BACKGROUND
Various storage systems are known for storing and preserving food items. For example, flexible bags made from pliable plastic material have been used to store food items, either temporarily as in the case of packaging snacks or long term as in the case of freezer storage. Plastic storage bags are utilized in both the commercial packaging and distribution of food items and domestic at-home packaging. Such plastic storage bags typically include a flexible or pliable thermoplastic sidewalls arranged to delineate an interior volume into which food items can be received and an opening for accessing the interior volume. To better contain the stored food items and to help preserve those items, the storage bags are often provided with a closure mechanism or closure arrangement for sealing closed the opening. It is desirable that the closure mechanism or arrangement be simple to employ and, in some instances, be reusable to allow for repeated use of the bag.
BRIEF SUMMARY
A flexible, thermoplastic storage bag may include a closure arrangement that facilitates reusability and vacuum storage. The storage bag can have overlaying first and second sidewalls that provide an interior volume that is accessible via an opening. In one aspect, the storage bag may include a first closure mechanism such as first and second interlocking fastening strips that extend proximate the opening. The fastening strips can interlockingly engage to close the opening and seal the interior volume. Furthermore, the interlocking fastening strips can be designed to engage in a releasable and reusable fashion to provide for repeated use of the storage bag.
The storage bag can also include a second closure mechanism in the form of a peel seal that can provide a more permanent or air-tight seal. The peel seal can be any suitable peel seal including a heat seal or a light tack adhesive seal. The peel seal can be provided proximate the opening and the first closure mechanism or can be provided proximate a second opening that is intended to be more permanently closed. In a particular aspect, the peel seal can be configured for repeated use to further the reusability of the storage bag.
An advantage of the storage bag is that it provides a bag with both a simple, reusable closure mechanism like the interlocking fastening strips and a more permanent and airtight closure mechanism like the peel seal. A related advantage is that the bag facilitates both reusability and vacuum storage. These and other features and advantages will be readily apparent from the following drawings and the foregoing detailed description of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a storage bag which includes a first closure mechanism and a second closure mechanism.
FIG. 2 is a cross sectional view taken along line A-A of FIG. 1 that illustrates the first and second closure mechanisms in a disengaged or opened state.
FIG. 3 is a cross sectional view taken along line A-A of FIG. 1 that illustrates the first and second closure mechanisms in an engaged or closed state.
FIG. 4 is a detailed view of the area indicated by circle B-B of FIG. 2 that illustrates one embodiment of interlocking fastening strips that provide the first closure mechanism wherein the fastening strips are in a disengaged position.
FIG. 5 is a detailed view of the fastening strips of FIG. 4 that illustrates the fastening strips in an engaged position.
FIG. 6 is a perspective view of the storage bag of FIG. 1 inserted into a device intended for domestic operation that can evacuate and seal the storage bag.
FIG. 7 is a perspective view of another embodiment of a storage bag having first and second closure mechanisms and which utilizes a one-way valve element to evacuate the interior volume, the storage bag further shown in relation to a handheld evacuation device.
FIG. 8 is a detailed view of the area indicated by circle C-C of FIG. 1 that illustrates the inner surface of the bag sidewall that is provided with a textured portion.
FIG. 9 is a detailed view of the area indicated by circle C-C of FIG. 1 that illustrates another embodiment of a textured portion formed as a plurality of grooves disposed into an inner surface of the bag sidewall.
FIG. 10 is a detailed view of the area indicated by circle C-C of FIG. 1 that illustrates another embodiment of a textured portion formed as a plurality of protrusions disposed on an inner surface of the bag sidewall.
FIG. 11 is a perspective view of another embodiment of a thermoplastic storage bag having first and second closure mechanisms located on opposite ends of the bag.
FIG. 12 is a detailed view of the area similar to that indicated by circle B-B of FIG. 2 that illustrates another embodiment of interlocking fastening strips in the form of “profile style” fastening strips.
