IL43968A - Automatically opening and closing closure device for a container - Google Patents

Abstract

An automatically opening and closing closure device adapted for use with a container having a liquid, pasty or foamy filling is described which comprises a head body, a discharge duct in the head body and having an orifice in the outside of the latter, the head body having an opening at a side thereof away from the discharge orifice and being destined for being joined to the container the head body comprising a continuous integral wall portion about the discharge duct and orifice, the wall portion comprising an elastically flexible zone extending from part of the circumference of the orifice toward the opening, the remaining part of the wall portion about the discharge duct and orifice being substantially rigid; and beak means comprising an elastically deflectable spring-loaded arm and being associated with the head body so that the free end of the arm is located on the side of the wall portion containing the flexible wall zone, the spring arm being biassed into engagement with the flexible wall zone near the orifice to hold the latter in sealing engagement with the rigid wall part and closing the orifice, the bias of the deflectable arm being so dimensioned as to yield to a determined excess pressure inside the discharge duct, the elastic wall zone to urge the free end of the beak arm away from the rigid wall part, and thereby to open the orifice while the excess pressure prevails in the duct. [US3858773A]

Description

n»0BieiK *no:n nnsan m*ao Automatically opening and closing closure device for a container FRANCO DEL BON This is a patent of addition to Israel patent application 42883 filed August 2, 1973.

Israel patent application 42883 provides automatically opening and closing closure device adapted for use with a container having a liquid, pasty or foamy filling, comprising a head body having a discharge duct extending therethrough, an orifice in the outside of the discharge duct, a recess and an opening at a side of the head body away from said discharge orifice and being destined for being joined to said container, said head body comprising a continuous integral circumferential wall portion about said discharge duct and orifice, said wall portion comprising an elastically flexible zone extending from part of the circumference of said orifice toward said opening, said flexible wall zone forming at least a part of the bottom of .said recess, the remainder of said wall portion about said discharge duct and orifice being substantially rigid, where the wall of the discharge duct and the head body are formed as one piece; a spring member provided at the base of said flexible wall zone; and beak means mounted in the recess of said head body and comprising a two™armed lever, one arm of which engages the spring member and the other arm of which is formed as an elastically deflectable spring-loaded arm associated with said head body so that the free end of said arm is located on the side of said wall portion containing said flexible wall zone, said spring-loaded arm being biassed into engagement with said flexible wall zone near said orifice to hold the latter in sealing engagement with said rigid wall portion part and closing said orifice, the bias of said deflectable arm being so dimensioned as to yield to a determined excess pressure inside said discharge duct to cause said elastic zone of said wall portion to urge the free arm end away from said rigid part thereof and thereby to open said orifice, while said excess pressure prevails in said duct.

BACKGROUND OF THE INVENTION This invention relates to an automatically opening and closing closure device adapted for use with a container having a liquid, pasty or foamy filling, comprising a head body, a discharge duct inside the head body and having an orifice in the outside of the latter, the head body having an opening at a side thereof away from the discharge orifice and being destined for being joined to the container, the head body comprising a continuous integral wall portion about the discharge duct and orifice, the wall portion comprising an elastically flexible zone extending from part of the circumference of the orifice toward the opening, the remaining part of the wall portion about the discharge duct and orifice being substantially rigid; and beak means comprising an elastically deflectable spring-loaded arm and being associated with the head body so that the free end of the arm is located on the side of the wall portion containing the flexible wall zone, the spring arm being biassed into engagement with the flexible wall zone near the orifice to hold the latter in sealing engagement with the rigid wall part and closing the orifice, the bias of the deflectable beak arm being so dimensioned as to yield to a determined excess pressure inside the discharge duct to cause the elastic wall zone to urge the free end of the beak arm away from the rigid wall part, and thereby to open the orifice while the excess pressure prevails in the duct. ? Many attempts have been made to provide such closure devices in particular for all kinds of tubes, .including tooth-paste tubes and the like. Thus, a tube described in German patent 436,054 comprises a beak member lodged in a recess formed in the tube head as an oblique slot in a plane extending through the longitudinal axis of the tube, the beak member being hingedly mounted in the recess and being held in closed position by an elastic ring about the same .

