Storing And Mixing Receptacle

Abstract

A storing and mixing receptacle including a container forming a first chamber at its lower end for initially storing a first ingredient, a first piston for separating the first chamber from a second chamber, a second piston movable in the second chamber and adapted to transfer a second ingredient from the latter chamber to the first chamber where the ingredients will be mixed. After removal of a closure means from the lower end of the container, the first piston will be actuated to expel the mixture from the receptacle in the form of a ready product such as a dental preparation ready for use.

Description

It has been proposed heretofore to provide multichamber receptacles for receiving ingredients required to make a ready product such as a dental preparation ready for use, the substances being capable of reacting with each other. Individual chambers of prior devices have been separated from each other by easily destroyable membranes, and receptacle parts receiving different components to be mixed have been slidably arranged relative to each other. Instead of employing a membrane, a bag-shaped or tubular storage means may be provided in the top cover of the receptacle for receiving one of the components, the storage means being formed, e.g., by a closed, preferably welded pouch of foil. An intermediate member or separator having perforations and spikes facing the pouch of foil if suitable, may be arranged between the main or mixing chamber of the receptacle and the pouch.

In prior receptacles of this type, the usually wall-shaped separator or the pouch of foil are caused to break or burst by moving the parts of the receptacle towards each other, whereby the chambers containing the individual ingredients will be interconnected.

In an improved type of the prior receptacle, the pouch of foil which is suitably filled with a liquid such as phosphoric acid, is arranged to be practically emptied by squeezing or pressing so that the contents of the pouch will be injected into the mixing chamber; the latter preferably contains a pulverulent substance such as zinc oxide or silicate cement. This type of device has certain advantages; in particular, no foil particles will enter into the mixture.

After the ingredients have been brought into contact with each other in the mixing chamber, a thorough mixing is required. This is normally accomplished by placing the receptacle in the clamping fork of an automatic, oscillating mixer; and an intense mixing action will be obtained with the aid of oscillating motions which rapidly follow each other.

However, it is not easy to remove the ready mixture from such prior receptacles after mixing, since, when the prior receptacles have been opened, the contents must be taken out of the interior thereof in a somewhat difficult manner, e.g., by means of a spatula.

It is an object of the invention to facilitate the removal of the ready mixture from the receptacle. Another object of the invention is to provide a storing and mixing receptacle by means of which the ready mixture may be applied directly to an area to be treated so that, for example, a dental cement may be introduced directly into a cavity developed in a tooth.

The invention is based on the idea of rendering a separator between individual chambers of a mixing receptacle movable so that after one ingredient has been transferred from a secondary chamber to the main or mixing chamber and the ingredients have been thoroughly mixed in the main chamber, the separator may serve as a piston for expelling the ready mixture from one end of the receptacle. Of course, it is necessary to provide the respective end of the receptacle with means permitting passage of the mixture from the main chamber to the outside.

Accordingly, the invention relates to a storing and mixing receptacle adapted to receive a plurality of ingredients for making a ready product, e.g., a dental preparation ready for use, the ingredients being capable of reacting with each other; the receptacle includes a first or mixing chamber for receiving a first, preferably pulverulent ingredient, and at least a second chamber for receiving a second ingredient which may be liquid, pasty or solid at room temperatures; the second chamber is separated from the first chamber by separating means and closed toward the outside by a movable, secondary piston which when moved in the direction towards the separating means will cause the main and second chambers to be interconnected; the improvement resides in the fact that the separating means between the first and second chambers is in the form of a primary or first piston movable to the discharge end of the first chamber, and that this discharge end has a removable cover thereon or is in the form of an initially closed, nozzle-shaped extension adapted to be opened after the ingredients have been mixed.

If a substance which is solid at room temperature is provided in the second chamber, it is desirable to melt this substance by heating the receptacle before mixing the ingredients. The receptacle is preferably cylindrical to facilitate its manufacture. This will further result in desirable sealing conditions between individual chambers.

