WO2003076079A1

WO2003076079A1 - Pump dispensers

Info

Publication number: WO2003076079A1
Application number: PCT/EP2002/002759
Authority: WO
Inventors: Reinhold Karl Jaeger-Waldau; Klaus Natersky
Original assignee: Crown Cork & Seal Technologies Corporation; Carnaudmetalbox Plc
Priority date: 2002-03-13
Filing date: 2002-03-13
Publication date: 2003-09-18
Also published as: AU2002308259A1; EP1494817A1

Abstract

A pump dispenser has its outlet valve disposed immediately upstream of its dispensing nozzle (19') and at a remote spacing from its inlet valve. The movable part of the outlet valve is formed by a circular disc (214) of a valve component (206) which is push-fitted into the hollow free end of the dispenser body (13'). The disc is flexible and carried on the valve component so as to be generally transverse to the product flow path. It faces in the upstream direction and is biassed by the valve component into engagement with a downstream facing, annular valve seat (242) which is formed within the body cavity.

Description

PUMP DISPENSERS

This invention relates to pump dispensers for liquids, such as are used in the home for spraying a cleaning liquid by pump action from a container onto a surface (e.g a window) to be cleaned. Usually such dispensers have a trigger operated by finger pressure of the user to pressurise the liquid for dispensing.

Except, possibly, for devices for use with products having a high viscosity, pump dispensers have an inlet non-return valve and an outlet non-return valve which are respectively arranged for allowing liquid to enter the pump mechanism during an induction stroke, and for allowing the liquid to pass to a nozzle for dispensing during a subsequent pressure stroke. As is discussed in European Patent Specification EP 0850695 Bl, for some applications it may be advantageous to provide the movable parts of the inlet and outlet valves by means of a single component, although it is alternatively known to use separate components for this purpose.

Irrespective of whether the inlet and outlet valves are provided by a common component, in most prior pump dispensers known to the present Applicants, the valves have been located relatively closely together; in particular, they have been located upstream of, and at a substantial spacing from the nozzle.

However, substantial benefits can be achieved if the outlet valve is located in the immediate vicinity of the nozzle rather than at substantial distance from it. Amongst the possible advantages of such an arrangement is that it can reduce the product residue open to atmosphere which remains in the dispenser after a dispensing stroke. It may also provide greater design freedom in the arrangement and dimensions which can be used for the dispenser.

According to a first aspect of the invention, there is provided a pump dispenser for a liquid product, the dispenser having a body, an outlet valve disposed within the body and arranged to allow one-way flow of product from the pump chamber during a dispensing stroke, and an outlet nozzle arranged for dispensing the product from the dispenser as a spray or jet, the dispenser further being characterised in that the outlet valve is located immediately upstream of the nozzle in the dispensing flow path and comprises an outlet valve component push-fitted to the body and having a flexible valving member, and a valve seat formed on the body for engagement by the valving member at an annular interface, the valving member being biassed against the valve seat longitudinally of the dispensing flow path and in the upstream direction thereof.

A pump dispenser embodying the invention is described below by way of example with reference to Figs. 4 to 11. For convenience the dispenser is regarded as being a modification of the dispensers which are described in European Patent specification No. EP 0850695 Bl, the disclosure of which is incorporated herein in its entirety. Figs .1 to 3 of the present application replicate some of the drawings of that specification, with the addition of some further reference numerals corresponding to those used.

