Mixer

Abstract

A disposable mixer adapted particularly for dental work. A rotary member has at its end a set of vanes, each having a unique shape for thoroughly intermixing constituents of a mixture within a disposable container. The outermost surface of each of the vanes fits snugly against the internal walls of the container. A shaft secured to the vanes may be driven by motor device for providing the mixing motion. The end of the container may be used to force the mixture from the container after completion of the mixing process.

Description

BACKGROUND OF THE INVENTION

In the art of dental technology, it is common to require the intermixing of two or more substances which yield a rapidly setting compound after mixing. Such a resulting compound may be used for the purpose of dental cement or tooth filler. The rapidly setting compound is realized by intermixing the particles of two or more separate substances or materials which are soft and workable when maintained individually apart from the other. Once the materials become intermixed, however, they react with each other and form a compound which sets rapidly upon intermixing. When setting, the compound becomes hard and unworkable and, as a result, it is necessary to intermix the materials or constituents rapidly so that the mixed compound may be applied or molded quickly in place.

Heretofore, the mixing of such hard setting materials for dental work was a relatively slow process, and the constituents were not thoroughly and completely intermixed with each other so as to result in a homogeneous compound. Such homogeneity is especially necessary if a long lasting filling or cement is to be realized. Furthermore, if too much time is consumed in the mixing process, partial setting of the materials takes place before filling or molding, and as a result the final structure of the filling or cement is weak and susceptible to fracture.

Accordingly, it is the intent of the present invention to overcome the aforementioned disadvantages.

SUMMARY OF THE INVENTION

A disposable mixing arrangement in which the mixing component has a shaft upon which a rotor is mounted. The rotor member has a plurality of vanes, each being preferably shaped to result in optimum mixing of a plurality of materials. The rotor and major portion of the shaft are confined within a disposable container sealed at both ends during the mixing process. When mixing has been completed, the top of the container becomes opened through the removal of a cap, and the contents of the container are emptied from therein. To facilitate emptying of the container, the bottom of the container is scored, so that through the application of pressure at the container bottom, the latter may be separated from the surrounding walls, and may be used as a piston or plunger to force the contents out of the container.

It is an object of the present invention to intermix completely the particles of two or more substances within the least possible time. It is also an object of the present invention to provide a mixer which is entirely disposable, when used in conjunction with materials that are hard setting. It is a specific object of the present invention to provide a disposable mixing unit which is economical to manufacture and reliable in operation.

A still further object of the invention is to make the container of squeezable or deformable material.

Various further and more specific purposes, features and advantages will clearly appear from the detailed description given below taken in connection with the accompanying drawing which forms part of this specification and illustrates merely by way of example one embodiment of the device of the invention.

BRIEF DESCRIPTION OF THE DRAWING

In the following description and in the claims, parts will be identified by specific names for convenience, but such names are intended to be as generic in their application to similar parts as the art will permit. Like reference characters denote like parts in the several figures of the drawing, in which

FIG. 1 is a sectional elevational view and shows the assembly of the disposable mixer, in accordance with the present invention:

FIG. 2 is a top view taken along line 2--2 in FIG. 1 and shows the shape of the mixing blades;

FIG. 3a, 3b and 3c, are partial views of the individual mixing blades seen in the directions a, b and c in FIG. 2 respectively; and

FIG. 4 is an exploded view of the upper portion of the center shaft seen in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawing, the mixing member 10 consists of a shaft 12 terminating in a rotor member 14. The shaft 12 may be of circular cross section, and may be made of plastic material. The rotor portion 14 may also be molded of plastic material and may be mounted upon the shaft 12, or may be molded integrally with the shaft.

Thus, when the rotor 14 is manufactured or molded as a separate member, the latter is provided with a bore into which the shaft 12 may be inserted. The rotor may be pinned to the shaft 12 or otherwise secured thereto as by means of, for example, a set screw. When using the design based on mounting the rotor 14 on the shaft 12 through means of a set screw, the latter may also be of molded plastic material. When the rotor member 14 is integrally molded with the shaft 12, on the other hand, no fastening devices are needed for securing the two parts together. An opening 16 may be provided for passage of the mix during stirring.

