CA2071322A1

CA2071322A1 - Squeeze pack

Info

Publication number: CA2071322A1
Application number: CA002071322A
Authority: CA
Inventors: Joachim Boll; Axel Wagner
Original assignee: Kautex Werk Reinold Hagen
Current assignee: Kautex Werk Reinold Hagen
Priority date: 1991-03-05
Filing date: 1992-06-16
Publication date: 1993-12-17
Also published as: GB9124743D0; GB2253387A; EP0505611A2; EP0505611A3; DE4106919A1

Abstract

ABSTRACT OF THE DISCLOSURE

A squeeze pack comprises an elastically deformable external container and an internal container arranged therein for accommodating the filling material. The internal container is divided into first and second portions in the middle region of its longitudinal extent, substantially transversely to its longitudinal axis. The portion of the internal container which is towards the delivery opening thereof provides a support body while at least a part of the other portion which is remote from the delivery opening of the internal container is flexible so that it can be easily plastically deformed under the effect of a pressure difference between atmospheric pressure and the pressure in the intermediate space between the internal and external containers, thereby causing material in the container to be displaced towards the delivery opening through the support body.

Description

2~7~ '?~ ?
BACXGRDUMD OF THE INVENTION
One fonm of squeeze pack for containing material to be discharged therefrom by squeezing the pack ha~ a delivery opening for discharge of the material, and comprises an external elastically defonmable container, within which is disposed a plastically deformable internal container for receiving the filling material. The pack further inclu~es a closure means having a delivery valve for the filling material, the valve being operable at least su~stantially to prevent the equalisation of pro8~ure between the internal container and the external atmosphere by the ingress of air into the internal container, even after the discharge of filling material, while the internal container is adapted to be deformable under the effect of a pressure difference between atmospheric pressure and the gas pressure in the space between the internal and external containers. The pack has a venting valve operatively disposed between the space between the external and internal containers and the external atmosphere, for communicating that space with the atmosphere.
In a pacX of that kind, which is to be found in European patent specification No 0 190 169, for containing viscous filling materials, difficulties may be encountered in completely emptying the internal container of the material contained therein. That is to be attributed to the fact that the air which iR compre~sed in the space between the external and internal container~, when the external container is compre_sed by a manual squeeze force being applied to the external container, may under some circumstances compress the bag-like flexible internal container in such a way that regions thereof which still contain filling material are cut off from the delivery opening by virtue of the bag-like internal container being tightly constricted between the delivery opening and the portions of the internal container which _till contain the material to be discharged therefrom. A major reason for that phenomenon is that it is not always possible to provide that the internal container iB unifonmly compressed under the effect of 2~7' ~.. ^~

the air which is compressed in the intermediate space between the internal and external containers, especially as the way m which the shape of the internal container changes under the effect of the increased pressure applied to the outside thereof may also depend on the position which the pack assumes during discharge of material therefrcm, by virtue of the external container being squeezed.
In an endeavour to counteract that probl~m, the teaching of EP-A-0 305 003 provides that the internal container is fixed to the external container approximately in the middle region of the axial extent of the internal container and at its upper end, around its periphery. The r~sult of that design configuration is that the portion of the internal container which is towards the delivery opening experience~ no deformation or only an immaterial degree of deformation, under the effect of the increased pressure which occurs in the intermediate space between the external and internal containers, when the former is ~queezed. In contrast, the increased pressure in the intenmediate space between the internal and external containers results in defonmation of ths portion of the internal container which is renote from the delivery opening, ln the sense of resulting in a reduction in the volume enclosed by that portion of the internal container. As a result, firstly the filling material disposed in that portion of the internal container is displaced towards the delivery opening and a corresponding amount of filling material flows outwardly from the pack through the delivery opening thereof. Ultimately, further discharge of material from the pack by suitably squeezing the external container results in more or le~s total emptying of the easily defonmable portion of the internal container, which is remote from the delivery opening, so that at that time the pack reaches an interim stage at which essentially only the portion of the internal container which is towards the dellvery opening is still filled with the filling material of the pack.
On the above-indicated assumption that the internal container is fixed~y joined substantially in the central region of its axial extent 27~