Another known tube, described in U.S. patent 2,755,974, granted on July 24, 1956, has a head part, a mouth part and a duct therethrough having a discharge orifice, a hose member lodged in the said duct, a slide member dxsplaceable at a right angle to the longitudinal axis of the mouth part, and a blade spring exerting pressure on the hose but yielding to permit the discharge of paste from the tube when the latter is squeezed, the blade spring, slide member and hose being mounted in the tube head part devised as a housing therefor. However, all previous attempts have failed to provide a closure device of the above-described type which would satisfy the two main requirements that must be met by such a device if it is to be commercially acceptable. Firstly, the construction of the closure device must be as simple as possible in order to permit a manufacture at costs which are not prohibitively higher and possibly even equal to those of manufacturing the well known types of screw cap closures for tubes; and, secondly, the novel closure device must be at least as safe in sealing its contents, or even safer than the hitherto known screw cap closures .

Only in fulfilling these two conditions will it be possible to provide a competitive closure device free from the drawbacks of the known screw cap closures and those of previously suggested automatic closure devices . It is well known that the form require three manual operations in order to dispense liquid or pasty content from the tube, namely, unscrewing of the tube cap, squeezing the tube more or less strongly to discharge a portion of liquid or cord of paste from the tube, and thirdly again screwing on the tube cap and carrying out a similar operation to close the tube. In doing so, it is practically unavoidable that residual contents of the tube are squeezed outwardly from the windings of the threading when the cap is screwed on again. This residue is left under and beside the cap on the tube wall, dirtying the fingers of the user and being exposed to drying, decomposition and bacterial growth.

OBJECTS AND SUMMARY OF THE INVENTION The objects of providing a closure device which is competitive with the known screw cap closures and which seals off the contents of a tube or the like container at least as safely, while avoiding the above mentioned drawbacks of screw cap closures, has been solved by providing a closure device of the initially described type wherein, according to the invention, the beak means comprise a rigid portion, and the head body has a recess for housing the elastically deflectable beak arm therein as well as a cavity open at the end of the recess away from the orifice and adapted to hold the aforesaid rigid beak portion firmly therein, while the elastically deflectable beak arm is biassed toward the flexible wall zone when in place with its free arm end against the last-mentioned zone at the orifice, such biassing being provided by a spring force inherently present in the deflectable beak arm due to tensioning of the latter .

Advantageously, the bottom of the recess is constituted, at least in the part thereof near and at the discharge orifice, by the elastically flexible wall zone.

Preferably, tensioning is achieved by providing the beak means with an obtuse angle between the elastically deflectable arm and the rigid portion thereof, which angle is smaller when the beak means is untensioned, i.e. when it is not 'yet inserted, than when it is inserted with its rigid portion into the cavity of the head body, and before the free end of its elastically deflectable arm is in place against the flexible wall zone at the discharge orifice in the head body .

Thanks to these features, the invention provides a closure device which can be made up of only two separable parts . A single manual operation is required whereby the user squeezes the wall of a collapsible tube remote from the discharge opening with, for instance, two fingers, or whereby he presses upon the closure device according to the invention, thereby opening the outlet valve of a pressure container when the closure device is used as an actuator for such a container . The discharge opening will close instantly and hermetically, as soon as manual pressure on the tube wall or on the actuator ceases . Any re-sidual contents adhering to the outside of the closed discharge slit, when these contents are particularly sticky, can be easily wiped off whith a cloth.