FIG. 13 is a detailed view of the area similar to that indicated by circle B-B of FIG. 2 that illustrates another embodiment of interlocking fastening strips in the form of “rib-and-groove” or “arrowhead” style fastening strips.
FIG. 14 is a front perspective view of an embodiment of a one-way valve element for use with flexible bags of the invention.
FIG. 15 is a rear perspective view of the one-way valve element of FIG. 14.
FIG. 16 is a cross-sectional view through the one-way valve element, as taken along line 16-16 of FIG. 14.
FIG. 17 is an exploded view of another embodiment of the one-way valve element for attachment to the flexible bag.
FIG. 18 is an exploded view of another embodiment of the one-way valve element for attachment to the flexible bag.
While the invention will be described in connection with certain embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.
DESCRIPTION OF THE EMBODIMENTS
FIG. 1 illustrates a thermoplastic storage bag 100 that can be used for receiving and storing food items. The storage bag 100 includes a first sidewall 102 and an opposing second sidewall 104 overlaying the first sidewall 102 to provide an internal volume 106. Accordingly, the first and second sidewall 102, 104 each includes a respective first inner surface 108 and an opposing second inner surface 109. The first and second sidewalls 102, 104 can be made from flexible webs of thermoplastic material such as, for example, polyethylene. The webs may be monolayer or multilayer films that are typically used for food storage. Multilayer films may be laminations or coextrusions. Resins may include polyethylene including high density polyethylene (HDPE), low density polyethylene (LDPE), and linear low density polyethylene (LLDPE). Other materials include nylon, ethylene vinyl alcohol (EVOH), polypropylene (PP), ethylene vinyl acetate (EVA), polyester, ionomers or metallized films. Examples of coextruded multilayer films suitable for the manufacturing of storage bags include layered combinations such as HDPE/tie-layer/EVOH/tie-layer/LDPE or nylon/tie-layer/LDPE. One embodiment of the multilayer film may include a layer of a blend of LDPE/PB-1 coextruded over part or all of the film surface next to the LDPE. By having a layer of LDPE/PB-1, a strong perimeter seal can be made while still allowing for a peelable seal across the top by varying the temperature and pressure.
The first and second sidewalls 102, 104 are joined together along a first side edge 110, a parallel second side edge 112, and a closed bottom edge 114 that extends perpendicularly between the first and second side edges. The edges of the first and second sidewalls 102, 104 can be joined together by a heat sealing operation. To access the internal volume 106, the portions of the first and second sidewalls 102, 104 extending along an open top edge 116 remain un-joined. Due to the four orthogonal edges, the flexible bag 100 has a generally rectangular shape. However, it will be appreciated that in other embodiments, the bag can have any suitable shape resulting from any number and orientation of sidewalls and edges.
To close the open top edge 116 after food items have been inserted into the bag 100, the bag can include a first closure mechanism such as first and second interlocking fastening strips 120, 122. The fastening strips 120, 122 can be made from extruded thermoplastic material and are joined to the bag 100 proximate the open top edge 116. More specifically, the first fastening strip 120 can be joined to the inner surface 108 of the first sidewall 102 and the second fastening strip 122 can be joined to the inner surface 109 of the second sidewall 104. The first and second fastening strips can engage and release with each other to allow for repeated opening and closing of the storage bag. For example, FIG. 2 shows the first and second fastening strips 120, 122 in a disengaged arrangement in which the interior volume 106 can be accessed via the opened top edge 116. FIG. 3 shows the first and second fastening strips 120, 122 in engaged with each other such that the interior volume 106 is no longer accessible.