to the external container, at that stage in the process of emptying the pack the pack is still about half full. Emptying of the portion of the internal container which is towards the delivery opening is effected by the portion of the internal container which is remote from the delivery opening being pressed into the other portion which is towards the delivery opening, being turned inside out as it does so, under the effect of the increased pressure produced by squeezing of the pack in the intermediate space between the internal and external containers.
When that happens, the material contained in the portion of the internal container which is tcwards the delivery opening and which is fixed to the external container is displaced towards the delivery opening. In that way, it is possible to avoid deformation of the internal container which would result in parts of the filling material therein being cut off from having access to the delivery opening by virtue of the formation of pockets of material within the internal contalner, at any event ~nen the free, easily deformable portion of the internal container is not of an excessive axial dimension.
However the usefulnes~ of the pack disclosed in EP-A-0 305 003 is ~till subject to certain linitations as the fact that the internal container is fixed to the external container therewithin means that it is not possible to refill the pack by fitting a fresh full internal container into the external container, after the pack has been previously e~ptied. Furt'nenmore, due to the fact that the internal container iB alBO m~unted to the external container at the end of the internal container which ~s towards the delivery opening, it is necessary for the valve by way of which the intermediate ~pace between the internal and external containers can be comnunicated with the external atmosphere to be disposed in the region of the pack which is remote from the delivery opening. That restricts the design options for a pack of that kind. In addition, the fact that the internal container is fixed to the external container gives rise to the necessity for the internal container to be filled after it has been positioned in and Z ~ ? f ~ q-~

joined to the external container. All in all, handling of the internal container which will predominantly consist of very thin foil material will involve a certain degree of difficulty. Althcugh the arrangenent just described above is such that the plastically deformable bag-like internal container extends only approximately over half the axial length of the pack and, at its open end which is towards the delivery opening, i6 sealingly ~ecured to the extPrnal container over it entire periphery in the middle region of the axial extent of the external container, that construction however also suffers from the above-indicated re6trictions from the point of view of utility thereof. Inaddition, it is not very suitable for filling material which is such that the wall of the container for accommodating it must be imQervious for glven ga~eous substances, for exa~ple oxygen. Squeeze pack of the kind which are being discussed herein generally comprise thermoplastic materials. rhe materials which are predominantly used for that purpose, for example polyolefins, suffer however from the disaavantage that they are permeable in relation to certain sub~stances. For that rea-~on, the u~ual practice is for the walls of plastic contalners to be of a nulti-layer or laminate construction, at least one of the layers thereof performing the function of a barrier layer which is impermeable to the respective sub~tances involved, that i~ to ~ay possibly for oxygen as already mentioned above, but also in relation to comQonents of the filling material. t~wever, hollow bodies of thermoplastic material, with a multi-layer or laminate wall of that kind, are comparatively expensive. In the cass of a ~queeze pack which has an internal container, the internal container will be provided with a barrier layer as air and thus oxygen pass into the intermediate space between the e~ternal container and the internal container, for the purpo~es of e~ptying the internal container.
SUMMARY OF THE INvENTIoN
An ob~ect of the present invention i9 to provide a squeeze pack which generally does not suffer fro~ the above-indicated disadvantages z~
of prevlou~ pack~.
Another object of the present invention is to prcvide a squeeze pack which can be readily at least virtually totally emptied, irrespective of the pcsition which it assumes during the discharge of material therefrom.
Still another object of the present invention is to provide a squeeze pack which is reliable in tenms of emptying procedure while however not involving complications in regard to manufacture and handling thereof.
Yet another object of the present invention is to provide a squeeze pack which affords a wide range of design configuration options according to manufacturer and user requirementfi.
Yet a further object of the pre~ent invention is to provide a ~queeze pack which is so designed that it can be repeatedly used in a simple fashion by replacing an emptied internal container of the pack by a filled container, ~ he foregoing and other objects are achieved by a squeeze pack in accordance with the principles of the present invention.
It will be seen therefore that in accordance with the present invention the fact that the internal container, in~ependently of the external container, in the region of its axial extent which is towards the delivery opening, is prevented from experiencing substantial defonmation under the effect of the increased pressure which takes effect due to squeezing of the pack, in the intenmediate space between the external container and the internal container, means that the pack affords a greater degree of flexibility in tenms of manufacture, han~ling, packaging and filling.
In a preferred feature of the invention, the wall thickness or gauge of the portion of the internal container which is towards the delivery opening and which serves as a support portion is greater than the wall thickness or gauge of the portion of the internal container, ~D."J?

