US1950463A - Controlling means for locomotive auxiliary ports - Google Patents

Description

H. J. TITUS March 13, 1934.

CONTROLLING MEANS FOR LOCOKOTIVE AUXILIARY PORTS Filed Aug. 4, 1928 2 Sheets-Sheet 1 I NVENTOR BY ya Yr ATTORNEYS H. J. TITUS March 13, 1934.

CONTROLLING MEANS FOR LOCOMOTIVE AUXILIARY PORTS Filed Aug. 4. 1928' 2 Sheets-Sheet ATTORNEYS Patented Mar. 13, 1934 R UNITED STATES PATENT OFFICE CONTROLLING MEANS FOR LOCOMOTIVE AUXILIARY PORTS Application August 4, 1928, Serial No. 297,427

3 Claims.

This invention relates to auxiliary port controlling means and is particularly applicable to locomotives which are equipped with What is now well known in the art as a limited cut-oii.

One of the important objects of the invention is the provision of means for closing the auxiliary or starting ports of a limited cut-off locomotive which may be operated at the will of the engineer in order to prevent waste of steam through such auxiliary ports when they are not required or not necessary in driving the locomotive.

More specifically the present invention contemplates the provision of means actuated by movement of the locomotive reverse gear for controlling the steam flow through the auxiliary or starting ports.

How the foregoing together with other objects and advantages are obtained will appear more readily from a consideration of the following description taken together with the accompanying drawings which illustrate a preferred embodiment.

Of the drawings:

Fig. 1 is a somewhat diagrammatic fragmentary side view of a locomotive with the auxiliary port controlling mechanism applied thereto;

Fig. 2 is a longitudinal sectional view of the valve mechanism employed for closing and opening the auxiliary port communications between the cylinders and their steam chests;

Fig. 3 is a sectional view througha steam chest and a portion of the associated cylinder illustrating an auxiliary port arrangement;

' Fig. 4 is a sectional view of the controlling 95' means for the auxiliary port valve mechanism which is adapted to be actuated by movement of the locomotive reverse lever and Fig. 5 is a sectional view illustrating certain details of the controlling mechanism.

Referring now particularly to Fig. 1 the reference character 6 indicates one of the locomotive cylinders and '7 indicates the steam chest which is associated therewith. The auxiliary ports in the steam chest communicate with the auxiliary port valve mechanism A through the pipes 8. The mechanism A in turn is provided with pipes 9 through which communication with the cylinder is had.

The controlling means for the mechanism A comprises a pilot valve B mounted at each end of the reverse lever quadrant 12 in position to be actuated by the reverse lever 13 when the latter is thrown into either corner. The valves B are adapted to supply fluid pressure (usually air) to 86 the mechanism A mounted on the cylinder 6 through the pipes 14 or 15 and 16. The pressure is supplied to the valves B from the reservoir 17 through the connections 18. The pipes 14 and 15 extend from the valves B to the double check valve mechanism 0 through which they communicate with the conduit or pipe 16 leading to the mechanism A.

Referring now to Fig. 3, it will be seen that I have therein shown a cylinder and valve construction of a common type including a piston 19 mounted for reciprocation in the cylinder 6, the latter being provided with main ports 20 extending upwardly and communicating with the steam chest 7 to be controlled by the valve 21 therein.

It will also be observed that the valve mechanism in general is of common construction, the same being of the inside admission type, the valve heads 22 serving to block communication between the central chamber 23 and the ports 20 according to the valve position. Still further, in accordance with usual practice, the cylinders exhaust through the ports 20 and the chambers 24 at the ends of the valve or steam chest.

It will be observed further from inspection of Figure 3 that the auxiliary or starting ports 25 are arranged in the valve chamber inside of the main ports 20 to be opened by the valve heads 22 prior to the opening of the main ports. The ports 25 communicate with the cylinder 6 through the pipes 8, the mechanism A, the pipes 9 and the ports 26 which it should be noted are spaced from the ends of the cylinder 6.

The auxiliary or starting port valve mechanism A (see Fig. 2) comprises a casing or valve chamber 2'? with which the conduits 8 and 9 communicate. It should be noted that the pipes 8 and 9 are arranged in pairs communicating with the casing 2'? at points diametrically opposed to each other. A valve 28 is arranged to reciprocate in the casing 27, the same being provided with two annular recesses or passages 29 which, when the valve is in open position, provide communication between each pair of the pipes 8 and 9. At one end the valve 28 is provided with a plunger or piston 30 which works in a chamber 31 in the end of the casing 27. Note that the pipe 16 communicates with the chamber 31 beyond or in front of the piston 30. The valve 28 is centrally hollowed and a helical compression spring 32 is arranged within the hollow to react against the inside of the piston or plunger 30 and the opposite end 33 of the chamber or casing 2'7. An exhaust passage 34 is provided in the casing end 33 for exhaust of air from the interior of the hollowed valve and the casing.