The rotor 14 has three vane portions 18, 20 and 22. The central axes of these three vanes are substantially equally displaced from each other. Accordingly, each vane portion is displaced substantially 120.degree. from its adjacent vane portion. In the preferred form of the device, each of the vanes or blades is uniquely shaped to provide optimum results. FIG. 3 illustrates the shapes of the three vanes or blades. Blade 17 shown in FIG. 3a has a hooked portion 18a at one end, and a hub portion 18b at the other end, in proximity of the axis of the shaft 12. A transition portion 18c connects the portions 18a and 18b and provides for a concave segment when looking at the blade or vane from the top. FIG. 3b illustrates the shape of the vane 22 adjoining the vane or blade 18. The vane or blade 22 has a paddle portion 22a extending from a holding or transition arm 22c. The arm 22c is supported by a hub portion 22b surrounding shaft 12. The paddle portion 22a extends above and below the upper and lower limits of the arm 22c. FIG. 3c shows the vane or blade 20 with an arm portion 20a extending from a hub portion 20b.

It is thus seen that the three vanes or blades vary radically from each other in shape and design. These particular shapes of the blades illustrated in the drawing, have been derived from empirical results by which an optimum mixing process is realized.

In the operation of mixing, the mixing member 10 resides within a disposable container 24. A cap 26 closes one end of the container during the mixing process. The center of the cap 26 is provided with an opening through which the shaft 12 extends. The rim 26a of the cap fits snugly against the outer walls of the container 24 so as to seal the latter during the mixing process. The extreme diametrically outer surfaces of the portions 18a, 22a and 20a fit closely against the internal walls of the container 24 but, at the same time, permit freedom of rotary motion of the rotor 14, and hence of the shaft 12. Thus, a minute amount of space prevails between the internal walls of the container 24 and the outer extreme surfaces of the rotor member 14 so as to freely permit relative motion between the container and the rotor, and at the same time, inhibit bypass flow of unmixed materials between the rotor and container walls. This design assures for complete intermixing of all of the particles of the mixture constituents.

The bottom portion 24a of the container 24 is held to the walls of the container by a score or cut 24b. In the fabrication of the container 24, the bottom of the latter is formed integrally with the walls. The container may be made of plastic material so that it may be readily disposable. In the fabrication process of the container, a score 24b is also provided which cuts through partially the bottom of the container so that the latter is only partially adherent to the walls of the container. The score or cut 24b does not penetrate through the entire thickness of the bottom or base 24a, and thereby retains the container in a fully leak-proof condition.

When the materials have been fully intermixed, and it is desired to remove the contents from within the container, pressure applied to the base 24a through, for example, a person's thumb, causes the score 24b to fracture and the base 24a to separate from the walls of the container. Upon removal of the cap 26 from the top of the container, the base 24a may then be used as a piston or plunger to force the contents or mixed materials out of the container. Thus, by further applying pressure on the base 24a after fracture of the score 24b,a person may force the base 24a upwards into the container causing the contents to spill from the rim at the top of the open container.

A ring 28 is provided on the shaft 12 so as to remove the mixing member 10 simultaneously with the removal of the cap from the container. Thus, when removing the cap 26, after the mixing process, the exterior surface of the cap is forced against the ring 28 and thereby pulls or draws the entire member 10 out of the interior of the container. At the same time, the ring 28 may be positioned along the longitudinal axis of the shaft 12 so as to established precisely the bottom space between the rotor 14 and the base or bottom 24a of the container during the mixing process. The ring 28 may be in the form of a split ring which fits into a groove 12a of the shaft 12. In an alternate design, the ring 28 may be molded directly upon the shaft 12 during fabrication. Thus, the ring may be manufactured integrally with the shaft 12.

All parts of the mixing assembly shown in FIG. 1, may be made of low cost disposable materials such as plastic to permit the discarding of the entire assembly or unit after the mixing process has been completed. This feature is especially desirable in dental work because the hard setting materials are difficult to remove from the mixer, as the latter may not be economically discarded after a single use.

In an embodiment of the invention, container 24 may be made out of suitable squeezable or deformable material, so that the mix after being formed may be readily squeezed and exuded from the mouth or opening of the container. In this embodiment, the bottom would be permanently part of the container.

While the invention has been described and illustrated with respect to a certain preferred example which gives satisfactory results, it will be understood by those skilled in the art after understanding the principle of the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended therefore in the appended claims to cover such changes and modifications.

