Dual fluid cartridges are used to store and dispense two fluids which must be kept separate until the time of use and then, at the time of dispensing, need to be mixed together very quickly in a precise pre-set ratio to ensure that the proper chemical reaction takes place. If the cartridge does not dispense the two fluids properly in the required pre-set ratio, the final fluid mixture may be greatly affected and may not function or adhere as required. Examples of such fluids are those that are used to create thermoset adhesives (i.e., a resin and a hardener).
Dual fluid cartridges have been used in industry for a long time and, over the years, differing types of dual fluid cartridges have been developed. An example of a relatively recently developed dual fluid cartridge is the one depicted and described in U.S. Pat. No. 5,310,091, entitled “Dual Product Dispenser”. The dual fluid cartridge depicted and described in the '091 patent is an effective dual fluid cartridge. It can be filled relatively easily and can be used in readily available dispensers, such as caulking guns. With fluids that need to be combined in a 1:1 ratio, the dual fluid cartridge of the '091 patent is especially effective. The dual fluid cartridge of the '091 patent may also be used with fluids that need to be combined in a non-1:1 ratio (e.g. 2:1 ratio). However, when the ratio of the two fluids that need to be combined starts to deviate from 1:1, the dual fluid cartridge of the '091 patent becomes less effective. Because the dual fluid cartridge of the '091 patent only has two chambers to hold fluid, as the ratio between the two fluids that need to be stored and dispensed increases, the space wasted in the cartridge increases and the amount of final product that can be produced decreases. At high ratios (e.g. a 10:1 ratio), the space wasted within the cartridge and the reduction in final product that can be produced becomes significant.
Accordingly, there is a need for a dual fluid cartridge that is effective in storing and dispensing fluids in unequal ratios such that there is minimal wasted space in the cartridge and the total final product capable of being dispensed is maximized.
In accordance with one aspect of the present invention, a fluid cartridge for storing and dispensing two fluids, wherein one of the fluids to be stored and dispensed is of a greater amount than the second fluid, includes an outer cartridge wall defining an outlet and an open end opposite the outlet and an inner cartridge wall disposed within the outer cartridge wall and defining an outlet that is co-located with the outlet defined by the outer cartridge wall. A first piston is disposed within the inner cartridge wall, such that the inner cartridge wall and the first piston define a fluid chamber for the fluid of lesser amount. A second piston is disposed between the outer cartridge wall and the inner cartridge wall to form a first fluid chamber for the fluid of greater amount. A third piston is disposed within the outer cartridge wall between first piston and the open end of the outer cartridge wall. Further, a fixed wall is disposed between the first piston and the third piston, such that the fixed wall and the third piston define a second fluid chamber for the fluid of greater amount. Means for transmitting force from the third piston to the first piston, and means for transmitting force from the third piston to the second piston are included. A delivery channel is disposed between the first and second fluid chambers for the fluid of greater amount to allow fluid communication between the first and second fluid chambers for the fluid of greater amount.
In the fluid cartridge in accordance with this aspect of the present invention, the ratio between the fluid of greater amount and the fluid of lesser amount may be 10:1, 2:1 or some other ratio. The fluid cartridge may also include a plurality of delivery channels disposed between the first and second fluid chambers for the fluid of greater amount. The delivery channel may also be the force transmitting means from the third piston to the second piston or the delivery channel may be the force transmitting means from the third piston to the first piston. The delivery channel may be formed integral with the inner cartridge wall. The delivery channel may be crescent-shaped or may be an annular passage. Also, the outlet defined by the outer cartridge wall may have an interior and the outlet defined by the inner cartridge wall may be disposed within and span the interior of the outer cartridge wall outlet. The inner cartridge wall outlet may also define a first opening for discharge of the fluid of greater amount and a second opening for discharge of the fluid of lesser amount. The inner cartridge wall outlet may also have an exterior surface with ribs formed along the exterior surface, wherein the ribs secure the inner cartridge wall outlet within the interior of the outer cartridge wall outlet.
