US2060278A - Locomotive steam cut-off control means - Google Patents

Description

N0V 10, 1936 E. E. CHAPMAN ET AL 2,060,278

LOCOMOTIVE STEAM CUT-OFF CONTROL MEANS Filed Nov. 7, 1931 4 Sheets-Sheet 1 s* z A rnv 'd ssp' l E A l a y NOV. 10, 1936. E,4 E CHAPMAN ET AL 2,060,278

LOCOMOTIVE STEAM CUT-OFF CONTROL MEANS Filed Nov. 7, 1951 4 Shee'l'.s-Sheel'I 2 Nov. 10, 1936.

E. IE. CHAPM'AN ET AL LOCOMOTIVE STEAM CUT-OFIIT1 CONTROL MEANS Filed Nov. 7, 1931 211v Sheets-Sheet 5 n SPSS mhmobm N0 10, 1936. E. E. CHAPMAN ET AL 2,050,278

LCOMOTIVE STEAM CUT-OFF CONTROL MEANS Filed NOV. 7, 1951 4 Sheets-Sheet 4 Patented Nov. 10, 1.936

UNiTED STATES PATENT FFIQE.

LOCOMOTIVE STEAM CUT-OFF CONTROL ANS Application November 7, 1931, Serial No. 573,560

4 Claims.

Our invention relates more particularly to a steam cut-oil control for locomotives whereby a novel limited cut-ofi starting valve arrangement is provided.

The invention has for its object the provision of means adapted to admit additional steam to the cylinders of the locomotive, after the main cut-ofi has been effected, for the purpose of providing additional power in moving the cylinder piston to the limit of its stroke; in other words, the purpose of our invention is to maintain full steam pressure in the cylinder after the main steam admitting port has been cut off, while at the same time preventing excessive preadmission of steam to the cylinder.

The objects and advantages of our invention will be readily comprehended from the detailed description of the particular exempliication of the invention which may have expression in modiiied embodiments.

In the drawings:-

Figure l is a longitudinal sectional View of a locomotive steam chest and. its piston-valve and a portion of a cylinder and its piston, with our improved means associated therewith; one part of said means being in section while the other part is in elevation; the operating medium conveying pipes being broken away.

Figure 2 is a side elevation of the locomotive reverse lever provided with our improved means, and showing portions of the operating medium conveying pipes with a portion shown in section.

Figure 3 is an end elevation of the mechanism shown in Figure 2 with a portion broken away.

Figure 4 illustrates, in side elevation, an arrangement of air pipes and valves for manual control.

Figure 5 is a detail sectional View of the hand operated valve shown in Figure 4, illustrating the valve condition when the hand lever is in the position shown in Figure 4.

Figure 6 is a similar view showing Valve condition when the hand lever is at an intermediate or Vertical position.

Figure 'I is a similar view showing the valve condition when the hand lever is in the opposite position from that shown in Figure 4.

Figure 8 is a diagrammatic View illustrating the reverse lever automatic control of the starting valves, with the pressure medium pipes.

Figure 9 is a similar view illustrating a modification involving booster mechanism and manual control whereby the starting valves may be actuated independently of the reverse lever.

Our invention relates to means whereby additional steam is admitted to the cylinder after the main steam port has been cut 01T or closed by the piston-valve in the steam chest, in order to provide additional power for moving the cylinder piston to the limit of its stroke, or to maintain full steam pressure in the cylinder after the main steam admitting port has been closed or cut off,a condition especially desirable when the locomotive is starting or moving a heavy train at slow speedwhile at the same time providing means which prevents excessive pre-admission of steam.

The invention, as exemplified in the drawings, is shown applied to a well known type of locomotive steam chest or chamber indicated at I8, associated with the cylinder of which only a portion is shown at II.

The steam chest Ii), at an intermediate point,

is provided with the usual steam receiving inlet as at I2; and steam passages or ports between the steam chest and 'the opposite ends of the cylinder are shown at i3, Iii.

The steam chest Ill, to opposite sides of the inlet, is provided with the usual sleeves or valve cages I5, I5, having the usual circumferentially arranged ports i6 communicating with steam passages in the wall of the steam chest and which in turn connect with the passages or ports I3, I4 leading to opposite ends of the cylinder Ii. A well known type of double piston slide valve is shown at Il, for controlling passage of steam from the intermediate steam incoming portion of the steam chest to the main steam ports I6 and hence to ports I3, I4. The opposite ends of the steam chest or chamber I0, are, of course, p-ro-l vided with the usual exhaust channels at i8.