Claims

What is claimed is:

1. A mixing device for intermixing at least two substances comprising in combination, a rotatable shaft member; a rotor member secured to said shaft member and having three differently shaped mixing blades mounted on said shaft member and spaced substantially equiangularly about the rotational axis of said shaft member, said mixing blades being mounted on said shaft member at substantially the same position on the longitudinal axis of said shaft member; container means for containing said substances to be intermixed and said rotor member, the interior walls of said container means surrounding said rotor member; and cap means attachable to said container means for enclosing said substances and said rotor member in said container after said substances and rotor member are introduced into the interior of said container means, said cap means having an opening through which a portion of said shaft member supporting said rotor member extends into the interior of said container means, an exterior portion of said shaft member projecting from the exterior surface of said cap means whereby rotation of said exterior portion of said shaft member rotates said rotor member and intermixes said substances.

2. The mixing device as defined in claim 1 wherein one of said rotor blades is hook-shaped with the hooked portion extending substantially transverse in one direction to the longitudinal axis of said blade.

3. The mixing device as defined in claim 1 wherein one of said rotor blades is paddle shaped with the paddle portion extending substantially transverse to the longitudinal axis of said blade.

4. The mixing device as defined in claim 1 wherein one of said rotor blades is arm shaped with an arm portion extending transverse to the rotational axis of said rotor member.

5. The mixing device as defined in claim 1 wherein said container is of deformable plastic material.

6. The mixing device as defined in claim 1 wherein the outermost surfaces of said rotor blades are substantially closed spaced from the interior walls of said container means.

7. The mixing device as defined in claim 1 wherein said cap means includes a bent rim portion for securing said cap means to said container means and facilitating removal of said cap means therefrom.

8. The mixing device as defined in claim 1 including a ring member attachable to said shaft member for withdrawing said rotor member from the interior of said container means simultaneously with removal of said cap means from said container means.

9. A mixing device for intermixing at least two substances comprising in combination, a rotatable shaft member; a rotor member secured to said shaft member and having a plurality of rotor blades, container means for containing said substances to be intermixed and said rotor member, the interior walls of said container means surrounding said rotor member; and cap means attachable to said container means for enclosing said substances and said rotor member in said container after said substances and rotor member are introduced into the interior of said container means, said cap means having an opening through which a portion of said shaft member supporting said rotor member extends into the interior of said container means, an exterior portion of said shaft member projecting from the exterior surface of said cap means whereby rotation of said exterior portion of said shaft member rotates said rotor member and intermixes said substances, said container means comprising a substantially thin-walled container open at one end and closed at the other end, the closed end having a score severable through application of pressure applied to said closed end.

10. A mixing device for intermixing at least two substances comprising in combination, a rotatable shaft member; a rotor member secured to said shaft member and having a plurality of rotor blades; container means for containing said substances to be intermixed and said rotor member, the interior walls of said container means surrounding said rotor member; and cap means attachable to said container means for enclosing said substances and said rotor member in said container after said substances and rotor member are introduced into the interior of said container means, said cap means having an opening through which a portion of said shaft member supporting said rotor member extends into the interior of said container means, an exterior portion of said shaft member projecting from the exterior surface of said cap means whereby rotation of said exterior portion of said shaft member rotates said rotor member and intermixes said substances, said rotor member comprising a hub portion surrounding said shaft member; a hook-shaped blade; a paddle-shaped blade; and an arm-shaped blade, said blades being spaced from each other substantially equiangularly.

11. The mixing device as defined in claim 10 wherein one of said rotor blades is hook-shaped with the hooked portion extending substantially transverse in one direction to the longitudinal axis of said blade.

12. The mixing device as defined in claim 11 wherein one of said rotor blades is arm-shaped with an arm portion extending transverse to the rotational axis of said rotor member.

13. A mixing device for intermixing at least two substances comprising in combination, a rotatable shaft member; a rotor member secured to said shaft member and having a plurality of rotor blades; container means for containing said substances to be intermixed and said rotor member, the interior walls of said container means surrounding said rotor member; and cap means attachable to said container means for enclosing said substances and said rotor member in said container after said substances and rotor member are introduced into the interior of said container means, said cap means having an opening through which a portion of said shaft member supporting said rotor member extends into the interior of said container means, an exterior portion of said shaft member projecting from the exterior surface of said cap means whereby rotation of said exterior portion of said shaft member rotates said rotor member and intermixes said substances, each of said rotor blades having a shape different from the shapes of the other blades, said container means comprising a substantially thin-walled container open at one end and closed at the other end, the closed end having a score severable through application of pressure applied to said closed end.