US552292A - Valve-controlling mechanism - Google Patents

Description

(NO Model.)

J. B. KNUDSEN. VALVE GONTROLLING MEGHANISM.

No. 552,292. Patented Deo. 31, 1895.

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JACOB B. KNUDSEN, OF FERNVVOOD, ILLINOIS.

VALVE-CONTROLLING MECHANISM.

SPECIFICATION forming part of Letters Patent No. 552,292, dated December 31, 1895. I

Application iiled November 20, 1893. Serial No. 491,489. (No modell) To all whom t may concern:

Be it known that I, JACOB B. KNUDSEN, a citizen of the United States, residing at Fernwood, county of Cook, and State of Illinois, have invented certain new and useful Improvem ents in Valve-Controlling Mechanism, of which I do declare the following to be a full, clear, and exact description, sufficient to enable others skilled in the art to make and use the same.

My present invention has for its object to provide improved means for controlling the passage of fluid through a valve casing or chamber, so that the degree of pressure requisite to open the valve shall be different from that required to close it. In certain apparatus in which valve mechanism is employed to control the iiow of fluid it is desirable that the degree of pressure exerted by the iiuid for the initial opening of the valve shall be greater than the pressure required to close the valve after it has been thus opened. Thus, for example, in Letters Patent No. 525,686, granted to me September il, 1894, is illustrated an air-brake mechanism for railway-cars comprising a main reservoir into which' air is forced under pressure by means of a pump operated through the medium of an eccentric mounted upon the car-axle. The eccentric in the mechanism illustrated in my said patent is united to the axle by means of certain clutch mechanism that is controlled by the pressure of air within the reservoir, so that when the air-pressure is diminished beyond a certain point the eccentric will be thrown into action so as to again operate the pump, and when the maximum pressure of the reservoir has been reached the eccentric will again be thrown out of action. It is manifest that as the maximum pressure of air within the reservoir serves to release the clutch mechanism of the eccentric, if any decrease-from such maximum pressure, however slight, should allow the eccentric to be again operated, there would be a constant shifting of the eccentric into and out of action which would be very injurious in practice. In such case, therefore, it is of great advantage to employ a valve mechanism of such construction that the maximum pressure of air within the reservoir shall open the valve so as to throw the clutch mechanism of the eccentric out of action, and that means should be employed for retaining the valve out of action until the pressure of air within the reservoir has been materially reduced. By providing differential spring mechanism for controlling the valve through which the supply of compressed air passes from the reservoir to the clutch mechanism I am enabled to insure that the clutch shall not be thrown out of action until the maximum pressure of the reservoir is reached, but

when thrown out of action it shall be so retained out of action until the pressure of air within the reservoir has been so far diminished as to require the pump to be again brought into operation.

Other'instances might be cited as illustrating the advantageous-use of a valve provided with differential spring mechanism for controlling its movement, but inasmuch as my present invention relates simply to the valvecontrolling mechanism, independent of the particular uses'to which it may be put, I do not deem it necessary to specify such uses at greater length.

My invention consists in the features of novelty hereinafter described, illustrated in the accompanying drawings, and particularly pointed out in the claims at the end of this specication.

Figure 1 is a central vertical sectional view of my improved mechanism. Fig. 2 is a view similar to Fig. 1, but showing the parts in different position. Fig. 3 is a view in hori- Zontal section on line 3 3 of Fig. 1. Fig. 4L is a view similar to Fig. 1,. but showing a slightly-modified construction.. Fig. 5 is a view similar to Fig. 4 with the parts in different position.

In the accompanying drawings I have illustrated what I regard as the preferred form of my-invention; but I do not wish the invention to be understood as restricted, except where it is specifically so stated in the claims, to the details of construction illustrated in such drawings and hereinafter described.

A designates the casing of the valve mechanism, this casing being provided with a base B, having a port b with which will connect a pipe 2 leading to a suitable reservoir or other source of fluid supply. The base B is preferably connected by a threaded joint 3 with the casing A, and intermediate the base and the IOO casing is by preference placed a plate or diaphragm C, provided with perforations c for the passage of fluid therethrough, and provided also with the central perforation to receive the guide-stem of the valve D, whereby the passage of fluid is controlled. Adjacent the bottom of Jthe valve-casing is formed a discharge-port a, and in the construction shown there are a series of perforations a leading through the wall of the casing opposite the expanded portion of this port a.. The valve D is carried at the lower end of the valve-stem D', this stem D extending upward through the chamber A and through the transverse plate a2 formed adjacent the top of the chamber. The upper end of the chamber A is preferably provided with a cap or cover E, connected to the casing or chamber by the threaded joint, as shown, and by preference the cap E has a flange c that serves to retain in place the spring-plate or diaphragm F that aids in controlling the valve D, as will presently more fully appear.

