admission is undesirable is "completely eliminated.

Very large and correspondinglyeffective'staiting passages, therefore, may be employed.

'Incorme'ction'with'the operation of the starting device it'ivill, of course, 'be und'erstoodthatwhenever the locomotive is being started there is no pressure present in the chai'nbers 11 and 42 because, after the throttle ha's'been closed, as'uflici'e'nt number of strokes, bothof the pistons 25 and of the valves 14, always take place tocomple't'ely "clear all passages of steam. No p'ressure,

therefore, will be trapped in the chambers 41 and 42 so that prop'er motion of the pistons 39 and"40 can take 'placewithout interference just as soon as the throttle of the locomotive is again'opened topermit'steam'to enter the chambers 15.

Iclaim: 1. Means for starting limited cut-off locomotive having the usual steam chest, main valve,

"and main steam passage, said means including in combination, a supplementary steam supply pas sage, a valve in said 'si'i'pplementary passage, means normally urging said valve to its closed position, a stea'in'actuated motor device *for opening said valve, 'asteam port in the steam 'chesto'f lat'e'r cut-bit than the main steam passage, and

a conduit for connecting said motor device with said port.

2. In a locomotive, the'combination of a cylinder, a piston, a steam chest, a main valve set to give a limited cut-'ofi in full gear position, main steam passages, supplementary steam supply passages, a normally closed valve in each supplemental-y passage, a double acting piston device for opening said valves, a steam port at each end of the steam chest of later cut-off than the main steam passages, and means connecting the opposite ends of said double acting piston with the corresponding ports, said piston acting to open one or the other 'of said valves until the opposing pressures on the piston become balanced.

'3. In a locomotive, the combination of acylinder, a piston, a steam chest, a main valve set to give a limited cut-off in full gear position, main steam passages, supplementary steam supply pas- T sages, a valve in *each supplementary passage, means normally urging said valves 'to their closed positions, a double acting piston device for opening said valves, a steam port at each end of the steam chest of later cut-off than the main steam passages, and means connecting the opposite ends of said double acting piston with the 'correspond ing ports, said "double acting piston acting to open one or the other of said valves until the opposing pressures on the piston become balanced.

valve against the closing pressure, a port in the chestcontrolled by the main valve, but of later cut-oft than said main passage and means establi'shing communication between the 'control port and the motor device.

5. In a starting mechanism for a limited cutthis o'ff locomotive having the usual main steam supply and valve "mechanism, a starting steam passage communicating with a source of steam supply independent of the main valve mechanism, a valve in said passage normally closed by steam pressure i therein and a motor device for opening said valve responsive to changes in position of the main valve.

6. In a starting mechanism for a limited cut-off locomotive having the usual main steam supply and valve mechanism, a starting steam supply chamber, a pair of starting passages communicating with the chamber, normally closed valves controlling flow of steam from the chamber into the passages and means for opening said valves, the operation of said means being dependent on changes in position of the main valve, and the said means including a double headed piston device mounted for reciprocation in said chamber with one face of each head exposed to steam pressure therein and operating connections between the piston device and said valves including a pivoted member having levers extended to engage the piston device and the valves.

7. In a starting mechanism for a limited cutoff locomotive having the usual main steam supply and valve mechanism, a starting steam supply chamber, a pair of starting passages com municating with the chamber, normally close valves controlling flow of steam from the chamber into the passages and means for opening said valves, the operation of said means being dependent on changes in position of the main valve, and the said means including a double headed piston device mounted for reciprocation in said chamber with one face of each head exposed to steam pressure therein and operating connections between the piston device and said valves including a pivoted member having levers extended to engage the piston device and the valves, all of said parts being positioned within the starting steam supply chamber.

8. In a starting mechanism for a limited cutoff locomotive having the usual main steam supply and valve mechanism, a starting steam supply chamber, a pair of starting passages communicating with the chamber, valves controlling flow of steam from the chamber into the passages and normally closed by the steam pressure therein and means for opening said valves against the closing pressure, the operation of said means being dependent on changes in position of the main valve and the said means including a piston device and operating connections between the device and the valves.