which is rem~te from the de~ivery opening. The latter can preferably be in one piece, for exa~ple being such that firstly a hollow body is produced by a blow mDlding process and then that portion of the hollow body which is to be easily deformable and which is to prcvide a bag-like configuration as the internal container is subjected to amechanical stretching effect in order ~ that portion to produce the ~mall wall thickness which is required for easy deformability thereof.
In that case the support bcdy or means which is formed by the portion of the internal container which is toward_ the delivery opening is a constituent part of the internal container. However that may also be the case when the two portions of the internal container are produced aq _eparate part~ and are joined together at least in a peripheral region which extends substantially perpendicularly to the longitudinal axiU of the internal container. Such an internal container would only consist of first and second portions which however have been assembled from separately produced parts. In that arrangement, the part which comprises the ea~ily deformable bag-like portion of the internal container can extend from the end of the internal container, which is remote from the delivery opening, to the end region of the support body which is remote from the dslivery opening. That means that the open end of the bag-like portion iq sealingly secured to the peripheral region of the support body, which is remote from the delivery opening. It is also possible however for the bag-like part which has the easily defonmable portion of the internal container to ~S extend as far as or closely adjacent to the delivery opening, being connected at its end region renDte from the delivery opening to the support body. In that case the part having the bag-like portion and the part forming the support body would overlap each ot~er over a large part of the support body, normally the greatest part thereof.
That configuration may be desirable when, for the reasons already referred to above, the pack m~st include a barrier layer in order to ensure that the internal container i5 not penmeable in relation to certain 6ubstances. It will be appreciated that it is possible for the support body also to be provided with a barrier layer. Generally speaking however that option w~uld be more expensive than the production of a bag-like and thus correspondingly thin-wall part which in the assembled condition of the internal container has on the one hand the easily deformable portion and in addition Ln the region of the support bcdy provides non-penmeability in relation to the respective substances involved.
Normally the support body wlll be arranged within the bag-like part because that is the simplest way of preventing the portion of the internal container, which is towards tne delivery opening, from experiencing a considerable degree of deformation, under the effect of the pressurised gas in the intermediate space between the internal and external containers. It will be noted that in that case it is desirable for the ~upport body and the part comprising the compressible bag to be sealingly connected together along the poriphery of both parts, at the end of the support body which is remote from the delivery opening. That is intended to ensure that material ~uch as toothpaste, skin cream and the like cannot pass between the support body and the part of the internal container which comprises the compressible bag-like portion.
Another preferred configuration is one which involve the production of a bag-like part which extends to or closely adjacent to the delivery opening, wherein in the portion which is towards the delivery opening, the support body is arranged outside that first part. With that arrangement, in order to achieve the desired support function, it would of course be necessary for the support body and the bag to be joined together in such a way that substantial deformation of the portion of the bag, which is towands the delivery opening, is prevented, under the effect of an increased pressure in the intenmediate sp~ce between the internal and external containers.

Z~7 '~
In accordance with a further preferred feature of the invention, at itB end which is towards the delivery opening, the internal container may be sealingly secured to an annular holding nEans which is arranged in the region of the opening of the external container, so S that the interior of the internal container is communicated with the delivery valve of ~he closure arrangement, through the opening in the holding means. In that configuration, the holding means which is disposed in the region of the opening of the external container may be part of the support bcdy. A design configuration which has been f~und to be particularly advantageous is one in which the venting valve, by way of which a communication can be made between the external atmosphere and the intenmediate space between the internal and external containers, is dispo ed in the closure arrangement which also ha~ the delivery valve. That configuration results in the external container being easier to produce as then there is no need for a separate venting valve to be mounted thereon. More specifically, that arrangement may be such that there is at least one passage means between ~he holding means and the wall of the region of the opening of the external container, said passage means communicating the intermediate space between the internal and external containers with the venting valve dlspo~ed in the closure arrangement.
It will be appreciated that the squeeze pack according to the invention also affords the possibility of the venting valve being disposed in a region of the external container which is away from the delivery opening, for example possibly in the bottom thereof.
It is possible and, depending on the respective considerations involved, al~o advantageous, for the external container to be made in one piece, for example by a blow molding process, from plastic material. However it may also be desirable for the external container to coTQrise at least two parts which can be releasably and sealingly connected together, in such a way that, after release of the at least two parts of the external container from each other and possibly the closure arrangement, a filled internal container can be inserted into the pack. That would also give the advantage that the internal container can be filled independently of the external container, that is to say outside same.
Furthermore, such an arrangement would afford the possibility of the internal container, after having ~een emptied, being replaced by a filled internal container, so that the external container with closure arrangement thereon can be repeatedly used.
In another preferred feature of the invention, the wall of the internal container may conprise at least first and second layers of different materials.
Further object~, features and advantages of the present invention w$11 be ~et forth in the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a diagrammatic perspective view of a pack in accordance with the invention, Figure 2 is a view in longitudinal ~ection throu4h the pack according to the invention without closure arrangement, Figure 3 is a view in longitudinal section through an internal container of the pack according to the invention, which still contains the major part of the filling material therein, Figure 4 is a view in longitudinal section through the internal container shcwn in Figure 3, in an emptied condition, Figure S is a view in longitudinal section through another preferred embodiment of the pack according to the invention, Figure 6 i9 a view in section taken along line Yl-YI in Figure 5, Figure 7 is a perspective view of a detail of the pack, and Figure 8 is a view in longitudinal section of a portion of a further embcdiment of a pack according to the invention.

