WO1998040147A1

WO1998040147A1 - Improved water filter cartridge container and method of assembly

Info

Publication number: WO1998040147A1
Application number: PCT/US1997/003717
Authority: WO
Inventors: Michael Trammell; Ralf Schewe
Original assignee: Alamo Water Refiners, Inc.; Plastomer, Inc.
Priority date: 1997-03-10
Filing date: 1997-03-10
Publication date: 1998-09-17
Also published as: AU2201797A

Abstract

An improved water filter cartridge container (10) generally comprising a container body (12) and a container cap (14). Filtration material is placed within the container body and the container cap is then attached to the container body. The container cap is held in place by one of a number of preferred means for mechanical attachment to the container body. A first snap lock configuration involves the insertion of the cylindrical container body walls into a receptive channel (30) formed in the container cap. Both the cylindrical container body walls and the inside of the channel on the container cap incorporate ridges (36, 38) that permit the container cap to snap lock into place on the container body in a manner that prevents removal without damage to the channel and/or the container wall. In a second preferred method of mechanical attachment, the container cap incorporates a lug section (78) insertable into a retention slot (80) formed in the container body wall. Placement of the container cap on the container body involves sliding the lug section to a position adjacent the container wall retention slot and rotating the container cap so that the lug section is held captive by the container wall retention slot. In an alternative embodiment of the present invention, a self-contained flow-through filter cartridge is described with the same snap lockorrotation lock closure mechanisms. Each of the embodiments described in the present invention provides a mechanical closure means to create an improved water filter cartridge container that eliminates the need for sealants, adhesives, or thermal welding mechanisms. The improvements reduce the cost of the filter cartridge container and in one embodiment eliminate the need for an external filter envelope.

Description

Title: IMPROVED WATER FILTER CARTRIDGE CONTAINER AND

METHOD OF ASSEMBLY

BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION The present invention relates generally to methods and devices for the filtration and purification of water. The present invention relates more specifically to methods and devices for economically enclosing water filtration media in replaceable cartridge containers in a manner that permits the flow of water through the media.

2. DESCRIPTION OF THE RELATED ART

Traditionally, water treatment and water purification systems operate through the use of various types of cartridge filtration devices. These cartridge filtration devices come in many configurations and structures. Among the filtration media that are utilized are blow-melted plastic materials, pleated paper or fabric materials, and other hard-packed or loose-packed particulate materials. Various types of containers have been designed to retain and hold these types of filtration media. Generally, these containers are designed to permit the flow of water through an inlet and guide it through the filtration media to an outlet where the treated water may then be utilized.

Currently, filter cartridge containers that are commonly used within the water treatment industry are manufactured using assembly methods that require adhesives, cements, solvents, thermal welding, or other bonding methods that often require a complex sequence of steps and equipment. In these methods and structures, there is generally a main body to the container and a cap or closure that is placed on the main body once the filtration media is inserted. In most instances, the expensive part of the process is the attachment of the cap or closure to the main body of the container.

There are many drawbacks to the current methods for attaching the cap or closure to the main body of the filtration container.

The use of adhesives, cements and solvents or the like introduces foreign substances into the process that could potentially contaminate the water filtration system. It would be desirable to have an attachment means that did not involve any toxic substances that could leave contaminants in the system after the completed manufacturing process . Other methods of attachment such as thermal welding and the like involve highly expensive manufacturing systems that increase the price of the container and the resultant filtration system. It would be desirable to utilize an assembly system that does not involve the use of either toxic cements, sealants or adhesives, and further does not involve complex and expensive assembly systems .

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a water filter cartridge container having a structure that permits the assembly of the container, with filtration material inside, without the use of adhesives, cements, or sealants and without the use of expensive thermal welding systems.

It is a further object of the present invention to provide a water filter cartridge container comprising a container body and a container cap with the cap being fixed to the container body by mechanical attachment without the use of thermal welding or toxic adhesives .

It is a further object of the present invention to provide a water filter cartridge container, assembled from a container body and container cap, wherein the container cap snaps into place on the container body and mechanically adheres to the container body in a manner sufficient to prevent the escape of the filtration material .