To mix the ingredients with each other, pressure is at the start exerted upon the secondary or second piston which limits the second chamber containing the normally liquid or pasty ingredients. Due to such pressure the second piston will be moved towards the separating means and, in a manner explained later, a connection to the first chamber will thereby be established so that the liquid or pasty ingredient will be transferred to the first or mixing chamber which contains a preferably pulverulent ingredient. To reduce the volume of the second chamber practically to zero, those surfaces of the first and second pistons which define the second chamber at the top and bottom thereof should be of substantially equal size. It is desirable to provide the first and second pistons with plane surfaces. The contents of the first chamber will be thoroughly mixed, e.g., in a vibrating or oscillating mixer. For this purpose, the receptacle must be made from a sufficiently rigid material. After mixing, the first piston representing the separating means will be moved toward the bottom of the first chamber, and the cover of the latter will be removed or the aforementioned nozzle-shaped extension opened. To avoid premature movement of the first piston in the first chamber during shifting of the second piston, the cross-section of the first piston may be enlarged outwardly or the wall of the first chamber may be enlarged inwardly to form a bead located at the border between the first and second chambers in the initial position of the parts, that is, during storage of the ingredients. Instead of arranging an integral bead on the first piston, the cross-section thereof may be enlarged by inserting a removable locking ring which is adapted to rest on the upper edge of a container forming the first chamber and will be removed before the first piston is advanced into the first chamber. Further, the interior wall of the container forming the first chamber may be provided with a recess or groove for engagement with a bead of the piston.

Premature movement of the first piston during shifting of the second piston may further be prevented from the outside by laterally compressing the container forming the first chamber.

Referring to the afore-mentioned modification of the receptacle according to the invention, wherein the lower end of the first chamber is connected to a nozzle-shaped extension, this modification is particularly advantageous in that the device may be used in the manner of a hand pump or syringe for direct application of the mixed contents of the first chamber to a predetermined area. For example, dental cement or plastic filling material may be injected directly into a cavity formed in a tooth.

When using the latter modification, it is advisable to keep the nozzle-shaped extension closed during mixing, that is, to perform the mixing operation only in that part of the first chamber which has a relatively large cross-section since otherwise the mixture might be inhomogeneous. To this end, the nozzle-shaped extension may be closed, e.g., by a portion integral with the bottom of the first chamber and to be ruptured after mixing the ingredients, or by means of a plug which will be pulled out after mixing. However, in simple cases it will be sufficient to make the nozzle-shaped extension integral with the container forming the first chamber while providing the extension with a closed tip, and merely to cut off the tip of the extension after the ingredients have been mixed (if the container consists of plastics or thin sheet metal) or to break off the tip (if the container consists of glass). Furthermore, a cannula may be connected to the nozzle-shaped extension.

In the drawings which illustrate several embodiments of the invention by way of example,

FIG. 1 is a longitudinal section through a receptacle according to the invention;

FIGS. 2, 3, 4, 4a, 5, and 6 are longitudinal sections through modified receptacles;

FIG. 7 is a cross-section along line 7--7 of FIG. 6; and

FIGS. 8 and 9 are longitudinal sections illustrating further modifications of the receptacle according to the invention.

Referring generally to the embodiments illustrated, FIGS. 1 to 5 show receptacles wherein a sub-chamber is formed by means of a rupturable pouch of foil or a breakable glass ampoule positioned in the second chamber between the first and second pistons. A common feature of these embodiments resides in the fact that an ingredient which is liquid, pasty or solid at room temperatures, is sealed in the foil member or ampoule by welding or melting of foil or glass material. Preferably, the pouch of foil consists of relatively thin plastic material which is inert or resistant to the liquid or pasty ingredient and will not be dissolved thereby or caused to swell. A glass ampoule closed by melting is particularly suitable in the case of substances which are liquid or pasty or solid at room temperatures, and which are not well adapted to be sealed in foil since they either have a high vapor pressure (e.g., organic solvents or monomeric liquids capable of being polymerized) or prevent the formation of a satisfactory welding seam (e.g., ethereal oils such as eugenol). Instead, an ampoule made from another brittle material, e.g., brittle plastics, may be used.

As shown in FIG. 5, a glass ampoule located in a secondary piston having relatively small openings at its bottom, may include a wall portion which is adapted to rest on the bottom of the secondary piston, and which is thinner than other wall portions of the ampoule. A second glass ampoule may be enclosed in the first-mentioned ampoule by melting and may have a wall portion which faces the bottom of the secondary piston and is again thinner than other wall portions.

If, in this type of receptacle, pressure is exerted on the secondary piston, only that wall portion of the glass ampoule which abuts the bottom of the secondary piston will break, whereby the amount of glass fragments is less than that which would be formed in the case of destruction of the entire ampoule. In this manner, clogging of the small bottom openings will be avoided so that a liquid substance contained in the glass ampoule may freely flow into the mixing chamber. Since in this type of arrangement the secondary piston will not be advanced entirely to the bottom of the hollow primary piston, it is advisable to place the receptacle in a centrifuge after the thin wall portion of the ampoule has been destroyed, whereby any liquid particles present in the ampoule will be forced into the mixing chamber.