The valve cages I5, at a predetermined point intermediate of the main ports I5 and the inner ends of the cages, are provided with auxiliary ports I9, which communicate with the passages 2li in the wall of the steam chest. The relation between the ports I6 and I9 and the Width of the heads of piston valve Il is such that the main ports I6 will be cut ofi before the st/eam edges of the Valve-heads reach the auxiliary ports i9 during the return stroke of the valve Il toward the opposite end oi the steam chamber I8.

The steam chest or chamber It, at opposite ends, is provided with a chambered housing 2l, provided in its bottom with a steam inlet port 22 arranged in steam tight communication with each steam passage '2li in the steam chest wall. One chamber 23 of each housing ZI is provided with a valve 24, adapted to close in the direction of flow of steam through port 22; the valve 24,

at the left in Figure 1, being shown depressed off its seat 25, thus allowing steam to flow into chamber 23 from the steam chest l0 while the pistonvalve li is in the position shown in Figure 1.

Chamber 23 of each housing 2| has a suitable outlet pipe 2S which leads down toward the cylinder and is suitably formed and connected with a port 27 in the wall of the cylinder Il. A port 21 is provided in each end of the cylinder at a predetermined distance from the main steam passages I3, lli; and these ports 21 in turn communicate with the small ports 28 in the cylinder liner or bushing 29 with which the bull-rings of the piston 33 having sliding steam-tight relation.

The valve 24, which is preferably shown somewhat in the nature of a poppet type of valve, is controlled or depressed by means of the bell-crank lever 3| suitably mounted in the housing 2i with its one end shown disposed upwardly and pivotally secured to the stem 3L of a slidable valve 33 mounted in the chamber 313 of the housing 2l. The valve 33 is held in its normal position by the action of spring 35; the valve 33, at the left in Figure 1, being shown in its actuated position induced by the air pressure in chamber 34.

The chamber 34 has a minute port 33 which communicates with pipe 37 which' leads to an air valve casing 33 shown in Figures 2, 3 and 4. The valve casing 38 is of a well known type provided with what is known as a pilot valve shown at 33 in Figure 2; the casing being also provided with the usual small air bleeding port at 38a. In view of auxiliary steam conveying and controlling means at both the ends of the steam chamber, it will be understood that the pipe 37 leading from valve casing 38 (see Figure 4) at its other end has two branches leading to the two air chambers 34 as shown in Figure 1.

This valve casing is suitably mounted adjacent to the lower' end of the usual locomotive reverse lever ll0; and the valve casing 38 has a pipe 4l connected with the main air reservoir A on the locomotive.

Mounted adjacent to valve casing 38 is a floating or vertically oscillatable lever 42, fulcrumed at 43; with the long depending arm of the lever l2 positioned so as to normally be in contact with and adapted to actuate or depress the stem 39 of the air pilot valve located in valve casing 38. The lever 42 is also provided with an upstanding arm 42a above the fulcrum point of the lever; and also preferably provided with an arm 42h extending laterally from the lever and adapted to contact with a suitable stop lug, as at 44, to prevent the too far outward swing or movement of the lever, namely to the right as viewed in Figure 2.

Associated with the reverse lever 4D, so as to move therewith, is the floating lever controlling means shown provided with arms l5 and 33. In the particular embodiment disclosed in the drawings, this means is shown comprising a hub portion 41 secured to the reverse lever 40.

The arms 45 and 43 are shown integral with the reverse lever 4D, so as to cause said arms to move with reverse lever 40.

As is apparent from the construction shown in Figure 2, when reverse lever 13!! is moved to the left, arm 35 will contact with short arm l2L of the floating lever 42 and cause the lower end of said lever to actuate stem 39 of the pilot valve in the casing 38; while movement of the reverse lever 4D to the right will move arm 45 away from the short arm 42e and cause arm ist to engage the lower end of the iioating lever l2 and force the latter into operating relation with the stem 39 of the pilot valve in casing 38.