The arrangements of the discharge orifice being formed by forcing an elastically flexible zone away from a rigid zone of the wall portion surrounding the discharge duct of the closure device, instead of providing the orifice, in a known manner, as an open end of a hose of rubber or the like resilient, flexible material, offers a greatly improved sealing effect in the closed position . The wall of the rubber hose surrounding the discharge orifice will always bulge at both terminal edges when compressed by the free lever arm of a beak member provided in many known closure devices . Consequently, thin strings of material will still emerge from the bulging ends of a hose which is already completely compressed in the central zone thereof . An additional amount of pressure will have to be applied to the beak member to completely flatten the marginal bulges of the hose. Such additional pressure must, however, be counteracted by a correspondingly higher pressure on the flexible tube wall to achieve sufficient internal pressure to open the discharge orifice . The feature of a slit provided between the rigid wall part and an elastic, deform-able wall portion, along which slit, when closed, the latter wall portion extends throughout in parallel with the rim of the rigid wall part and merges with the latter at an acute angle, free from any rounded marginal wall portions causing bulging when being closed, ensures a greatly superior sealing effect achieved with a weaker bias on the free end of the beak member; and a correspondingly lower pressure increase is needed to discharge a part of the contents from the interior of the tube or container connected to the closure device according to the invention . 43968/2 In a preferred embodiment of the closure device according to the invention, the elastically deflectable arm is joined to the rigid beak portion forming an external shoulder which comes to rest on the upper end rim of the recess of the head body, in which the deflectable arm is lodged, while the rigid beak portion is inwardly displaced relative to the deflectable arm due to the said shoulder and is inserted in the above-mentioned deep cavity of the head body. Due to the fact that the rigid portion is securely anchored in the cavity, the deflectable arm acts like a blade spring on the elastically flexible wall zone at the orifice at all times and is deflected outwardly by the bulging flexible wall zone when the internal pressure in the duct leading to the discharge orifice is increased, e.g. by squeezing the flexible wall of a collapsible tube to which the closure device is permanently attached .

Preferably, the deflectable beak arm has its largest diameter at its juncture with the rigid b.eak portion, and is of gradually diminishing thickness toward the free end thereof, so as to obtain an optimal inherent spring effect when mounting the beak means in tensioned condition into the head body .

A particularly safe sealing effect is achieved if the rim of the discharge orifice constituted by the rigid part of the wall portion surrounding the discharge duct is of concave contour in the plane extending perpendicularly to the discharge duct axis, while the contact edge of the free end of the deflectable beak arm is of correspondingly convex shape .

Or, vice-versa, the rim of the rigid wall part can be of convex shape, while the shape of the terminal edge of the free end of the flexible beak arm is correspondingly concave .

The sealing effect can also be enhanced by providing a groove across the contact face of the rigid wall zone adjacent the discharge orifice and a corresponding bead across the contact edge of the free end of the beak arm, or vice-versa, which groove and bead means extend preferably at a right angle to the discharge duct axis .

It is also possible to provide, on the outside of the flexible wall zone intermediate the discharge orifice and the end of the deflectable beak arm away from the orifice, a rigid projection in the shape of a finger or nose of such length that it contacts the inside wall of the deflectable beak arm, when liquid or paste advances in the discharge duct of the head body, due to manual pressure on the attached container or tube, and reaches an intermediate zone in the duct before arriving at the orifice. Thereby, the lifting cf the flexible beak arm off the elastically flexible wall zone at the orifice will be gradually initiated and thereby facilitated.

Finally, the beak means may comprise an arresting device which prevents an opening of the discharge orifice due to unintentional application of pressure on the wall of a collapsible tube bearing the closure device, or on the latter while attached to a pressurized container, for instance during storage or travel. When the tube or other container is to be used, the arresting device is disengaged, and there is no need to reengage it during the remainder of its use except, possibly, as a safety measure, when packing away the tube or pressure container for travelling . In a preferred embodiment of the arresting device, the closing edge at the free end of the deflectable beak arm is so devised that it will hold the orifice hermetically closed, at and between two limit positions superimposed in the direction of the discharge duct axis. Securing means such as projections or grooves or abutments are provided at the beak means and at the adjacent wall of the recess of the head body in which the beak means is lodged, whereby the deflectable beak arm can be rigidly connected to the head body when these arresting means are engaged. They can be released, and the beak arm can be deflected to open the orifice, by simply pushing the beak means in the recess a short distance toward the discharge orifice .

