WO2003069199A1 - Concrete pumping safety valve - Google Patents

Abstract

High strength, low weight pinch valves (10) formed from high performance composite materials are particularly well adapted for use as concrete boom discharge valves (10) to control concrete flow out of concrete booms without adding unnecessary weight to the ends of such booms. Valve adaptation include the use of a non-cylindrical housing (100) conforming to the exterior of a sleeve (200) abutting two end fittings (300).

Description

CONCRETE PUMPING SAFETY VALVE

This application claims the benefit of U.S. provisional application number 60/356558, titled "Concrete Pumping Safety Valve", filed on February 11, 2002, and incorporated herein by reference in its entirety.

Field of The Invention

The field of the invention is concrete delivery systems and pinch valves.

Background of The Invention

In some instances concrete must be delivered to a location that is not readily accessible using some concrete delivery methods. In such instances concrete delivery may be accomplished by pumping concrete through a long pipe or hose to the destination. In many instances, particularly for long pipes and hoses, the pipe or hose is part of a boom mounted on a truck that is moved via hydraulic pistons. Such a truck will often comprise a concrete pump, a boom, and a discharge tip/hose. Unfortunately, movement of the boom after pumping concrete through it may cause concrete to spill out of the end of the discharge hose. Wet concrete is very caustic, can cause burns to the skin, and is very dangerous to the human eye. In order to minimize the amount of concrete that spills out, a boom discharge valve such as is described in U.S. Patent No. 5, 950,988 may be used. Unfortunately, concrete boom trucks have a tendency to tip, particularly when the boom is fully extended and filled with concrete. As such, the use of known discharge valves is not always feasible, particularly when the weight added by the valve will unbalance the boom truck. Unfortunately, decreasing the weight of the valve is often not feasible due to the pressures that it must withstand. As an example, if a discharge hose has concrete solidify in it and the concrete pump is subsequently started, the pressure within the valve can be explosive.

High-performance composites are generally composites offering properties better than conventional structural metals, typically on a strength-to-weight or stiffhess-to-weight basis. One type of high-performance composite is formed by filament winding. Filament winding is a fabrication method that can be highly automated and repeatable with relatively low material costs. A long, circular tool called a mandrel (typically a form, fixture or male mold used as the base for production of a part in processes such as lay-up or filament winding) is placed horizontally between end structures that support and rotate it. The "head" (a fiber application instrument) moves back and forth along the length of the rotating mandrel, winding fiber onto the tool in a predetermined configuration. Frequently, the fiber is pre-impregnated with resin, thermoplastic, or some other material, or is passed through a resin bath (or a bath of some other material) just before it touches the mandrel. Either during or after winding, the shape is cured and/or dried, and in some instances the mandrel is removed. Filament winding yields strong parts.

Pinch valves comprise a flexible resilient sleeve within a housing such as a conduit, duct, pipe or tube along with means to constrict the sleeve. Constricting or "pinching" the sleeve within the housing prevents material from flowing through the sleeve. Examples of pinch valves can be seen in U.S. Patent Nos. 4,172,580, 4,258,004 and 4,569,502.

Summary of the Invention

The present invention is directed to high strength, low weight pinch valves formed from high performance composite materials and their use. In particular, preferred valves may be advantageously used as concrete boom discharge valves to control concrete flow out of concrete booms without adding unnecessary weight to the ends of such booms.

High pressures and lightweight are generally mutually exclusive design criteria. However, as described herein, high performance composite materials consisting of very high strength fibers in a bonding matrix can be used to obtain a valve that is lightweight but still able to withstand the pressures it may be subjected to. Preferred high performance composite pinch valves will comprise one or more of the features described herein.

In some instances preferred valves will comprise a housing that tapers at its ends so as to inhibit movement along the primary axis of the valve, particularly in a direction out of the valve. In other instances, the housing will comprise a tapered center region adapted to inhibit movement along the primary axis of the valve, particularly in a direction towards the center of the valve. In the most preferred valves, the housing will comprise an hourglass or other shape adapted to prevent movement in any direction along the primary axis of the valve. Valves having such housings can utilize shaped sleeves and end fittings rings such that the valve body inhibits further separation of the end fittings, and inhibits the ends of the sleeves from pulling away from the end fittings.