As the air pilot Valve may be of a well known construction at present in use, detailed description thereof is not deemed necessary; it being understood that the pilot Valve is normally held on its seat so as to prevent passage of compressed air from supply pipe il through the casing 33 and into pipe 31 by means of the spring shown at 39a.

The piston 30 is shown at an intermediate point in cylinder l l and is assumed to be moving toward the right inFigure 1,with the piston-valve I1 in the steam chamber having traveled suiciently toward the right where it has closed oi steam admission through the main steam port I6 at the left of the steam chamber l0, while the auxiliary port i 3 at said end is still in steam admitting condition; the main port i3 and auxiliary port i9 at the right hand end of the steam chamber l0 being closed by the piston valve l'! against steam admission.

When reverse lever (il) is placed in either extreme foward or extreme backward position, the air valve in casing 38 will be opened by means of arm 45 or arm 45, which in turn actuate lever 42 so as to engage the air valve-stem 39. When this air valve is open compressed air from the main air reservoir of the locomotive will ilow through pipe 3? into air chamber 33. entering chamber 34 will force piston 33 against the action of spring 35, causing lever 3l to be rocked on its fulcrum point, which in turn will force valve 21'! downwardly oir its seat and permit steam to flow from port 2B into chambers 23 and thence into auxiliary steam pipe 2B, as shown at the left in Figure l.

When reverse lever 4U is moved a suitable distance away from either of its extreme positions, the air valve 39 will close the valve being usually provided with a spring for normally moving it toward its seat) and shut ol supply of compressed air to pipe 3?, allowing the air contained in pipe 3'! and chamber 34 to exhaust through a minute bleeding or vent port 38a. The spring 35 will then cause piston 33 to move toward the left in Figure 1, back to normal position, thereby rocking bell-crank lever 3l upwardly, which in turn will pull valve 2li upwardly to its seat, thereby cutting oir admission of steam into chamber 23 and into pipe 25.

In other words, the starting means is put into operation by the opening of the valve 23 at oppcsite ends of the steam chamber; it being understood that the construction and operation of the means at the right of the steam chamber is identical with that shown in section at the left and as heretofore described; the mechanism at the left being operative when the piston valve I'l is at the left hand end of the steam chamber, and the reverse lever 3B is in one of its extreme positions, while the mechanism at the right comes into play when the piston valve l? is at the right-hand end of the steam chamber and the reverse lever is in one of its extreme positions.

In the drawings, it is assumed that either arm 45 or arm 33 is in the dotted line position shown in Figure 2, thus admitting air through air valve 39 into both pipes 3'.' and chambers 34 of the chambered housings 2i at both ends of the steam chamber l0. Therefore, the valve 24 in both housings 2l have been moved or depressed ol their seats 25 so as to establish communication between the steam ports 20 in the wall of the steam chamber EL' and the two pipes 26 leading to opposite ends of the cylinder ll. In Figure 1 we n The compressed air have shown the piston 30 in full lines in one phase of its operation and in dotted lines in another phase of its operation, but for clarity in the drawings have not endeavored to show different phases of piston-valve operation or positions.

It is understood, ho-wever, that the operations of the piston-valve I 'I, piston 30 and the locations of auxiliary ports I9 and ports 2'I-28 are so correlated that admission of steam through ports 21-28 takes place at either one end or the other, after the piston has traveled in its return stroke toward the opposite end of the cylinder far enough to uncover the adjacent port 28 and valve I'I has traveled suiciently to admit steam through the complemental auxiliary port I9.

In Figure 1, piston 3G in the dotted lines and the valve Il are both moving toward the back limit of their respective travels; the valve I1 having uncovered auxiliary port I9 at the left while main port I6 at the left is still covered or shut off. Live steam therefore may enter said auxiliary port I9 and ll the associated pipe 26 and port 2'I. The steam, however, is prevented from entering the cylinder il because port 28 is covered by the piston 3G. 'I'his arrangement of ports is quite essential, particularly when auxiliary ports of large area are employed, as steam admitted to the back end of the cylinder when the piston is moving toward the end of its travel would cause what is commonly termed excessive preadmission and would seriously interfere with tne normal movement of the piston.