FIGS. 6 to 9 illustrate embodiments including a container forming the mixing chamber, wherein the second chamber is defined directly by the interior wall of the container in conjunction with the first and second pistons. It is possible to provide a third chamber, see FIG. 9. To this end, the second piston serves as the lower limit for the third chamber which will be closed by a third piston at the top. A common feature of these embodiments is the provision of longitudinal channels or grooves in the wall of the container below the first piston in its initial position in which the piston is arranged during storage of the ingredients; upon downward movement of one or both of the second and third pistons, liquid or pasty material stored in the second and/or third chamber will be forced through the channels or grooves into the first mixing chamber, and the volume of the second and/or third chamber will be reduced practically to zero.

Referring now to FIG. 1 in greater detail, the storing and mixing receptacle shown comprises a container 1 forming a first or mixing chamber 1m in its interior adjacent its lower end, and further comprises separating means in the form of a first piston 3 perforated at 11 which is movable in the container 1 and arranged to substantially separate the first chamber from a second chamber 2. As will be apparent from the drawing, container 1 has a longitudinal axis, and the internal wall surface thereof is shaped so as to guide piston 3 throughout its stroke in coaxial relationship with the container. A second piston 4 which in this type of embodiment is likewise movable in the container serves to close the second chamber at the top. The mixing chamber 1m contains a pulverulent, first ingredient 5, for example, zinc oxide. A liquid, second ingredient 7, for example, phosphoric acid, is enclosed in a welded pouch of foil 6 positioned within the second chamber 2. Intermediate the second piston 4 and the pouch of foil 6, there is provided a disk 8 of elastic material such as soft rubber for uniform distribution of pressure exerted by the piston 4 upon the pouch of foil; when piston 4 is moved downwards towards piston 3, the pouch of foil will burst and the contents of the pouch will be injected into the mixing chamber through opening 11 in the bottom of piston 3. After injection of the contents of the pouch of foil into the mixing chamber, the receptacle will be clamped in an oscillating mixer so that the ingredients contained in the chamber 1m will be thoroughly mixed within a few seconds and a ready product such as a dental preparation ready for use will be obtained. To avoid a premature movement of piston 3 in the container 1 before the mixing operation is completed, the interior wall of container 1 is provided with an internal annular bead engaging piston 3 symmetrically 9.

However, it is also possible to squeeze the container 1 laterally from the outside in a manner such that premature movement of piston 3 in the container 1 will be avoided.

If after the mixing operation a sufficient pressure is exerted upon piston 4, the latter together with piston 3 will move towards the lower end of the mixing chamber which is closed by a plug-like cover 10 held in place by frictional engagement with the container 1. Upon continued movement of the pistons, the ready dental preparation together with the cover 10 will be expelled from container 1. Instead of the shape shown, cover 10 may be in the form of a plain cap, a threaded cap or a snap member.

FIG. 2 shows a modified embodiment which is similar to the first embodiment in certain respects, and reference numerals 2, 3, 5 to 9, and 11 relate to the same parts as in FIG. 1. On the other hand, piston 24 is longer than the corresponding piston in FIG. 1 and therefore is easier to manipulate. Instead of the cover 10 of the first embodiment, a nozzle-shaped extension 26 is provided at the lower end of container 21 and is closed by a relatively thin bottom portion 27 of the container until the ingredients have been mixed; the bottom portion 27 will be pierced after the mixing operation has been completed. Furthermore, the upper portion of container 21 is provided with handle means 28 so that the receptacle may be gripped like a syringe such as a hypodermic syringe. When piston 3 and piston 24 are pushed down together, the desired dental preparation which is ready for use will be discharged through the nozzle-shaped extension and may be applied directly to the area to be treated, for example, to a cavity developed in a tooth.

FIG. 3 shows a similar embodiment wherein reference numerals 2, 3, 5 to 9, and 11 again relate to the same parts as in FIG. 1. However, piston 34 is in the form of a cap adapted to encompass the upper edge of container 31; this piston or cap 34 will be removed after the pouch of foil 6 has been emptied. After removal of piston or cap 34, a long pusher 35 may be inserted for moving piston 3 downwardly. A cannula 39 may be connected to the nozzle-shaped extension 36. The parts 37 and 38 correspond to the parts 27 and 28 in FIG. 2.