The invention will be better understood and further objects and advantages will become apparent from the ensuing detailed description of preferred, but merely exemplary embodiments taken in conjunction with the drawings .

BRIEF DESCRIPTION OF THE DRAWINGS Fig . 1 shows a front view of a first embodiment of the closure device according to the invention; Fig . 2 is an axial sectional view of the same embodiment as shown in Fig. 1, but turned by an angle of 90° about the central axis of the device; Fig. 3 shows in perspective view a beak member as used in the embodiment shown in Figs . 1 and 2 ; Fig . 4 is a side view of the beak member shown in Fig . 3 , prior to mounting in the head body of the embodiment shown in- Figs . 1 and 2 , and indicating in phantom lines the position of the beak member inserted in the head body and biassed to close the discharge orifice of the latter; Figs . 5a and 5b show in top view an embodiment similar to that shown in Figs. 1 and 2, with the discharge orifice open and closed, respectively, but with a preferred embodiment of the wall portion of the head body and of a portion of the beak member at the orifice; Fig. 6 is a partial sectional view of yet another embodiment of the part of the closure device about the discharge orifice thereof, when closed; Fig. 7 shows in partial sectional view a further embodiment of the part of the closure device about the discharge orifice thereof, when open; Figs. 8a and 8b are axial sectional views of a still further embodiment of the closure device according to the invention, being equipped with arresting means which are engaged in Fig. 8a to hold the discharge orifice shut, while, in Fig. 8b, the arresting means are disengaged and the discharge orifice is open; Fig. 9 is a cross sectional view, taken along the plane indicated by IX-IX in Fig. 8a; Fig . 10 is a bottom view of the closure device shown in Fig. 8b, having its discharge orifice opened; Fig. 11 is a perspective view of another, preferred embo diment of the beak member, similar to that shown in Figs. 8a and 8b; and Fig. 12a is a perspective view of the embodiment of the closure device shown in Figs. 1 and 2, and Fig . 12b is a perspective view of the embodiment of the closure device shown in Figs. 8a and 8b.

DETAILED DESCRIPTION OF THE EMBODIMENTS In the drawings, the embodiment shown in Figs. 1 to 4 comprises a head body 1 which is of substantial rigidity owing to its shape and the thickness of its walls and which is preferably made by injection molding from a suitable synthetic plastics material. This material must be suited to have thin walls molded therefrom which are elastically flexible and, preferably slightly expandable, in order to produce therefrom a flexible wall zone partly surrounding the discharge orifice of the device . The high-molecular types of polyethylene or polypropylene and the like thermoplastic synthetic resins, and among the polyethylenes especially Lupolen 1800 S made by BASF AG, Ludwigshafen , Germany, are suitable for this purpose .

Head body 1 is open at its hollowed bottom face, whereby it is to be attached to a conventional collapsible tube having a mouth-piece or discharge socket with external threading or to the movable member of an outlet valve of a pressure container of the type normally used in aerosol spray dispensers. In its hollow interior, head body 1 has a dependent wall portion 2, which surrounds a discharge duct 3 having a discharge orifice 4 in the outside wall of head body 1. At its opposite end of duct 3, wall portion 2 surrounding the same bears an inner threading 2a, by means of which it can be screwed onto the threaded mouth-piece of a collapsible tube . Instead of the threading, the inner end of preferably cylindrical wall portion 2, i.e. the end thereof facing toward the open underside of head body 1 may also be equipped with means for a bayonet connection, or it may be welded to the outlet opening of a collapsible tube or a pressurized container . Wall portion 2 of head body 1 should surround the orifice 4 uninterruptedly and is preferably integral with the remainder of head body 1. When closed, orifice 4 appears as a hermetically sealed slit in the top face of head body 1. The half of wall portion 2, which merges with the outer wall la of head body 1, constitutes a rigid longitudinal zone 5, which, in the vicinity of orifice 4, has approximately the configuration of a hemi-cylinder , while the other half of wall portion 2 , which separates duct 3 from the bottom of a recess lb in head body 1 is, at least in the vicinity and up to orifice 4 elastically flexible and preferably slightly expandable . This zone thus extends from the orifice over at least part of the length of wall portion 2 toward the opposite duct opening. The thickness of this flexible zone of wall portion 2 depends on the elasticity of the material from which the head body and the wall portion therein are made. It also depends on the viscosity of the product to be discharged, which is also a factor in determining the length, in a direction transverse to the duct axis, of the slit which is constituted by the closed orifice .

