WO2006054889A1

WO2006054889A1 - Self-closing valve

Info

Publication number: WO2006054889A1
Application number: PCT/NL2005/000787
Authority: WO
Inventors: Johannes Antonius Maria Holsink
Original assignee: Akzo Nobel Coatings International B.V.
Priority date: 2004-11-16
Filing date: 2005-11-10
Publication date: 2006-05-26
Also published as: NL1027521C1

Abstract

A self-closing valve assembly (34) comprises a valve of the duckbill type having a flexible body (35) made of flexible material, which body has an inner cavity which forms a duct (3) for a substance, which flexible body has a conical part (35b) with tapering wall sections which, near a discharge end of the duct, form a pair of opposite lips (36) with an elongate discharge slit (36a) between them, which lips lie against one another in the closed position of the valve. The valve assembly furthermore comprises an element (60) which is arranged in the inner cavity of the flexible body (35) and produces a closing force, which element acts on the flexible body and produces a force forcing the lips into the closed position. Preferably, the element producing a closing force acts on the flexible body near the two ends of the discharge slit (36a), the element (60) forcing these ends apart, as a result of which the lips (36) are forced into their closed position.

Description

SELF-CLOSING VALVE

The invention relates to a self-closing valve assembly and a system for dispensing a liquid or pasty substance provided with a valve assembly of this type.

Various designs of valves of the duckbill type are known from the state of the art. In this case, the duckbill valve has a flexible body with lips which, in the closed state of the valve, lie against one another and, in the open state of the valve, form a nozzle. In practice, the flexible body is made of an elastomeric plastic.

The known duckbill valves are for example used as non-return valves in a duct for liquid. Valves of this type are also used as a dispensing element, with a substance being dispensed from a reservoir via the self-closing valve.

The self-closing action of the known duckbill valves is unsatisfactory, for example when the valve is being used as a dispensing element. For such an application, it may, for example, be a requirement that the valve seals the reservoir in an airtight manner against the outside atmosphere. It could also be a requirement that the valve must not open under the pressure of the substance in an orientation in which the valve is located under the reservoir. It is difficult, if not impossible, to meet these requirements with the known valves.

It is also difficult to achieve accurate metering of a substance using the known duckbill valves, for example because the valves close relatively slowly.

In particular, when a duckbill valve is combined with a reservoir in the form of a bag from which the substance is dispensed the sealing action of the known duckbill valve is unsatisfactory.

It is an object of the invention to provide a self-closing valve assembly with an improved action.

Furthermore, it is an object of the invention to provide a self-closing assembly in which the opening behaviour and closing behaviour of the valve can be optimized. Furthermore, it is an object of the invention to provide a valve assembly which is suitable as a dispensing element for dispensing a substance from a reservoir.

A first aspect of the invention provides a valve assembly according to the preamble of claim 1, which is characterized in that the valve assembly furthermore comprises an element which is arranged in the inner cavity and produces a closing force, which element acts on the flexible body and produces a force forcing the lips into the closed position.

As a result of the arrangement of the respective element in the cavity, the element cannot (or at least cannot easily) be manipulated or damaged, for example by a user of a system in which the valve assembly serves as a dispensing valve for dispensing a substance, for example from a bag. Furthermore, arranging the element in the interior prevents soiling, for example by an accumulation of dispensed substance on the exterior of the flexible body. Cleaning of the flexible body is not adversely affected thereby either.

By suitable design of the element producing a closing force, the closing and opening behaviour of the valve can be influenced and adapted to the requirements imposed.

In a preferred embodiment, the element producing a closing force acts on the flexible body at locations near the two ends of the discharge slit, the element forcing these locations apart, as a result of which the lips are forced into their closed position.

This arrangement and design of the corresponding element has proved to be very expedient, partly due to the fact that it acts directly on the lips.