DESCRIPTION OF PREFERRED EMeoDlMENTs Referring firstly now to Fig~res 1 and 2, shown therein is a pack which is in the fonm of a squeeze bottle, comprising an internal container 10, an external container 12 and a closure arran~ement 14 which can be screwed or fitted, as by a push fit, on to the neck 16 of the external container 12. The external c~ntainer 12 i3 substantially dimensionally stable but elastically defonmable under the effect of manually applied forces. me actual body as indicated at la of the external container 12 and a shoulder portion 20 thereof, which bears the neck 16, are produced separately and joined together subsequently, after the filled internal container 10 has been introduced into the external container 12. me connection 25 between the two parts 18 and 20 may be releasable but it must be air-tight. The external container 12 and the internal container 10 and possibly also the closure arrangement 14 are made from suitable plastic material.
The internal container 10 comprises first and second portions 22 and 24 of approximately equal volume while being of different wall thicknesses, The portion 22 which is remote from the neck 16 of the external container 12 is of smaller wall thickness or gauge and is of a bag-like configuration BO that it can be easily penmanently defonned.
The portlon 22 generally conpri~es a thin film. The portion 24 which acts as a support body is of greater wall thickness and is such that, under the effect of external manually applied forces it is elastically deformable but in other respects is such that, when the external forces applied thereto to cause it to be squeezed together are released, it returns to its original shape and in so doing also returns the portion 22 to the original container cross-section, at any event in the region of the connection formed between the first and second portions 22 and 24 by the overlapping parts 26 and 23 thereof. The two portions 22 and 24 therefore present substantial differences in regard to deformability thereof. As the two portions 22 and 24 are produced separately, it is possible for those differences to be taken into account by virtue of 2~ '?fi,~,.~

suitable choice of the materials for making the ~wo portions 22 and 24.
me ~wo portions 22 and 24 are sealingly joined together by any suitable procedure, for example by glueing, welding and the like, in such a way that, in the embodiment shown in Figures 1 and 2, the easily deformable bag-like portion 22 which is closed at its end 44 remote from the neck 16 is fixed at its opposite open end by way of its above-mentioned edge part 26, to the above~mentioned edge part 28, which i8 remote from the neck 16, of the portion 24. That configuration can be clearly seen, in various shapes, in Figures 2 through 4. Figures 2 through 4 al~o show that the cross-sectional dlmensions of the two portions 22 and 24 of the containers correspond to each other in the region of the connection formed by the mutually overlapping parts 26, 28 thereof.
The portion 24 of the internal container 10 is extended into a lS neck-like extenffion portlon 30 which serves as a holding means and the outside diameter of which iB such that it can be suitably fitted into the neck 16 of the external container 16. At its free end region, which i9 at the upward end in for example Figure 2, the hold~ng means 30 is provided with a rib 32 which extends therearound and which is supported against the end face of the neck 16 and which thus provides a form-locking or positive connection between the two parts, namely the extenoion portion 30 and the neck 16, thereby to fix the position of the internal container 10 relative to the external container 12, at least in the region of the neck of the pack. ThUB, when the closure arrangement indicated at 14 in Figure 1 i9 fitted into position, the rib 32 i~ pre~sed firmly again~t the neck 16 in order there also to provide an air-tight closure effect with an axial and/or radial sealing action.
Looking now at Figure 2, arranged at the botton 34 of the ~0 external container 12 i9 a one-way valve 36 which only penmits air to flow from the external atmosphere into the intermediats ~pace indicated at 33 bstween the external container 12 and the internal container 10.

2~f ~

The closure arrangement 14 (see Figure 1) is provided with a delivery opening which is adapted to be closed by the action of a valve 40. The valve 40 opens under the effect of an increased pressure produced in the internal container 10 and/or in the intenmediate space 38. The valve 40 closes automatically as soon as a condition of pressure equilibrium ob~ains. Further details in this respect will be set forth in the description hereinafter with reference to Figures 5 through 7.
For the purposes of discharging material frcm the pack, it is manually compressed to a greater or lesser degree, in a manner which is conventional procedure in relation to squeeze packs. In the first phase of the emptying operation, that is to say when the internal container 10 is still completely full or almost completely full, it may happen under some circumstances that the forces which are man~ally applied by compressing or ~queezing the external container also act lS directly on the internal container so that the latter is also subjected to a manual squeezing effect. Whether that occurs and if so to what extent will also depend on the ratio of the volume of the external container when in a non-loaded condition, to the volume of the filled internal container, thus depending on the volume of the intenmediate space 38 between the internal ContainOE 10 and the external container 12. At any event, when the external container ia squeezed, as a result of the resulting reduction in volume of the external container 12, the air in the intermediate space 38 experienceR an increase in pressu~e as the intermediate space 38 is air-tightly closed off relative to the external atmosphere by virtue of the above-desCribed sealed connections between the components parts of the pack and the valve 36 only opens when tnere is a reduced pre~sure in the intermediate space 38, that is to say the valve 36 only opens to provide for a direction of flow of gas from t~e external atmosphere into the intermediate space 3B. The increase in pressure produced in the intermediate space 38 by virtue of the external container 12 being squeezed acts on the internal container 10, the 2~