It is contemplated that the sleeves/actuators of preferred valves will be substantially thinner in a center region than on its ends and that such center thinness will help prevent the ends of the sleeve from pulling away from the housing or from any end fittings.

It is preferred that an elongated sleeve/actuator be bonded at either end to an end fitting, and to a housing. Such bonding will also help prevent the ends of the sleeve from pulling away from the housing or from the end fittings during use. It is also preferred that end fittings extend into a groove of the actuator to help prevent leakage at the junction of the rings and the actuator.

A preferred valve will comprise a flow path that is at least partially formed by exposed surfaces of its end fittings, and that the exposed surfaces will be hardened either by treatment of the material of the end fittings or use of hardened liners in the end fittings.

Preferred valves will comprise a valve adapted to allow air enter the space between the sleeve and the housing such that the sleeve can be constricted by filling that space with pressurized air.

Preferred valves will be adapted to be coupled to concrete booms, and will more preferably be part of a concrete pumping system comprising a concrete pump, concrete boom, and discharge hose wherein the preferred valve is positioned at or near an end of the boom coupled to the discharge hose.

Preferred valves will comprise a high performance composite body. Most preferred valves will be formed by filament/fiber winding with the fibers being oriented to maximize the strength of the body in all directions, but particularly along the primary axis of the valve and radially outward from that axis. Such preferred valves may be formed by placing a sleeve and two end fittings onto a mandrel, bonding the sleeve to the end fittings (either before or after being placed on the mandrel), and utilizing filament winding techniques to form the housing around at least portions of the exteriors of the sleeve and end fittings. Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.

Brief Description of The Drawings

Fig. 1 A is a side view of a preferred pinch valve in an open state.

Fig. IB is an end view of the valve of figure 1A.

Fig. 1C is a cutaway view of the valve of figure 1A in an open state.

Fig. ID is a cutaway view of the valve of figure 1A in a closed state and containing concrete.

Fig. 2 is a cutaway view of the valve body of figures 1A-1D.

Fig. 3 is a cutaway view of the elastomer valve actuator of figures 1A-1D.

Fig. 4 is a side view of an end fitting of the valve of figures 1A-1D.

Fig. 5 is a cutaway view illustrating a method of forming the valve of figure 1.

Fig. 6 is a side view of the valve of figure 1 in use on the end of a boom coupled to a concrete pump truck.

Detailed Description

Referring first to figures 1A-1D, a high strength, low weight pinch valve 10 comprises a housing 100, a sleeve/actuator 200, end fittings 300, pressure inlet 400, and cavity/flow path 500. Valve 10 is elongated and, other than inlet 400, radially symmetrical around primary axis Al as each of housing 100, sleeve 200, fittings 300, and cavity 500 are radially symmetrical around axis Al . Cavity 500 is preferably cylindrical and having sides defined by interior surfaces of sleeve 200 and fittings 300, although less preferred embodiments may have cavities that are not cylindrical and/or not radially symmetrical. As shown in figure ID, the various members of valve 10 are adapted to cooperate with each other such that forcing air or some other fluid through inlet 400 into space 600 closes valve 10 by causing sleeve 200 to pinch shut. If valve 10 is being used to control the flow of concrete or some other material or combination of materials 70 passing through cavity 500 of valve 10 in direction Dl, closing valve 10 divides cavity 500 into sub-cavities 510, 520, and 530 with cavity 510 being at least partially filled with concrete that has flowed into valve 10 but is blocked from flowing out, cavities 520 being at least partially filled with trapped concrete, and cavity 530 being essentially empty once any concrete within it flows out of valve 10. Removing air from space 600 via valve 400 causes sleeve 200 to open and allow concrete or other material to once again flow through valve 10.