In the embodiment of Figs. 1 to 4, the upper liplike end of flexible wall zone 6 rests smoothly on, and may extend a little outwardly beyond, the opposite lip-face 5a of rigid wall zone 5 of the orifice-forming wall portion 2.

Preferably, duct 3 extends through wall portion 2 of head body 1 coaxially with the main central axis of head body 1. At the transverse rim lc , formed in the head body 1 at the end of recess lb remote from orifice 4, a transverse wall 9 extends from the outer wall of head body 1 to the socket constituted by cylindrical wall portion 2 and is preferably integral with both these parts . At the inside of wall zone 10 of head body 1, below the zone thereof where transverse wall 9 merges therewith, the outer head body wall is of increased thickness and a deep - cavity Ls provided therein which opens out of the upper side of transverse wall 9, i.e. at the end of recess lb, remote from orifice 4. The peripheral width of ca-vity" 11/ is approximately equal to the peripheral diameter d of fecess lb . The rigid portion 7a of a beak member 7 is inserted in cavity 11 and is held securely therein, the thickness and width of beak portion 7a fitting snugly or with slight friction into the cavity 11 of matching dimension .

Beak member 7 is preferably made of a material which is harder than that of head body 1, e.g. of the polyethylene R type of Ultraform , sold by BASG AG, Ludwigshafen , Germany. Beak member 7 has a long, spring-like elastic lever arm 7b, which is transposed at its juncture with rigid beak portion 7a outwardly to form an external shoulder 12a, and preferably also an inner shoulder 12b which latter is formed by the rigid beak portion 7a projecting inwardly beyond the inside face of elastic arm 7b. However, it is also possible to provide in lieu of shoulder 12b a gradual merging of the inside faces of the two parts of beak member 7.

When beak member 7 is inserted into cavity fill its external shoulder 12a comes to rest on the outside rim 11a of cavity j 111: When not yet introduced into the head body 1, the two parts of beak member 7 are so joined to each other that the angle enclosed between rigid portion 7a and the connecting line from the root of elastic arm 7b where it joins portion 7a to the terminal edge of lip 7c of arm 7b at the free end of the latter is an obtuse angle, in other words, that the last mentioned connecting line deviates from the outward prolongation of the longitudinal axis of portion 7a by an acute deviation , as shown in Fig. 4. This deviation is slightly larger than the deviation by which the aforesaid connecting line deviates from the prolongation of the axis of rigid portion 7a, when the latter portion has been inserted in cavity' 11, and the terminal edge of lip 7c has been brought to rest against the outer lip of the flexible zone 6 of wall portion 2. This means that elastic arm 7b is at all times biassed against the flexible wall zone 6 at orifice 4. At the same time, friction between the side walls of rigid beak portion 7a and the inner walls of cavity 11 is so increased that the beak member is prevented from falling out or being pushed out of cavity 11, when a pressure increase occurring in duct 3 in the direction toward discharge orifice 4 is transmitted to the beak member 7.