To enable the first and second fastening strips 120, 122 to releasably interlock, a respective first and second closure profile may be formed continuously along the length of each strip. The first and second closure profiles may have a complementary shape such that they can engage or mate with each other in an interlocking manner. Referring to FIG. 4, there is illustrated one example of interlocking fastening strips that can be used with the storage bag. The illustrated fastening strips 120, 122 may be referred to as “U-channel” style fastening strips. The first fastening strip 120 is formed with a male closure profile 130 that projects from a flat base member 140 that may be adapted to be attached to an inner surface of the first sidewall. The projecting male closure profile 130 may include first and second projections 142, 144 that are generally parallel to and spaced-apart from each other a first distance. Formed at the distal tip of each projection 142, 144 are respective first and second hooks or barbs 146, 148 that are generally directed back toward the base member 140. Moreover, the barbs 146, 148 are directed oppositely or away from each other. The distal most surface of the barbs 146, 148 are generally shaped or rounded to provide respective first and second guide surfaces 150, 152. It will be appreciated that the male closure profile 130 including the first and second projections 142, 144 may extend substantially over the entire length of the first fastening strip 120.
The second fastening strip 122 of the pair illustrated in FIG. 4 may be formed as a female closure profile 132 that likewise projects from a flat base member 160 that may be adapted to be attached to an inner surface of the second sidewall. The projecting female closure profile 132 may include first and second projections 162, 164 that are parallel to and spaced-apart from each other a second distance. The second distance should be slightly greater than the first distance so that the female closure profile 132 is adapted to receive the projections 142, 144 of the male closure profile 130. Formed at the distal tip of each projection 162, 164 of the female closure profile 132 are respective first and second hooks or barbs 166, 168 that are generally directed back toward the base member 160. Furthermore, the barbs 166, 168 are facing and directed towards each other. The distal most surface of the barbs 166, 168 are generally shaped or rounded to provide respective first and second guide surfaces 170, 172. Additionally, the female closure profile 132 may also include a flange 174 projecting from the base member 160 approximately midway between the first and second projections 162, 164 that extends to approximately the same height as the first and second projections. In other embodiments, the closure profile may not include the flange 174. It will be appreciated that the female closure profile 132 including the first and second projections 162, 164 may extend substantially over the entire length of the second fastening strip 122.
To engage the male and female closure profiles 130, 132 as illustrated in FIG. 5, the first and second interlocking fastening strips 120, 122 are pressed toward each other until the guide surface 150, 152 on the male projections 142, 144 contact the guide surfaces 170, 172 on the female projections 162, 164. Due to the flexible characteristic of the thermoplastic fastening strip material, contact between the guide surfaces causes the male projections 142, 144 to flex inwardly and the female projections 162, 164 to flex outwardly. The barbs 146, 148 on the male projections 142, 144 and the barbs 166, 168 on the female projections 162, 164 can thereby slide past each other. Once past each other, the flexible characteristic of the fastening strip material causes the male and female projections to flex back moving the barbs into an interlocking engagement with each other. Furthermore, because of the flexible and resilient characteristics of the fastening strip material, a sufficient, oppositely applied pulling force can disengage the male and female closure profiles. In various embodiments, the fastening strips may also use a slider to engage and disengage the fastening strips as noted herein.
As illustrated in FIG. 1, to improve closing of the open top edge 116 of the storage bag 100, the bag can include a secondary closure mechanism in the form of a peel seal 180. The peel seal 180 can include a first component 182 that extends along the inner surface 108 of the first sidewall 102 proximate the open top edge 116 and a second component 184 that extends along the inner surface 109 of the second sidewall 104. In the illustrated embodiment, the peel seal 180 is located between and parallel to the top edge 116 and the interlocking strips 120, 122 of the first closure mechanism. However, in other embodiments, the peel seal can be located elsewhere on the bag.