Valve 10 preferably has flow path (inside) diameter equal to that of the outlet of a standard concrete boom. As such, preferred valves will have a diameter of Y inches where Y is 4.88 (125 mm), but for alternative valves Y will be between 4.75 and 5, 4.5 and 5.25, and 3 and 6. Less preferred valves can have other diameters. Valve 10 is preferably at least X inches long where X is 5.5Y, but for alternative valves X will be between 5.25Y and 5.75Y, 5Y and 6Y, and 3Y and 7Y. For a 4.88 inch diameter valve X is preferred to be 27. Valve 10 preferably weighs less than W pounds for a 4.88 inch diameter valve where W is one of 28, 26, 25, and 24.5. Most preferably valve 10 will weigh 24 pounds for a 4.88 inch diameter valve. Valve 10 preferably has a burst pressure of at least P PSI where P is one of 3000, 280q, 2600, 2550, and 2500. A most preferred pinch valves has X, Y, W, and Z values of (4.88, 27, 24, 3000). The features of valve 10 can be used in essentially any combination of one or more features to obtain valves having desirable characteristics.

Housing 100, as shown in figure 2, comprises fitting regions 110, sleeve coupling regions 120, and pinch region 130. Preferred valves will comprise a housing that has a reduced diameter at its ends (regions 110) so as to inhibit movement of end fittings 300 along the primary axis Al of the valve, particularly in a direction out of the valve. In other instances, the housing will comprise a reduced diameter center region (regions 120) adapted to inhibit movement of actuator 200 along the primary axis Al of the valve, particularly in a direction towards the center of the valve. In the most preferred valves, the housing will comprise an hourglass or other shape adapted to prevent movement in any direction along the primary axis Al of the valve by any combination of fittings 300 and sleeve 200. Having a housing shaped to prevent movement of end fittings 300 and sleeve 200 helps, at least in part, to increase the amount of internal pressure the valve can withstand without failure. In preferred embodiments, fitting regions 110 will be curved and will fit into fiber traps in fittings 300.

It is preferred that housing 100 be formed by filament winding and, after curing, be seamless. The pattern used in filament winding will preferably be chosen to maximize the burst pressure of valve 10. A preferred pattern comprises at least two winding layers, one with the filaments oriented substantially in a direction parallel to axis Al, and a second with the filaments wound substantially in a circle around Al. Although any filament type and binding matrix may be used that results in a valve having desired properties, preferred embodiments use an aramid filament and an epoxy binding matrix. Less preferred embodiments may use methods other than filament winding to form housing 100 such as hand lay-up, resin transfer molding, and chopped spray-up. In preferred embodiments housing 100 will be substantially uniform in thickness throughout its length and will conform in shape to the exterior shapes of sleeve 200 and portions of fittings 300. However, alternative embodiments may vary the thickness of housing 100 and/or utilize a non-conforming shape.

Sleeve 200, as shown in figure 3, comprises an elastomeric sleeve having end regions

220, pinch region 230, housing bonding surfaces 221, ring bonding surfaces 260, and ring recesses 261. Although sleeve 200 may comprise any material or combination of materials suitable for use as a pinch valve sleeve, it is preferred that sleeve 200 comprise polyurethane or silicone rubber. In deciding the composition for sleeve 200, abrasion resistance is a significant factor. Sleeve 200 have thinner walls in pinch region 230 than in end regions 220. It is contemplated that such center thinness will help prevent the ends of the sleeve from pulling away from the housing or from any end fittings. It is contemplated that having the thickest portion of end regions 220 be at least three times as thick as pinch region 230 may be advantageous.

