US1753297A - Throttle-operating mechanism - Google Patents

Description

April 8, 1930. N; T. M KEE THROTTLE OPERATING MECHANISM File d Sept. 50 192' 2 Sheets-Sheet l A TTORNE Y.

April 8, 1930. N. T. M KEE THROTTLE OPERATING MECHANISM Filed Sept. 30, 1927 2 Sheets-Sheet 2 INVENTOR.

A TTORNE Y.

Patented Apr. 8, 1930 UNITED STATES PATENT OFFICE NEAL T. MICKEY), OF BRONXVILLE, NEW YORK, ASSIGNOR TO AMERICAN THROTTLE COMPANY, INC., OF NEW YORK, N. Y.

THROTTLE-OPERATING MEOHAN ISM Application filed September 30, 1927. Serial No. 223,041.

The invention relates to the mechanism required to operate, from the cab, locomotive throttles located in the smoke-box of the locomotive, and has for its main purpose the provision of such mechanism which will admit of rapid opening or closing of the throttle, at the same time permitting very accurate adjustment to any desired position, and which will be quickly and easily put into the drifting position.

Other and more detailed advantages will appear from the ensuing description.

The invention is illustrated in connection with throttles of the so-called multiple type,

but as will be apparent from the following specification, its use is not limited to multiple throttles, but is of equal advantage in connection with throttles of other kinds.

The invention is illustrated in the drawings herewith in which Fig. 1 illustrates a fragmentary lateral elevation of a locomotive with my invention applied; Fig. 2 shows a portion illustrating a modification; Fig. 3 is a half sectional view on line 3-3 of Fig. 1;

Fig. 4: is an enlarged plan view of the rear portion of my mechanism; Fig. 5 is a vertical central section of the same portion; Fig. 6 is a view on line 6-6 of Fig. 5; and Fig. 7 is a detail on a still larger scale of an element of the mechanism.

Before the use of superheaters on locomotives, and in fact even after their introduction, the throttle controlling the flow of steam from the boiler to the distribution valves of ,the engines in a locomotive was almost invariably located in the steam dome at the intake end of the dry pipe. The rod from the throttle to the cab extended through the steam and water space of the boiler, passing through a stufling box in the rear sheet. The expansion and contraction of the rod was, therefore, always commensurate tothat of the boiler shell.

It has recently become more general practice, however, in locomotivesequipped with superheaters to place the throttling means which control the flow of steam from the boiler to the engine at a point between the superheater and the engine. In the standard form of superheater in which the superheater header is located in the upper portion of the smoke-box, the throttle is placed somewhere between the header and the steam chests. One of the most advantageous arrangements is that disclosed in United States Reissue Patent 16,285 granted to Ray M. Brown. The arrangement comprises a plurality of valves, integral with the superheater header and the shaft actuating them extends out from the smoke-box, the rod to the cab lying outside of the boiler shell. The expansion and contraction of the rod will, therefore, be different from that of the boiler. If the rear end of the rod is anchored in the cab, this differential expansion will result in a movement of the forward end of the rod relatively -to the throttle, and a movement of the rod may result in an opening of the throttle when it is meant to remain closed, which is obviously a serious matter.

I am aware that this difficulty has beenrecognized in the past and that remedies for it have been suggested. One feature of my invention is to present throttle operating means of improved design which among other things shall take care of the differential expansion referred to.

Referring to Fig. 1, of the drawings, the shaft actuating the throttle is shown at 1. This extends through a stufiing box 2 into the interior of the valve housing 3. This valve housing is preferably made an integral part of the superheater header 4; in accordance with the disclosure of the Brown patent referred to above. The superheater header is located in the upper portion of the smoke-box 5. The structure and operation of the superheater is no part of the present invention, and the superheater is, therefore, not illustrated in the drawings.