The slight curvature of the elastic arm 7b of beak member 7 helps to increase the desired bias and also adapts the outside face of the beak member smoothly to the overall rounded surface of head body 1. This bias of elastic arm 7b increases as the pressure inside duct 3 is increased either by manual squeezing of the flexible wall of a collapsible tube connected leak-free to the - - inside open end of duct 3 away from orifice 4, or by-depressing head body 1 when the latter is mounted on a movable member of the outlet valve of a pressure container, whereby the pressurized' contents of the latter can penetrate into duct 3 and pressure against the flexible wall zone 6 at orifice 4 rises . Flexible wall zone 6 is thereby deformed and/or expanded to move away from the closing edge 5a of rigid wall zone 5, pushing the lip part 7c, and thereby bending the arm 7b, away from closing edge 5a in the direction of arrow P as shown in Fig . 4, and opening the orifice 4, while at the same time the resulting increased bias of beak arm 7b lasts as long as the increased pressure prevails in the interior of duct 3.

In Figs. 5a and 5b, the closing edge 5a of rigid wall zone 5 is of concave configuration and the corresponding terminal lip edge of lip 7c of beak member 7 is of a corresponding convex© shape. Thereby, the sealing effect at orifice 4 when closed (Fig. 5a) is increased and the cut-off effect on the extruded cord of product is improved .

Fig. 6 shows another embodiment of improved sealing means for orifice 4, wherein the closing edge 5a bears a transverse bead 5b and wherein the terminal lip edge of lip -7c bears a corresponding groove 7d, whereby during closing of orifice 4, the bead 5b presses the de-formable and/or expandable, flexible wall zone 6 into transverse groove 7d, thereby further improving the sealing effect. Of course, the transverse groove can also be provided in the face of closing edge 5a. and the transverse bead at the terminal lip edge of beak member 7.

Fig . 7 shows an embodiment corresponding in all essential parts to that of Figs. 1 to 4. However, the flexible wall zone 6 bears on its outside surface facing beak member 7a finger or nose 13 which will contact the inside face of arm 7b and begin to bend the same outwardly while a pasty product from the interior of a collapsible tube is being squeezed into duct 3 and before such product reaches orifice 4. Thereby, the lifting of the terminal edge of beak lip 7c off the flexible wall zone 6 is initiated and may thus be considerably facilitated.

Finally, the embodiment of a closure device shown in Figs. 8a, 8b and 9 also contains all the essential parts found in the embodiment shown in Figs. 1 to 4, but it is further equipped with a very simple arresting device . The latter comprises two short pegs 14 projecting inwardly from lip part 7c of beak member 7 to engage, in the arresting position shown in Fig. 8a, two lugs 15 projecting inwardly and upwardly from the rigid lower part, of wall portion 2, from which flexible wall zone 6 extends forward toward orifice 4. In this arrested position, the elastic arm 7b of beak member 7 cannot be bent outwardly and discharge orifice 4 will not open even when relatively strong pressure is exerted on a tube attached to the closure device. In this arresting position, the inner rigid portion 7a of beak member 7 rests with its external shoulder 12a on transverse rim 11a of recess lb . The lower end of beak portion 7a bears a radially inwardly directed projection or flange 16, which extends into a recess 17 of the wall part 10, of increased diameter, of head body 1. On its outside, arm 7b of beak member 7 bears an actuating nose 18 by means of which beak member 7 may be pushed upwardly in the direction toward orifice 4 into the non-arrested position shown in Fig. 8b. Thereby, flange 16, which is provided at the inner end of rigid beak portion 7a, comes to rest against the downwardly directed face 17a of recess 17, which face acts as an abutment preventing beak member 7 from being pushed out of recess lb .

In the position shown in Fig. 8b, beak member 7 is seen to abut with its flange 16 against the underside 17 of transverse wall 10a. Pegs 14 have been raised, together with beak member 7, above the upper end of lugs 15 and beak arm 7b is thus free to bend outwardly if urged to do so by flexible wall zone 6 under increased pressure of product in duct 3.

