BACKGROUND OF THE INVENTION The use of closure devices for fastening storage containers, including plastic bags, is generally known.

Furthermore, the manufacture of closure devices made of plastic materials is generally known to those skilled in the art, as demonstrated by the numerous patents in this area.

A particularly well-known use for closure devices is in connection with flexible storage containers, such as plastic bags. In some instances, the closure device and the associated container are formed from thermoplastic materials, and the closure device and the sidewalls of the container are integrally formed by extrusion as a single piece. Alternatively, the closure device and sidewalls of the container may be formed as separate pieces and then connected by heat sealing or any other suitable connecting process. In either event, such closure devices are particularly useful in providing a closure means for retaining matter within the bag.

Conventional closure devices typically utilize mating fastening strips or closure elements, which are used to selectively seal the bag. In addition, sliders may be provided for use in opening and closing the fastening strips. The sliders may include a separator which extends at least partially between the fastening strips. When the slider is moved in the appropriate direction, the separator divides the fastening strips and opens the bag.

SUMMARY OF THE INVENTION According to the teachings of the present invention, the closure device includes interlocking fastening strips disposed along respective edge portions of the opposing sidewalls. The closure device also includes a slider slidably disposed on the interlocking fastening strips for facilitating the occlusion and deocclusion of the fastening strips when moved towards first and second ends of the fastening strips. The slider includes a pair of shoulders that are disposed at the bottom and near the center of the side portions of the slider.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a container according to the present invention in the form of a plastic bag; Fig. 2 is a front view of an embodiment of a slider according to the present invention ; Fig. 3 is a side view of the slider in Fig. 2; Fig. 4 is a rear view of the slider in Fig. 2; Fig. 5 is a top view of the slider in Fig. 2 ; Fig. 6 is a bottom view of the slider in Fig. 2 ;

Fig. 7 is a partial front view of the container in Fig. 1 ; Fig. 8 is a cross-sectional view taken at line 8-8 in Fig. 5; Fig. 9 is a cross-sectional view taken at line 9-9 in Fig. 5 ; Fig. 10 is a cross-sectional view taken at line 10-10 in Fig. 5 ; Fig. 11 is a cross-sectional view of fastening strips and slider; Fig. 12 is a cross-sectional view of another embodiment of fastening strips and slider; Fig. 13 is a cross-sectional view of another embodiment of fastening strips and slider; and Fig. 14 is a cross-sectional view of another embodiment of fastening strips and slider.

DESCRIPTION OF THE EMBODIMENTS Fig. 1 illustrates an embodiment of a container in the form of a plastic bag 120 having a salable closure device 121. The bag 120 includes a first sidewall 122 and a second sidewall 123 joined at seams 125,126 to define a compartment accessible through the open top end but salable by means of the closure device 121. The closure device 121 includes first and second fastening strips 130, 131 and a slider 132.

The fastening strips 130,131 and the slider 132 have a longitudinal X axis 102, a transverse Y axis 104 and a vertical Z axis 106. The transverse Y axis 104 is perpendicular to the longitudinal X axis 102. The vertical Z axis 106 is perpendicular to the longitudinal X axis 102 and the vertical Z axis 106 is perpendicular to the transverse Y axis 104.

The fastening strips 130,131 are adapted to be interlocked between a first end and a second end. The slider 132 is mounted onto the fastening strips 130,131 so that the slider 132 is restrained from being removed from the fastening strips 130,131 but free to slide along the X axis 102. The slider 132 engages the fastening strips 130,131 so that when the slider 132 moves in an occlusion direction 114, the fastening strips 130,131 interlock and the bag 120 is sealed, and when the slider 132 moves in a deocclusion direction 116, the fastening strips 130,131 separate and the bag 120 is open.

Figs. 2-9 illustrate multiple views of a slider 132 that may be used with a closure device. The slider includes first and second top portions 140,141. The first top portion 140 includes a separator 133 that extends downward from the top portion. The separator 133 may be triangular in shape and may have a narrower first end 134 and a wider second end 135. In use, the narrower first end of the separator 134 engages the fastening strips 130,131. As the slider is moved in the deocclusion direction, the wider second end of the separator 135 deoccludes the fastening strips 130,131.