In the attached drawings : -

Fig.l generally corresponds to Fig.9 of EP 0850695 Bl, showing the general arrangement of a prior art dispenser;

Figs.2A, 2B and 3A, 3B generally correspond respectively to Figs. 4, 5 and 3, 3B of EP 0850695 Bl, showing the valve member and the spring of the prior art dispenser;

Fig.4 shows the general arrangement of the embodiment of the present invention, the dispenser being shown in an assembled state but with some components omitted for clarity; Fig.5 corresponds to Fig.4 and is a perspective exploded view of the embodiment of the present invention;

Fig.6 shows the outlet valve component of the embodiment, as it appears in end elevation looking on its outlet end; Fig.7 shows the outlet valve component as seen on diametral section AA in Fig.6;

Fig.8 shows the outlet valve component in side e1evation;

Fig.9 shows the outlet valve component in end elevation taken on section BB in Fig.8;

Fig.10 shows the outlet valve component as seen in longitudinal section taken along line CC in Fig.6; and

Fig.11 is an enlarged view of the part of the embodiment which is indicated by the circle 11 in Fig.4. Referring firstly to Figs .1 to 3 of this Application, the known trigger pump dispenser has a screw-on closure 12, body 13, diptube 14, valve member 15, piston 16, trigger 17, spring 18, dispensing nozzle 19 and shroud 20 assembled together as shown. All components are made of suitable plastics materials, the dispenser having no metal content and being readily recyclable after use. The valve member and the spring are individually shown in Figs.2A, 2B and Figs. 3A, 3B respectively.

For the assembly of the dispenser the valve member 15 is push-fitted to the closed, back end of the pump cylinder 40 of the body 13 (Fig.l), the piston 16 is push-fitted into the pump cylinder in front of the valve member, the spring 16 is clipped to the body 13 with a pair of cantilevered arms 68A, 68A (Figs. 3A, 3B) straddling the pump chamber and joined at their free ends by a yoke 72, and the trigger 17 is snap-engaged in a movable manner with the valve member, piston and the yoke 72 of the spring. At a suitable time in relation to these actions the closure 12, the nozzle 19 and the shroud 20 are each snap-engaged to the body.

The valve member 15 is shown in greater detail in Figs. 2A and 2B. It is moulded from a thermoplastic elastomer material and is generally cup-shaped and circular, having a base 110 and a tubular skirt 112 which extends around the periphery of the base. The junction of the base with the skirt is surrounded by a collar portion 114. The base 110 has an imperforate central dome 116 which projects from it in the same direction as the skirt 112. It is joined integrally to the inside diameter of the skirt by four thin and flexible arms 118 which are spaced around the valve member so as to form apertures 120 between them. The arms are generally S-shaped, having generally radially extending inner and outer end portions 122 and 124 and a generally circumferentially extending central portion 126. Because of their bent shape and substantial flexibility, the arms present little resistance to movement of the dome perpendicularly to the plane of the base.

The collar 114 provides the means by which the valve member 15 is held captive in the body 13. For that purpose it is received and held in an inwardly facing, complementary groove which is formed in the body (Fig.l), this engagement being established when the valve member is push-fitted into position in the body in the assembly of the dispenser as described briefly above. In the valve member as fitted the dome 16 is accommodated at the open front end of an entry passage 36 which is formed in the body 13 on the centreline of the pump chamber 38, whilst the skirt 112 is accommodated within an annular outlet passage 86 which is formed in the body concentrically outside the entry passage.

In operation of the dispenser for use, pulling of the trigger 17 against the action of the spring 18 causes the piston to move backwardly of the dispenser along the pump cylinder 40, so generating a superatmospheric pressure in the pump chamber 38. This pressure is transmitted through the apertures 120 of the valve member 15, and by expanding the skirt 112 lifts it outwardly off its seat (not referenced) provided by the body. Any product which is already in the pump chamber is therefore forced to leave via the apertures 120 and the outlet passage 86, after which it moves through a port 88 formed in the body, and thence along the barrel 92 of the dispenser to the nozzle 19. In conventional manner the nozzle forms it into a desired spray or jet of product as may be required.