Fig . 10 shows in a bottom view the closure device according to the invention, not yet attached to a collapsible tube or pressure container . Orifice 4 is shown in opened condition. The rigid portion 7a of beak member 7 is securely held against bending in the interspace 11a (Figs. 8a and 8b) between transverse wall 10a and the inside surface of the outer wall of head body 1. For this purpose, transverse wall 10a is stiffened by means of two parallel supporting plates 19a and 19b which are rigidly connected to the wall portion 2 about duct 3 and the outside wall of head body 1 as well as to transverse wall 10a, and are preferably made integral with all of these walls .

In order to obtain an optimal blade spring effect of beak member 7, the latter can be designed, as shown in Fig. 11, wherein the spring-acting beak arm 7b is joined to the rigid portion 7a of beak member 7 without any, or without any substantial, reduction in cross-section, i.e. avoiding the formation of an actual "hinge" of reduced thickness; rather, its thickness d' gradually decreases from its root where it is joined to rigid beak portion 7a, to the convex (or concave) terminal edge of beak lip 7c . The decrease is preferably a continuous one in order to obtain a maximal spring effect. In order to avoid any obstruction of the movement of elastic beak arm 7b due to friction at the side walls of recess lb, the transverse diameter d" of beak arm 7b intermediate lip 7c and the root of the arm at shoulder 12 is preferably slightly smaller than the corresponding transverse diameter of recess lb to leave a slight play between them as indicated 20 in Figs . 12a and 12b While beak member 7 is preferably made from a suitable synthetic plastics material, it can also be made from a suitable metal, such as V2A steel, or a similar stainless steel . A beak member made of metal or of a high temperature-resistant thermoplastic resin, e.g. a polycarbonate, is recommended when the closure device is to be used in tropical countries .

Owing to the feature of having the orifice surrounded by an integrally closed wall 5, 6, the closure device according to the invention does not require any sealing between the lateral edges of elastic arm 7b of beak member 7 and the side walls of recess lb, while this is nces-sary and presents a special problem in the case of known closure devices (see, e.g., U.S. Patent 1,881,488) .

The closure device according to the invention has also an improved sealing effect compared with those automatic and non-automatic closure devices in which the discharge orifice is constituted by the open end of a hose member having an continuous flexible wall thereabout (Belgium Patent 508,572 to 0. Cupper and U.S. Patent 2,755,974 to W.H. Godfrey) . For, in such hose members the drawback of bulging at the ends of the compressed slit will occur, which has been described in detail hereinbefore. In fact, 0. Cupper did not contemplate any automatic opening of his closure device by an increase of pressure in the dis- charge duct, but rather a direct manual actuation of a beak or lever at the discharge orifice against the bias of a strong return spring. In the case of such manual actuation, the spring force can, of course, be much greater and will then be sufficient to squeeze shut the aforesaid bulges occurring in the compressed part of the hose, and will thus prevent leakage of product from the tube . The same is true for the closure device of British Patent 240,091.

In contrast to these known types of discharge orifices, the elastic, deformable and/or expandable wall zone 6 lies flat against the opposite closing edge 5a of rigid wall zone 5 and no bulging at the ends of the slit representing the sealed orifice 4 will occur . In the case of tooth pastes of standard consistency, a closure device according to the invention has been found particularly satisfactory, in which the flexible wall zone 6, at and near the orifice 4, has a thickness of from 0.05 to 0,2 mm, and preferably of 0.15 mm. Products which can be dispensed from a collapsible tube or from a valve-equipped pressure container bearing a closure device according to the invention are liquids, especially those of increased viscosity, such as honey, furthermore products of pasty consistency, such as ointments, tooth pastes, shaving creams, oil prints, mustard, liverwurst, mayonnaise, shoe polish, facial creams, but also products such as shaving foam, whipped cream and the like, which can be dispensed from

Claims (15)

I CLAIM:

