US1647755A - Air-regulating valve - Google Patents

Description

Nov. 1, 1927.

J. J. STOETZEL AIR REGULATING VALVE Filed June 30, 1924 ATTORNEY Patented Nov. 1, 1927.

UNITED STATES JOSEPH J. STOETZEL,

OF NEW YORK, N. Y.

AIR-REGULATING VALVE.

Application filed June 30,

My invention relates, more particularly, to valves which are used, in pneumatic despatch tube apparatus, or systems, for regulating the flow of air through such apparatus or system, to conform to the demands for quantity, or speed, of flow, created, by the presence in transit of varyingnumbers of carriers, by variations in the length of line, and by discharge of various carriers. In modern practice it has been found desirable to keep up a slight, or minimum, flow of air through the system when no carrier is in 1ine,such air being substantially at atmospheric pressure, and to be capable of attaining a full, or maximum, flow of air great enough to provide for a large number of carriers simultaneously in transit,-.and so controlled, or regulated, that the actual flow at any time corresponds to the requirements or variations in flow caused by the introduction or discharge of any carrier when there are other carriers in line.

The object of my inventionv is to provide such an air-regulating valve which is selfacting, in the sense that it does not require any so-called operating mechanism at all but swings, or slides, from a more-open to a lessopen position, or vice versa, to permit less or greater passage of air through the system, in response to changes in the force or diflerential pressure of air, on opposite ends of the valve, somewhat as a weather-vane moves from point to point, in response to changes in the direction of the air which blows upon the vane. In other words, I rely wholly upon the difi'erential pressure or kinetic energy of the air flowing through the system, or, more definitely, flowing past the valve, as compared with the outside air to cause the valve to move in the direction and to the extent, called for by the presence, absence, introduction, or discharge, or carriers, at each and every variation of operation of the pneumatic apparatus or system.

One form of my invention is shown in the accompanying drawing in which Figure 1, is a vertical section.

Figure 2, is a perspective view of the valve-spool.

Same letters indicate similar parts in the different figures.

A, B, represent an exhaust tube of any system of piping, preferably a pneumatic despatch tube system. It will be understood that the upper portion A, connects with the transit tubing, while the lower por- 1924. Serial N0. 723,407.

tion B, communicates with the exhauster. Connecting these two sections of exhaust tube is the casing C, which is open to the atmosphere, as shown, by a spider D, (in preference to a perforated cover or plate) with its hub containing a bearing cl, for supporting the valve rod E, and provided at the other end of the valve rod with a removable plate orcover F, the bushing of which serves as a bearing for the rod E, as shown, at that point. The casing C, is, preferably, divided. into two parts, or chambers, G, H, by a partition J, through which is a passage-way, K, preferably circular, of a capacity to permit the maximum flow of air which it may be desirable for the system to attain.

It will be understood that this passage- I way K, is always open to some, or to greater, extent, and that air 18 always flowing through in the dn-ection of the arrows whenever the exhauster is in operation, whether 7 any carriers are in line or not. This flow varies therefore, from the minimum to the maximum, making a complete accommodation to the varying calls made upon it by the insertion or discharge of carriers.

In this casing is located by improved airregulating valve, which is operated pneu matically, without the use of any auxiliary operating mechanism, either for opening or closing the valve. This valve consists primarily of a spool, one type of which is shown in Figure 2. In the form shown, the valve consists of a tube L, mounted on rod E which is adapted to slide easily, in either direction between its bearings at D and F. This spool is provided at one end with a suitable plate or spool endM, of a size sufficient to overlap the passageway K, and close it complete- 1y it allowed so to do,and at the other end with a plate or spool end of smaller diameter which cooperates with an adjustable, or flexible, plate or diaphragm, O, which automatically adjusts the effective pressure area of that end of the spool so as to exert as against the pressure area of plate M, a greater pressure than that ofsaid plate, when it is required that the spool move toward the cover F, and exert a lesser pressure than plate M, when the spool is required to slide toward spider D. For convenience or' construction, and replacement in case of wear, this expansible, or flexible plate is shown as made in two pieces, a, Z), the outer of which is made of leather or other flexible material and the inner of metal or other hard material,but such two-part structure is not mechanically required as a single piece of flexible material with a hardened centre may constitute the spool end N if preferred.

The to and fro motion of the spool L is limited as follows The motion to close the passage-way K, is preferably stopped at a predetermined point, as by set screw, 0, at bearing (Z-(Z, so that the plate M never closes the mouth of the passage-way wholly, but leaves a channel between the plate and the passage-way of sufficient capacity to permit the desired minimum flow before spoken of. A spring 6, of any desired construction, is preferably provided to aid the movement of the spool toward said partly closing point, and to resist gradually the movement of the spool in the other direction,which is limited by set screw 0 in bearing F.

The flexible part of spool-end, N, is preferably circular and is steadied, stifiened, and held fast to the casing inside the spider D, by screws, as at g, 9, so as to make a tight joint at its periphery.