FIG. 4 shows a modification wherein reference numerals 2, 5 and 7 relate to the same elements as in FIG. 1. Piston 43 is in the form of a hollow cylinder or a sleeve provided with a bottom 40 having a plurality of relatively small openings 42 therein. Instead of a pouch of foil, a glass ampoule 46 is provided and arranged to be destroyed by pressure applied to piston 44. The small openings 42 are adapted to prevent glass chips from entering the mixing chamber. In this embodiment, projection 49 which may be bead-like or pointed is not located on the interior wall of container 41, but at the lower edge of piston 43; a groove may be provided in the adjoining area of the interior wall of container 41 for engagement with the projection on the piston 43. In addition, a ring 48 is attached to the top of piston 43 by means of a bayonet joint to secure the piston against undesired downward movement. A nozzle-shaped extension 45 communicates with the mixing chamber, but is closed at its tip. After mixing, the tip of the extension may be cut off (if the container 41 consists of plastics or metal) or broken off (if the container 41 consists of glass).

The embodiment according to FIG. 4A corresponds substantially to the embodiment of FIG. 4, but the nozzle-shaped extension 45' of container 41' is initially closed by means of a removable plug 47. Instead of a glass ampoule, a pouch of foil 46' is provided so that in analogy to FIG. 1, only one relatively large opening 42' need be provided in the bottom of piston 43'.

FIG. 5 illustrates a modified receptacle comprising a first, hollow piston 53 which has relatively small openings 52 at its bottom. A glass ampoule 56 sealed by melting encloses the liquid ingredient 7 and is positioned in the second chamber 2 which in turn is located within the hollow piston 53. A hemispherical wall portion 56b of the ampoule forms the bottom thereof and is arranged to rest on piston 53 which has a concave bottom 50. The wall portion 56b is thinner than other wall portions of the ampoule. A second, solid piston or pusher 54 is movable in the hollow piston 53. At the start of a mixing operation, piston 54 will be pushed down cautiously so that only the wall portion 56b of the ampoule will be broken and thus relatively few glass fragments will be formed. The liquid ingredient 7 will then flow into the mixing chamber. As indicated in connection with the embodiment of FIG. 4, liquid particles still present in the second chamber 2 may be forced into the mixing chamber by means of a centrifuge. After the ingredients have been thoroughly mixed in an oscillating mixer, they are ready to be discharged. The bottom of container 51 is provided with a nozzle-shaped extension 55 initially closed by a plug 57 which is generally similar to the plug shown in FIG. 4A and will be removed after mixing. Piston 53 will then be pushed down to expel the ready mixture from the receptacle. The handle means 58 and internal projection 59 correspond to similar parts described hereinbefore.

If piston 53 is shortened, manual pressure may be applied directly to the relatively thick top wall of the ampoule to break the thin bottom thereof. In this case, the ampoule will serve as the second piston.

In the embodiment according to FIGS. 6 and 7, the second chamber 2 which serves for initially storing the liquid ingredient 7 is defined directly by the internal wall 65 of container 61 in conjunction with a first piston 63 and a second piston 64; both of the pistons are equipped with sealing rings 68 such as O-rings. When piston 64 is pushed down, piston 63 will likewise move downwards a certain distance since pressure exerted upon piston 64 will be transmitted through vapor formed in chamber 2 and through the ingredient 7 to piston 63. The ingredient 7 will then be permitted to escape through longitudinal channels or grooves 62 in the internal wall 65 of container 61 to the mixing chamber and will thus reach the pulverulent ingredient 5. Piston 64 will eventually contact piston 63 directly so that the volume of chamber 2 will be reduced practically to zero. By exerting external pressure upon the wall of container 61 from opposite sides, it is possible to prevent further movement of piston 63 before the mixing step is completed. In addition, however, the interior wall of container 61 or the outer, lower edge of piston 63 may be provided with a bead-shaped enlargement or projection to be effective after chamber 2 has been emptied; in both cases, the projection of one of the parts may engage a groove or recess provided in the other part. Of course, bead-shaped projections and grooves may be provided additionally to be effective in the initial position of the parts, i.e., the position for storage of the ingredients, so that undesired movements of pistons 63 and 64 will be prevented while the receptacle is shipped or transported. The cover 10 has the same function as in FIG. 1.

The embodiment of FIG. 8 is similar to that shown in FIGS. 6 and 7, except for the fact that cover 80 is provided with a nozzle-shaped extension 85; the latter is initially closed by a removable plug as in certain preceding embodiments, the plug being designated 87.