It is also preferred that end regions 220 have a larger external diameter than pinch region 230. As housing 100 will conform to the exterior shape of sleeve 200 in preferred embodiments, decreasing the diameter helps to prevent the end regions 220 of sleeve 200 from pulling away from rings 300 when valve 10 is closed. In still more preferred embodiments, sleeve 200 will continue a curve begun by fittings 300 such that housing 100 will have not comprise any bends or discontinuities that may weaken housing 100. Sleeve 200 will preferably be bonded to both housing 100 and fittings 300. Bonding to housing 100 will be at end regions 220, but not pinch region 230 such that a space 600 exists between sleeve 200 and housing 100 in pinch region 230. Depending on the method used to form housing 100, it may be necessary to take steps to insure sleeve 200 bonds to housing 100 in end regions 220, or to prevent sleeve 200 from bonding to housing 100 in pinch region 230. Bonding sleeve 200 to housing 100 may be accomplished during formation of housing 100 or at a subsequent time. Bonding sleeve 200 to fittings 300 will typically comprise aligning the center axis of fittings 300 and sleeve 200, insuring that ring seal 361 of each of fittings 300 is positioned within recesses 261 of sleeve 200, and using a bonding material (or possibly the material of fitting 300 or sleeve 200) to bond sleeve 200 to fittings 300.

End fittings 300, as shown in figure 4, each comprise sleeve boom pipe attach ring 310, boom pipe clamp groove 320, fiber stop collar 330, fiber trap flange 340, housing bonding surface 341, inner surface 350, sleeve bonding surface 360, and ring seal 361. Fittings 300 are preferred to comprise a metal such as heat treated steel (where heat treatment is to increase the hardness of the metal), but any material or combination materials may be used as long as fitting 300 can be formed into the desired shape and will subsequently withstand the forces that end fittings 300 are subjected to during operation of valve 10. It is preferred that surface 350 be hardened or otherwise treated to minimize wearing of the surface during operation of valve 10. Preferred valves will have a hardness of at least Rockwell 55C. Fittings 300 are also preferred to be radially symmetrical about axis Al, and to each consist of a single piece. However, less preferred embodiments may comprise other shapes and may comprise multiple pieces. As an example, hardened inner surface 350 may be a surface of a sleeve inserted into a body of a fitting 300.

Fittings 300 may viewed as being divided into four functional areas. The first, comprising attach ring 310 and clamp groove 320 is adapted to facilitate coupling valve 10 via fittings 300 to other devices such as concrete booms and discharge hoses. The attachment mechanism shown is preferred as it is suitable for use with a standard boom pipe attachment clamp. However, fittings 300 may comprise other attachment mechanisms with the mechanism being adapted to correspond with an intended use of valve 10. The second functional area comprises fiber stop collar 330, fiber trap flange 340, and housing bonding surface 341, and is adapted to facilitate coupling fittings 300 to housing 100, particularly when housing 100 is formed by filament winding. Stop collar 330 helps prevent any filaments being wound about fitting 300 during formation of housing 100 from intruding into the clamp groove 320. Fiber trap flange 340 cooperates with housing 100 to prevent fitting 300 from being pushed out of housing 100. As can be seen, the radius of fitting 300 increases between stop collar 330 and surface 360. As housing 100 is formed around fitting 300, once housing 100 is formed, fitting 300 cannot be removed from housing 100 without damage either housing 100 or fitting 300. It is preferred that housing bonding surface 341 cooperate with sleeve 200 to form a curved surface such that housing 100 does not comprise any sharp bends or corners which might weaken housing 100. In preferred embodiments, housing 100 will be bonded to rings 300 due at least in part to the filament winding process as the binding matrix used in housing 100 will also bond housing 100 to fittings 300.

The third functional area comprises, sleeve bonding surface 360 and ring seal 361, and is adapted to facilitate coupling sleeve 200 to fittings 300 in a manner that will create a fluid-tight seal between them. Ring seals 361 are preferred to have a close tolerance fit with sleeve ring recesses 261. Ring seals 361 are preferred to be sized to fit into ring recesses 261 that are 0.125 inches across and 0.375 inches deep.

The fourth functional area comprises surface 350 and the passage through the ring that it defines. Although it is preferred that surface 350 define a cylindrical passage having a diameter equal to both the inner diameter of a boom valve 10 is to be attached to and to the inner diameter of sleeve 200, less preferred embodiments may comprise other shapes and sizes.