portion 22 of which $hereby also experiences defonmation in the sense of a reduction in the volume of the portion 22.
As the external container 12 is elastically defonmable, after the squeeze forces cease to be applied thereto, it returns to its original shape as shown in Figures l, 2 and 5, which results in an increase in its volume and an increase in the intenmediate space 38, in comparison wi$h the previous condition in which the pack was squeezed. That increase in the volume of the external container 12 causes a reduction in the pressure in the intermediate space 38, such that that pressure falls below atmospheric p~ressure if material had been dlscharged from the internal container lO of the pack during the squeezing procedure which had just taken place. The result of that reduced pressure in the intermediate space 38 is that the valve 36 opens and thus air flows into the intermediate space 38 until there is approximately a condition of pressure equilibrium between the atmospheric pressure and the pressure in the intermediate space 38.
The forces resulting from the pressure difference between the internal container lO on the one hand and the intermediate space 38 on the other hand are relatively low, with the result that only the bag-like portion 32 which is of a thin-wall structure and thus easily plastically deformable is defonmed thereby, whereas the portion 24 is not defonmed by that pressure difference. Admittedly, depending on where the forces which produce the squeeze effect on the pack act thereon, it is possible for the portion 24 of the internal container lO also to experience deformation during the pack-squeezing process, but as the portion 24 is elastically deformable, after the squeezing process 18 concluded it will return to its original shape, similarly to,the behaviour of the external container 12, and will thereby also return the cross-section of the pack in the region of the connection at 26, 2~ between the two portions 22, 24 to the original dimensions, that is to say the non-deformed condition, the result thereof being that the portion 22 experiences a corresponding reduction in its 2 ~: 7 volume and thus the total volume of the internal container remains unchanged.
Reference will now be made to Figures 3 and 4 which only show an internal container 10 of the pack, to describe the deformation to S which the internal container is subjected during the procedure for emptying material fro~ the pack.
Looking firstly at Figure 3 , shown therein is the internal container in a condition in which a small p2rt of the filling material contained therein has already been removed and consequently the portion 22 of the internal container, the contour of which in the completely filled condition is shown in dash-dotted lines, has already experienced a certain reduction in its volume, which resulted in material in the internal container 10 beLng displaced into the portion 24 and from there through the holding means 30 to the delivery valve indicated at 40 in Figure 1. Figure 3 is a samewhat diagrammatic view showing that, in that intenmediate condition, the easily deformable portion 22 is somewhat compressed axially and radially. Figure 3 also ~hows that, in particular when the axial extent of the easily deformable portion 22 is of a suitable dimension in reLation to the cross-sectional dimension in the edge region 28, there is no fear of deformation of the portion 22 in such a way that region~ thereof are cut off from the delivery opening of the pack, with the possibility in that case of parts of the material in the internal container being enclosed in pockets in such a way that they can no longer be displaced towards the delivery opening for discharge therefrom. In actual fact the reduction in volume of the portion 22 occurs in any case in such a way that the filling material contained therein is more or less completely urged towards the portion 24. Ccmpression of the portion 22, with a simultaneous reduction in its volume, can also be additionally controlled by the wall of the portion 22 being provided with regions of different thicknesses or being of such a configuration in same other fashion that deformation of the portion 22, which 2 ~ 7 ~ o ~ ~