Referring now to Figure 4, which shows in cross section the right hand or forward pilot or controlling valve B, (the reverse pilot valve being the same but in reverse position) it will be seen that therein are provided a chamber and a chamber 36 between which is arranged the valve seat 37. The pipe 18 communicates with the chamber 35 and the pipe 15 communicates with the chamber 36. A valve 38 is arranged to move longitudinally within the control valve mechanism and has a head 39 adapted to seat on and close the valve seat 37. To the left of the chambers 35 and 36 (as shown in Fig. 4) is arranged a plunger 40 having a head 41 adapted to be engaged by the reverse lever 13 when it is thrown into the corner. At the other end the plunger 40 is provided with a stem 42 extending outwardly therefrom to engage the head of a valve 53, the same being arranged to control the exhaust from pipe 15 past the valve seat 44 as will appear more fully hereinafter. The stem 42 is resiliently retained in its position by the spring 43 adapted to prevent excessive shocks to the valves 53 and 38. As shown in Figure 4 a valve seat 44 is provided in the left hand wall of the chamber 36. This seat is controlled by the head-45 of the valve 53 which is oppositely disposed to the valve 38 with its end remote from the head 45 abutting against the end of the valve 38 remote from its head 39. A

n compression spring 52 is arranged to react against 40 moves.

The double check valve mechanism C (see Fig. 5) comprises a cylindrical chamber 48 with the ends of which the pipes 14 and 15 are arranged to communicate. A plunger or valve 49 having balllike projections 50 at its ends is arranged to reciprocate in the chamber or casing 48 and control the communication of the pipes 14 and 15 therewith. At one side of the chamber 48 and longitudinally spaced from each other are a pair of ports 51 both of which communicate with the pipe 16.

In order that the operation of the controlling mechanism of the present invention may be more clearly understood, a brief description of the operation of a limited cut-off locomotive is presented herebelow.

To begin with, in a locomotive operating at limited cut-offs, say, for example, at 50% cutoff when the valve gear is in full gear position,

.- steam will be admitted through the port 20 at the working end of the cylinder during 50% or onehalf of a piston stroke, the remainder of the stroke being accomplished by the expansive working of the steam so admitted. Thus, it is apparent that when the locomotive stops or is standing idle and the main valve has just closed one of the main ports, the other cylinder or cylinders of the locomotive must bear the entire burden of starting which, as is well known in the art, is a condition which usually completely prevents starting. The above condition is also disadvantageous, of course, when the locomotive is running at very low speeds, although the condition presents the most serious difficulties at times of actual starting. In order to overcome this difficulty, auxiliary or starting ports in the main valve chamber have been provided. These ports are usually arranged intermediate the main ports in positions to be opened by the valve prior to the opening of the main ports and also to be closed by the Valve after the main ports have been closed. The effect of these starting ports is to extend the cut off or steam admission particularly at starting as will appear more fully hereinafter. 8o:

It will be observed from inspection of Figure 3 that the ports 26 communicating with the starting port pipes 9 are arranged in the cylinder at points spaced from the ends thereof. The position of the valve and piston shown in Figure 3 is that which those parts occupy just prior to the opening of the left hand main port 20 by the valve 21, the piston 19 being approximately at the extremity of its left hand movement. Note that the left hand port 26 is closed by the piston 19 and will remain so until the piston moves to the right thereacross. From the foregoing it will be seen that the left hand port 26 will be effective in admitting steam for starting purposes at any position of the piston 19 to the right of the left hand port 26.

According to standard practice the auxiliary ports have a relatively small cross sectional area. They are so made in order to prevent an excessive quantity of steam from passing into the cylinder at times when the engine should be operating by the expansion of the steam admitted through the main ports, that is, shortly after the locomotive has started. However, when the locomotive is standing idle, there is, of course, a substantially unlimited time during which starting steam may flow into the cylinders through the auxiliary ports and at such times their relatively small cross sectional area is sufficient to assist in starting. As the locomotive gains speed the time during which steam may flow through the auxiliary ports into the cylinders becomes shorter and a smaller quantity of steam will, therefore, be so admitted.

However, at practically all speeds an appreci- 11-5 able quantity of steam enters the cylinders through the auxiliary ports. This is particularly so just after starting and at very low speeds. The present invention contemplates a controlling mechanism for the auxiliary ports of a limited cut-off locomotive, which may be operated to render them effective or ineffective at the will of the engineman. Thus, in the normal operation of a locomotive, the engineman will operate the controlling mechanism to open the auxiliary ports only when they are needed for starting purposes. It is obvious, therefore, that the starting ports may be made of larger dimensions and, therefore, more effective, and also that considerable wastage of steam is prevented by the cutting off of the auxiliary ports at times when the locomotive should be working expansively.