Preferably, the element producing a closing force is a pre- tensioning element which presses the lips together into the closed position under pre-tension. The result of this is that the valve remains closed as long as the pressure of the substance in the dispensing duct is insufficient to overcome the pre-tension.

In a further preferred embodiment, the element producing a closing force is provided with one or more resilient parts which force the lips into the closed position. By suitably designing the resilient parts, it is possible to achieve a spring action which is tailored to the desired behaviour of the valve.

Preferably, the element producing a closing force is made of spring steel. Spring steel retains its resilient action over a long period of time. In addition, it is relatively easy to achieve the desired spring action with spring steel. Alternatively, an element made from a suitable plastic is, for example, conceivable, but the phenomenon of relaxation of the plastic may become a problem, especially over time.

In an embodiment which is advantageous in practice, the element producing a closing force is a spring element having two limbs, which respectively act on the flexible body near one end of the discharge slit.

In a preferred embodiment, the element is a torsion spring having a torsion part which comprises at least one complete turn, and having two limbs which act on the flexible body.

In order to retain the element producing a closing force in its position relative to the flexible body, the interior of the flexible body may be provided, near each end of the discharge slit, with a socket adjoining the inner cavity for accommodating a part of the element producing a closing force.

Advantageously, the element producing a closing force is made from spring steel wire. In this case, at the ends acting on the flexible body, the element may be provided with wire sections which are bent, preferably bent round to substantially form a circle.

A second aspect of the invention provides a self-closing valve assembly according to claim 10. The second aspect of the invention provides a self-closing valve assembly comprising a valve of the duckbill type having a flexible body made by injection-moulding elastomeric material, which body has an inner cavity which forms a duct for a substance, which flexible body has a conical part with tapering wall sections which, near a discharge end of the duct, form a pair of opposite lips with an elongate discharge slit between them, which lips lie against one another in the closed position of the valve.

According to the second aspect of the invention, provision is made for the lips in a central region thereof to be thicker than in end regions of the lips located near the ends of the discharge slit.

This measure is advantageous in combination with the first aspect of the invention but could also be applied separately.

With a suitable injection-moulding process and associated cooling, it may be possible for shrinkage resulting from the cooling of the injection-moulded flexible body to cause the lips to be pressed together.

The valve assembly may furthermore comprise a cap which extends over the flexible body.

The invention furthermore relates to a system for dispensing a liquid or pasty substance, comprising a Valve assembly according to the invention and a reservoir for a substance, in which the valve assembly is designed as a dispensing element for dispensing a substance from the reservoir. Preferably, a container is furthermore provided for accommodating the reservoir.

In particular, the invention provides a dispensing system in which the reservoir is designed as a collapsible reservoir, in particular a bag. In one possible use, the invention provides for the reservoir to be filled with, for example, ink, glue, soap, cosmetics, foodstuff, or for example paint, in particular car paint.

The self-closing valve assembly may form part of a pump, for example as an intake valve or a discharge valve. The pump could have a variable pump chamber which is designed as a bellows having a body of flexible material, for example such that the body of the valve forms an integral part of the bellows. Optionally, the bellows is provided with two such valves acting as intake valve and discharge valve.

The invention will be explained in more detail below with reference to the drawing, in which: Figs, la-d show a dispensing assembly provided with an exemplary embodiment of the self-closing valve assembly according to the invention as well as a first connector element coupled thereto in perspective, side view, front view and top view, respectively;

Fig. 2 shows the dispensing assembly and associated first connector element of Fig. 1 in sectional view;

Figs. 3a, b show the second connector element of the dispensing assembly of Figs. 1 and 2 in perspective and sectional view, respectively;

Figs. 4a-d show the self-closing valve assembly of Figs. 1 and 2 in perspective, top view and two side views, respectively;

Figs. 4e-g show the self-closing valve assembly in vertical section so that the element which produces a closing force is visible in perspective, top view and side view, respectively;

Fig. 4h shows an example of the element producing a closing force on a larger scale;

Fig. 5 shows the fastening element of the assembly of Figs. 1 and 2 in side view;

Fig. 6 shows a perspective view of a bag to be accommodated in a container with the first connector element of Fig. 1 arranged therein.

