US 996588 A
Description (OCR text may contain errors)
G. L. KENNEDY. COMBINED UNION AND CHECK VALVE. APPLICATION FILED smmz, 1909.
996,588. Patented June 27, 1911.
I v WITNESSES:
' INVENTOR A TTORNE Y UNITED STATES PATENT 'OFFIGE.
emz'n KENNEDY, or sAN rRANcIsc'o, CALIFORNIA, AssIGNo r0 NATIONAL cAR- BONATED LIQUID 00., or sAN rRANcIsco, CALIFORNIA, .A CORPORATION or cALI- roRN A.
Application filed September 2, 1909. Serial No. 515,973
To all whom it may concern:
Be it known that I, GUY L. KENNEDY, a citizen of the United States, residing at San Francisco, in the county of San Francisco and State of California, have invented new and useful Improvements in Combined Union and Check Valves, of which the following'is a specification.
The present invention relates to an improved check valve'for preventing the backward flow of gas, especially of mixed gases and liquids under pressune.
In devising an apparatus whereby a liquid and a gas, as for instance, carbonic acid gas, both under high pressure, can be drawn simultaneously spectively containing them and caused to commingle so that the liquid is carbonated by the carbonic acid gas, and can be inimediately thereupon used, or bottled without the necessity of employing expensive carbonators for that purpose, and so that, upon drawing oil any given quantity of the carbonated liquid, immediately thereupon fresh supplies of the liquid and carbonic acid gas under pressure escape from the reservoirs and 4 are automatically commingled and replenish the supply of carbonated liquid, I found it impossible to procure upon the market a check valve which, while permitting the liquid to flow freely therethrough to supply the place of that which had been drawn ofl, would prevent the gas escaping backward therethrough. Gas flows and escapes so much more readily than liquid, that with an ordinary check valve, placed in a pipe and separatingliquid on one side from a mixture of liquid and gas under pressure on the other side, when the flow of the liquid from the first to the second side is checked, and the check valve begins to close, because the pressure upon the side from which it flows begins to drop to anequality to that toward which it flows, there is a short period of time during which the pressures on both sides of the check valves are equal, and at which the, check valve has not quite closed but hangs slightly open, this delay in closing being due to its inertia. Of course such interval of time is very minute, but the escape of the gas is so rapid that, with any check valve heretofore constructed that I have been able to find on the market, the gas leaks backward through the check valve at the instant of closure.
rom reservoirs re- One object of the IIIVBIltlOII is to provide a check valve which will prevent the escape of gas, and which, moreover, is com aratively cheap, and durable and reliab e in its action.
A further object of the invention is to provide a combined check valve and union which will permit of the check valve beingremoved and replaced by another without having to displace the pipes to which it is connected.
In the accompanying drawing, Figure 1 is a broken side elevation, partly in longitudinal section, of two pipes connected by my improved union and check valve, showing the check valve just as it closes by. its own resiliency at the time the pressures on opposite sides are equalized or showing the check valve in its natural state when not subjected to pressure; Fig. 2 is a similar view showing the valve open, when the liquid is flowing forward therethrough; Fig. 3 is tached. r
Referring to the drawing, 1 indicates a pipe leading to, and 2 a pipe leading'from,
at 6. Between said threaded end and the flange 5 is interposed the flange 7 of the check valve, Whichvalve is formed of rubber, the central part 8, within the flange, being hollow and conoidal and having a rounded apex 9 and being formed with a transverse slit 10 through its apex? Upon said sleeve 3 is passed a collar 11 having an internal flange '12 abutting against the flange 5, and threaded on its inner surface, and screwed upon the threaded end 6 of the sleeve 4, thereby firmly clamping the rubber flange of the check valve in position. In or der to prevent introversion of the valve by back pressure, the apex of the valve is made thicker than the side wall valve. great importance that while the return motion of the-liquid shall be absolutely prevented by said valve, the forward motion thereof shall be as. free and unobstructed as possible. For this reason the slit 10 through the side wall to a sufficient distance to allow said slit to open-as shown in Fig. 3 to a considerable extent, permitting a ree forward motion of the liquid therethrough. Upon It is of- Specification of Letters Patent. Patented J une 27, 1911.
a'perspective view of the valve de 'proximates that on the left, the lips on the within the cone. As the chamber is thus reimpossible for the valve to be introverted liquidflowing from left to right, as shown in Fig. '2, the pressure of the liquid opens the slit or mouth in the rubber valve, so that the liquid can escape therethrough, but, as the pressure on the right increases, and apopposite sides of the slit in the check'valve close slowly and in correspondence with the approximation to equality of pressure, but actually close before the pressures are equal, this closure being due to ,the natural-resiliency of the rubber of the check valve, which causes said lips to assume a closed position normally and unless forcibly separated. On account of this closure being made slightly before the pressure on the right equalizes that on the left, there is no possibility of gas flowing backward through the check valve, because, wlien the check valve is closed, the pressure on the left, being greater than that on the right, tends to carry any gas contained in the liquid from left to right:
,The shape and the dimensions'of the conical body of the valve must here be specifically detailed, 'asupon these depend to an important degree the successful operation of the valve. In the; first place, the axial length or altitude of the cone is considerable as'compared with the diameter thereof at the base. In the drawings, the altitude is approximately the same as the diameter at the base. This means that the cone has a large lateral surface against which inwardly-acting radially applied forces are brought to bear on the cone. These forces have a powerful effect in not only holding the lips of the valves closed, but more especially in collapsing or caving inwardly the side walls of the cone so as to materially reduce the cross-sectional area of the chamber duced in size and as the walls of the cone are of considerable thickness at 'the' apex, it is.