The peel seal can be any suitable peel seal including a heat activated peel seal or a light tack adhesive peel seal. For example, referring to FIG. 2, the first and second components 182, 184 of a heat activated peel seal 180 are normally distinct or separated components having a rigid or semi-rigid characteristic. Referring to FIG. 3, when the first and second portions 182, 184 of the peel seal 180 are pressed adjacent to each other and localized heating is applied, the first and second components may partially liquefy and merge or unite together. A heating element such as electrically conductive wires or gripping jaws can be applied against the first and second sidewalls 102, 104 proximate the peel seal 180. To enable the first and second portions 182, 184 to unite when heat is applied, the components of the peel seal can be made from polybutene, polyethylene, ethylene vinyl acetate, polypropylene, ionomers, and/or acid copolymers. Examples of coextruded multilayer films may include layered combinations such as HDPE/tie-layer/EVOH/tie-layer/LDPE, HDPE/tie-layer/EVOH/tie-layer/LDPE/LDPE+20% PB-1, LLDPE/LDPE+20% PB-1, nylon/tie-layer/LDPE, nylon/tie-layer/LDPE+20% PB-1, or nylon/tie-layer/LDPE/LDPE+20% PB-1. The PB-1 can be dry blended with the LDPE and extruded as part of the coextrusion process. In one embodiment, the blending level may be 20% PB-1 and 80% LDPE. A suitable PB-1 resin may be Bassell PB-1 1600M. The range for blending PB-1 may be 10-30 wt %. The PB-1 could also be blended with polyolefins or polyolefin copolymers including ionomers, ethylene vinyl acetate, LLDPE, or HDPE. The peal seal may include the peal seals disclosed in U.S. Pat. No. 4,870,134, 4,944,409, or 5,547,752 which are incorporated herein in their entirety. In one embodiment, the peal seal 180 may be applied or coextruded as a strip, for example, as shown in FIG. 2. The strip may be located on one sidewall or both sidewalls. In one embodiment, the strip may be about one inch (2.54 cm) in width. In another embodiment, the sidewalls 102, 104 of the bag may be made of a multilayer film and the fastening strips 120, 122 may be attached to the sidewalls, for example, as shown in FIG. 4. One sidewall or both sidewalls may be made of a multilayer film.
In the embodiments in which the peel seal 180 is, for example, a light tack adhesive seal, no heating need be applied to co join the first and second portions 182, 184. The adhesive seal may be a hot melt adhesive. Hot melt adhesives may include a base polymer and various components such as waxes, tackifiers, oils, and fillers to create the desired level of tack. Examples of polymers include ethylene vinyl acetate, poly alpha-olefins, styrene block copolymers, polyamides, polyurethanes, and polyethylene. Another example of a pressure sensitive adhesive includes aqueous or latex-base emulsions. In one embodiment, the adhesive seal may be the adhesive seal disclosed in U.S. Pat. No. 5,454,909. In another embodiment, the adhesive seal may be the adhesive seal disclosed in EP 874,765, such as, Fuller HL-2115X. The adhesive may be applied as a strip to one sidewall or to both sidewalls. In one embodiment, the adhesive may be a strip of about 1 inch (2.54 cm) in width.
The peel seal 180 can provide a more permanent closure of the open top edge 116 than the first closure mechanism alone. The bonding or uniting of the materials of the first and second components 182, 184 is preferably sufficiently weak so that the peel seal 180 can be opened. Thus, a sufficient, oppositely applied pulling force can break the peel seal 180 to open the storage bag 100 without corresponding stretching or tearing of the bag sidewalls. The peal seal can be applied by spray coating, by slot coating, or by co-extrusion as part of the bag.
In various embodiments, the peel seal can be configured for repeated use to further the reusability of the storage bag. For example, where the peel seal is a heat seal, the material selected for the components can be susceptible to multiple applications of heat to repeatedly join or unite together. Examples of materials suitable for heat seals capable of repeat activation include blends of polybutene-1 with a polyolefin-based resin such as polyethylene, ethylene vinyl acetate, polypropylene, ionomers or acid copolymers. Polybutene-1 can be in the minor phase. In other embodiments, the height dimension of the peel seal components, indicated by reference number 186 in FIG. 1, can be sufficiently large so that a heating element can be applied multiple times to create heat seals at a number of different locations over the height of the components. In the embodiments in which the peel seal is a light tack adhesive seal, the adhesive can be formulated to repeatedly adhere and disassociate from itself. Hence, the peel seal, whether heat activated or light tack adhesive, can be a re-sealable seal and thereby further improving reusability of the storage bag.