It will be readily understood by those familiar with the art that my improved airregulating valve is of extremely simple construction, and that its operation is equally simple. This operation may be briefly described. as follows lNhen there is no carrier in transit the parts will be as shown in full lines in Figure 1,the spool-end M, being sufficiently away from the edge of the passage-way K to permit the constant minimum flow as shown by the arrows. The spool-end N, will be statically balanced between the atmospheric air which permeates the spider, and the air of the minimum flow which, of course, is also atmospheric.

Upon the insertion of a carrier anywhere in the system, the minimum How of air is at once blocked, or cut off. The exhauster at once begins to rarify the air which constitutes the minimum flow (practically this rarification is almost instantaneous) and to build up a vacuum by suction, so-called. Almost immediately the differential pressure on the outer side of spool-end N,that is, the difference between the atmospheric air filling the spider, and the rarifying air inside the casing,causes the spool to slide toward the cap F and thus open the passageway K, entrance wider, against the resilient force of spring 6. As the spool slides inwardly, the effective differential pressure surface as shown in dotted line of the part a, of spool-end N.

WVhen the carrier passes out of the discharge-outlet, the sudden rush of atmos pheric air which was driving said carrier from behind, strikes the spool-end M, praetically head-on, and adds its kinetic energy to the resilient force of the spring 6, to cause the spool to slide outwardly again into the position shown in full lines in Figure 1. This over-balancing of the atmospheric pressure constantly exerted against the outer area of spool-end N, is easily attained owing to the diminished effective pressure, area, above referred to. But as the spool-end N thus slides toward the spider E, this pressure area increases, returning to its original extent, and thus, by the time the usual minimum flow is reestablish-ed by the part-closing of the passage-way K, the spool-end N, is equipoised as at the beginning.

Such is the operation when only a single carrier is inserted in the line and is allowed to pass out through the discharge outlet before a second carrier is inserted. But, in practice, this is of comparatively rare occurrence.

()ne of the great advantages of my improved valve is that by permitting the spool a longer slide than would be necessary for the above described action of a single carrier, I am able to take care of as many can riers at a time as the line of tubing is capable of receiving. In such case the first carrier inserted only causes the valve to slide, and the passage-way K, to open, sufficiently to take care of that particular carrier. Upon the insertion of a second and each subsequent carrier, the air-valve slides open a little further, thus enlarging the opening of the passageway accordingly, and as soon as the first carrier inserted leaves the line this relief of pressure permits the air-valve to slide back correspondingly towards its normal position. And the same is true of every succeeding carrier until the last carrier has left the line.

It must be borne in mind that by the term .spool whether in claim or description, I mean any sort of member or device of whatever shape, which, is adapted to serve the purposes of the structure described and shown herein as a spool.-

I claim 1. In a regulating valve structure for a pneumatic dispatch tube, a valve chamber, a longitudinally slidable valve rod mounted in the chamber and extending transversely of the tube, a cap member at each end of the chamber in which the ends of the valve rod have sliding engagement a partition in said chamber provided with an opening through which the valve rod passes, a disk valve carried by the rod and tending to close the opening when moved in the direction of flow of air through the opening, a second disk carried by the rod on the other side of the partition and spaced therefrom, a diaphragm closing the chamber and located adjacent to the position of the second disk said valve rod passing through said diaphragm, and said diaphragm being exposed to atmosphere whereby upon a diminution of tending longitudinally of the tube to divide the valve chamber into two compartments, said partition being provided with an opening through which the valve rod extends, a

' valve disk carried by the valve rod and mounted in one of said compartments to cooperate with the opening in the partition to open or close the same, a disk member mounted on the valve rod in the other compartment adjacent the outer end thereof, a flexible diaphragm closing the outer end of the second compartment, said second disk having a less diameter than the diameter of the valve disk, and said flexible diaphragm being exposed to atmosphere on its outer surface whereby upon a diminution of pressure within the tube the diaphragm will engage the adjacent disk to move the valve rod and the valve disk carried thereby to open position to permit a flow of air to pass through the opening in the partition.

3. In a regulating valve structure for a pneumatic dispatch tube, a valve chamber,

a longitudinally slidable valve rod mounted in the chamber and extending transversely of the tube, a sleeve carried by the valve rod, a partition in said chamber extending longitudinally of the tube to divide the valve chamber into two compartments, a valve disk mounted on one end of the sleeve at one side of the partition whereby to open or close the opening in the partition, a spring engaging the valve disk and tending to move the same to closed position, means for preventing the complete closing of the opening in the partition, a disk member mounted on the other end of the sleeve at the other side of the partition, a flexible diaphragm closing the end of the valve chamber adjacent the second named disk, said flexible diaphragm being exposed to atmosphere on its outer surface whereby upon a diminution of pressure within the tube the diaphragm will engage the adjacent disk to move the connected valve disk to open position, said diaphragm engaging a decreased area of the adjacent disk when the valve is in open position whereby to produce dilferential pressure areas on opposite sides of the disk, whereby said differential pressure areas in cooperation with the spring will operate to move the valve into closing relation to the opening upon a rise of pressure within the tube.

JOSEPH J. STOETZEL.

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