The present invention relates to a specific type of aerosol can that uses a valve called the “bag on” valve. More specifically, the invention described and claimed here relates to an improvement that enables “bag on” valve aerosol cans to be refilled and/or reused rather than discarded after a one-time use.
Bag on valve cans are significantly different from conventional aerosol cans in that they physically separate the product to be dispensed (“dispensed product”) from the propellant gas. The dispensed product is self-contained within a flexible bag inside the can, surrounded by the propellant gas (gas that is under pressure). The pressure of the propellant gas squeezes the bag when the valve is open, pushing the dispensed product through the valve and then typically out through a spray nozzle.
Other aerosol cans typically do not use gas to propel the product in the same way. Today, it is common to use liquid hydrocarbon fluids or other highly volatile fluids in aerosol cans that are mixed with the can's product in the same interior space (the product might be a chemical like a glass cleaner, for example). In some cases pressurized gas like nitrogen or carbon dioxide is used, with the gas sitting in the top portion of the can and the liquid sitting below. The liquid product covers the end of a straw-like outlet tube. The pressure of the gas above pushes the liquid down and then back up through the tube when the can's valve is pushed open, usually by depressing a spray nozzle.
All of these designs are well-known. However, the “bag on” design is environmentally friendly because the propellant gas never exits and remains sealed in the can after product discharge. The basic “bag on” design involves a valve that is connected to a rolled up bag (rolled up before filling). The valve/bag arrangement is inserted into a canister-type container (“the can”) and the region surrounding the bag, inside the can, is permanently pressurized with a gas, like nitrogen. After this is done, the liquid product is pumped into the empty bag, through the valve, thus unfurling and filling the bag against the pressure of the gas inside the can—with the gas functioning as a propellant gas that pushes against the outside of the bag's wall. The valve is opened in the same way as conventional aerosol cans to spray out the product, but with the propellant gas squeezing the liquid product bag and ejecting product through the opened valve and a spray nozzle.
However, once the product in the “bag on” can is fully discharged, the can remains pressurized with the collapsed bag inside. And it remains pressurized during the course of being discarded or recycling the metal that is used to make the can's walls. At some point in time during that process, the pressurized gas is released.
The problem with bag on valve cans is that they require highly sophisticated and expensive machines to fill them—which is done on a mass production basis. These machines commonly use metered pumps to fill the bag inside the can after pressurization, with the pump running a certain amount of time to fill each can to the appropriate level, in sequence, one after another. Pressurization and sealing of the propellant gas in the can is done as part of the same process.
Because of the complexity of these filling machines, they are usually installed in locations where manufacturers are filling large numbers of cans and then shipping them out for distribution. It is also not easy to do line changes with these machines (that is, filling cans with one type of product and then switching to another) because of machine cleaning requirements. As a consequence, no one has recognized that bag on valve cans could be refilled and reused if an economical and efficient means was developed to refill cans in the field, in lieu of collecting cans in the distribution network and returning them to a filling machine location.
The present invention provides a simplified process and machine that enables a small business to cheaply refill bag on valve cans on-site. As an example, the automotive industry uses large numbers of bag on valve cans for brake cleaning fluid or other kinds of oils or solvents. A typical automotive shop might buy and discard cans by the case, as consumables, during the normal course of doing auto repair work. The present invention allows the shop to easily refill the cans on site—which means the shop only needs to buy replacement product in bulk and not individual cans that are prefilled, thus providing a means for reducing overall costs over time.
The invention or inventions disclosed in this document relate to a process and machine for refilling an empty liquid product bag inside a bag on valve can (sometimes called the “container” or “dispensing container”). The dispensing container has a certain volume of pressurized gas that collapsed the bag (“the liquid product bag”), on the “bag on” valve, during the course of spraying product from the can.
According to the present disclosure, the can or container is coupled to a liquid product refilling chamber of an apparatus, with the refilling chamber containing a measured amount of liquid product that is to be used to refill the collapsed liquid product bag. The liquid product is delivered into the refilling chamber before coupling the can, although there may be ways of altering the sequence. Once coupled, however, the measured amount of liquid product is pushed into the liquid product bag from the refilling chamber, at a sufficient pressure to counteract the pressure of the gas inside (surrounding the product bag), thus inflating the liquid product bag (with the product) against the pressure of the gas. The can is decoupled after refilling is completed.
Preferably, the liquid product is delivered into the refilling chamber via a “drawing” action, similar to a vacuum effect, although there may be other ways of putting product into the chamber. It might be possible to push the product into the chamber by an external pump, for example, during the course of the filling action. Either way, the refilling chamber is preferably constructed as a swappable module that houses a reciprocating piston. When the piston retracts inside the chamber, it allows liquid product to be drawn into the refilling chamber through a one-way check valve or one-way inlet. The size of the chamber is defined by the diameter of the piston and the linear distance of its travel, back-and-forth.
Reversing direction of the piston causes it to push the liquid product out from the refilling chamber, through a needle valve mechanism, and into the liquid product bag. The needle valve mechanism also has a one-way flow control design that operates opposite to the one-way inlet. In other words, when the one-way inlet into the refilling chamber is “open,” during the drawing and filling process summarized above, the one-way flow mechanism in the valve mechanism is closed. Reversal of the piston's direction causes these functional directions to switch as well.