A preferred embodiment of a system for dispensing a liquid or pasty substance will now be explained by means of Figs. 1-6 using a preferred embodiment of a self-closing valve assembly according to the invention.

Figs, la-d and 2 show a dispensing assembly 2 which can be coupled to the bag 1 shown in Fig. 6 which is filled with the substance to be dispensed. The dispensing assembly 2 comprises a self-closing valve assembly 34 which, in this example, serves as dispensing element for dispensing a substance from the bag 1.

The bag 1 with the dispensing assembly 2 coupled thereto is in this example intended to be accommodated in a container (not shown) , for example a container which can be held in the hand and is designed to squeeze the bag 1 using manual force.

The dispensing assembly 2 comprises a second connector element 31 which is intended to be coupled to a first connector element 30, which is arranged on the bag 1 (see Fig. 6) .

The second connector element 31 has a tubular part 33, which forms a dispensing duct 3 for a substance to be dispensed and is intended to be inserted into the connector element 30. The discharge end of the dispensing duct 3 is provided with the self-closing valve assembly 34.

The first connector element 30 is a female connector element provided with a bore 32 and the second connector element 31 is a male connector element, the tubular part 33 of which fits the bore 32 of the female connector element 30.

The valve assembly comprises a valve of the duckbill type with a flexible body 35 (see Figs. 4a, 4b), for example made of rubber or an elastomeric plastic. Preferably, the flexible body is produced in a suitable mould by injection-moulding.

The body 35 in this example has a substantially cylindrical part 35a and a conical part 35b with the interior of the body 35 forming a cavity. This cavity has an inlet opening which is formed by the cylindrical part 35a and faces the bag 1. The cavity forms

(part of) a discharge duct 3 for the substance to be dispensed from the bag. The cylindrical part 35a fits onto or into a projecting tube part 42 of the second connector element 31.

A fastening element 37 is placed over the flexible body 35 on the outside thereof, in such a manner that a lower flanged edge 35c of the body 35 is clamped between the fastening element 37 and the second connector element 31.

The fastening element 37 in this case has a double-walled annular base 38 with an inner ring 38a, which lies around the cylindrical part 35a and an outer ring 38b. Openings 39 are provided in the . outer ring 38b for hook fingers 40, which are formed on the second connector element 31. These hook fingers 40 extend between the rings 38a, 38b from below and form a snap connection with the base 38.

The conical part 35b has two tapering wall sections, which, near a discharge end of the duct for the substance, form a pair of opposite lips 36 with an elongate, in this example rectilinear, discharge slit 36a. The lips 36 abut in the closed position of the valve 34.

The valve assembly 34 further comprises an element 60 arranged in the inner cavity of the flexible body 35 and producing a closing force, which element 60 acts on the flexible body 35 and produces a force forcing the lips 36 into the closed position.

As can be seen in particular in Figs. 4a and 4c, the element 60 acts on the flexible body 35 at locations which are situated near the two ends of the discharge slit 36a. The element 60 forces these locations, the ends of the discharge slit 36a as it were, apart, as a result of which the lips 36 are forced into their closed position.

In the preferred embodiment shown, the element 60 producing a closing force is a pre-tensioning element 60 which is mounted in the flexible body 35 under pre-tension and presses the lips 36 together into the closed position under pre-tension. As a result, before delivery is effected, the pressure of the substance in the dispensing duct 3 has to be increased first, for example by operating a pressure-exerting plate of the container in which the bag is accommodated, to such an extent that the pre-tension is overcome and the valve 34 opens. Thus, it is for example possible to prevent substance from being discharged if the valve 34 is below the bag 1, for example when the container is held upside down. The element 60 shown is constructed from spring steel wire, in particular by bending. The embodiment shown is a torsion spring with a torsion part 61, which comprises at least one full turn, and with two limbs 62, 63 which each act on the flexible body 35 near one end of the discharge slit 36a. In this example, the limbs 62, 63 are substantially in the plane of the turn of the torsion part 61.