9. In a starting mechanism for a limited cutoff locomotive having the usual main team supply and valve mechanism, a starting steam supply chamber, a pair of starting passages communicating with the chamber, valves controlling flow of steam from the chamber into the passages and normally closed by the steam pressure therein and means for opening said valves against the closing pressure, the operation of said means being dependent on changes in position of the main valve and the said means including a piston device and operating connections between the device and the valves, said device and connections being positioned within the starting steam chamber.

10. In a limited cut-off locomotive, a cylinder having a main steam supply valve mechanism, starting steam passages, a control valve for each of said passages and actuating means for the valves including ports communicating with and controlled by the main valve mechanism and a fluid pressure operated member associated with said ports and actuated by passage of steam therethrough, the said member being operative- 1y coupled with both of the control valves by means of a double rocker-like element.

11. In a limited cut-cit locomotive, a cylinder having a main steam supply valve mechanism, starting steam passages, a control valve for each of said passages and actuating means for the valves including ports communicating with and controlled by the main valve mechanism but of later cut-off than the main passages, and a fluid pressure operated member associated with said ports and actuated by passage of steam therethrough.

12. In a limited cut-off locomotive, a cylinder having a main steam supply valve mechanism, starting steam passages, a control valve for each of said passages and actuating means for the valves including ports communicating with and controlled by the main valve mechanism but of later cut-oil than the main passages, and a fluid pressure operated member for opening said valves, the said member being associated with said ports and actuated by passage of steam therethrough.

13. In a limited cut-off locomotive, a cylinder having a main steam supply valve mechanism, st rting steam passages, a normally closed control valve for each of said passages, and actuatin means for the valves including ports communicating with and controlled by the main valve mechanism but of later cut-ofi than the main passages, and a fluid pressure operated member for opening said valves, the said memher being associater with said ports and actuator by passage of steam therethrough.

14. In a limited cut-off loccmotive; a cylinder; a main steam supply chest having exhaust and live steam chambers, main steam passages and a main valve; a starting steam passage for each end of the cylinder communicating with the live steam chamber; and a mechanism for controlling steam flow in the starting passages including a normally closed control valve in each passage, and means for opening control valves including a chamber with a piston device working therein and passages for supplying steam to opposite sides of the piston device, the said sages communicating with the main steam chest and being controlled by the main valve but being of later cut-01f than the main steam passages.

15. In a limited cut-off locomotive having a cylinder and a main steam supply valve mechanism, the combination of a starting steam chamber, a starting passage for each end of the cylinder extending between th cylinder and said chamber and valve means associated with said chamber and said passages and controlling ad mission from the former into the latter, said valve means being arranged to close under the influence of steam pressure in said chamber, and

a device for opening the valve means against the pressure in the chamber including an actuating member positioned in the chamber with a pair of piston elements forming portions of the wall of the chamber and an operating connection between the valve means and the actuating member.

16. In a limited cut-off locomotive having a cylinder and a main steam supply valve mechanism, the combination of a starting steam chamber, a starting passage for each end of the cylinder extending between the cylinder and said chamber and valve means associated with said chamber and said passages and controlling admission from the former into the latter, said valve means being arranged to close under the influence of steam pressure in said chamber, and

a device for opening the valve means against the pressure in the chamber including an actuating member positioned. in the chamber with a pair of piston elements, one face of each of which cooperates in completing the chamber enclosure, an operating connection between the valve means and the actuating member and means for applying steam pressure to the other face of each one of the piston elements.

17. In a limited cut-on locomotive having a cylinder and a main steam supply valve mechanism, the combination of a starting steam chamber, a starting passage for each end of the cylinder extending between the cylinder and said chamber and valve means associated with said chamber and said passages and controlling admission from the former into the latter, said valve means being arranged to close under the iniiuence of steam pressure in said chamber, and a device for opening the valve means against the pressure in the chamber including an actuating member positioned in the chamber with a pair of piston elements, one face of each of which cooperates in completing the chamber enclosure, an operating connection between the valve means and the actuating member and means for applying steam pressure to the other face of each one of the piston elements, the pressure applied through said last mentioned means being controlled by the main valve mechanism.

18. A starting steam control mechanism including a chamber with means for supplying live steam thereto, a starting passage communicating with the chamber and a poppet valve for controlsteam thereto, a pair of startin passages communicating with the chamber, a valve for each passage controlling fiow of steam thereinto from the chamber and positioned in such manner with respect to the chamber as to cause a closing ,movement thereof under the influence of steam pressure in the chamber and control means for the valves including a double-headed piston device connected to the valves and means for actuating said device.