On subsequent release of the trigger 17 the spring 18 (Figs. 3A, 3B) resiliently forces the trigger back to the position shown in Fig.l, thereby advancing the piston 16 to a forward position in the pump chamber 38 and generating a partial vacuum in the pump chamber. The dome 116 of the valve member 15 is thereby moved forwardly (i.e. towards the pump chamber) on its arms 118, so breaking the seal which had existed during the dispensing stroke between the dome and its seat (not referenced) on the body 13. Product is accordingly drawn from the container on which the dispenser is mounted, to enter the pump chamber 38 via diptube 14, entry passage 36 and apertures 120 so as to recharge the pump chamber with product in preparation for a further dispensing operation.

Although it has achieved substantial commercial success, the trigger pump dispenser described above with reference to Figs. 1 to 3 is considered by the present Applicants to suffer from disadvantages which the present invention seeks to overcome. In particular, in the dispenser of Figs .1 to 3, from the viewpoint of their operating characteristics it may be desirable for the movable valve parts 116, 112 of the valve member 15 to be formed of different polymer materials. Accordingly it may be attractive to form the valve member in two parts, as a bi-injection moulding. Such a component however, may be difficult to mould and/or may be unsatisfactory to handle or to use. Moreover, the outlet valve (of the dispenser of Figs 1 to 3 ) is disposed at a remote location from the nozzle 19, and a substantial product residue can therefore remain in the dispenser after a dispensing operation.

Reference is now made to Figs. 4 to 11 showing an embodiment of the present invention. Wherever appropriate the same reference numerals as before are used, with primes, to indicate like or analogous parts.

Figs . 4 and 5 show the body 13 ' of the embodiment of this invention, with the valve member 15' and nozzle 19' present but with the associated closure, diptube, piston, trigger, spring and shroud omitted for clarity. These latter components are identical or similar to the corresponding components of the dispenser of Figs. 1 to 3.

The valve member 15 ' has been modified so that it no longer acts to form the outlet valve for the dispenser. Conveniently, this is achieved by forming its skirt 112 with a plurality, e.g three, of generally V-shaped notches or cut-outs; one such notch is represented by broken line 300 in Fig.2B. Because of the modification, the interior of the pump chamber 38' is now in open communication at all times with the passage 90' which extends along the dispenser barrel 92 ' upstream of the dispensing nozzle 19 ' . Alternatively the valve skirt 112 may be omitted entirely. The function of the valve member to provide the inlet valve, is unaffected; for that purpose it is formed, as before, with a peripheral collar portion 114' capable of being snap-engaged in the body 13' and with a dome 116' which is movably carried by aperture-forming arms 126' so as to be capable of engaging and disengaging a seat on the body during the dispensing and induction strokes of the dispenser. Also as before, the apertures 120' between the arms 126' serve to provide passages for product flow both out of and into the pump chamber 38' during operation. As can be seen from Figs. 4 and 11 in particular, at the outlet end of the dispenser and attached to the body 13 ' , are two components each moulded from a suitable thermoplastics resin material, namely an outlet valve component 202 and a nozzle component 204. These components are rotatable in relation to one another through an unlimited angle, but the outlet valve component is held by the body against rotation, as will be described later.

The valve component, particularly shown in Figs .6 to 10, is generally cup-shaped. It has a hollow bowl-like portion 206 having a tubular side wall 207 with front end face 208, and a base 209 which is formed as a spider of four arms 210 separated by apertures 212. The valve component further has a foot 214 in the form of an imperforate circular disc which is attached to the centre of the base 209 on the centreline of the valve component by a short stem 216.

The apertures 212 communicate the outside of the valve component 202 with the hollow interior of its bowl 206 for product flow. At is front end, remote from the foot 214, the valve component 202 is formed externally with a peripheral flange 220. In addition, an annular chamfer 221 is formed around the side wall 207 partway along its length. Internally the side wall is formed with a pair of diametrically opposed grooves 222 each extending longitudinally of the valve component from a rounded blind end 224 located partway along the side wall, to discharge at the front end face 208 of the valve member within the flange. In use of the valve the portion 206 is held firmly in the body 13 ' and the arms 210 act as a spring to resiliently bias the foot 214 into sealing engagement with the valve seat 242.