produces the reduction in volume, takes place in a controlled manner.
Suitable configurations for achieving that purpose are to be found for example in EU-A-0 1~2 094 to which reference is therefore specifically directed in this respect.
After emptying of the bag-like portion 22 which constitutes approximately half of the volume of the internal container 10, further squeezing of the pack to provide for further discharge of filling material therefrom causes the bag-like portion 22 to enter into the portion 24 which serves as a support body until, at the end of the emptying procedure, the component parts of the internal container occupy approximately the pcsition shown in Figure 4. In other words, during the emptying of the portion 24 which serves as a ~upport body for the internal container 10, the bag-like portion 22 acts as a kind of material-displacement me~ber by penetrating into the portion 24, turning itself inside out aq it does so, thus displacing the filling materlal in the portion 24 towards the delivery opening of the pack.
Figure 4 further shows that, in the last phase of the emptying operat~on, the lower edge of the support body 24 limits the extent by which the easily defonmable portion 22 can be displaced. Figure 4 additionally shows that very substantial emptying of the pack can be achieved if the co-operating components thereof are of a suitable configuration, that is to say, as shown in Figure 4, the portion 22 is such as very closely to match the internal configuration of the portion 24 when the portion 22 is fully within the portion 24 in the condition shown in Figure 4. It should be noted at this point that any amount of filling material which may still remain in the neck region at least approximately corresponds to the amount which usually inevitably remains in that way in other previous packs. That also depends on the shape of the co-operating components.
Reference will now be made to Figures S through 7 in which parts which are the same as those to bs found in the embodiment shown in Figures 1 through 4 are identified by the same reference numerals but 2g71 increased by 100. The embodiment of Figuras 5 through 7 differs fron that shown in Figures 1 through 4 in that the internal container 110 is of a somewhat different configuration. ffle internal container 110 ha~ an easily defonmable portion 122 which is remote from the hDlding S means 130 and which fonms the portion of a larger, bag-like part 142 which extends from the bottom end 144 to the neck-like holding means 130. The part 142 is also sealingly mounted on its outside at least at the edge region 128 of the portion 124 which acts a a ~up~ort body for the internal container 110, in order thereby to prevent filling material in the internal container 110 from passing into the region between the part 142 and the support body or portion 124. In addition the bag-like part 142 which in the region of the support body 124 ifi adapted to the contour thereof is sealingly mounted with its end having the opening to the periphery of the holding means 130 80 that the internal container 110 is of a double-wall configuration in the region of the support body 124. As already mentioned above, that will be desirable when the internal con~ainer 110 is to be imçermeable in relation to certain substances. For that purpose, the part 142 i~ made from a different material frcm the sup~ort body 124 or may be additionally provided with a barrier layer to give the desired impenmeable nature for the internal container. A short region which poseibly remains on the neck-like holding means and which i~ not covered over by the part 142 can be disregarded in that respect as the holding means 130 is normally of a somewhat greater wall thickness, thufi affording a corresponding reduction in the possibly inherent permeability of the material forming the holding means 130.
~ owever the above-described fitructural differences are generally immaterial in regard to the progress of a pack-emptying procedure which here too takes place in the manner described hereinbefore with reference to Figures 3 and 4. In all cases, that is to say also in the other embodiments herein, the important consideration is that the portion of the internal container ~hich is remote from the delivery opening is easily deformable so that the above-mentioned pressure difference is sufficient to cause defonmation thereof.
A further structural difference in the embodiment of Figures 5 through 7 is that venting of the intenmediate space 138 between the internal container 110 and the external container 112 takes place by way of the closure arrangement 114. In regard to it6 external dimensions, the holding means 130 which carries the internal container 110 also corresponds in this embodiment to those of the neck 116 of the external container 112. In contrast to the embodiments shown in 10 Figures 1 through 4, the holding means 130 whose external diameter is adapted to the internal diameter of the neck 116 in order to provide a satisfactory fit is provided with longitudinally extending groove-like recesses 148 which extend into groove-like recesses lS0. The latter are provided at the side of the rib 132, which is towards the end face 15 of the neck 116. The rib 132 provides a positive connection between the internal and external containers, in the manner already described above with reference to Figures 2 through 4. The recesses 148, 150 define with the neck 116 passages by way of which the intenmediate space 138 between the external container 112 and the internal container 110 can be communicated with the external atmosphere. For that purpose the substantially radially extending recesse~ 150 each open into a respective longitudinal passage 152 in the body of the closure arrangement 114. All the passage~ 152 open into an annular passage 154. They are also connected by way of passages 156 to a further annular pas~age 158.
The closure body 114 is pravided with a diaphragm 160 which has a sealing lip 162 extending along its outer periphery and co-operating with the wall region 163 of the closure body 114, to cloqe the annular pa~age 158. In that respect the sealing lip 162 i8 of sw h a configuration and arrangement that it i~ only displaced somewhat towards the containers when there is a reduced pressure in the intermediate space 138, and thus affords air access to the intenmediate space 138. In other words, the sealing lip 162 and the wall region 163 of the closure bcdy 114, which co-operates with the sealing lip 162, constitute the venting valve 136 for the intermediate space 13B. The venting valve 136 is closed when there is an increased pressure in the intermediate space 138.
The diaphragm 160 which has an extension portion 164 extending therearound, which is held in a groove 166 in the clo~ure body 114, also has a sealing lip 168 which defines a substantially circular opening 170 and by co-operating with a projection 172 on the closure body 174 forms the delivery valve 140. The sealing lip 168 represents the extension of an annular region 174 of the diaphragm 160. It closes an annular passage 176 which is arranged coaxially with respect to the projection 172 and which is ccmmunicated by way of longitudinal pas~ages 178 in the closure body 114 with the internal space of the lnternal container, in which the filling material of the pack is to be found. The closure body 114 is provided with a plug-like pro~ection 18C whose cros~-~ection corresponds to the internal cross-section of the hoLding means 130. In the assembled condition of the camponent r~rts, the projection 180 campletely fills the region 146 of the holding means 130 ~o that it sealingly closes off the internal container 110, apart frcm the longitudinal passages 178. In particular no air can pass fram the longitudinal passages 1S2 into the internal container 110. The projection 180 is defined by a step 182, the shoulder configuration of which sits on the peripherally extending rib 132 of the holding means 130 and ~hus clamps the holding means 130 between the neck 116 of the external container 112 and the closure body 114. That arrangement provides an additlonal sealing effect for the internal space of the internal container 110. In order to seal off the annular passage 176 for the filling material, relative to the annular passage 154 which i9 designed to carry a flow of air, the diaphra~n 160 carries an annular extension or projection portion 184 which extend~ inwardly of the pack and is arranged coaxially with lB