The piston in the liquid refilling module is driven by an air pump mechanism. According to the design disclosed below, one possible version of an air pump mechanism consists of an independent air-driven piston member that reciprocates back and forth by using an air valve mechanism to create high/low pressure differentials on each side of the air piston.
Because it is swappable, one size of liquid filling module can be exchanged with another. This would be done to accommodate different sizes of the liquid product bag for different cans or when it is desired to put different kinds of liquid products (typically different chemicals) in different cans. Swapping modules reduces time spent in cleaning lines when the same machine is used to put different product into different cans.
The foregoing summary will become better understood after reviewing the accompanying description below and the accompanying schematics.
In the drawings, like reference numbers refer to like parts throughout the various views, and wherein:
Referring now to the drawings, and first to
First, the lower portion of the machine has a base, indicated generally at 12, for creating a support for holding the can 14 during the filling operation (The can 14 is schematically shown in
When the can 14 is placed on the platform 16 (see
During the coupling stage of the filling operation (which is also described in greater detail later), the can 14 is placed on platform 16 and piston 20 (
There are different ways of creating can-guiding structure that can perform the needed alignment/holding function described above. In the present design, and referring now to
While it may be possible to change operational sequences, before the can 14 is lifted into position for refilling, the machine has a liquid refilling module that is loaded with a measured amount of liquid product that is to be put into the can 14. The liquid refilling module portion of the machine is generally indicated at 40 and illustrated, specifically, in
Directing attention to
Before specific details of the filling operation are further described, and as was generally described earlier, it should be appreciated that the liquid refilling module 40 is designed to be a fully “swappable” unit to and from the machine 10. Referring back to
The area below piston 60 defines a product refilling chamber. When the piston 60 is in the position shown in
The piston 60 is moved up (vertically) by an air pump mechanism portion of the machine, shown generally at 62 in
Referring to the upper right-hand corner of
The air piston 68 is connected to a shaft 74 that slides through a plate 76 that defines the bottom part of the air pump mechanism 62. Similar to the refilling module 40 previously described, the air pump mechanism 62 has a cylindrical housing 78, closed at the top by plate 80 and at the bottom by plate 76 just described.
The shaft 64 is connected to the shaft 48 on the liquid refilling module 40 via a removable pin 82 or the like (see
As piston 60 inside the refilling module 40 moves, in the direction indicated by arrow 84 in the upper part of
The definition of the term “liquid product” would be understood by anyone knowledgeable about bag on valve cans. It could be any type of liquid that is normally dispensed by a bag-on valve can. A penetrating oil or solvent might be an example.
As illustrated in
However, referring to the earlier description of the base structure illustrated in
Directing attention there, the needle valve mechanism 92 also functions as a one-way check valve that closes when the liquid module 40 is filled. There are many different ways this can be done. However, when the can 14 is lifted, it comes into registration and couples with the needle 94 of the valve mechanism 92. The can pushes against collar part 41 on the module 40 (see
Referring now to the exploded view of the valve mechanism 92 illustrated in
To explain the above in terms of the sequence of filling the module 40 and then driving product into the can 14, the valve mechanism 92 functions like a one-way valve that works oppositely to the one-way inlet into the module (items 58, 88 in the upper left-hand portion of
After the module 40 is refilled, then the can 14 is lifted into position. When the needle 94 enters the can, the can then pushes the needle (and annular member 108 upwardly, away from washer 114. This opens orifices 110, 112 and allows the product to flow through the valve into needle orifice structure. Thus, according to the sequence described above, the liquid module 40 draws product into its refilling chamber via one-way inlet/check valve 58, 88. The needle valve mechanism 92 is closed during that operation. The bag on valve inside the can 14 is also closed, which would be its normal state. Then, the base 12 lifts can 14 in a coupling action with needle 94. This action pushes the valve mechanism 92 “open.” At the same time, the bag on valve inside the can is pushed “open.” At that point, the can 14 (the liquid product bag inside the can) is coupled to the refilling chamber of module 40 via the bag on valve that was initially built into the can. The direction of piston 60 is reversed and it pushes the liquid product through the bag on valve (product pressure created by the piston 60 opens the bag on valve) and into the empty product bag inside the can 14, against the pressure of the propellant gas that is already there. When the travel of piston 60 is complete, the base 12 is allowed to retract, as described above, so that the refilled can 14 can be decoupled from module 40 and removed. That bag on valve inside the can closes to retain the product inside the can.
The foregoing description is not intended to limit the scope of the invention. For example, the liquid filling module is described as a “draw” then “push” filling mechanism. It might be possible to fill the module in a different way with some sort of pump mechanism. Also, an advantage to swapping the module 40 is that a user can have one module that contains one kind of liquid product and, rather than clean the module to use a different kind, the user can instead simply swap in a different module. Commercial grade filling machines require cleaning when the product is changed.
The above description sets forth a design that is under development and has not been released for marketing purposes. This means that the design could be changed during the reasonable course of developing a marketable machine. That means the mechanical structures described above could be altered that nevertheless follow the overall framework of the machine design described above. For this reason, the invention and scope of patent right is to be limited only by the claims that follow, the interpretation of which is to be done in accordance with the standard conventions of patent claim interpretation.
Number | Date | Country | |
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61634842 | Mar 2012 | US |