The piston 30 in full line position is moving toward the forward limit of travel. The pistonvalve Il at this time is also presumed to be moving toward the right in Figure 1, having closed off main port I6 (after having been opened for steamadmission in the usual manner) but not sufliciently to close off the associated auxiliary port I9, and, of course, not suiciently to open the ports at the right hand end of the steam chamber. With the auxiliary port I9 still open, live steam may ow through this port, through chamber 23 (valve 22 being open) into pipe 26, through ports 21-28, into the back end of the cylinder I I, thus maintaining steam pressure behind the piston 3B after the main steam port I6 has been closed or covered by the steam valve Il.

This function of our improved means, namely admitting steam after the main steam ports have been closed, is desirable in starting the locomotivey or when moving a heavy load at very slow speed. It is not desirable, however, at ordinary speeds, and therefore we have devised our improved means so as to be operable only when the reverse lever 40 has been placed in either of its extreme positions, positions which are not assumed in the ordinary running speed of the locomotive. Hence, valves 24 will be closed during the ordinary or normal operation of the locomotive, as reverse lever 40 is kept in its extreme forward or backward position only when the locomotive is starting a train or moving very slowly.

Consequently, by reason of our improved means and its arrangement, the appropriate manipulation of the reverse lever 40 causes the respective valves 24 to be operated in accordance with the best practice without necessitating extra effort or attention on the part ci the enginemen.

It is understood, of course, that a similar condition obtains at the right of the steam chamber and cylinder during the reciprocating movements of the piston-valve I'I and piston 30, when the reverse lever 4D is in one of its extreme positions.

We .have described the exemplication of our invention, shown in the rst three gures of the drawings, wherein the pneumatically operated starting valves of our limited cut-off arrangement are designed so that under normal operating conditions the starting valves will open auto'- matically when the reverse lever 40 is placed in either of its extreme positions.

Our improved system or means is also designed so that the starting valves may be manually controlled by the enginemen independently of the reverse lever if desired. The arrangement of pipes and valves, whereby this may be accomplished, is shown in Figures 4 to 7, inclusive.

During both automatic and manual operations, compressed air is admitted to the system through the pipe 4I.

Where the locomotive is provided with a booster, compressed air for coordinating the actions of the starting valves with those of the booster is obtained from the pneumatic control system of the booster through the pipe 48 which is provided with a non-return check valve at 49 in order to prevent back flow of compressed air through the cock or valve D and pipe 48. The pipe arrangement and v-alve 50, which is provided with hand lever 5I, enables manual operation of the starting Valves as well as coordination of the action between the starting valves and the booster (if one is employed). The valve 5) receives compressed air from pipe 4I by the pipe 52 while the opposite side of the valve or cock is provided with a pipe 53 which is shown connected by means of pipe 54 with pipe 3l on one side of the locomotive and connected by means of pipe 54.EL with the air chambers 34 located on the opposite sides of the locomotive and in manner similar to pipe 3l, whereby compressed air is admitted into all of the air chambers 34 on both sides of the locomotive as previously described.

With the valve or cock 59, namely with its hand lever 5I in the position shown in Figures 4 and'5, our improved means is shown innormal running position, thus enabling the starting valves to open automatically when the reverse lever 40 is placed in either of its extreme positions, or when the booster (if one is employed) is cut in by means of a suitable valve as shown in Figure 4 by booster operating valve a. The starting valves will also close automatically, as previously described, when the reverse lever is placed to running position or when the booster (if one is used) is cut out by closing'booster operating valve a.

Assuming the reverse lever 49 to be at or near its central position (and the booster not in operation), compressed air in the locomotive main reservoir would be present in pipes 4I and 52 and would be retained therein by the valve or cock 56 when the latter is in the position shown in Figures 4 and 5 and the air would also be held by the valve 33 (which is normally closed). The air in pipe 48 would be at atmospheric pressure with the boosternot in operation. If the reverse lever 40 should then be moved to either of its extreme positions, the valve 38 would be unseated, exhaust or vent'port 38a Will be closed by the stem 39 of valve 38 and compressed air would flow from pipe 4I through valve body 38 in the manner hereto-fore described. When the reverse lever 40 is moved away from an extreme position, valve 38 is restored to its seat and the exhaust or vent port 38@L is opened causing the air to exhaust from pipe 3'! and chamber 34 by means of port 36 and allowing spring 35 to force the piston 33 to normal position, thereby rocking bell-crank lever 3l and lifting valve 24 to its seat, the air in pipes 54 and 3l' exhausting through the port 38a.