Secured to the shaft 1 is the arm 6. A slot 7 in the lower portion of the arm 6 is engaged by a pin 8 carried by the forward end of the rod 9. This rod 9 extends back toward the cab through a pipe 10. The pipe is anchored to the body of the locomotive by means of the support 11, and extends slidably through other supports, which are shown at 12. The forward end of the pipe is closed by the cap 13 through which the pipe 9 extends.

The arrangement described makes it possible to make the arm 6 as long as necessary for easy operation of the throttle, as there are no such space limitations present as there are with the throttle in the dome.

The rear end of the rod 9 is connected to the forward end of rod 9* in such a manner that the latter can turn and advance and recede, and transmit the advancing and receding motion to the former without the former turning. The specific means shown by way of illustration appear clearly from Figs. 4 and 5. The rear end of the rod 9 and forward end of the rod 9 have enlarged heads 14 and 15 respectively which lie in the hollow interior of the connecting sleeve 16, the outer surfaces of the heads bearing against the shoulders 17 and 18. The sleeve is divided longitudinally into halves. To assemble the structure, the rods 9 and 9* are pushed into such position that the enlarged heads 14 and 15 lie in the open-sided casing 19. The two halves of the sleeve 16 are then placed over the two heads and the assemblage is pushed back into the tube 10. The forward end of this tube 10 and the rear end of the tube 10 are permanently fixed in the casing 19. The opening through which access is had to the interior of the casing 19 is normally closed by the cover 19. The rear end of the rod 9 is threaded as at 9" and the threaded portion engages the upper half-nut 20 and the lower blank piece 21. These two are in a housing 22 which is permanently fixed to the'rear end of the tube 10. The half-nut 20 is fixed immovably in the housing by means of the screw 23, while the piece 21 can slide in the ways 24. It is normally held in its upper position as shown in Fig. 5 by means of the spring 25. This spring lies in the hollow interior of the piece '21 abutting with one end against the bottom of the cavity, and with its opposite end against the yoke 26. The rear end of the rod 9 extends out through the casing 22 and is equipped with the handle 27.

The function of the device as so far described is as follows: When the engineer wishes to open the throttle he depresses the outer end of the rod 9 by downward pressure on the handle 27. This causes the piece 21 to move downward compressing the spring 25 a little more and disengages the threads 9 from the half-nut 20; The rod 9 and as a result the rod 9 can now be pulled backward freely. This motion results in a swinging of the arm 6 in a clockwise direction as viewed in Fig. 1, the throttles being arranged to open with this movement. The engineer will pull out the rod the required distance to give the desired amount of opening to the throttles, and then will allow spring 25 to return the rod 9 to its upper position in which the half-nut 20 will prevent any further direct longitudlnal motlon of the rod 9 lVith the threads in engagement there is now possible a finer or micrometer adjustment of the throttles by rotation of the rod 9 by means of the handle 27. Such rotary motion of the rod 9 will draw the sleeve 16 back or push itforward and thereby give corresponding motions to the rod 9 and corresponding motion to the throttles. To close the throttles the engineer will depress'the handle 27 and push rod 9 inward to its full extent.

It will be obvious that this mechanism provides means for quickly givingthe approximate position of the valve desired, and then to give it a finer regulation'by a slower movement.

The rods 9 and 9 will have the same temperature as the sleeves or pipes 10 and 10, and will, therefore, contract and expand together so that up to the fixed point 11 the fact that there is differential expansion between the boiler and the operating mechanism will have no harmful effect. The difierential expansion between the boiler or smoke-box shell and the rod 9 from the point 11 forward is negligible because the portion forward from this point is small relative to the total distance from the cab.

In locomotive operation it is very desirable at times when the locomotive is mov ing along and not using steam to admit enough steam to the cylinders to keep them filled so that air will not be drawn in through the exhaust nozzle. This so-called drifting steam is ordinarily supplied by cracking the throttle, that is, by opening the throttle a slight amount. An experienced engineer will know how much he must crack his throttle to supply just the proper amount of steam for this purpose. In my mechanism I provide means whereby the proper amount ofdrifting steam can 'be supplied by even an unskilled engineer. This portion of the mechanism will next be described.