2~

respect to the projection 172. The free edge 186 at the lower end of the projection portion 184 bears sealingly against the wall 187 of the projection 172, which thus defines the recess in the closure b~dy 114 which is partly fonmed by the annular passage 154. The extension portion 184 follDws the movements of the part of the diaphragm 160 which carries it, with a sufficient degree of sealing integrity being ensured between the annular passages 154 and 176 in any position of the assembly.
In the case of the embodiment shown in Figures 5 through 7, a pressure or squeeze loading applied to the pack, which results in ela~tic deformation of the external container 112, causes an increase in the pressure in the intermediate space 138 which, as the intermediate space 138 communicates with the annular passage 154 in the above-described manner, in turn results in a corresponding pressure being applied to the region of the diaphragm 160, which lies within the projection portion 164 thereof. The force applied to the above-mentioned region of the diaphrag~ 160 is in the direction of opening of the sealing lip 168. At the same time, the filling material in the internal container 110 is subjected to the effect of a pressure whic~ is produced by a directly applied manual force and/or by the increased pres~ure produced in the intermediate space 138 by virtue of the external container being squeezed. That also results in the sealing llp 168 being urged in the direction of opening thereof, so that the delivery valve 140 opens and material can issue from the interior of the internal container 110. An important consideration in that respect is that termunation of the application of pressure ~o the pack immediately results in closure of the delivery valve 140 as the elastically defonmable sealing lip 16~ has corresponding return forces which readily return it to its closed position. That rapid closure of the delivery valve 140 means that no or only a ~mall amount of air can pass by way of the delivery valve into the ~nternal container 1 1 0 or the regions of the closure body 114 which are in communication therewith. That has the above-described consequence that the intenmediate space 138 between the internal container 110 and the external container 112, after termination of the application of pressure to the pack and the increase in volume caused by the resilient return for~es of the external container 112, remains in communication with the atmosphere through the venting valve fonmed by the sealing lip 162, until atmospheric pressure obtains again in the intermediate space 138.
As the embodiment described above with reference to and illustrated in Figures 5 through 1 provides that venting of the intermediate Rpace 138 OCCUrB by way of the closure arrangement 114, there i9 no need for the external container 112 also to be provide~
with a separate venting valve, as is the case in the e~bcdiment snown ln Figures 1 and 2.
Referring now to Figure 8 in which parts which are identicd to those shcwn in Figures 1 through 4 are identified by the same reference numerals but increased by 200, it will be noted that the embodiment of which part is shown in Figure 8 differs from the other embodiments of the invention as described above only in that the internal container 210 is of an integral configuration. In other w~rds, the portion 224 which serves as the support body and the easily deformable bag-like portion 222 are adnittedly of different wall thicknesses but they are not produced separately. To achieve that aim, the manufacturing procedure may take as its starting point for example a m~lded blank which is subjected to an additional stretching effect only over the region thereof which is to fonn the easily deonmable portion 222 of the internal container. Manufacturing procedures of that kind are known to the man skilled in the art and do not therefore need to be described in full detail herein. The external container 212 may al~o be produced in the usual manner in the Figure 8 embodiment. Advantageously, that kind of internal container is used 5 . ~ - .a when it is to be of a multi-layer or laminate structure as all the layers occur over the entire axial extent ~f the internal container.
As noted above, internal containers of this kind are advantageously produced by blow molding.
It will be appreciated that the above-described embodiments of the invention have been set forth solely by way o~ example and illustration of the principles thereof and that various modiflcations and alterations may be made without thereby departing from the spirit and scope of the invention.