The slider 132 additionally includes first and second side portions 142,144 that merge into the first

and second top portions 140,141. The first side portion 142 includes a first shoulder 146 that is disposed near the bottom edge of the first side portion 142 and near the center of the first side portion 142. The second side portion 144 includes a second shoulder 148 disposed near the bottom edge of the second side portion 144 and near the center of the second side portion 144. The second shoulder 148 opposes the first shoulder 146. The first and second shoulders 146,148 include angled portions 147,149 that angle downwards and outwards, creating a v-shaped gap. The v-shaped gap guides the fastening strips 130,131 into the slider 132 upon attaching the slider 132 to the closure device. The shoulders 146,148 additionally prevent the slider 132 from being disengaged from the fastening strips 130,131 in the Z axis 106.

The first top portion 140 additionally includes first and second occlusion members 150,154 that extend downward along the first and second side portions 142, 144. The occlusion members 150,154 facilitate the occlusion of the fastening strips 130,131 by applying pressure along the fastening strips 130,131 forcing them to occlude. Additionally, the occlusion members 150,154 include angled portions 151,155 that angle downwards and outwards, creating a v-shape similar to that created by the shoulders. The v-shape guides the fastening strips 130,131 into the occlusion members 150,154 upon attachment of the slider 132 onto the fastening strips 130,131.

The second side portion 141 includes third and fourth occlusion members 152,156 that extend downward along the first and second side portions 142,144. The third and fourth occlusion members 152,156 additionally

facilitate the occlusion of the fastening strips 130,131 and further guide the slider 132 along the fastening strips 130,131. The occlusion members 152,156 include angled portions 153,157 to guide the fastening strips 130,131 into the occlusion members 152,156.

Fig. 7 illustrates a partial front view of the container 120 and depicts the slider 132 attached to the first and second fastening strips 130,131. The fastening strips 130,131 include a guide rail 129 that the first and second shoulders 146,148 of the slider 132 engage. The fastening strips are melted at the ends to create an end seal 127. The separator 133 engages the end seal 127 and prevents the slider from being disengaged from the fastening strips 130,131 in the direction of the X axis 102.

In addition, when the end seal 127 is formed, the end seal eliminates the guide rail 129 at the location of the end seal. However, the guide rail 129 is not needed on the end seal 127 in order to prevent removal of the slider in the Z axis 106. Specifically, when the separator 133 engages the end seal 127, the shoulders 146,148 remain engaged with the guide rail 129 as shown in Fig. 7. Because the separator 133 is positioned before the shoulders 146,148, the guide rail 129 is not needed on the end seal 127.

Fig. 8 illustrates a cross sectional view of the slider 132 and fastening strips 130,131. The fastening strips 130,131 are shown being partially deoccluded by the separator 133. Due to the proximity to the end seal 127 and the location of the occlusion members 150,154, the bottom legs of the fastening strips 130,131 remain occluded when the slider engages the end seal 127 as

shown in Fig. 8. Fig. 9 illustrates the fastening strips 130,131 being occluded by the occlusion members 150, 154. Fig. 10 depicts the first and second shoulders 146, 148 engaging the fastening strips 130,131. The third and fourth occlusion members 150,154 are also shown engaging the fastening strips 130,131 and facilitating the guidance of the slider 132.

The slider may be multiple parts and snapped together. In addition, the slider may. be made from multiple parts and fused or welded together. The slider may also be a one piece construction. The slider can be colored, opaque, translucent or transparent. The slider may be injection molded or made by any other method. The slider may be molded from any suitable plastic material, such as, nylon, polypropylene, polystyrene, acetal, toughened acetal, polyketone, polybutylene terrephthalate, high density polyethylene, polycarbonate or ABS (acrylonitrile-butadiene-styrene).