The enlarged section shown in Fig. 7 shows that the screw threads 9 are notched in four places, 99. The drifting nut 28 is equipped with a small ball-ended pawl or latch 29 pressed against the thread 9 by the spring 30. This spring is housed in the little hollow plug 31 screwed into the nut 28. The notches 9 and the ball end of the pawl 29 are so shaped that the nut 28 is held fairly firmly in its position when once the pawl and a notch have registered but that, with the exertion of a certain amount of force, the pawl can be moved out of its notch and the nut moved along the thread. The purpose of this arrangement is to fix the nut rather permanently in its correct position once this has been determined.

Cooperating with this nut 28 for the purpose of giving the throttles the drifting position is a peculiarly shaped spring 32. Its shape can be readily gathered from Fig. 5.

In this figure the rod 9 is in the position in which the throttle is closed. In its open position the nut 28 will be at some point to the left of the end 32 of the spring 32. Should the engineer desire to bring the throttle into the correct drifting position from the open position, he depresses the handle 27 as above described and pushes the rod 9 in. In its depressed position the nut 28 will strike the end 32 of the spring 32 with the shoulder 28*. The nut 28 has been given the correct position relatively to the rod 9 so that when this has happened the throttle is in the correct drifting position. To close the throttle after the period of drifting is over the engineer will allow the rod to return to its upper position with its thread engaging that of the half-nut 20, in which position the nut 28 will readily pass over the end 32 of spring 32. Should the engineer wish to open the throttle from closed position quickly, that is by depressing the rod 9 and pulling it out, the spring action of 32 will permit him to do this readily.

In Fig. 2 is shown a variation of the forward end of rod 9. Instead of slotting the outer end of 6 and enlarging it by means of pin 8, the arm 6 is directly pivotally connected with the forward end of rod 9 by means of the pin 8, and the forward portion here designated as 9 is made somewhat longer so that the fixed point 11 is a little further back from the throttle; The portion 9 is slender enough so that it bends without any particular resistance. With this arrangement there is a slightly greater differential in the expansion of the locomotive body, and the portion from the fixed oint '11 forward but with a great length of t e locomotive even this may be negligible and where such is the case this form may be used.

I claim: 1

1. In a locomotive having valve means located at the smoke-box end of the boiler to control steam flow from the boiler, means to operate said valve means comprising in combination a rod for operating said valve means and extendin back from it to the cab, a member associate with said rod and extending from a point near the front end of the boiler to the cab, its front end being rigidly secured relatively to the boiler and its remaining portions bein free to expand and contract independent of the boiler, the rear portion of the rod eing jointed to the main portion to permit rotary but not longitudinal movement between the two, said rear portion being provided with a screw thread and means to rotate it, the member having a corresponding segmental thread less than 180 degrees; and resilient means normally tending to keep the two threads in engagement and when compressed to permit their disengagement and a consequent free longitudinal movement of the rod.

2. In a locomotive having valve means located at the smoke-box end of the boiler to control steam flow from the boiler, means to operate said valve means comprising in combination, a rod for operating said valve means and extending back from it to the cab, a pipe member enclosing said rod and extending from a point near thefront end of the boiler to the cab, its front end being rigidly secured relatively to the boiler and its remaining portions being longitudinally slidably supported, the rear portion of the rod being jointed to the main portion to permit rotary but not longitudinal movement between the two, said rear portion being provided with a screw thread and means to rotate it, the pipe member carrying a half-nut engaging said screw thread, a block having ablank semi-cylindrical surface engaging the opposite side of the screw thread, and resilient means pressing the block against the screw thread.

3. A combination according to claim 2, the rear end of the rod carrying a nut whose position is longitudinally adjustable, a resilient member secured to the pipe member, the dis osition of thenut and resilient member being such that with the rod thread in engagement the half-nut will readily pass the end of the resilient means, but in the position with the threads out of engagement the nut will engage the end of the resilient means.

NEAL T. MCKEE.

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