Depending on the thickness and material of the foot 214 it may flex to a greater or lesser extent under fluid pressure. However, the main component of movement of the foot is facilitated by the spring action of the arms 210, which allows axial movement of the whole foot. Therefore the foot does not have to be flexible (other than for sealing considerations) and it does not have to be of a thickness which permits flexing. The force to lift the foot in this way is lower than a foot which is fixed but flexible . It will be appreciated that the flexibility of the arms 210 is one way of dictating at what product pressure the foot 214 is lifted from the seat 242.

This valve arrangement therefore incorporates an outlet valve and a pre-compression function, both of which are immediately upstream of the nozzle. In this case the two functions are fulfilled by the same valve component .

The nozzle component 204 has a front face 226 which is formed with an offset dispensing aperture 228 for the dispenser, and inner and outer tubular skirts 230, 232 which depend backwardly from the front face in spaced relation.

As can be seen in particular from Fig.11, the inner skirt 230 of the nozzle component 204 is dimensioned to be a sealing push-fit along the bowl 206 of the valve component 202. It is cut away at a pair of diametrically opposed rectangular notches 234 which are capable of revealing the blind ends 224 of the grooves 222 in the side wall 207 in two diametrically opposed "SPRAY" positions of the nozzle component. Otherwise, the grooves are closed off by the skirt 230.

The other skirt 232 of the nozzle component 204 itself has inner and outer spaced parts 236, 238. The inner part of the skirt is generally circular and dimensioned to be a sealing push-fit over the flange 220 of the valve component 202 when, as shown in Fig.8, the components are assembled together with the front 226 of the nozzle component in abutment with the front face 208 of the valve component. The outer skirt part 238 is of generally square contour, so as to assist operation by the user whilst providing an aesthetically pleasing appearance for the nozzle.

For the manufacture of the dispenser the valve is push-fitted into the body 13 ' , and the nozzle component 204, is subsequently push-fitted onto the body and valve component. As can clearly be seen in Fig.11, at the free end of the barrel 92 ' of the dispenser, the body is formed internally with a forwardly projecting chamfer 240 and a valve seat 242 located behind the chamfer and on a smaller radius. In the fitted position of the valve component on the body the valve seat 242 engages the periphery of the foot 214 of the valve component to form the outlet valve for the dispenser, the engagement of the chamfers 221, 240 and of the flange 220 with the free end of the body then determining the longitudinal position of the valve component in relation to the body so as to provide accurate control for the outlet valve, in particular the product pressure at which it operates. The operating characteristics of the outlet valve can be further determined, if required, by adjusting the contact surface between the valve foot 208 and the valve seat 242 for example by ribs or grooves formed in the free front face, of the valve foot 208 or valve seat 242. Alternatively, the outlet valve operating characteristics may be controlled by shaping the valve foot so that it is convex or concave to the product flow path thereby altering the contact pressure between the valve foot 208 and valve seat 242, and/or by varying the thickness of the foot from its centre outwards to its free edge. For the retention of the nozzle subassembly 200 on the body 13' the part 236 of the nozzle outer skirt 232 is formed internally with a pair of longitudinally spaced beads 246 which are arranged to make an interference fit with the body as shown in Fig.11. The beads have inclined leading faces, (shown but not referenced) to facilitate assembly.

As previously mentioned, the outlet valve component 202 is restrained from rotation on the body 13', but the nozzle component 204 is free to rotate. In the preferred OFF position of the nozzle component, midway between the two SPRAY positions, its inner skirt 230 closes off the grooves 222 in the valve component, and no product can leave the dispenser. However, in either of the two SPRAY positions of the nozzle component, shown in Figs. 4 and 11, the notches are angularly aligned with the grooves, and product can therefore pass to the dispensing aperture 228 via an annular chamber 246 (Fig.11) which is formed around the inside of the front 226 of the nozzle component.