As an alternative (not shown) , the element 60 could be produced from suitable plastic material.

Figs. 4a, c show that the interior of the flexible body 35, near each end of the discharge slit 36a, is provided with a socket 64 adjoining the inner cavity for accommodating therein part of the element 60 producing a closing force.

In the embodiment shown, each end of a limb 62, 63 is provided with a wire section 62a, 63a which is bent, for example bent round to form a (semi-) circle.

The element 60 can be installed in the flexible body 35 in a simple manner.

It will be clear that the spring action of the element 60 can be influenced by the design, dimensioning and choice of material, thus in turn affecting the behaviour of the self-closing valve assembly 34 during opening and closing.

It can be seen in the top view in Fig. 4b that the lips 36 in a central region 36b thereof are thicker than in end regions 36c of the lips 36 located near the ends of the discharge slit. This measure is advantageous in combination with the "extension" of the lips 36, as effected by the element 60, in the longitudinal direction of the discharge slit 36a. The stress in the relatively thick central region of each lip forces that central region as it were in the direction of the other lip.

The relatively thick central regions 36b of the lips 36 may also lead to the shrinkage resulting from the cooling of the injection-moulded flexible body pressing the lips together. In order to ensure that no discharge and/or leakage from the valve assembly 34 can occur, for example during storage and transportation of the container, the valve assembly may, next to the valve assembly 34, comprise securing means so that the lips 36 are secured in the closed position.

In the embodiment shown, a cap 44 is provided which extends over the valve 34 in the closed position of the cap 44. In this case, the cap 44 snaps onto a peripheral edge of the second connector element 31 (see Fig. 2) . In a variant, the cap 44 is a screw cap which can be screwed onto a threaded section of the connector element 31.

In another variant (not shown) , the cap has means associated with it for removing substance residue from the body 35 on the side of the discharge slit 36a. The cap is for example provided with a scraping element which scrapes over said side of the discharge slit

36a when the cap is unscrewed and thus removes any residue.

It can furthermore be seen from Figs. 1 and 2 that the first connector element 30 has a sealing element 50 for sealing the inlet end of the discharge duct 3. The sealing element 50 interacts with the second connector element 31 in such a manner that the seal is removed when the first .and second connector elements 30, 31 are coupled together. In particular, the sealing element 50 is a stopper, fitting into a seat, which is coupled via one or more, preferably flexible, arms 51 to the body of the connector element 30. The tubular part 33 is provided with a head 52 which fits into the stopper 50. It should be noted that a seal of this type is known per se from the state of the art, for example from EP 749 358 and EP 998 664.

The second connector element 31 and the first connector element

30 are coupled to one another by means of a snap connection at 55 in Fig. 2, thus keeping the stopper 50 out of its seat. This snap connection is so strong that it cannot, for example, be released by a user.

It will be clear that the container may be designed in various ways, for example as a container which can be placed in a support or mounted on a wall (optionally with the ^' dispensing nozzle at the bottom) . Furthermore, means may be provided on the container to assist the dispensing of substance from the reservoir, for example a pump, mechanically operated pressure means which act on the exterior of the reservoir, means ^'for pressurizing a medium acting on the outside of the reservoir, etc.

Claims

C L A I M S

1. Self-closing valve assembly (34) comprising a valve of the duckbill type having a body (35) made of flexible material, which body has an inner cavity which forms a duct (3) for a substance, which flexible body (35) has a conical part (35b) with tapering wall sections which, near a discharge end of the duct, form a pair of opposite lips (36) with an elongate discharge slit (36a) between them, which lips lie against one another in the closed position of the valve, characterized in that the valve assembly (34) furthermore comprises an element (60) which is arranged in the inner cavity of the flexible body (35) and produces a closing force, which element (60) acts on the flexible body (35) and produces a force forcing the lips (36) into the closed position.