Pressure inlet 400 can be any that permits fluid to flow into and out of space 600 between housing 100 and sleeve 200. In a preferred embodiment inlet 400 will comprise a fitting to which a pressure hose can be attached and flow into and out of space 600 will be controlled externally. In less preferred embodiments, inlet 400 may comprise a valve such that fluid flow can be directly controlled at or near inlet 400.

Pinch valve 10 is adapted to be coupled between a concrete boom 151 and discharge hose 152 as shown in figure 3, and is preferably part of a concrete pumping system 150 comprising a concrete pump 154 in addition to concrete boom 151 and discharge hose 152. When used in such a manner, valve 10 can be used to control concrete flow out boom 151.

As partially illustrated in figure 5, valve 10 may be formed by placing sleeve 200 and fittings 300 onto a mandrel 700 and then forming housing 100 via filament winding methods about the exterior of the sleeve 200 and end fittings 300, and subsequently removing mandrel 700. Preferred valves will comprise a high performance composite body. Most preferred valves will be formed by filament/fiber winding with the fibers being oriented to maximize the strength of the body in all directions, but particularly along the primary axis of the valve and radially outward from that axis. Such preferred valves may be formed by placing a sleeve and two end fittings onto a mandrel, bonding the sleeve to the end fittings (either before or after being placed on the mandrel), and utilizing filament winding or other high performance composite manufacturing techniques to form the housing around at least portions of the exteriors of the sleeve and end fittings.'

A preferred method of making a pinch valve comprises: (a) providing a polyurethane sleeve; (b) providing two hardened steel end fittings, each fitting comprising a fiber trap flange; (c) using a two part polyurethane film adhesive to bond an end fitting to opposite ends of the sleeve to form a sleeve-fitting assembly; (d) positioning the sleeve-fitting assembly on a mandrel; (e) coating an exterior surface of the sleeve-fitting assembly with both a two part polyurethane film adhesive and a release agent, the release agent coating a center portion of the sleeve-fitting assembly, and the two part polyurethane film adhesive coating portions of the end fittings and portions of the sleeve adjacent to the end fittings; (f) coupling a pressure inlet comprising a sleeve contacting saddle and a pipe nipple to the sleeve, preferably by tying it on with an epoxy coated aramid fiber encircling the sleeve; and (g) forming a housing via filament winding using aramid filament in an epoxy matrix, the housing extending from the fiber trap of a first of the two end fittings to the fiber trap of a second of the two end fittings.

Thus, specific embodiments and applications of high performance composite pinch valves and concrete pumping systems using such pinch valves have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in inteφreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a nonexclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.

Claims

CLAIMSWhat is claimed is:

1. A pinch valve comprising a high performance composite housing.

2. The valve of claim having a non-cylindrical interior surface.

3. The pinch valve of claim 2 wherein the valve also comprises a sleeve and two end fittings.

4. The pinch valve of claim 3 wherein the sleeve and two end fittings each comprise cylindrical interiors and the sleeve and rings are positioned adjacent each other such that the cylindrical interiors form an elongated cylindrical flow path through the valve.

5. The pinch valve of claim 4 wherein the cylindrical interiors of each of the two end fittings have a hardness of at least Rockwell 55C.

6. The pinch valve of claim 4 wherein the housing is formed by filament winding.

7. The pinch valve of claim 4 wherein the housing is formed on the sleeve and two end fittings while the sleeve and two end fittings are positioned on a mandrel passing through the cylindrical flow path.

8. The pinch valve of claim 3 wherein the sleeve comprises a non-cylindrical exterior surface positioned adjacent to the non-cylindrical interior surface of the housing.

9. The pinch valve of claim 3 wherein the end fittings comprise non-cylindrical exterior surfaces positioned adjacent to the non-cylindrical interior surface of the housing.