Claims

1. In a squeeze pack comprising an elastically deformable external container; an internal container for receiving the filling material disposed within the external container and defining therewith an intermediate space which is closed off from the external atmosphere and adapted to be readily deformable under the action of a pressure difference between atmospheric pressure and the pressure in the intermediate space between the internal and external containers, a closure means having a delivery opening with delivery valve for discharge of the filling material, the delivery valve being operable at least substantially to prevent equalisation of pressure between the internal container and the external atmosphere by the ingress of air into the internal container after the discharge of filling material therefrom, and a venting valve for communicating said intermediate space with the external atmosphere, the improvement that the internal container in the middle region of its longitudinal extent is divided substantially transversely to its longitudinal axis into first and second portions, the portion which is towards said delivery opening comprisinga support means which is elastically deformable such that when a squeeze force applied to the pack ceases it returns to its original shape but does not experience a noticeable deformation under the effect of said pressure difference between atmospheric pressure and said pressure in said intermediate space, and at least the portion of the internal container which is remote from the delivery opening being of a flexible bag-like configuration and easily plastically deformable under the effect of said pressure difference between atmospheric pressure and said pressure in said intermediate space, thereby displacing the filling material contained in the internal container towards the delivery opening.

2. A pack as set forth in claim 1 wherein the wall thickness of said portion towards said delivery opening is greater than the wall thickness of the portion of the internal container which is remote therefrom.

3. A pack as set forth in claim 1 wherein the internal container is in one piece.

4. A pack as set forth in claim 1 wherein the support means is a component part of the internal container.

5. A pack as set forth in claim 1 wherein the first and second portions of the internal container are produced in the form of separate parts and are joined together at least in a peripheral region extending at least substantially perpendicularly to the longitudinal axis of the internal container.

6. A pack as set forth in claim 1 wherein the part which has the deformable portion of the internal container extends from the end of the internal container which is remote from the delivery opening as far as an end region of the support means which is remote from said delivery opening.

7. A pack as set forth in claim 1 wherein the part having the deformable portion of the internal container extends at least to close to said delivery opening and is also connected to said support means at the end region of said part, which is towards the delivery opening.

8. A pack as set forth in claim 1 including an annular holding means arranged in the region of the opening of the external container wherein at its end towards the delivery opening the internal container is sealingly secured to said holding means.

9. A pack as set forth in claim 8 wherein the holding means is part of the support body.

10. A pack as set forth in claim 8 wherein the holding means is connected to said support body.

11. A pack as set forth in claim 1 wherein said venting valve adapted to communicate said intermediate space with the atmosphere is disposed in the closure means.

12. A pack as set forth in claim 8 and further including at least one passage means between the holding means and the wall of said opening region, adapted to communicate said intermediate space with the venting valve.

13. A pack as set forth in claim 1 wherein the venting valve is disposed in a region of the external container which is remote from said delivery valve.

14. A pack as set forth in claim 1 wherein the venting valve is disposed at the bottom of the external container.

15. A pack as set forth in claim 1 wherein the external container comprises at least first and second portions, and further including means for releasably and sealingly joining said first and second portions together, such that after release of said at least first and second portions of the external container a filled internal container can be inserted into the external container.

16. A pack as set forth in claim 1 wherein the wall of the internal container comprises at least first and second layers of different materials.

17.A squeeze pack comprising: an elastically deformable external container having an opening for discharge of filling material from the pack; an internal container for receiving the filling material, disposed within the external container and defining therewith an intermediate space which is closed off from the external atmosphere, the internal container being adapted to be readily deformable under the effect of a pressure difference between atmospheric pressure and the gas pressure in said intermediate space, the internal container substantially in the middle region of its longitudinal extent being divided substantially transversely to its longitudinal axis into first and second portions, the portion of the internal container which is towards said external container opening involving a support means which is elastically deformable such that when an applied squeeze force ceases the support means returns to its original shape but it does not experience a noticeable deformation under the effect of said pressure difference between atmospheric pressure and said pressure in said intermediate space, and at least the portion of the internal container which is remote from said external container opening being of a flexible bag-like configuration easily plastically deformable under the effect of said pressure difference between atmospheric pressure and said pressure in said intermediate space, thereby displacing the filling material in the internal container towards said external container opening; a closure means having a delivery opening with delivery valve for said filling material, communicating with the interior of said internal container, the delivery valve being operable at least substantially to prevent equalisation of pressure between the internal container and the atmosphere by the ingress of air into the internal container after the discharge of filling material therefrom; and a venting valve for communicating said intermediate space with the external atmosphere.