It is a further object of the present invention to provide an improved water filter cartridge container wherein the container comprises a container body and a container cap with the container cap locking into place when placed over and rotated on the container body.

It is a further object of the present invention to provide an improved water filter cartridge container comprising a container body and a container cap, wherein the container cap includes an outlet port such that the filter cartridge is self-contained and requires no further enclosures to permit the flow of water therethrough.

In fulfillment of these and other objectives, the present invention provides an improved water filter cartridge container generally comprising a container body and a container cap. Filtration material is placed within the container body and the container cap is then attached to the container body to enclose the filtration material. The container cap is held in place by one of a number of preferred means for mechanical attachment to the container body. A first snap lock configuration involves the insertion of the cylindrical container body walls into a receptive channel formed in the container cap. Both the cylindrical container body walls and the inside of the channel on the container cap incorporate ridges that permit the container cap to snap lock into place on the container body in a manner that prevents removal without damage to the channel and/or the container wall.

In a second preferred method of mechanical attachment, the container cap incorporates a lug section insertable into a retention slot formed in the container body wall. Placement of the container cap on the container body involves sliding the lug section to a position adjacent the container wall retention slot and rotating the container cap so that the lug section is held captive by the container wall retention slot.

In an alternative embodiment of the present invention, a self- contained flow-through filter cartridge is described with the same snap lock or rotation lock closure mechanisms. Each of the embodiments described in the present invention provide a mechanical closure means to create an improved water filter cartridge container that eliminates the need for sealants, adhesives, or thermal welding mechanisms. The improvements reduce the cost of the filter cartridge container and in one embodiment eliminate the need for an external filter envelope. BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a partial cross-sectional view showing the internal construction of a standard water filter cartridge container incorporating the improved snap lock configuration of the present invention. FIG. 2 is a partial cross-sectional view showing an exploded assembly of the improved filter cartridge container shown in Fig. 1.

FIG. 3 is a partial cross-sectional view showing an exploded assembly of an alternative embodiment of the present invention with a rotational locking cap.

FIG. 4 is a partial cross-sectional view showing a second alternative embodiment of the present invention showing a self- contained flow-through filter cartridge with inlet and outlet ports that does not require an additional housing.

DESCRIPTION OF THE PREFERRED EMBODIMENT Reference is first made to Fig. 1 for a brief description of the standard configuration of a water filter cartridge. Cartridge (10) in Fig. 1 is of generally cylindrical construction and is made up primarily of cylindrical body (12) and end cap (14) . Cylinder body (12) defines an internal volume (16) within which filtration media is placed. The water to be purified is permitted to flow in through inlet port (18) into inlet chamber (22) . Screen (20) is snapped into place within cylindrical body (12) and serves to position the filtration material within internal volume (16) . Water flows through screen (20) into the filtration media within internal volume (16) and exits through a plurality of ports (26) in end cap (14) .

Most often, cartridges of the construction shown in Fig. 1 are inserted into a cylindrical envelope (not shown) which captures the purified water that flows from end cap (14) and ducts it off to be used. Cartridge (10) shown in Fig. 1, therefore, is typically inserted into a cylindrical envelope of a size slightly larger than the construction of the cartridge itself. Most often, therefore, replacement of the entire filter cartridge does not involve disconnection of any of the flow lines in the system, but simply involves the removal of the envelope container's lid and the replacement of the entire filter cartridge.

As indicated above, the construction of filter cartridges such as shown in Fig. 1 has previously involved the use of adhesives or thermal welding. Typically, end cap (14) was provided with a sufficient chemical adhesive such that when physically attached to cylindrical body (12) a permanent bond was formed to close the cartridge container. In the present invention shown in Fig. 1, this chemical or thermal bonding is replaced with a mechanical snap lock configuration that sufficiently adheres end cap (14) to container body (12) .