The storage bag 100 can be used with various vacuum systems to evacuate the interior volume 106 and thereby help preserve the stored food items. For example, referring to FIG. 6, there is illustrated an evacuation apparatus 200 of the type designed for domestic in-home use and which is particularly configured to sit on a countertop or tabletop. The device 200 includes a base 202 and a pivoting lid 204 which can be hingedly attached to the base 202. A vacuum chamber 206 maybe provided between the base 202 and lid 204. When the lid 204 is pivotally opened with respect to the base 202, the open top edge 116 of a storage bag 100 can be inserted into the evacuation device 200. The lid 204 is then pivoted to a closed position adjacent to the base 202 and thereby traps the bag 100 in the vacuum chamber 206. The device then removes air from the vacuum chamber 206 which also draws air from the interior volume of the bag out through the open top edge.
To seal closed the opening in those embodiments in which the bag 100 has a heat produced peel seal 180, the evacuation device 200 can include first and second heating elements 210, 212 that are attached respectively to the base 202 and lid 204. The device can include a shoulder or similar feature against which the bag can be placed to align the peel seal 180 with the first and second heating elements 210, 212. Once evacuation of the interior volume has occurred, the heating elements 210, 212 are activated causing the first and second components of the peel seal 180 to unite and thereby sealing the bag 100. The lid 204 can then be pivoted open and the evacuated and sealed bag removed from the evacuation device thereby facilitating long term storage and preservation of any stored food items. The food items can be accessed by breaking open the peel seal 180, and can be subsequently stored for shorter durations using the interlocking closing strips 120, 122.
Referring to FIG. 7, there is illustrated another embodiment of a storage bag 300 which utilizes a one-way valve element 330 to facilitate evacuation. In addition to the valve element 330, the storage bag 300 includes first and second sidewalls 302, 304 that are joined together to provide an interior volume 306 which can be accessed through an open top edge 316. To seal closed the open top edge 316, the bag includes a first closure mechanism that can be in the form of first and second interlocking fastening strips 320, 322 that extend proximately along the open top edge. In addition to the fastening strips, to further improve closing of the open top end 316 the bag can include a second closure mechanism that can be in the form of a peel seal 380. The peel seal also extends proximately along the open top edge 316.
To remove air that can become trapped in the interior volume 306 after one or both of the closure mechanisms are engaged, the air is drawn or directed out the one-way valve element 330. In an embodiment, the valve element 330 can be interfaced with an evacuation device to draw air out. For example, as illustrated in FIG. 7, the evacuation device 390 can be configured as a hand held device having a nozzle 392 formed at a forward end and a rearward situated handle 394. Located inside the device is an air flow generating unit that draws air into the nozzle 392. To facilitate evacuation of a storage bag 300, the nozzle 392 is placed adjacent the first sidewall 302 generally about the valve element 330 and the air flow generating unit is activated to withdraw air. In other embodiments, to remove air, the sidewalls 302, 304 can be compressed together to force air out of the valve element. As will be appreciated, the valve element can be included with other types and styles of storage bags disclosed herein.
Referring back to FIG. 1, in various embodiments, to facilitate and improve evacuation of the storage bag 100, the bag can include a textured portion 400 formed on the inner surface of one or both of the sidewalls 102, 104. The textured portion 400 provides a plurality of raised peaks or points that are directed outward of the sidewall. The voids that exist between the raised peaks in the textured portion can provide airflow paths or channels. When the storage bag is being evacuated and the first and second sidewalls 102, 104 collapse adjacent to each other, air can still move and be withdrawn via the voids. Hence, the peaks and voids facilitate more complete evacuation of the storage bag. The textured portion can be formed by embossing the sidewall material or by providing a separate web or film with a textured pattern formed thereon and attaching that web to the sidewall. The textured portion can be utilized with a bag intended to be evacuated with device like that illustrated in FIG. 6 and with a bag having a valve element such as discussed with respect to FIG. 7.