by axially applied external pressures. In describing the action that prevents introversion of the valve, or the same turning inside out, with an accompanying loss of gas through the valve, it may be considered that there are two main external forces acting on the valve when the pressure at the right or discharge side thereof is in excess of the pressure at the left or inlet side. As liquid under pressure acts equally in all directions, there will be a. main axialpressur'e acting on the valve and a main lateral or transverse pressure acting inwardlyv entirely around the valve. Since the side walls of the. valve are thinner than the apex, +18 transverselyacting or radial pressures cause the valve at a point. intermediate its apex and base to cave inwardly, reducing the cross-sectional can be inserted in its area of the chamber of the valve so that the apex cannot be forced inside out. The i length of the conical chamber in the valve is i an important feature, because the longer the of the relatively thin side walls to be acted on, by lateral pressures. The chamberof the valve is of greater length than width so that the caving in of the walls of the chamber can more effectively take. place than would be the case if thechamber were shallower.
A .most valuable advantage possessed by this check'valv'e is that'its efiiciency is not of check valves. A further advantage is the great simplicity and economy in construction of the check valve, it being possible to supply these check valves at about one-hundr'edth of the cost. of check valves now on the market whichare not equally efl'ective. A further important feature of this invention is that: the che kvalve is contained within an ordinary s ock union, so that it can beremoved immediately and another I placewithoutdisturbing the adjacent pipes.
In taking'outithe valve, it is merely necessary to unscrew the collar 11 and slip it outwardly off the sleeve 3 to the pipe 1. The disconnected pipes" can now be sprung or chamber, the greater will be the lateral area' moved laterally apart so that their meeting ends will be out of alinement to render the valve accessible. The valve is bodily removed and another substituted, it being -merely necessary to' insert the conical portion of the valve into the proper coupling member. The pipes are then brought into l1 on the member 4 until the flanges 5 and 12 egga e each other. It is to be not ed that t e diameter and are of substantially the same diameter as the base of the valve, sothat the .valve can be inserted in either coupling member,'according to the direction of flow of liquid to be created through the pipes. This reversible feature of the valve is important because the valve can be used with standard couplin changem design. The flange,.being clamped between the coupling members, forms a gasket and it also serves to support the body of the valve spaced from the internal surface of the coupling member 4, so that liquid under pressure can impinge transversely on the sides of the valve entirely around the same. By reason of the peculiar construction of the valve body, introversion is prevented without requiring a base support, on the inlet side of the valve, and, as no base support is required, the valve can be usedwith ordinary couplings, as before stated. In this respect,
alinement and coupled by screwing the collar embers 3 and 4 are of the same internal or unions without requiring any it from turning inside out.
I am aware that, prior to my invention;
rubber check. valves have been used of aconical form and having a transverse narrow'opening in the apex of the cone, but the narrow slit in said prior. form is made by casting it in the rubber valve, Consequently, the lips on opposite sides of said slit do not normally meet and close upon one another, as may be readily observed by looking through the slit at a light back round, In my invention, on the other han the slit is formed by cutting the same with a sharp instrument in the apex of the cone after it is cast, so that, when the instrumentis removed, the lips of the slit close tightly upon each other by the natural resiliency of the rubber and are air tight except when slight pressure is used to open them. The prior device above referred to requires greater pressure on the outside of the cone than on the inside to close the aperture, whereas with my devicethe aperture not only does not require such greater pressure, but closes pergreater than the width to cause external ra-v of the chamber.
fectly even though there is a slightly" greater pressure on the inside. In other words the prior device is always open in its normal pos1t1on, whereas mine is always closed 1n 1ts normal position.
I claim l 1. A-check valve comprising a soft rubber conical body having a conical chamber whose walls are thinner atthe side than at the apex, the axial length of the chamber being dially-acting pressures to reduce the crosssectional area of the chamber to such a point that the thicker walls at the apex are prevented frOnfpassing backwardly into the body under an external axially applied pressure, said apex having a slit extending across the same and terminating in the side walls of the body at a 2. A check valve consisting of a soft rubber conical body having an altitude or axial length approximately the same as the di ameter of the base and provided with a chamber ,of greater axial length than width, the walls of the body being thinner at the sides than at the apex to cause, the sides of the chamber toyield inwardly under external laterally applied pressure at all points around the body for reducing the cross-sec- ,tional area of the chamber when the valve is closed, said apex having a slit cut diametrically therein and extending a considerable distance into the side walls of the chamber, said slit forming oppositelydisposed lips that are normally held in closed position by their inherent resiliency.
3. A. check valve comprising a soft rubber conical body having a conical chamber whose walls are thinner at the side than at the apex, the axial length of the chamber being greater than the width to cause external radially-acting pressures to reduce the cross-sectional area of the chamber to such a point that the thicker walls at the apex are prevented from passing backwardly into thebody under an external axially applied pressure, said apex having a slit extending across the same and terminating in the side walls of the body at a point intermediate the ends of the chamber, a base flange extending around the base of the body, oppositly-disposed coupling members of the same diameter approximately at the base of the body and between which the entirebase flange is confined and clamped, and means for clamping the coupling members together whereby the base flange forms a gasket between the members and serves to support the valve body in one coupling member or the other in spaced relation from the internal surface thereof to permit liquid under pressure to 'act transversely as well as ax1ally on the external side of the valve body.
In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses. v
v GUY L. KENNEDY;
- Witnesses: I
FRANCIS M. WRIGHT,
point intermediate the ends -D. B. RICHARDS.