Container body wall (24) terminates in a bayonet structured edge (28) at its lower end, which bayonet structure (28) is insertable into a receiving channel (30) formed in end cap (14) . Receiving channel (30) is peripherally positioned adjacent to portals (26) that permit the flow of water from the cartridge filter. Because a flow of water is expected through end cap (14) , the attachment of end cap (14) to cylindrical walls (24) is sufficiently tight when the mechanical closure disclosed above is made .

Reference is now made to Fig. 2 for an exploded view of the same filter cartridge container shown in Fig. 1. In Fig. 2, the lower end of container body wall (24) is shown in more detail. Bayonet structure (28) is comprised of channel (32) positioned below cap stop (34) and insertion edge (36) . These wall features are received in end cap (14) into channel (30) which is made up of external wall (38) and internal wall (40) . A slight indentation in external wall (38) receives an upper edge of insertion edge (36) which holds the assembly together and prevents the subsequent removal of end cap (14) .

Reference is now made to Fig. 3 for a detailed description of an alternative embodiment of the attachment means for the improved filter cartridge container of the present invention. The upper structure of the cartridge is nearly identical to that disclosed in Figs. 1 and 2. Cartridge (50) is comprised of cylindrical body

(52) and end cap (54) . Cylindrical body (52) defines an internal volume (56) within which filtration media is placed. The water to be purified flows through inlet port (58) into inlet chamber (62) defined by screen (60) separating out and positioning the filtration media. Water then flows through the filtration media and out through portals (66) in end cap (54) .

As opposed to the snap lock configuration shown in Figs. 1 and 2, the embodiment shown in Fig. 3 incorporates a mechanical attachment that involves the insertion and rotation of cylindrical body (52) into a receiving portion of end cap (54) . Rather than a channel, end cap (54) is provided with at least two lugs (78) positioned on the walls (70) on the sides of end cap (54) . These lugs (78) amount to partial ridge sections positioned peripherally about the edge of end cap (54) .

Container body wall (64) is provided with a receiving surface

(72) and a cap stop (74) . In addition, lug slots (80) are defined by raised sections (76) on container body wall (64) . Raised sections (76) define lugs slots (80) and are of a geometry appropriate for the captive reception of lugs (78) . Attachment of end cap (54) to cylindrical body (52) involves the insertion of the cap onto the body at a position where lugs (78) do not encounter raised sections (76) , followed by a rotation of end cap (54) such that lugs (78) slide into and are held captive by lug slots (80) . The length of lug slots (80) nearly matches the length of lugs (78) .

Reference is now made to Fig. 4 for a detailed description of an alternative embodiment to the design shown in Fig. 3. In each case described above (Figs. 1-3), the improved cartridge container was designed to be inserted within a surrounding envelope. In contrast, the embodiment shown in Fig. 4 is a self-contained filter cartridge wherein a flow of fluid enters the cartridge through an inlet port (much as described above) but exits the cartridge through a similarly constructed outlet port.

Cartridge container (100) is comprised of cylindrical body (102) and end cap (104) . These structures define internal volume (106) within which the filtration media is held. Inlet port (108) permits the flow of water into the cartridge by way of inlet chamber (112) and screen (110) . Screen (110) is snapped into place as is well known in the art.

The difference in the container shown in Fig. 4 is that instead of providing a plurality of outlets through the walls of the end cap, a single outlet port is provided for a controlled flow of the purified liquid. End cap (104) in Fig. 4 is attached to cylindrical body (102) in a manner similar to that shown and described above with respect to Fig. 3. In addition to lugs (128) which are insertable into lug slots (130) , an O-ring seal (132) is provided to prevent the unintended flow of fluid from the filter cartridge. In addition, threaded sections (138) on both inlet port (108) and outlet port (136) are provided so as to attached fluid conduits for the inlet and the outlet of the liquid. Screen (134) serves to hold the filtration medium within internal volume (106) of the cartridge container. The structure of end cap (104) is significantly simpler insofar as a single outlet port (136) is provided as opposed to the plurality of outlet ports in the embodiments described above.