2. Valve assembly according to claim 1, in which the element (60) producing a closing force acts on the flexible body (35) near the two ends of the discharge slit (36a) , the element (60) forcing these ends apart, as a result of which the lips (36) are forced into their closed position.

3. Valve assembly according to claim 1 or 2, in which the element (60) producing a closing force is a pre-tensioning element which presses the lips (36) together into the closed position under pre¬ tension.

4. Valve assembly according to one or more of the preceding claims, in which the element (60) producing a closing force is provided with one or more resilient parts which force the lips (36) into the closed position.

5. Valve assembly according to one or more of the preceding claims, in which the element (60) producing a closing force is made of spring steel, for example spring steel wire.

6. Valve assembly according to one or more of the preceding claims, in which the element (60) producing a closing force is a spring element having two limbs, which respectively act on the flexible body near one end of the discharge slit (36a) .

7. Valve assembly according to claim 6, in which the element (60) is a torsion spring having a torsion part (61) which comprises at least one complete turn, and having two limbs (62, 63) which act on the flexible body.

8. Valve assembly according to one or more of the preceding claims, in which the interior of the flexible body is provided, near each end of the discharge slit, with a socket (64) adjoining the inner cavity for accommodating a part of the element (60) producing a closing force.

9. Valve assembly according to one or more of the preceding claims, in which the element (60) , at the ends acting on the flexible body, is provided with wire sections (62c, 63c) which are bent, preferably bent round to substantially form a circle.

10. Self-closing valve assembly (34) comprising a valve of the duckbill type having a flexible body (35) made by injection-moulding elastomeric material, which body has an inner cavity which forms a duct (3) for a substance, which flexible body has a conical part

(35b) with tapering wall sections which, near a discharge end of the duct, form a pair of opposite lips (36) with an elongate discharge slit (36c) between them, which lips lie against one another in the closed position of the valve, characterized in that the lips (36) , in a central region (36b) thereof, are thicker than in end regions

(36c) of the lips located near the ends of the discharge slit.

11. Valve assembly according to one or more of the preceding claims, in which the valve assembly furthermore comprises a base (31) with a tube part (33) to which the flexible body is attached in such a manner that a substance can be dispensed via the discharge slit by means of the tube part and the duct in the flexible body.

12. Valve assembly according to claim 11, in which the valve assembly furthermore comprises a cap (44) which can be attached to the base and extends over the flexible body, for example when the base has a threaded section and the cap is designed as a screw cap interacting with said threaded section.

13. System for dispensing a liquid or pasty substance, comprising a valve assembly (34) according to one or more of the preceding claims and a reservoir (1) for a substance, in which the valve assembly is designed as a dispensing element for dispensing a substance from the reservoir.

14. System according to claim 13, in which a container is furthermore provided, for example a container which can be held in the hand, for accommodating the reservoir (1) .

15. System according to claim 13 or 14, in which the reservoir is filled with a substance chosen from the group of: ink, glue, soap, cosmetics, foodstuffs, paint, for example car paint.

16. System according to one or more of claims 13-15, in which the reservoir is provided with a first connector element (31) and the valve assembly with a second connector element (32) for coupling the reservoir and the dispensing assembly together, optionally releasably, in such a manner that a dispensing duct is provided.

17. System according to claim 16, in which the first connector element has a sealing element (50) for sealing the dispensing duct, which sealing element interacts with the second connector element in such a manner that the seal is removed when the first and second connector elements are coupled together.

18. System according to one or more of claims 13-17, in which the reservoir is a compressible reservoir, for example a bag, for accommodating the substance to be dispensed.