Between the upper face of the valve D and the transverse plate a2 of the valve-casing is interposed the coil-spring G, which serves to normally force the valve D downward, so as to close the ports a and thus prevent the passage of fluid through the valve-casing. The stem D of the valve is preferably hollow at its upper end and is interiorly screw-threaded to receive the spindle D2 that is connected to a washer 5 that encircles the stem D' and serves to limit the downward movement of the diaphragm F. The connection between the spindle D2 and the washer 5 is preferably effected by the pins G that pass through slot 7 formed in the stem D and into the annular groove S formed in the spindle D2 adjacent its lower end, the ends of the pins 6 entering the washer 5. Hence it will be seen that as the spindle D2 is turned the washer 5 will be raised or lowered, so as to correspondingly determine the downward thrust of the diaphragm F, and the position of the spindle can be fixed as desired by means of a set-nut l0 that encircles the spindle and can be jammed against the upper end of the valve-stem D. The exterior of' the stem D is also screwthreaded adjacent its upper end to receive the adjusting-nut K and its jam-nut 7c, the nut K serving to determine the upward movement of the diaphragm F. The diaphragm F is preferably held in place between the plates a2 of the main casing and the lower end of the cap or cover E. The plate u? at the top of the casing A is preferably depressed, as shown, so as to allow for the downward movement of the stem D and of the diaphragm F. rlhe side walls of the casing A are formed with suitable vent-holes l5, the purpose of which will presently appear.

B y reference to Fig. l of the drawings it will be seen that when the valve D is in the position there illustrated fluid passing through the pipe 2 and the port l) cannot reach the escape-port ce, as the passages a', leading into this port, are closed by the valve D; and it will be seen also that the valve D is normally held in its closed position not only by the spring G but also by the pressure of the diaphragm F. Thus, fOr example, if the maximum pressure necessary to lift thevalve D, so as to permit the passage of fluid through the port a, be forty pounds, the spring G may exert a pressure of thirty pounds and the daphragm F a pressure of ten pounds upon the valve D. Inasmueh, however, as the diaphragm F is concavo-convex, it is obvious that as soon as the pressure beneath the valve D passes the limit of forty pounds and lifts the valve the diaphragm F will be forced from the position shown in Fig. l to the position shown in Fig. 2, and consequently the ten pounds ofv pressure in downward direction upon the valve D, due to the diaphragnl, will be instantly relieved, and the diaphragm, being in the position shown in Fig. 2, will then exert a pressure of ten pounds, tending to hold the valve D in its raised position. Hence, while forty pounds of pressure are thus required to raise the valve D, so as to permit the passage of fluid through the valvecasing, it is manifest that, inasmuch as the diaphragm F in its raised position will exert a pressure of ten pounds in upward direction against the pressure of thirty pounds of the spring G in downward direction, the valve D must remain open until the pressure of fluid beneath the valve is reduced below twenty pounds. Hence it is that when the valve I) is once raised by the predetermined pressure beneath it it will remain raised and permit the passage of fluid through the valve-casing until there has been a very material decrease in the pressure of fluid, and .not until such decrease has occurred will the valve close. It will therefore be seen that the spring G and the spring diaphragm or plate F together constitute a differential spring mechanism for controlling the valve D, since a different degree of spring-pressure is exerted upon the valve for holding it in closed position than is required for retaining it in its open position. lVhile I prefer that the diaphragm or plate F should be so arranged as to serve to resist the downward movement of the valve, it is manifest that such arrangement is not absolutely necessary.

It is obvious that other forms of differential spring mechanism might be employed for controlling the valve D without departing from the spirit of my invention.

In the modified form of' my invention illustrated in Figs. 3 and 4 of the drawings the construction is the same as that hereinbefore described with the exception that in this form of the invention the valve D is shown as having its periphery formed of rings di and (Z4 in order to insure a snug bearing between the valve and the casing. In this form of the invention also the casing A is provided with a double series of ports a and a5, the ports c' serving when the valve D is raised to permit IOO IIO

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the passage of fluid from the port 1') to the port CL, as illustrated in Fig. 3 of the drawings, whereas when the valve A is in closed position, as illustrated in Fig. 4 of the drawings, the back-pressure within the pipe to which the port a is connected may escape freely through the ports a5 into the body of the casing A, and thence to the open air through the ports or vent-holes l5. My purpose in arranging a series of ports or perforations a in the wall of the casing is primarily to permit the valve to move freely past these ports or perforations without undue wear upon its packing-ring. It willbe seen also by reference to Figs. l and 2 that when the valve is in closed position a like escape for any back-pressure within the pipe to which the port a may be connected is afforded by the vent-holes l5 in the wall of the main casing A. The adjusting mechanism at the back of the valve-spindle D/ will serve not only for the adjustment of the diaphragm, as hereinbefore described, but by properly setting the nuts and washers upon the spindle the diaphragm will be relieved from pressure of the spring G when the valve has been seated, and yet will be in readiness to co-operate with this spring in resisting any upward movement of the valve.