Nonetheless, the primarily improvement feature of the embodiment shown in Fig. 4 remains the mechanical locking system that, in conjunction with the O-ring, provides a sufficient seal against the unintended flow of liquid from the container without the use of toxic adhesives or the expense of thermal welding mechanisms.

In general, the above described embodiments provide a versatile set of filter cartridge container structures that permit the easy assembly of filtration cartridges for a number of applications including both enveloped filtration cartridges and in- line filtration devices. In each case, a mechanical means of attachment between the end cap and cartridge container body are described. It is anticipated that a variety of other embodiments showing similar mechanical attachment mechanisms could be anticipated from the present disclosure wherein the same goals of avoiding the use of toxic substances and expensive welding systems are achieved.

Claims

1. A water filter cartridge container for enclosing an amount of water filtration media, said cartridge container comprising: a container body for receiving said filtration media, said container body comprising a generally cylindrical wall, said container body open at a first end of said cylindrical wall and at least partially closed at a second distal end of said cylindrical wall, said second distal end having a means for retaining said filtration media within said container body while permitting a flow of water through said filtration media from without said container body; a container cap for closure of said container body and retention of said filtration media therein, said container cap being generally circular in structure and mateable to said first end of said cylindrical wall, said container cap comprising a circular channel for reception of said first end of said cylindrical wall, said first end of said cylindrical wall further comprising a means for mechanically locking said cylindrical wall into place within said circular channel, said container cap further having means for retaining said filtration media within said container while permitting a flow of water through said filtration media from without said container cap.

2. The water filter cartridge container of Claim 1 wherein said container body and said container cap are constructed of polypropylene material .

3. The water filter cartridge container of Claim 1 wherein said means for retaining said filtration media within said container body defines a plurality of apertures sized to permit the passage of water therethrough and to prevent the passage of said filtration media therethrough.

4. The water filter cartridge container of Claim 1 wherein said means for mechanically locking said cylindrical wall into place within said circular channel comprises a first and a second opposing retention edges, said first retention edge positioned on said cylindrical wall and said second retention edge positioned in said circular channel, said retention edges positioned such that insertion of said cylindrical wall into said circular channel places said retention edges in opposition to each other in a manner that prevents removal of said cylindrical wall from said circular channel .

5. A water filter cartridge container for enclosing an amount of water filtration media, said cartridge container comprising: a container body for receiving said filtration media, said container body comprising a generally cylindrical wall, said container body open at a first end of said cylindrical wall and at least partially closed at a second distal end of said cylindrical wall, said second distal end having a means for retaining said filtration media within said container body while permitting a flow of water through said filtration media from without said container body; a container cap for closure of said container body and retention of said filtration media therein, said container cap being generally circular in structure and mateable to said first end of said cylindrical wall, said container cap comprising at least one retention slot for reception of a matching retention lug on said first end of said cylindrical wall, said retention lug on first end of said cylindrical wall insertable into a first open section of said retention slot and slidable into a second closed section of said retention slot upon rotation of said container cap on said container body, said container cap further having means for retaining said filtration media within said container while permitting a flow of water through said filtration media from without said container cap .

6. The water filter cartridge container of Claim 5 wherein said container body and said container cap are constructed of polypropylene material .

7. The water filter cartridge container of Claim 5 wherein said means for retaining said filtration media within said container body defines a plurality of apertures sized to permit the passage of water therethrough and to prevent the passage of said filtration media therethrough.

8. A method for manufacturing a water filter cartridge, said method comprising the steps of : providing a container body having a generally cylindrical wall, said container body open at a first end of said cylindrical wall and at least partially closed at a second distal end of said cylindrical wall; inserting a quantity of filtration media into said container body, said filtration media being retained within said container body, said partially closed second end of said cylindrical wall permitting a flow of water through said filtration material from without said container body; providing a container cap generally circular in structure and mateable to said first end of said cylindrical wall of said container body, said container cap comprising a circular channel; covering said first open end of said cylindrical wall with said container cap by inserting said cylindrical wall into said circular channel; and locking said container cap onto said container body through a mechanical mating of structures on said container body with structures on said container cap.