In the embodiment illustrated in FIG. 8, the peaks 402 can be formed along the crests of a first plurality of raised ridges 404 that extend along the inner surface. The first plurality of ridges 404 can be arranged parallel to and spaced-apart from each other. The recesses 406 are therefore defined within the clearances between the ridges 402. In the illustrated embodiment, a second plurality of parallel ridges 410 extends along the inner surface normal to and intersecting the first plurality of ridges 410 to form a grid-like pattern. In another embodiment, the recesses can be formed within a grid-like pattern of grooves disposed into the inner surface, thus forming the raised peaks as a series of protuberances separated by the grooves. For example, in the embodiment illustrated in FIG. 9, a first and a second plurality of grooves 420,422 are disposed into the textured portion 400 and may be arranged orthogonally to each other. The grooves 420, 422 define a plurality of raised portions 424 that are square in shape. It will be appreciated that air can communicate along the grooves 420, 422 between the raised portions 424 even after the sidewalls have been collapsed together. In another embodiment illustrated in FIG. 10, the textured portion 400 can include protuberances 430 having smaller, circular shapes that are randomly dispersed along the inner surface and that are segregated from each other by arbitrarily-shaped recessed spaces 432 therebetween. Of course, the textured portion can have any other suitable shape, such as diamond-shaped ridges or grooves, horizontally arranged ridges or grooves, vertically arranged ridges or grooves, patterned or random curved-shaped ridges or grooves, etc.
Referring to FIG. 11, there is illustrated a storage bag 500 that includes two openings for accessing the interior volume 506. More particularly, the storage bag 500 can have a first rectangular sidewall 502 overlaying and joined to a corresponding second sidewall 504 to provide the interior volume 506 therebetween. Both of the sidewalls can be manufactured from a suitable flexible, thermoplastic material such as polyethylene. The sidewalls 502, 504 are joined together along a first side edge 510 and parallel second side edge 512. However, in the present embodiment, the bottom edge 514 and oppositely located top edge 516 remain unsealed so that the bag 500 has a generally tubular configuration.
To close the interior volume 506 after food items have been inserted, a first closure mechanism that can be in the form of first and second interlocking closure strips 520, 522 extends proximately along the open top edge 516. Additionally, a second closure mechanism that can be in the form of a peel seal 580 can be provided extending proximately along the open bottom edge 514. The peel seal 580 can be a heat activated peel seal or can comprise light tack adhesive material that adheres the sidewalls 502, 504 together along the bottom edge 514. To facilitate the reusability of the storage bag, the peel seal can be opened and can be used for multiple uses.
Food items can be inserted into the storage bag through either the open top end 516 or the open bottom end 514. The first closure mechanism can then be closed by pressing the interlocking fastening strips 520, 522 together while the second closure mechanism can be closed by application of heat to the heat activated peel seal or by pressing the light tack adhesive material together. In those embodiments in which the peel seal is heat activated, a device such as the one described in reference to FIG. 6, which is also capable of evacuating the storage bag, can be used to activate the peel seal. The stored food items can later be accessed either by breaking open the peel seal or by disengaging the interlocking fastening strips. In various embodiments, the storage bag can include a textured portion to facilitate evacuation and/or a valve element.
The above-described storage bags can include various different types of closure mechanisms to seal closed the interior volume. For example, referring to FIG. 12, there is illustrated another embodiment of interlocking fastening strips, such as those disclosed and described in U.S. Pat. No. 5,664,299, herein incorporated by reference in its entirety, that can be employed as the first closure mechanism. The fastening strips may be referred to as “profile” style fastening strips. The interlocking fastening strips 602, 604, may include a first closure profile 610 projecting from a base member 620 of the first fastening strip 602 adapted to engage a corresponding second closure profile 612 projecting from a base member 622 of the second fastening strip 604. The first and second closure profiles 610, 612 of the fastening strips 602, 604 can be made from any suitable, semi-flexible thermoplastic material and can be manufactured by, for example an extrusion process.