The operation of the auxiliary or starting port controlling mechanism of the present invention is as follows:

Assuming that the locomotive is standing idle and that the engineman desires to start the same, he will move the reverse lever into the forward corner, in which position the lever will engage the plunger 40 and move the valves 53 and 38 in 14 the control device B to open communication between the chambers 35 and 36 and close communication between the chambers 36 and 47.

Air pressure now passes from the reservoir 17 through the connections 18, chamber 35 to cham- 1 5 ber 36 from where it is conducted through the pipe 15 to the double check valve mechanism C. The air pressure admitted to the left end of the chamber 48 of the check valve will move the plunger or valve 49 to the right, closing communi- 5g cation between the pipes 14 and 16 and opening communication between the pipes 15 and 16. This pressure is now conducted through the pipe 16 to the chamber 31 at the right hand end of the valve mechanism A (see Figure 2). This pressure in the chamber 31 acts on the piston 30 to move the same to the left against the spring 32 and bring the annular grooves 29 into registry with each of the pairs of pipes 8 and 9. Steam may now flow from the auxiliary ports 25 through the pipes 8 to the pipes 9, through the valve mechanism A and thus into the cylinders through the ports 26.

The ports are now eifective in starting the locomotive, but as soon as the reverse lever 13 is hooked back, the plunger 40 is again released and the valves 53 and 38 are moved to the right by the spring 52 to close the seat 37 by the head 39 and open communication between the chambers 36 and 47 by movement of the valve head 45 away from its seat 44. Air pressure may now exhaust from the chamber 31 in the valve mechanism A through the pipe 16, the left hand port 51 in the check valve C, the pipe 15, chamber 36, chamber 47 and through the exhaust passage 46 or around the plunger 40 to the atmosphere. The valve 28 in the mechanism A will now be moved to the right by the spring 32 to again close communication between pipes 8 and 9.

In case the reverse lever 13 is thrown into the other corner, the operation will be the same, except that the left hand pilot mechanism B will come into action. In this case the air pressure will pass through the connection 14 to the right hand end of the check valve C, causing the plunger 49 to move to the left and close communication between pipes 15 and 16 and open the right hand pc t 51 between the ports 14 and 16. Of course, the exhaust in this case will take place through the right hand port 51, pipe 14 and the left hand mechanism B.

According to the foregoing I have provided a controlling means for the auxiliary or starting ports of a limited cut-off locomotive which is positive in action and by which considerable wastage of steam is eliminated. Furthermore, the starting ports may be made larger and more effective.

I claim:

1. In a limited cut off locomotive having the usual reversing mechanism, the combination of supplementary steam supply passages of later cut off for starting, valve means normally closing said passages, fluid pressure actuated means for opening said valve means, a pilot valve adapted to be opened when the reversing mechanism is in its extreme position for starting the locomotive in forward motion, a second pilot valve adapted to be opened when the reversing mechanism is in its extreme position for starting the locomotive in backward motion, a source of fluid pressure connected to said pilot valves, a double acting check valve, a connection from each pilot valve to said check valve, and a connection from the check valve to said fluid pressure actuated means.

2. In a limited cut off locomotive having the usual reversing mechanism, the combination of supplementary steam supply passages of later cut 01f for starting, valve means normally closing said passages, fluid pressure actuated means for opening said valve means, a pilot valve adapted to be opened when the reversing mechanism is in its extreme position for starting the locomotive in forward motion, a second pilot valve adapted to be opened when the reversing mechanism is in its extreme position for starting the locomotive in backward motion, a source of fluid pressure connected to said pilot valves, a double acting check valve, a connection from each pilot valve to said check valve, a connection from the check valve to said fluid pressure actuated means, and means in each pilot valve for exhausting the pressure from said fluid pressure actuated means when the reversing mechanism is retracted from its extreme position.

3. In a limited cut off locomotive having the usual reversing mechanism, the combination of supplementary steam supply passages of later cut off for starting, valve means normally closing said passages, fluid pressure actuated means for opening said valve means, a pilot valve adapted to be opened when the reversing mechanism is in its extreme position for starting the locomotive in forward motion, a second pilot valve adapted to be opened when the reversing mechanism is in its extreme position for starting the locomotive in backward motion, a source of fluid pressure connected to said pilot valves, means connecting the pilot valves to said fluid pressure actuated means, and means in each pilot valve for exhausting the pressure from said fluid pressure actuated means when the reversing mechanism is retracted from its extreme position.

HUBERT J. TITUS.

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