Dispensing – Plural sources – compartment – containers and/or spaced jacket
Reexamination Certificate
2002-11-27
2004-04-06
Mancene, Gene (Department: 3754)
Dispensing
Plural sources, compartment, containers and/or spaced jacket
C222S145100, C222S001000
Reexamination Certificate
active
06715645
ABSTRACT:
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to a mixing capsule and to a mixer unit which includes a mixing capsule, in particular for the production of a dental material which preferably contains a plurality of components.
Mixing capsules which are filled with the components in separate chambers by the manufacturer are used to produce mixtures of two or more components. The components are brought into communication and mixed with one another by the user, for example by destroying a wall separating the chamber.
Mixing capsules for the production of dental materials which are often mixed from a pulverulent component and a liquid component, the mixing procedure usually taking place in a shaker unit, are known in the dental sector. The fully mixed substance is then dispensed directly onto the working area, for example into a tooth cavity, through a dispensing spout formed integrally on the mixing capsule.
DE 36 35 574 A discloses a mixing capsule intended for the production of jointing and sealing compounds. In an illustrative embodiment described in said document, an auxiliary chamber which is present in the dispensing piston is delimited, on the side facing the main chamber of the capsule, by a foil and, on the opposite side, by an auxiliary piston which is arranged displaceably in the dispensing piston. In the initial state of the mixing capsule, in addition to the second component, a mixer body is accommodated in the auxiliary chamber, which mixer body initially serves to destroy the foil by means of manual displacement of the auxiliary piston and then assists in the mixing procedure. To allow the reduction in volume which is necessary for displacement of the inner piston together with ball, a gas cushion is provided in the mixing chamber.
In a further embodiment of the known mixing capsule, the mixing ball is initially situated in the main chamber. In this case, the auxiliary chamber present in the piston is closed off from the main chamber by means of a cover and on its rear side by a bellows. As a result of manual pressure being applied to the bellows, the cover is pressed away from the piston, so that the two chambers are brought into communication for the purpose of activating the capsule.
In both cases, a dedicated working step which has to be carried out manually is required for activation of the capsule. Furthermore, a gas cushion is required in order to permit the reduction in volume which is required for removal of the cover.
In a multicomponent mixing capsule for dental purposes which is known from DE 94 00 374 U1, a first component is contained in a mixing chamber and a second, liquid component is contained in a foil bag which is arranged in an auxiliary chamber which is separated from the mixing chamber by a displaceable wall element. A cylindrical mixing body which is present in the mixing chamber is used to displace the wall element at the start of the mixing procedure and thus to compress the foil bag, so that the latter bursts open and releases the liquid component through a liquid passage which is present in the wall element.
One difficulty with this device lies in designing the wall element, the film bag and the capsule itself in such a way, and in dimensioning these components with sufficiently low tolerances, for the wall element to be held in its starting position while the capsule is being stored and transported but to be displaced sufficiently far and with such force, under the action of the mixing body, that the foil bag bursts open. In this context, it should be borne in mind that the fact that the foil bag is often only partially emptied leads to undesirable changes in the mixing ratio and therefore to deterioration in the properties of the finished mixture. Another drawback is that this arrangement is suitable only for mixing, but not for application of the paste.
DE 93 03 268 U1 describes a multicomponent mixing capsule with ejection device for a mixed compound, primarily for dental purposes. This mixing capsule has an activation mandrel which is located in the interior of the capsule and is anchored against the direction of ejection by means of holders in the interior of the capsule body, and a liquid compartment which is accommodated in the interior of a ram and is sealed off with respect to the activation mandrel by a destructible membrane. The activation mandrel fits flush into the empty vessel in the interior of the ram and seals the latter while the material is being forced out.
While the material is being forced out in the longitudinal direction, the liquid passes through the thin capillary, which comes to lie in the interior of the activation mandrel, into the mixing space. It is explained that, even during the mixing operation in a vibration mixer and during the dispensing of the compound via the ejection nozzle, a small residue of liquid, which is not precisely reproducible, always remains in the capillary. This impairs the quality of the results of mixing.
A comparable mixing capsule is described in WO 00/30953.
The object of the present invention can primarily be regarded as that of making available an improved mixing capsule which avoids the abovementioned problems without impairing the desired results of mixing.
A further object can be regarded as that of making available a method for mixing and dispensing mixtures from mixing capsules, which method requires a smaller number of steps.
This object is achieved by a mixing capsule and a method for producing a mixing capsule as described in the claims.
The words “comprise” or “include” within the meaning of the invention precede a nonexhaustive list of features. The word “one” is to be interpreted as an indefinite quantity with the meaning of “at least one”.
The mixing capsule according to the invention has, inter alia, the following advantages:
The movable body which is present in the mixing capsule serves not only to activate the capsule by destroying the separating device and to assist in the mixing procedure, but also serves as a displacement body during emptying.
The mixing capsule according to the invention also permits reproducible mixing of highly viscous substances.
Since, in the initial state, the body is situated in the main chamber, the activation preferably takes place automatically at the start of the mixing procedure, in contrast to the activation steps, known from the prior art, which have to be carried out manually.
Since, furthermore, the auxiliary chamber is separated from the main chamber by the separating device through which the body can penetrate, during the subsequent mixing procedure it forms part of the mixing chamber itself. This ensures that the second component included in the auxiliary chamber completely enters the mixture which is being formed.
Moreover, the unification of main chamber and auxiliary chamber advantageously increases the available mixing volume.
In the final phase of the dispensing procedure, the body assists in the virtually complete emptying of the mixing capsule interior formed by the main chamber and auxiliary chamber.
A further advantage is the small number and simple design of the components of the mixing capsule.
An advantage over the mixing capsule known for example from DE 23 24 296 A is that, because there is no need to arrange a foil cushion on the outside of the cartridge, together with a clasp for holding it, the capsule can have a smaller radial diameter with the same volume. This makes it easier to apply the mixture or compound from the capsule into a cavity of a tooth.
As appropriate, a plurality of freely movable bodies are located in the mixing capsule.
The movable body is preferably of spherical configuration. The diameter of the sphere is preferably in the range of 4 to 10 mm, particularly preferably in the range of 5 to 8 mm.
However, any other configuration of the body is also conceivable, for example an egg-shaped or lens-shaped configuration, or a configuration in the form of a platonic body. Depending on the chosen separating layer, such a configuration can more easily destroy the separating
Eckhardt Gunther
Hager Gabriele
Peuker Marc
Sick Michael
Stefan Klaus-Peter
3M ESPE AG
Cartagena M A
Crowell & Moring LLP
Mancene Gene
LandOfFree
Mixing capsule and method of making and using same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Mixing capsule and method of making and using same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mixing capsule and method of making and using same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3221841