The first closure profile 610 includes a first pair of projections 624, 626 projecting from the base member 620 that are parallel and spaced-apart from each other a first distance. Formed on the distal ends of each of the first projections 624, 626 are respective first hook-like barbs 630, 632 which are pointed generally back toward the base member 620. Moreover, the projections are shaped so that the barbs are arranged in the same direction. The distal most surface of the first projections are generally rounded or shaped to provide first guide surfaces 634, 636.
The second closure profile 612 also includes a pair of second projections 640, 642 projecting from the base member 622 and that are parallel and spaced-apart from each other a second distance. The second distance between the second projections 640, 642 dimensionally corresponds to the first distance between the first projections 624, 626. Formed on the distal ends of the second projection 640, 642 are respective second hook-like barbs 644, 646 which are generally pointed back toward the base member 622. Moreover, the second projections 640, 642 are shaped so that the second barbs are arranged in the same direction and opposite the direction of the first barbs 630, 632. The distal most surfaces of the second projections are generally rounded or shaped to provide second guide surfaces 650, 652.
To engage the first and second closure profiles of FIG. 12, the first and second fastening strips 602, 604 are pressed together so that the first projections 624, 626 abut the correspondingly spaced-apart second projections 640, 642. Particularly, the first guide surfaces 634, 636 contact the second guide surfaces 650, 652 causing the first projections 624, 626 and second projections 640, 642 to flex such that the first barbs 630, 632 and oppositely directed second barbs 644, 646 slide about each other and engage. Hence, the first and second fastening strips 602, 604 are hooked together. To disengage the first and second fastening strips 602, 604, a sufficient pulling force is applied which causes the flexible projections to displace and release each other.
Referring to FIG. 13, there is illustrated in cross-section fastening strips 702, 704 such as those disclosed in U.S. Pat. No. 3,806,998, herein incorporated by reference in its entirety. These fastening strips may be referred to as “arrow-head” or “rib and groove” style fastening strips. The first fastening strip 702 may have a projecting head portion 720 extending from a flat base member 722. The head portion 720 includes a mushroom-shaped head 724 that is located at the end of a reduced neck portion 726 that is connected to the base member 722. The second fastening strip 704 may include a base member 732 and a C-shaped groove portion 730. The projecting head portion 720 of the first fastening strip 702 is receivable in the groove portion 730 of the second fastening strip 704. Through this arrangement, the fastening strips 702, 704 are adapted to be interlockingly engaged when pressed together and separated by being forcibly pulled apart.
One embodiment of a one way valve element is shown in FIGS. 14, 15, and 16. The one-way valve element 800 can include a rigid valve body 810 that cooperates with a movable disk 812 to open and close the valve element. The valve body 810 includes a circular flange portion 814 extending between parallel first and second flange faces 820, 822. Concentric to the flange portion 814 and projecting from the second flange face 822 is a circular boss portion 818 which terminates in a planar boss face 824 that is parallel to the first and second flange faces. The circular boss portion 818 is smaller in diameter than the flange portion 814 so that the outermost annular rim of the second flange face 822 remains exposed. The valve body 810 can be made from any suitable material such as a moldable thermoplastic material like nylon, HDPE, high impact polystyrene (HIPS), polycarbonates (PC), and the like.
Disposed concentrically into the valve body 810 is a counter-bore 828. The counter-bore 828 extends from the first flange face 820 part way towards the boss face 824. The counter-bore 828 defines a cylindrical bore wall 830. Because it extends only part way toward the boss face 824, the counter-bore 828 forms within the valve body 810 a preferably planar valve seat 832. To establish fluid communication across the valve body 810, there is disposed through the valve seat 832 at least one aperture 834. In fact, in the illustrated embodiment, a plurality of apertures 834 are arranged concentrically and spaced inwardly from the cylindrical bore wall 830.
