This invention relates to dispensers for liquids sold in plunger tubes, and more particularly to such liquids that require re-mixing before use.
Epoxy glues are one example of a product in which two liquids are mixed at the time of use but must be contained separately until that time. Examples of such “two-part liquids” are epoxies comprising a resin and hardener, silicones comprising a catalyst and resin, and other products having thermosetting reactants.
Often, the two-part liquid is sold in a double-tube dispenser. Each tube has a plunger to push the stored liquid through a dispenser hole at the other end.
The double-tube dispensers may be sold as part of a dispenser pump-gun or may be designed to be subsequently loaded into a dispenser gun. In either case, at the time of use, the end user operates the dispenser pump-gun so as to simultaneously depress both plungers. This action pushes both liquids out of the double-tube dispenser, through a simple mixer, and out from a nozzle.
A problem with conventional double-tube dispensers is that if one of the liquid components has additives, such additives may separate and settle over time during storage prior to use. This can result in an inconsistent appearance among tubes and over the course of use of a single dispenser tube. This rendered the product unusable for the intended application. The current process requires removing the settled component from the tube, remixing it, and adding it back to the tube to be used.
A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein:
The following description is directed to a dispenser designed to re-mix the components contained in a tube, syringe, or other plunger-operated container that dispenses a product in liquid form. For purposes of this description, such containers are generally referred to as “plunger tubes”.
The dispenser allows the user to re-mix a component that has settled while the component has been kept in its plunger tube. It can also be used to initially mix the components in the tube. The mixing is in-situ, meaning that the liquid remains in its tube during mixing.
Multi-Tube Dispensers
This section is directed to a double-tube dispenser designed to re-mix one of the components of a multi-component liquid. As indicated in the Background, two-part liquids are used for many epoxy products, but the same concepts may apply to any “multi-component” liquid.
In the example of this description, the multi-component liquid is a two-part epoxy that contains soluble and non-soluble material additives. The mixing is applied to the epoxy resin. However, the invention described herein can be used with any multi-component liquid, without departing from the scope of the invention.
Tubes 11 and 12 are arranged parallel to each other. They are adjoined or otherwise in a permanent rigid pairing. They are typically the same length and share a bottom opening 19. Otherwise, they are generally the same size and shape, but the size and shape of one may vary slightly from the other.
As explained below, both tubes 11 and 12 have a plunger 13 and 16, respectively. However, the plunger 16 of tube 12 is a two-piece plunger. In the example of this description, where the two-part liquid is an epoxy and the liquid components are resin and hardener, the resin is a “settling liquid” that often needs re-mixing before use. The two-piece plunger 16 is used with this “settling liquid”.
A first tube 11, here the epoxy's hardener tube, has a plunger 13 that remains at its top end until the two-part liquid is dispensed. Plunger 13 has a sealed fit to the inner diameter of tube 11 but is slidable downward into the tube 11 to push the liquid out of the tube through dispenser opening 19. Plunger is designed to accept the plunger rod of a conventional dispenser gun.
The second tube 12 has a special plunger rod 15 and a two-piece plunger 16. As explained below, plunger rod 15 and two-piece plunger 16 are used for purposes of re-mixing the contents of tube 12 in situ. The plunger rod 15 has a handle to aid in the mixing. After re-mixing, plunger rod 15 is detached, and plunger 16 remains to serve as a plunger for a dispenser pump-gun, operating in a manner similar to plunger 13.
In
The two-piece plunger 16 comprises a top piece 16a and mixer piece 16b. Two-piece plunger 16 allows re-mixer piece 16b to separate from top piece 16a for mixing. In
As shown in
Top piece 16a is generally solid except for a hole that allows the plunger rod to pass through to the mixer piece 16b. Its outer shape conforms to that of its associated tube 12 so that it may properly act as a plunger.
Top piece 16a also has grooves for inner and outer O-ring seals, illustrated in
The re-mixer piece 16b has fan-blade shaped mixing vanes 61. In the example of
An outer rim 63 wipes settled material away from the inner wall of tube 12 when plunger rod 15 is moved up and down within tube 12. The re-mixer piece 16b swirl-mixes the material in tube 12 over a number of passes.
Re-mixer piece 16b further has raised features 64 on the top of rim 63. Referring to both
In operation, the user pushes the plunger rod 15 through the center hole in the dispenser plunger 16a. The user then screws the threaded end of the plunger rod 15 into the threaded insert 32 of the re-mixer plunger 16b. The user moves the plunger rod 15 back and forth along the entire length of tube 12, causing the mixer piece 16b to mix the liquid within the tube 12. The top piece 16a remains at the top of tube 12 due to the friction of the o-ring seal 37, which is greater than the friction of the o-ring seal 36.
After mixing, the user pulls the mixer piece 16b up toward the top of tube 12 until it interfaces with and rests against top piece 16a. Referring again to
After mixing and interfacing mixer piece 16b with top piece 16a at the top of tube 16, the user unthreads the plunger rod 15 and puts it aside. The user can then use dispenser 10 with a dispenser pump-gun. In the case of a separate dispenser, the user loads the dispenser 10 into a pump-gun and uses the pump-gun as directed.
Single-Tube Dispensers
A single tube 71 contains the liquid. Tube 71 is typically round, such as the barrel of a syringe, but may be various elongated shapes.
Dispenser 71 has a two-piece plunger 76, having a top piece 76a and a re-mixer piece 76b. Together with rod 75, these three pieces operate in the same manner as the rod 15 and plunger 16 described above. After re-mixing, the user pulls the plunger rod 75 up so that the pieces of plunger 76 interlock.
Dispenser 71 may or may not be designed to be loaded into a dispenser pump-gun, such as that of
This invention was made with United States Government Support under Contract No. H98230-19-C-0344 funded by the Maryland Procurement Office. The Government has certain rights in this invention.