In the described embodiment angular restraint for preventing the outlet valve component 202 from rotating in relation to the dispenser body is provided by a pair of straight beads (not shown) which are formed across the interior wall of the barrel 92' between its chamfer 240 and the adjacent free end of the body. When the valve component is push-fitted (with appropriate orientation) into the body, these beads come into engagement with a pair of complementary flats 218 formed on the exterior of the valve component - See Figs. 5 and 8. Reverting again to Fig.11, it will be seen that the valve seat 242 is in the form of an annular rib which faces downstream of the product flow path with a transverse orientation. It is preferred for the rib to be of part-circular cross-section, with a radius of curvature which is as small as possible commensurate with moulding limitations. It will also be seen that the rib is surrounded by a relief channel 302 by which it is spaced from the adjacent interior wall of the dispenser barrel 92'. The free edge of the foot 214 is located within this channel (transversely of the barrel), and Applicants prefer for the depth D of the channel longitudinally of the barrel to be at most twice the radius of curvature R of the rib. It will be readily apparent to those skilled in the art, that the outlet valve component 218 may also be used in combination with the dual inlet/outlet valve of the prior art, shown in Figs. 2A and 2B. In this arrangement, the outlet valve 218 acts as a pre- compression feature, to ensure product is only dispensed once a threshold pressure is reached. This threshold pressure may be controlled as previously described.

Claims

1. A pump dispenser for a liquid product, the dispenser having a body (13') an outlet valve (202,242) disposed within the body and arranged to allow one-way flow of product from the pump chamber during a dispensing stroke, and an outlet nozzle (19') arranged for dispensing the product from the dispenser as a spray or jet, the outlet valve is located immediately upstream of the nozzle in the dispensing flow path and comprises an outlet valve component (202) fitted to the body and having a valving member (214), and a valve seat (242) formed on the body for engagement by the valving member at an annular interface, the valving member (214) being biassed against the valve seat longitudinally of the dispensing flow path and in the upstream direction thereof, characterised in that the valving member (214) is resiliently biassed against the valve seat (242) by one or more flexible arms (210) .

2. A pump dispenser according to Claim 1, wherein the valving member is flexible.

3. A pump dispenser according to any preceding claim, wherein the valving member (214) is an imperforate disc supported centrally so as to face upstream and with a generally transverse orientation, the disc engaging the valve seat (242) adjacent its periphery.

4. A pump dispenser according to Claim 3, wherein the disc (202) is concave in the upstream direction.

5. A pump dispenser according to Claim 3, wherein the disc (202) is convex in the upstream direction.

6. A pump dispenser according to any claim of Claims 3 to 5, wherein the disc's (202) thickness varies on a radial line from its centre outwards to its free edge.

7. A pump dispenser according to any preceding claim, wherein the valve seat (242) has the form of a circular rib presented in the downstream direction of product flow for engagement by the disc (202) .

8. A pump dispenser according to Claim 7, wherein the rib (242) is surrounded by a channel (302).

9. A pump dispenser according to Claim 8, wherein the channel has a depth (D) which is at most twice the radius of curvature (R) of the rib.

10. A pump dispenser according to any preceding claim, wherein the outlet valve component (202) is push-fitted into the body (13') to a position in which a peripheral flange (220) engages the body to prevent further movement .

11. A pump dispenser according to any preceding claim, wherein the outlet valve component (202) is push-fitted into the body (13') to a position in which opposed chamfers (221,240) of the valve component and the body engage one another to prevent further movement .

12. A pump dispenser according to any preceding claim, wherein the outlet valve component (202) has a hollow body (206) disposed downstream of the valving member (214) and formed internally with a longitudinal groove (222) opening to its free end (208), the nozzle component (204) having a skirt (230) arranged for push-fit engagement into the body of the outlet valve component, the skirt having an opening (234) which in a predetermined relative angular position of the outlet valve and nozzle components allows product to pass into the groove for dispensing by the nozzle component.