To cooperatively accommodate the movable disk 812, the disk is inserted into the counter-bore 828. Accordingly, the disk 812 is preferably smaller in diameter than the counter-bore 828 and has a thickness as measured between a first disk face 840 and a second disk face 842 that is substantially less than the length of the counter-bore 828 between the first flange face 820 and the valve seat 832. To retain the disk 812 within the counter-bore 828, there is formed proximate to the first flange face 820 a plurality of radially inward extending fingers 844. The disk 812 can be made from any suitable material such, as for example, a resilient elastomer.
Referring to FIG. 16, when the disk 812 within the counter-bore 828 is moved adjacent to the fingers 844, the valve element 800 is in its open configuration allowing air to communicate between the first flange face 820 and the boss face 824. However, when the disk 812 is adjacent the valve seat 832 thereby covering the apertures 834, the valve element 800 is in its closed configuration. To assist in sealing the disk 812 over the apertures 834, a sealing liquid can be applied to the valve seat 832. Furthermore, a foam or other resilient member may be placed in the counter-bore 828 to provide a tight fit of the disk 812 and the valve seat 832 in the closed position.
To attach the valve element 800 to the first sidewall, referring to FIG. 15, an adhesive can be applied to the exposed annular rim portion of the second flange face 822. The valve element 800 can then be placed adjacent the exterior surface of the first sidewall with the boss portion 818 being received through the hole disposed into the sidewall and thereby pass into the internal volume. Of course, in other embodiments, adhesive can be placed on other portions of the valve element, such as the first flange face, prior to attachment to the sidewall.
In other embodiments, the one-way valve element can have a different construction. As illustrated in FIG. 17, a flexible one-way valve element 910 can include a flexible, circular base layer 912 that cooperates with a correspondingly circular shaped, resilient top layer 914 to open and close the valve element. The top and bottom layers can be made from any suitable material such as, for example, a flexible thermoplastic film. Disposed through the center of the base layer 912 is an aperture 916, thus providing the base layer with an annular shape. The top layer 914 is placed over and adhered to the base layer 912 by two parallel strips of adhesive 918 that extend along either side of the aperture 916, thereby covering the aperture with the top layer and forming a channel. The base layer 912 is then adhered by a ring of adhesive 920 to the flexible bag 900 so as to cover the hole 908 disposed through the first sidewall 902.
When the sidewalls 902, 904 of the bag 900 are compressed together, such as by using an evacuation device, air from the internal volume 906 will pass through the hole 908 and the aperture 916 thereby partially displacing the top layer 914 from the base layer 912. The air can then pass along the channel formed between the adhesive strips 918 and escape to the environment. After the evacuation of air from the internal volume, the resilient top layer 914 will return to its prior configuration covering and sealing the aperture 916. The valve element 910 may also contain a viscous material such as an oil, grease, or lubricant between the two layers in order to prevent air from reentering the bag. In an embodiment, base layer 912 may also be a rigid sheet material.
Illustrated in FIG. 18 is another embodiment of the valve element 1010 that can be attached to the flexible plastic bag 1000. The valve element 1010 is a rectangular piece of flexible thermoplastic film that includes a first end 1012 and a second end 1014. The valve element 1010 is attached to the first sidewall 1002 so as to cover and seal a hole 1008 disposed through the first sidewall. The valve element 1010 can be attached to the sidewall 1002 by patches of adhesive 1018 placed on either side of the hole 1008 so as to correspond to the first and second ends 1012, 1014. When the sidewalls 1002, 1004 of the flexible bag 1000 are collapsed together, air from the internal volume 1006 displaces the flexible valve element 1010 so as to unseal the hole 1008. After evacuation of air from the internal volume 1006, the valve element 1020 will again cover and seal the hole 1008.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventor(s) for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor(s) expect skilled artisans to employ such variations as appropriate, and the inventor(s) intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
Patent Application
20100205909