According to another aspect of the invention, a fluid cartridge for storing and dispensing two fluids, wherein one of the fluids to be stored and dispensed is of a greater amount than the second fluid, includes an outer cartridge wall defining an outlet and an open end opposite the outlet and an inner cartridge wall disposed within the outer cartridge wall and defining an outlet that is co-located with the outlet defined by the outer cartridge wall. A first piston is disposed within the inner cartridge wall, such that the inner cartridge wall and the first piston define a fluid chamber for the fluid of lesser amount. A second piston is disposed between the outer cartridge wall and the inner cartridge wall to form a first fluid chamber for the fluid of greater amount. A third piston is disposed within the outer cartridge wall between first piston and the open end of the outer cartridge wall. Further, a fixed wall is disposed between the first piston and the third piston, such that the fixed wall and the third piston define a second fluid chamber for the fluid of greater amount. A first transmission structure is disposed between the third piston and the first piston, and a second transmission structure is disposed between the third piston and the second piston. A delivery channel is disposed between the first and second fluid chambers for the fluid of greater amount to allow fluid communication between the first and second fluid chambers for the fluid of greater amount.
In the fluid cartridge in accordance with this aspect of the present invention, the ratio between the fluid of greater amount and the fluid of lesser amount may be 10:1, 2:1 or some other ratio. The fluid cartridge may also include a plurality of delivery channels disposed between the first and second fluid chambers for the fluid of greater amount. The delivery channel may also be formed integral with the first transmission structure or the second transmission structure. The delivery channel may be formed integral with the inner cartridge wall. The delivery channel may be crescent-shaped or may be an annular passage. Also, the outlet defined by the outer cartridge wall may have an interior and the outlet defined by the inner cartridge wall may be disposed within and span the interior of the outer cartridge wall outlet. The inner cartridge wall outlet may also define a first opening for discharge of the fluid of greater amount and a second opening for discharge of the fluid of lesser amount. The inner cartridge wall outlet may also have an exterior surface with ribs formed along the exterior surface, wherein the ribs secure the inner cartridge wall outlet within the interior of the outer cartridge wall outlet.
According to another aspect of the present invention, a fluid cartridge for storing and dispensing two fluids, wherein one of the fluids to be stored and dispensed is of a greater amount than the second fluid, includes an outer cartridge wall defining an outlet and an open end opposite the outlet and an inner cartridge wall disposed within the outer cartridge wall and defining an outlet that is co-located with the outlet defined by the outer cartridge wall. A first piston is disposed within the inner cartridge wall, such that the inner cartridge wall and the first piston define a first fluid chamber for the fluid of greater amount. A second piston is disposed between the outer cartridge wall and the inner cartridge wall forming a fluid chamber for the fluid of lesser amount. A third piston is disposed within the outer cartridge wall between first piston and the open end of the outer cartridge wall. Further, a fixed wall is disposed between the first piston and the third piston, such that the fixed wall and the third piston define a second fluid chamber for the fluid of greater amount. Means for transmitting force from the third piston to the first piston, and means for transmitting force from the third piston to the second piston are included. A delivery channel is disposed between the first and second fluid chambers for the fluid of greater amount to allow fluid communication between the first and second fluid chambers for the fluid of greater amount. In the fluid cartridge in accordance with this aspect of the present invention, the ratio between the fluid of greater amount and the fluid of lesser amount may be 10:1, 2:1 or some other ratio.