Locomotive boosters are operated by a pneumatic control system devised therefore; the booster being placed in operation by the admission of compressed air from the locomotive main air reservoir as shown at A in Figure 4 into the booster control system and the booster is cut out by exhausting the air from its control system by a suitable vent opening in the booster control valve.

On a booster type of locomotive, with the valve 50 in the position shown in Figures 4 and 5, the starting valves would open automatically when the booster is cut in by opening valve a, located in pipe 58, connected with pipe 4l, and having connection with pipe 5l which is connected by pipe 56 with pipe 48, because the compressed air reaches the starting valve cylinders from the booster control system by passing through pipe 48 and into pipes 53 and 54a. When the booster is out out, the supply of air through pipe 48 will also be cut oi and air from the starting valve cylinder would be exhausted through the restricted vent port 38a of the valve 38. If a quicker closing of the starting valve is desired, the handle 5| of valve or cock 55 may be moved to the position indicated in Figure 6 which places the valve in the position shown in said gure, thereby allowing air from pipes 53, 5d and 3'! to exhaust through the vent port 55 shown in Figure 6 arranged in the valve 58; this vent port acting in addition to the vent port 38a as previously described.

If it is desired to manually open the starting valves heretofore described at any time independently of the reverse lever and locomotive booster (if one is employed), this may be accomplished by proper manipulation of the handle 5I of valve or cock by moving the handle 5l to the position shown in Figure 7, thereby allowing air from pipe ll and pipe 52 to pass through the valve 55 into pipe 53 and into pipe 5de which is connected with the respective chambers 34 on the opposite sides of the locomotive. The starting valves would then open irrespective of the reverse lever position or regardless of whether the locomotive booster is cut in or out.

By moving handle 5l of valve or cock 5G to the position shown in Figure 6, air will be exhausted from the operating cylinders through vent ports 38aor 55 or both when the starting valves will immediately close.

It is desirable to have the starting valves open at all times when the locomotive is working under conditions which necessitate placing or keeping the reverse lever in either of its extreme forward or backward positions. Consequently no provision is made for forestalling the automatic opening of the starting valves when the reverse lever is in either of its extreme positions. It is similarly desirable to keep the starting valves open when the booster is in operation, although the booster may be used for short periods of time at speeds above those which call for extreme full gear position of the reverse lever. The arrangement is therefore made so that starting valves will open automatically when the booster is cut in, but with the starting valves open under conditions of booster operation and with the reverse lever removed from its extreme position, the vent port 38at will discharge air continuously from pipe 54 as long as the starting valve cylinders are receiving air from the booster control system. This discharge of air warns the engineer and prevents him from overlooking the duty of closing the starting valves promptly when the necessity for their use is past, the closing operation being performed by moving the handle 5l of cock 59 into the position shown in Figure 6.

Vent port 55 sounds a similar warning if the handle of cock 59 is inadvertently left in the position shown in Figure 6 and allowed to remain in that position when the reverse lever is again placed in either of its extreme positions. This Warning reminds the engineer of his duty to maintain the handle of cock 5i) in position shown in Figures 4 and 5 at all times except when service condition requires it to be in other positions.

It is obvious that on a locomotive which is not equipped with a booster and where manual operation of the starting valves is not contemplated, that cock 5G, the booster operating valve a, pipes 48, 52, 53, 56, 5l and 58 and the booster cylinder mechanism, as shown in Figure 4, are not needed and may be omitted; while pipes 563 and 54a with its bifurcated end then in reality are made as continuations of pipe 3l to connect with both starting valves on each side of the locomotive, as previously described.

We have shown desirable embodiments of our invention, which have been described in terms employed merely as terms or description and not as terms of limitation, as structural modications may be made without, however, departing from the spirit of our invention.