1. An automatically opening and closing closure device adapted for use with a container having a liquid, pasty or foamy filling, and comprising a head body, a discharge duct in said head body and having an orifice in the outside of the latter, said head body having an opening at a side thereof away from said discharge orifice and being destined for being joined to said container, said head body comprising a continuous integral wall portion about said discharge duct and orifice, said wall portion comprising an elastical-ly flexible zone extending from part of the circumference of said orifice toward said opening, the remaining part of said wall portion about said discharge duct and orifice being substantially rigid; and beak means comprising an elastically deflectable spring-loaded arm and being associated with said head body so that the free end of said arm is located on the side of said wall portion containing said flexible wall zone, said spring arm being biassed into engagement with said flexible wall zone near said orifice to hold the latter in sealing engagement with said rigid wall part and closing said orifice, the bias of said deflectable arm being so dimensioned as to yield to a determined excess pressure inside said discharge duct, said, elastic wall zone to urge the free end of said beak arm away from said rigid wall part, and thereby to open said orifice while said excess pressure prevails in the duct, said beak means further comprising a rigid portion and said head body having a recess for housing said beak arm therein as well as a cavity open at the end of said recess away from said orifice and adapted to hold said rigid beak portion firmly therein, while said elastically deflectable beak arm is biassed toward said elastically flexible wall zone when placed with its free arm end against the last-mentioned zone at said orifice, such biassing being provided by a spring force inherently present in said deflectable beak arm due to tensioning of the latter .

2. A closure device as described in claim 1, wherein the bottom of said recess is constituted, at least near and at said discharge orifice, by said elastically flexible wall zone .

3. A closure device as described in claim 1, wherein said elastically deflectable arm and said rigid portion of said beak means are joined with each other forming between them an obtuse angle which is smaller when said beak means is untensioned, while it is larger when said beak means is inserted in closing position in said head body, thereby tensioning said elastically deflectable arm thereof.

4. A closure device as described in claim 3, wherein said elastically deflectable beak arm has a thickness which is largest at its juncture with said rigid beak portion and gradually decreases toward the free end of said arm serving to engage said elastically flexible wall zone .

5. A closure device as described in claim 3, ■ wherein said rigid beak portion is inwardly displaced at the juncture with said elastically deflectable beak arm, so as to form a shoulder with the latter, destined for abutting the transverse rim of said recess away from said orifice .

6. A closure device as described in claim 3, wherein bead and groove means are provided, respectively, in the terminal face at the free end of said elastically deflectable beak arm and in the opposite face of said rigid wall zone, so as to squeeze therebetween the portion of said flexible wall zone lying between the said two faces .

7. A closure device as described in claim 3, wherein the terminal face at the free end of said elastically flexible beak arm and the opposite face of said rigid wall zone are one of concave and the other of corresponding convex configuration.

8. A closure device as described in claim.1, wherein said flexible wall zone bears on its outside a rigid projection extending toward the inside surface of said elastically deflectable beak arm and adapted for moving the latter outwardly and thereby initiating the opening of said discharge orifice .

9. A closure device as described in claim 1, wherein releasable arresting means are provided, for mutual engagement, on said beak arm and said head body, respectively.

10. A closure device as described in claim 9, wherein said arresting means comprise lug and peg means preventing said elastically deflectable arm of said beak means from being bent outwardly of said recess, when said beak means is shifted into arresting position. «

11. A closure device as described in claim 10, wherein said beak means is moved into and out of arresting position by a limited displacement thereof in axial direction within said recess.

12. A closure device as described in claim 1, wherein said rigid beak portion bears securing means and wherein abutment means are provided with said cavity for engaging said securing means, thereby preventing removal of said beak means from said recess by increased pressure in said duct.

13. A closure device as described in claim 1, wherein said elastically flexible wall zone and said rigid wall part merge with each other to form therebetween a slit adapted for opening to constitute said discharge orifice, at a determined pressure increase in said discharge duct.

14. A closure device as described in claim 1, further comprising stiffening means connecting said wall port ion surrounding said discharge duct with the part of the wall of said head body surrounding said cavity.

15. A closure device as described in claim 1, wherein said wall portion surrounding said duct comprises a threading at the open end of said duct away from said discharge orifice .