The details of construction above set out may be varied within wide limits without departing from the spirit of my invention, which is designed to cover broadly the feature of providing a fluid-controlling valve with differential spring mechanism of such character that a greater amount of pressure is required to move said valve in one direction than to shift it in the opposite direction.

Having thus described the invention, what I claim as new, and desire to secure by Letters Patent, is

l. The combination with a suitable valve for controlling the passage of fluid under pressure, of a restoring pressure mechanism arranged to force said valve to its normal position, and counter-pressure mechanism arranged to supplement the uid pressure in resisting the return of said valve to its normal position and acting in opposition to said restoring pressure mechanism; said counterpressure mechanism being of less power than the restoring pressure mechanism and being arranged to diminish the power of the restoring pressure mechanism to a greater extent after the valve is shifted from normal position than while in normal position, whereby said counter-pressure mechanism will aid in holding said valve away from its normal position until the fluid pressure is materially changed, substantially as described.

2. The combination with a suitable valve for controlling the flow of fluid under pressure, of a pressure mechanism arranged to exert power for forcing said valve to its normal position and a spring arranged to exert power for resisting the return of said valve to its normal position, said spring acting in opposition to the pressure that forces said valve to its normal position, whereby said spring will aid in holding said valve away from the normal position until the fluid pressure is materially decreased, substantially as described.

3. The combination with a suitable valve for controlling the passage of fluid under pressure, of a spring arranged to force said valve to its normal position and a counterpressure spring arranged to supplement the fluid pressure in resisting the return of said valve to its normal position and acting in opposition to said first-mentioned spring; saic counter-pressure spring being arranged to diminish the power of said first-mentioned spring to a greater extent after the valve is shifted from its normal position and While in said normal position, whereby said counterpressure spring will aid in holding said valve away from its normal position until the uid pressure is materially changed, substantially as described.

4. The combination with a suitable valve for controlling the passage of fluid under pressure, of a pressure mechanism arranged to exert power for forcing said valve to its normal position and a spring in addition to said pressure mechanism and serving to aid in forcing said valve to its normal position, said spring being arranged to exert no tendency to force the valve to normal position after it has been moved to a considerable distance therefrom, substantially as described.

5. The combination with a suitable casing of a valve for controlling the flow of fluid under pressure, a spring for forcing said valve to its normal position and another spring also arranged to aid in forcing said valve to its normal position, said last mentioned spring being arranged also to exert no tendency to force the valve to normal position after it has been moved to a considerable distance therefrom, substantially as described.

6. The combination with a suitable casing of a valve for controlling the flow of fluid under pressure, a spring for forcing said valve against its seat and another spring aiding also to force said valve against its seat, but arranged to be shifted so as to exert no closing pressure upon the valve when the latter has been opened, substantially as described.

7. The combination with a suitable casing of a valve for controlling the flow of fluid under pressure, a spring for forcing said valve to its seat and another spring arranged to exert a pressure upon said valve to retain it both in closed and open position, substantially as described.

8. The combination with a suitable casing of a valve for controlling the flow of fluid under pressure, a spring for forcing said valve against its seat and a spring acting plate or diaphragm tending to hold said valve to its seat, said plate or diaphragm being so arranged that it will exert no closing pressure upon the valve while the valve is in open position, substantially as described.

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9. The combination With a valve for controlling the passage of fluid under pressure, of a stem or spindle connected to said valve, a spring G for holding said valve against its seat and a concavo-convex spring plate or diaphragm F for aiding in holding said valve in closed position, but so arranged that it will exert no closing pressure upon the valve When vin its open position, substantially as described.

l0. The combination With a suitablecasing of a valve D for controlling the flow of luid therethrough, a spring G for forcing said valve to its seat, a diaphragm or spring plate F for aiding in holding said valve in closed and also in open position and suitable adjusting mechanism forsaid diaphragm or spring plate, substantially as described.

l l. A valve mechanism comprising a casin g A having a suitable ingress and egress port an d having a cover E, a concave-convex sp rin g plate or diaphragm F Within said cover, a valve D, a coil spring arranged to shift said valve, and a valve spindle D to which said diaphragm is connected, said spring' plate or diaphragm F being arranged to aid in holding said valve in closed position and also to aid in holding said valve open after it has been moved to a considerable distance from its seat, substantially as described.

In Witness that I claim the foregoing as my invention I have hereunto set my hand, this 18th da5T of November, A. D. 1893, in presence of two witnesses,

JACOB B. KNUDSEN. lVitnesses:

GEo. P. FISHER, J r., ALBERTA ADAMICK.

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