What We claim is:-

1. In a locomotive provided with cylinders, steam chests, a reverse lever and a fixed pivot point for the lever, the combination of auxiliary steam admission ports at opposite ends of the cylinders; independent steam conveying conduits intermediate of points in the steam chests controlled by the main valve in said chests and the said auxiliary ports at opposite ends of the cylinders; a valve in each of said conduits for controlling passage of steam to the auxiliary ports of the cylinders when the main valves of the steam chests are in predetermined positions; separate air operated means for separately controlling the valves in said conduits; a compressed air supply for said air operated means; a normally closed valve located adjacent to said reverse lever for controlling the iiow of compressed air to said air operated means; a loosely pivoted member disposed beneath the reverse lever with one end arranged in operative relation with said normally closed valve; and a pair of depending arms associated with the reverse level` and extending to opposite sides of the vertical plane of the pivot point of the reverse lever, each arm being adapted to actuate said loosely pivoted member when the reverse lever is moved to either one of its extreme positions.

2. In a locomotive provided with a reverse lever, a pivot point for said lever, cylinders, and steam chambers provided with piston valves and main steam ports at opposite ends controlled by said piston valves; the combination of aufrliary steam ports in said steam chambers at opposite ends adjacent to the main steam ports, said auxiliary steam ports being controlled by said piston valves; auxiliary steam admitting ports at opposite ends of the cylinders; steam conveying conduits intermediate of the respective auxiliary ports at the same ends of the steam chambers and the cylinders; a valve in each of said conduits closable in the direction of flow of steam through said conduits; air operated means for controlling said last valves; a compressed air supply line for said air operated means provided with a selfclosing valve disposed adjacent the fulcrum point of the reverse lever; movably mounted means beneath the reverse lever for actuating said selfclosing valve; and bifurcated means associated with the reverse lever and extending to opposite sides of the pivot point of said lever, with the bifurcations of said means adapted to actuate the movably mounted means when the reverse lever is moved into either one of its extreme positions.

3. In a locomotive provided with a reverse lever, cylinders provided with pistons, and steam chambers provided with piston valves and main steam ports at opposite ends communicating With opi posite ends of the cylinders; the combination of auxiliary ports in said steam chambers adjacent said main ports and controlled by said piston valves; auxiliary steam admitting ports adjacent the ends of the cylinders and closable by the pistons of the cylinders; separate steam conveying conduits intermediate of the auxiliary ports at the corresponding ends of the steam chambers and the cylinders adapted to admit an auxiliary steam supply to the cylinders after the pistons are on their return stro-kes; normally closed valves in said conduits for controlling the iiow of steam therethrough; pressure medium operated means for opening said normally closed valves; a pressure medium supply line communieating with said last mentioned means and provided With a normally closed pilot valve disposed adjacent to the reverse lever; a member pivoted intermediate of its end and arranged beneath the reverse lever with one end thereof adapted to engage the pilot valve to open same; and a bifurcated lever operatively associated with the reverse lever, the bifurcations of the lever being adapted to engage with opposite sides of one end of said pivoted member and thereby force the other end of said pivoted member into valve operating position when the reverse lever is moved into an extreme forward or extreme backward position.

4. In a locomotive provided with a reverse lever, steam chests provided with piston valves, and cylinders provided with pistons; the combination of auxiliary steam ports adjacent opposite ends of the steam chests and controlled by said piston valves; auxiliary steam ports adjacent opposite ends of the cylinders and closable by the pistons; separate steam conduits intermediate of the auxiliary ports at the corresponding ends of the steam chests and of the cylinders whereby auxiliary steam supplies to opposite ends of the cylinders may be provided; normally closed valves in said conduits for controlling the iiow of steam therethrough; housings, each provided With a spring controlled piston operable by a pressure medium; bell-crank levers intermediate of the spring controlled pistons in the housings and the valves in said auxiliary steam conduits; pressure medium supply lines connected with said housings and with a main pressure medium supply line; a normally closed valve in said pressure supply line arranged adjacent the fulcrum point of the reverse lever; a member pivoted intermediate of its ends With one end in operative relation with said last mentioned normally closed valve; a pair of arms depending from the fulcrum point of the reverse lever and adapted to engage one end of said pivoted member when the reverse lever is moved to either one of its extreme positions whereby said last mentioned normally closed valve is opened, pressure medium admitted to said housings, the spring controlled pistons actuated and said bell-crank levers tilted so as to open the normally closed valves in the auxiliary steam conduits and thereby admit an auxiliary steam supply to the cylinders.

EARL E. CHAPMAN. HOWARD I-I. LANNING.

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