FIG. 9 is similar to FIG. 6 to a certain extent, but above the second chamber 2 there is provided a third chamber 2' for initially storing a third ingredient 7' which like the second ingredient 7 is preferably liquid or pasty. Chamber 2' is defined by the internal wall 95 of container 91 in conjunction with second and third pistons indicated at 94 and 94', respectively, which are equipped with sealing rings 98. Likewise, primary or first piston 93 has sealing rings 98 thereon. Pressure exerted upon piston 94' will be transmitted through vapor pressures, ingredients 7, 7' and intermediate second piston 94 to the first piston 93 so that all three pistons will move downwardly at the same time until the liquid or pasty ingredient 7 is permitted to pass from chamber 2 through longitudinal channels or grooves 92 into the mixing chamber where the preferably pulverulent ingredient 5 is stored. Piston 93 will then temporarily remain substantially stationary.

As soon as piston 94 contacts piston 93, however, both pistons will descend as a unit simultaneously with piston 94' until the liquid or pasty ingredient 7' communicates with the longitudinal channels 92 and is thus permitted to pass therethrough to the mixing chamber. Thereby, any particles of the ingredient 7 present in the channels 92 will be flushed out into the mixing chamber. Preferably, the ingredient 7' has a viscosity lower than that of the ingredient 7. Here again, bead-shaped projections and recesses may be provided on the internal wall of container 91 or on the pistons 93, 94 and 94', respectively. To accomodate the third piston and chamber, the container 91 is longer than the containers of FIGS. 6 and 8 as will be apparent from the drawings. Cover 10 has the same function as in FIGS. 1 and 6.

Of course, various modifications of upper and lower elements of the receptacle may be combined with each other; for example, the upper portion according to FIG. 1, 6 or 9 may be combined with the lower portion according to FIG. 2, 4 or 8. Further, the upper portion according to FIG. 4 or 5 may be combined with the lower portion according to FIG. 1, etc.

As indicated, for thorough mixing of ingredients the receptacle is preferably clamped in the fork of an automatic oscillating mixer (frequency range about 3,500 to 10,000, or preferably 4,000 to 7,000, oscillations per minute) whereby a homogeneous mixture will be obtained within a few seconds. If desired, the mixing operation may be performed in a vacuum. To this end, the receptacle may be enclosed in an outer capsule which will be evacuated.

Various other modifications and changes may be made without departing from the scope of the invention as defined in the appended claims. For example, instead of a single bottom opening 11 or 42' in the primary piston 3 or 43' as shown in FIGS. 1, 2, 3, and 4A, respectively, several openings may be provided. The openings may be arranged in a manner such that, in effect, a screen or sieve is formed.

In the appended claims, the term "first ingredient" refers to a substance which is preferably pulverulent, while the term "second ingredient" or "third ingredient" refers to a substance which is liquid or pasty or solid at room temperatures.

Claims

What is claimed is:

1. A storing and mixing receptacle adapted to receive a first ingredient and at least one second ingredient for making a dental preparation ready for use, said ingredients being capable of reacting with each other; comprising a container having a longitudinal axis and an internal wall surface, said container forming a first chamber located in its interior adjacent one of its ends and adapted to store said first ingredient initially; a first piston comprising a perforated bottom and located in said container for bordering said first chamber and for forming at least one second chamber extending in said container from said perforated bottom of the first piston in the direction towards the other end of said container, said first piston being movable in said container from a predetermined initial position substantially to said one end thereof, said internal wall surface of the container being shaped so as to guide said first piston throughout its stroke in coaxial relationship with said container; rupturable enclosure means positioned in said second chamber for storing said second ingredient initially, said enclosure means being arranged to abut said perforated bottom of the first piston; a second piston arranged to close said second chamber towards the outside and movable in said second chamber in the direction towards said first chamber for rupturing said enclosure means and for forcing said second ingredient from said second chamber through said perforated bottom into said first chamber to mix said first and second ingredients therein; and releasable closure means for closing said one end of the container until completion of the mixing step; whereby after mixing said ingredients, said closure means may be released and the mixed ingredients may be expelled from said receptacle by moving said first piston substantially to said one end of the container.

2. A receptacle as defined in claim 1, wherein said container has a portion of increased cross-section projecting inwardly from said internal wall surface thereof and located and shaped so as to engage said first piston symmetrically when the latter is in said predetermined initial position.

3. A receptacle as defined in claim 2, wherein the projecting portion is in the form of an internal, annular bead.