EP0043698B1

EP0043698B1 - Taps

Info

Publication number: EP0043698B1
Application number: EP81302996A
Authority: EP
Inventors: Lee Tasman Mellett
Original assignee: Wrightcel Ltd
Current assignee: Wrightcel Ltd
Priority date: 1980-07-03
Filing date: 1981-07-01
Publication date: 1984-10-03
Also published as: ATE9675T1; DE3166460D1; EP0043698A1

Abstract

A tap for use with flexible containers which is capable of rupturing a fracturable diaphragm. The tap comprises a plunger 7 carrying a piercing spigot 8 and having attached thereto a rearwardly extending valve 10 which closes the tap outlet. The piercing spigot 8 is located adjacent the inlet of the tap. The plunger 7 is secured to a diaphragm 6. In use on a container depression of the diaphragm 6 enables the piercing spigot to rupture a membrane 13 which is part of the flexible container for fluids.

Description

This invention relates to taps and valves particularly for use with flexible containers for liquids.
Australian Patents 402,978 and 435,591 (Malpas) disclose flexible bulk containers having a dispensing tap which is designed to rupture a membrane in the wall of the bulk container when it is fitted to the container. Bulk containers of this sort have proved commercially successful for the storage and marketing of wine.
The tap proposed by Malpas in Patent 402,978 is inserted into a socket mounted on a wall of the flexible container. This socket incorporates a portion of the container wall to form a rupturable membrane which is broken when the tap is inserted into the socket. An improved construction of the flexible container and socket is disclosed in Australian Patent Application 47367/79. Because the taps have to be assembled into the socket of the container by the end user there has been consumer resistance to the use of taps of this kind. However, it is also important to delay the rupturing of the membrane sealing the container until the contents are to be dispensed. This requirement is important where the contents of the flexible container are to be kept airtight to avoid deterioration by oxidation.
Another disadvantage of other designs is that the closure valve is distant from the outlet and because liquid can accumulate between the valve and the outlet, these taps are susceptible to dripping, which is unacceptable to consumers.
It is an object of this invention to provide a tap convenient for end users and which avoids or diminishes the problem outlined above.
' In other constructions such as US-A-1763924 (Erwin) which is primarily concerned with attachments for the tops of bottles, a piercing member is mounted on a shaft which also carries a valve member. However, part of the shaft may be exposed to the exterior ambient conditions when the tap is not in use. This can clearly lead to unhygienic conditions.
A similar arrangement is shown in EP-A-0046754 (European Patent Application No. 80.901986.2 (Christine) though this is specifically concerned with a tap for a flexible bag and part of the shaft is always exposed to the atmosphere.
It is a further object of the present invention to provide a tap construction which can be hygienic at all times.
To this end the present invention provides a tap, adapted for use with a container having a rupturable membrane seal, the tap comprising a body; an inlet in the body adapted to be positioned in use adjacent the rupturable membrane of the container; an outlet in the body of the tap communicating with the inlet; membrane rupturing means disposed within the body of the tap; an axially movable shaft actuable externally of the body of the tap and remote from the inlet; and outlet sealing means is located downstream of the rupturing means and the shaft as disclosed in US-A-1763924. The invention is characterised in that the outlet is formed with a valve seat within the tap body; the outlet sealing means comprises a valve member having a valve stem connected to the shaft, the valve member being arranged to co-operate with the valve seat; and in that the membrane rupturing means comprises a membrane piercing head carried by the shaft adjacent the inlet, whereby, when the tap is located on the container and the shaft is moved axially towards the inlet, the piercing head breaks the membrane and the valve member is simultaneously lifted from the valve seal to open the outlet.
The present invention thus provides a tap which can be placed in position on the container without rupturing the membrane seal. When it is desired to dispense the contents of the container the membrane is ruptured by the first operation of the tap.
The tap of this invention can take several forms. Ideally the shaft, the piercing head and the outlet sealing means are integral.
A resilient diaphragm may be connected to the shaft, whereby, when the tap is in use on a container, displacement of the resilient diaphragm acts to move the shaft to open the outlet and move the piercing head to break the membrane seal of the container. In this arrangement the diaphragm in its normal position may be stressed toward and over the outlet. In this arrangement it may be difficult to provide a long travel path for the piercing head.
Preferably one end of the body portion of the tap, opposite the fluid inlet, accommodates a resilient diaphragm to which the shaft is attached. In its initial or normal position the resilience of the diaphragm retains the end of the shaft just out of contact with the membrane. In this normal position the valve member also closes the fluid outlet. Depression of the diaphragm pushes the shaft through the membrane and removes the valve member from the valve seat of the liquid outlet. Because of the relatively long distance of travel required by the valve stem to ensure that rupture occurs the diaphragm is preferably formed to include a resilient fold or concertina shape rather than a shallow dome. One such diaphragm is prescribed in British Patent 977,660. Thus the tap of this invention is designed to rupture the membrane on its first operation. Because of this the tap of this invention can be assembled with the flexible container prior to rupturing of the membrane which is a distinct advantage over much of the prior art.
Ideally the valve stem extends in a nearly opposite direction to the shaft so that the straightline motion of the shaft results in almost straight line motion of the valve member. It is possible for the shaft and valve stem to be offset but parallel and the outlet would then be disposed below the diaphragm. Because the valve member closes the outlet within the body portion the outlet can be exposed so that there is no possibility that dirt could accumulate in an outlet tube.
Also, with such construction, the first partial axial movement of the shaft may unseal the outlet so that only the first operation of the tap would require large axial movement to rupture the membrane seal. Axial movement of the shaft may be provided by sliding or rotary movement a screw threaded shaft being preferred.
Thus, the present invention also provides a flexible walled liquid container having secured to a wall thereof a tap socket incorporating a rupturable membrane sealing the liquid contents thereof, a tap inserted and secured within the said socket the said tap being made according to one of the embodiments of this invention.
The invention may be put into practice in various ways and one specific embodiment will be described by way of example to illustrate the invention with reference to the accompanying drawings in which:

Figure 1 is a side sectional view of a tap in accordance with the present invention;
Figure 2 is a view along the line A-A of Figure 1; and
Figure 3 is a side elevation of the tap shown in Figure 1 with the valve open.

The tap illustrated comprises a body section 11 having an inlet end 4 and an outlet 5. One end of the body section is closed by a resilient diaphragm 6. The body section 11 is preferably composed of polypropylene and the preferred material for the diaphragm 6 is polyethyl vinyl acetate. The diaphragm may be provided in any suitable form e.g. a concertina type resilient panel as long as the diaphragm is resilient, capable of large deformation and of subsequently resuming its normal shape under its own resilience.
Disposed within the body section is the plunger 7 which is preferably formed from nylon. At one end 14 of the shaft it is connected to the diaphragm 6. This connection at the end 14 in this embodiment is a snap fit into a recessed boss on the inside face of the diaphragm 6. The plunger 7 extends through a guide ring 1 5 within the body portion 11. The plunger 7 carries at the end adjacent the inlet 4 a piercing spigot 8. Extending rearwardly from the spigot 8 is a valve stem 9 and a valve 10 which seals a valve seat 17 provided on the inside of the outlet 5.
Figure 2 which shows the end view of the spigot 8 illustrates one preferred form. Guide grooves 19 are provided on the inside of the tap body 11 and guide ribs 18 are provided on the spigot 8 and their interengagement assists in ensuring direct movement of the plunger 7 and the spigot 8 past the inlet end 4 of the body section 11.
Figure 3 shows the tap in use fitted in a collar on the wall 12 of a flexible container. The inlet 4 of the body section 11 abuts the membrane 13 which seals the container. When (as shown in Figure 3) the diaphragm 6 is depressed the piercing spigot 8 ruptures the membrane 13 and at the same time the valve closure 10 is withdrawn from the seating 17 of the outlet 5 thus allowing the fluid contents of the container to be dispensed. On removal of the deforming pressure from the diaphragm it resiliently springs back to its normal position.
From the above description it can be seen that the present invention provides a tap convenient for consumers to use which still enables the rupturing of the sealed container to be delayed until dispensing of the fluid contents is commenced.

Claims

1. A tap, adapted for use with a container (12) having a rupturable membrane seal (13), the tap comprising a body (11); an inlet (4) in the body adapted to be positioned in use adjacent the rupturable membrane (13) of the container; an outlet (5) in the body of the tap communicating with the inlet (4); membrane rupturing means (8) disposed within the body of the tap; an axially movable shaft (7) actuatable externally of the body of the tap and remote from the inlet (4); and outlet sealing means (10) is located downstream of the rupturing means (8) and the shaft (7) characterised in that the outlet (5) is formed with a valve seat (17) within the tap body (11); the outlet sealing means comprises a valve member (10) having a valve stem (9) connected to the shaft (7), the valve member being arranged to co-operate with the valve seat (17); and in that the membrane rupturing means comprises a membrane piercing head (8) carried by the shaft (7) adjacent the inlet (4), whereby, when the tap is located on the container and the shaft (7) is moved axially towards the inlet (4), the piercing head (8) breaks the membrane (13) and the valve member (10) is simultaneously lifted from the valve seat (17) to open the outlet (5).

2. A tap as claimed in Claim 1 characterised by a resilient diaphragm (6) which is connected to the shaft (7), whereby, when the tap is in use on a container, displacement of the resilient diaphragm (6) acts to move the shaft (7) to open the outlet (5) and move the piercing head (8) to break the membrane seal (13) of the container.

3. A tap as claimed in Claim 1 characterised in that the shaft (7) or the piercing head (8) or both are engaged by guide means (15) afforded by the body (11) of the tap whereby movement of the shaft (7) and piercing head (8) longitudinally of the tap body (11) is facilitated.

4. A flexible walled liquid container having secured to a wall (12) thereof a tap socket incorporating a rupturable membrane (13) adapted to seal the liquid contents thereof, and a tap inserted and secured within the said socket characterised in that the tap is as defined in any one of Claims 1 to 3.