These and other features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims and accompanying drawings where:
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The dual fluid cartridge 20 in
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In this embodiment of the dual fluid cartridge 20, the cartridge 20, in addition, includes an outer cartridge wall 52, an inner chamber structure 54, a first piston 56, a second piston 58, a compression wall 60 and a rear piston assembly 62. The outer cartridge wall 52 in this embodiment is a cylindrical wall defining a hollow interior 64. In a preferred embodiment, the outer cartridge wall 52 of the cartridge 20 is an industry standard design that is designed to fit into a standardized piece of dispensing equipment, such as a caulking gun as described above. The outer cartridge wall 52, in this embodiment, at one end defines an opening 66 and has the external threaded outer outlet wall 21 of the dual fluid cartridge 20 at the other end. The inner chamber structure 54 of the cartridge 20 is disposed within the hollow interior 64 of the outer cartridge wall 52. The inner chamber structure 54 includes an inner cartridge wall 68 and, in this embodiment, the inner outlet portion 70 which defines two discharge openings 72, 74. In this embodiment, the opening 72 is for the fluid of greater amount 48 to pass through, and the opening 74 is for the fluid of lesser amount 50 to pass through. The ratio in which the fluids 48, 50 must be dispensed from the cartridge 20 determines the size of the openings 72, 74 relative to one another. In this embodiment, the inner chamber structure 54 snaps into locking engagement with the outer cartridge wall 52 to form the outlet 71. The inner outlet portion 70 of the inner chamber structure 54 has an annular engagement lip 76 formed at the end of the inner outlet portion 70. When the inner chamber structure 54 is inserted into the hollow interior 64 of the outer cartridge wall 52, the inner outlet portion 70 of the inner chamber structure 54 is inserted into the interior of the outer outlet wall 21 of the outer cartridge wall 52. The inner chamber structure 54 is pushed forward within the interior 64 of the outer cartridge wall 52 until the engagement lip 76 pushes through and emerges from the interior of the outer outlet wall 21, engaging the end of the outer outlet wall 21. The inner outlet portion 70, in this embodiment, also has a series of ribs 78 formed along its length. In the assembled configuration, the ribs 78 contact the interior of the outer outlet wall 21. This causes the inner outlet portion 70 to fit snugly against the interior of the outer outlet wall 21, keeping fluid from leaking between the inner outlet portion 70 of the outlet 71 and the outer outlet wall 21.
The first piston 56 of the dual fluid cartridge 20 is disposed within the inner chamber structure 54. The first piston 56 and the inner cartridge wall 68 define the chamber 40 which holds the fluid required in lesser amount 50. The second piston 58 of the dual fluid cartridge 20 is disposed within the cartridge 20 between the exterior of the inner cartridge wall 68 and the interior of the outer cartridge wall 52. In this embodiment, the second piston 58 surrounds the inner cartridge wall 68. The second piston, in conjunction with the exterior of the inner cartridge wall 68 and the interior of the outer cartridge wall 52, defines the chamber 42, which in this embodiment is a first chamber for holding a portion of the fluid required in greater amount 48.
The compression wall 60 is disposed between the inner chamber structure 54 and the rear piston assembly 62. In this embodiment, the compression wall 60 is connected to the inner chamber structure 54 which fixes the compression wall 60 in place. The rear piston assembly 62 and the compression wall 60 define the chamber 44, which in this embodiment is a second chamber for holding the remaining portion of the fluid required in greater amount 48. The delivery channel 46 provides fluid communication between the first and second chambers 42, 44 for the fluid of greater amount 48. The delivery channel 46 defines an entry opening 86 which, in this embodiment, is positioned in the second chamber 44 for the fluid of greater amount 48. The delivery channel 46 also defines an exit 88 which, in this embodiment, opens into the first chamber 42 for the fluid of greater amount 48.
The rear piston assembly 62 includes a rear piston surface 80, a first transmission structure 82 and a second transmission structure 84. In this embodiment, the differing portions 80, 82, 84 of the rear piston assembly are all integral with one another, but this is not necessary. One of ordinary skill in the art would understand that it is possible that each portion of the rear piston assembly 62 could be its own separate structure. In this embodiment, the first transmission structure 82 extends from the rear piston surface 80 of the rear piston assembly 62, passes through the compression wall 60 and is in engagement with the first piston 56. In this embodiment, the second transmission structure 84 extends from the rear piston surface 80 of the rear piston assembly 62, passes snugly between the compression wall 60 and the interior of the outer cartridge wall 52 forming a seal and is in engagement with the second piston 58.
To dispense the fluids from the dual fluid cartridge 20, the rear piston assembly 62 is pressed forward towards the cartridge outlet 71. In the embodiment described, this is done by actuation of the caulking gun plunger 24. As the plunger 24 is actuated forward, in the direction indicated by the arrow in
This fluid discharge and mixing process continues as long as the caulking gun plunger 24 is being actuated and as long as fluids are still left to be dispensed from the dual fluid cartridge 20.
The arrangement of the dual fluid cartridge 20 in
It should be understood that many differing embodiments of the dual fluid cartridge 20 of the present invention may be designed and employed. Referring to
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While the invention has been discussed in terms of certain embodiments, it should be appreciated that the invention is not so limited. The embodiments are explained herein by way of example, and there are numerous modifications, variations and other embodiments that may be employed that would still be within the scope of the present invention.