20. A starting steam control mechanism including a chamber with means for supplying live steam thereto, a pair of starting passages communicating with the chamber, a valve for each passage controlling flow of steam thereinto from .the chamber and positioned in such manner with respect to the chamber as to cause a closing movement thereof under the influence of steam pressure in the chamber and control means for the valves including a double-headed piston device one side of each head of which is exposed to steam pressure in the chamber, operating connection means between the valves and the device and means for applying steam pressure to the other side of each head of the said device.

21. In a locomotive the combination of a cylinder, a piston, a valve chest, main steam passages, a valve set to give a limited cut oil when in full gear position, an auxiliary steam supply passage for each end of the cylinder, means normally closing said auxiliary passages, a control port at each end of the valve chest of later out 01f than the main port, and a motor device controlled by steam from one of said ports to open said closing means and by steam from the other control port to efiect a closing of said means during the first stroke of the piston.

22. in a starting mechanism for a limited cutoff locomotive, the combination of a cylinder, a piston, a valve chest, main steam supply passages between the chest and the cylinder, a main valve set to give a limited cut-off in full gear position, starting steam supply passages, valve means normally closing said starting steam supply passages, a control port at each end of the valve chest of later cut-off than the main passages, means for moving said valve means to open one of said starting steam supply passages upon admission of steam pressure to one of said control ports during the first stroke of the piston, and means for moving said valve means to effect a closure of said starting steam supply passage upon the subsequent admission of pressure to the other of said control ports during the first stroke of the piston.

23. Means for starting a limited cut-off steam locomotive including in combination with the usual cylinder, piston, steam chest, main valve, and main steam ports and passages, a supplementary passage to each end of the cylinder for supplying steam to start the locomotive, means normally closing said passages, a motor device for opening said means, a control port at each end of the steam chest of later cut-off than the main port, means for delivering steam from one of said control ports to said motor device to effect the opening of the closing means for one of said supplementary passages, and means for subsequently delivering steam from the other of said control ports to said motor device to effect the closing of the means which was opened by steam from said first mentioned control port.

24. Means for starting a limited cut-01f steam locomotive including in combination with a cylinder, piston, steam chest, main valve, and main steam ports and passages; a supplementary passage to each end of the cylinder for supplying steam to start the locomotive, a valve normally closing each supplementary passage, a control port at each end of the steam chest of later cut off than the main port, a reciprocatory operating member for controlling the valves in the supplementary passages, means for delivering steam from one of said control ports to said reciprocatory member to effect opening of the valve in one of said supplementary passages, and

means for subsequently delivering steam from the other of said control ports to said reciprocatory member to effect the closing of said valve after the locomotive has been started.

25. Means for starting a limited cut-off steam locomotive including in combination with a cylinder, a piston, steam chest, main valve, and main steam ports and passages; a supplementary passage to each end of the cylinder for supplying steam to start the locomotive, a valve normally closing each supplementary passage, a control port at each end of the steam chest of later cut ofi than the main port, a double head piston device having opposed faces on the said heads exposed to the pressure of the steam in the steam chest, operating connections between said double head piston and the valves in the supplementary passages, means for delivering steam from one of said control ports to one of the two remaining faces of said double head piston to effect opening of the valve in one of said supplementary passages, and means for subsequently delivering steam from the other of said control ports to the other of said remaining faces to effect the closing of said valve after the locomotive has been started, the double head piston, during operation of the locomotive, being held in a neutral position by a balance of pressures whereby both supplementary valves remain closed.

26. Means for starting a limited cut-oil steam locomotive including in combination with the usual cylinder, piston, steam chest, main valve, and main steam ports and passages, a supplementary passage to each end of the cylinder for supplying steam to start the locomotive, means normally closing said passages, a motor device for opening said means, a control port at each end of the steam chest of later cut-off than the main port, means for delivering steam from one of said control ports when uncovered by said main valve to said motor device to efiect the opening of the closing means for one of said supplementary passages, and means for subsequently delivering steam from the other of said control ports when uncovered by the main valve to said motor device to effect the closing of the means which was opened by steam from said first mentioned control port.

ALBERT J. TOWNSEND.

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