10. The pinch valve of claim 3 wherein the sleeve and end fittings cooperate to form a mating surface conforming with and adjacent to the non-cylindrical interior surface of the housing.

11. The pinch valve of claim 10 wherein the non-cylindrical interior surface is radially symmetrical and has the shape of a surface formed by rotating a smooth curve around the primary axis of the valve.

12. The pinch valve of claim 11 wherein the sleeve varies in thickness along its length and comprises regions of increased thickness near its ends.

13. The pinch valve of claim 3 wherein each of the end fittings comprises a flange extending into an end of the sleeve.

14. The pinch valve of claim 3 wherein each of the end fittings is bonded to an end of the sleeve.

15. The pinch valve of claim 14 wherein the end fittings and end portions of the sleeve are bonded to the housing.

16. The pinch valve of claim 1 wherein the valve has a burst pressure of at least 2500 PSI.

17. The pinch valve of claim 1 wherein the valve also comprises a sleeve, two end fittings, and an inlet valve, wherein: the sleeve and two end fittings each comprise cylindrical interiors and the sleeve and rings are positioned adjacent each other such that the cylindrical interiors form an elongated cylindrical flow path through the valve; the cylindrical interiors of each of the two end fittings have a hardness of at least Rockwell 55C; the housing is formed by filament winding on the sleeve and two end fittings while the sleeve and two end fittings are positioned on a mandrel passing through the cylindrical flow path; the sleeve and end fittings cooperate to form a mating surface conforming with and adjacent to the non-cylindrical interior surface of the housing where the non- cylindrical interior surface is radially symmetrical and has the shape of a surface formed by rotating a smooth curve around the primary axis of the valve; the sleeve varies in thickness along its length and comprises regions of increased thickness near its ends each of the end fittings comprises a flange extending into an end of the sleeve, and each of the end fittings is bonded to an end of the sleeve; the end fittings and end portions of the sleeve are bonded to the housing; at least one of the end fittings comprises a mechanism for coupling the valve to a boom; the inlet valve is adapted to control fluid flow into and out of a region between the sleeve and the housing; and the valve can withstand a pressure within the flow path of at least 2500 PSI.

18. A concrete delivery system comprising the valve of claim 1 coupled between a boom and a discharge hose, the boom also being coupled to a concrete pump.

19. A method of delivering concrete comprising pumping concrete out of a boom and through a pinch valve according to claim 1, and subsequently using the pinch valve to inhibit further concrete flow out of the boom.

20. The method of claim 19 further comprising providing pressurized air to the pinch valve so as to inhibit the flow of concrete through the pinch valve.

21. A method of making a pinch valve comprising placing a sleeve and two end fittings on a mandrel and forming a high performance composite housing at least partially around the sleeve and rings.

22. The method of 21 wherein the sleeve comprises two ends and the method comprises bonding each of the two ends to one of the two end fittings.

23. The method of 22 further comprising bonding the sleeve and two end fittings to the housing.

24. The method of 23 wherein the method of bonding the sleeve to the rings differs from that used to bond the rings to the housing.

5. The method of claim 21 wherein the method comprises: providing a polyurethane sleeve; providing two hardened steel end fittings, each fitting comprising a fiber trap flange; using a two part polyurethane film adhesive to bond an end fitting to opposite ends of the sleeve to form a sleeve-fitting assembly; positioning the sleeve-fitting assembly on a mandrel; coating an exterior surface of the sleeve-fitting assembly with both a two part polyurethane film adhesive and a release agent, the release agent coating a center portion of the sleeve-fitting assembly, and the two part polyurethane film adhesive coating portions of the end fittings and portions of the sleeve adjacent to the end fittings; coupling a pressure inlet comprising a sleeve contacting saddle and a pipe nipple to the sleeve by tying it on with an epoxy coated aramid fiber encircling the sleeve; and forming a housing via filament winding using aramid filament in an epoxy matrix, the housing extending from the fiber trap of a first of the two end fittings to the fiber trap of a second of the two end fittings.