In keeping with a general aspect of the present invention and as will be described in greater detail below, the interlocking fastening strips of the present invention may be of virtually any type or form.

As shown in Fig. 11, the fastening strips may be U- channel fastening strips as described in U. S. Patent 4,829,641. U-channel fastening strips include a first fastening strip 230 with a first closure element 236 and a second fastening strip 231 with a second closure element 234. The first closure element 236 engages the second closure element 234. The first fastening strip 230 may include a flange 263 disposed at the upper end of the first fastening strip 230 and a rib 267 disposed at the lower end of the first fastening strip 230. The first

fastening strip 230 may include a flange portion 269.

Likewise, the second fastening strip 231 may include a flange 253 disposed at the upper end of the second fastening strip 231 and a rib 257 disposed at the lower end of the second fastening strip 231. The second fastening strip 231 may include a flange portion 259. The side walls 222,223 of the plastic bag 220 may be attached to the fastening strips 230,231 by conventional manufacturing techniques.

The second closure element 234 includes a base portion 238 having a pair of spaced-apart parallely disposed webs 240,241, extending from the base portion 238. The base and the webs form a U-channel closure element. The webs 240, include hook closure portions 242, 244 extending from the webs 240,241 respectively, and facing towards each other. The hook closure portions 242, 244 include guide surfaces 246., 247 which serve to guide the hook closure portions 242,244 for occluding with the hook closure portions 252, 254 of the first closure element 236.

The first closure element 236 includes a base portion 248 including a pair of spaced-apart, parallely disposed webs 250,251 extending from the base portion 248. The base and the webs form a U-channel closure element. The webs 250,251 include hook closure portions 252,254 extending from the webs 250,251 respectively and facing away from each other. The hook closure portions 252, 254 include guide surfaces 245,255, which generally serve to guide, the hook closure portions 252,254 for occlusion with the hook closure portions 242,244 of the second closure element 234. The guide surfaces 245,255 may also have a rounded crown surface.

The slider 232 includes a top portion 272. The top portion provides a separator 243 having a first end and a second end wherein the first end may be wider than the second end. In addition, the separator 243 may be triangular in shape. When the slider is moved in the occlusion direction, the separator 243 deoccludes the fastening strips 230,231 as shown in Fig. 11. Referring to Fig. 11, the closure elements 234,236 are deoccluded and specifically, the upper hook portions 242,252 and the lower hook portions 244, 254 are deoccluded.

The interlocking fastening strips may comprise "arrowhead-type"or"rib and groove"fastening strips as shown in Fig. 12 and as described in U. S. Patent 3,806,998. The rib element 305 interlocks with the groove element 307. The rib element 305 is of generally arrow- shape in transverse cross section including a head 310 comprising interlock shoulder hook portions 311 and 312 generally convergently related to provide a cam ridge 313 generally aligned with a stem flange 314 by which the head is connected in spaced relation with respect to the supporting flange portion 308. (U. S. Patent 3,806,998, Col. 2, lines 16-23). At their surfaces nearest the connecting stem flange 314, the shoulder portions 311 and 312 define reentrant angles therewith providing interlock hooks engageable with interlock hook flanges 315 and 317 respectively of the groove element 307. (U. S. Patent 3,806,998, Col. 2, lines 23-28). Said hook flanges generally converge toward one another and are spread open to receive the head 310 therebetween when said head is pressed into said groove element 307 until the head is fully received in a groove 318 of said groove element 307 generally complementary to the head and within which the head is interlocked by interengagement of the head shoulder hook portions 311 and 312 and the groove hook

flanges 315 and 317. (U. S. Patent 3,806,998, Col. 2, lines 28-36). Through this arrangement, as indicated, the head and groove elements 305 and 307 are adapted to be interlockingly engaged by being pressed together and to be separated when forcably pulled apart, as by means of a generally U-shaped slider 319. (U. S. Patent 3,806,998, Col. 2, lines 36-41).

The slider 319 includes a flat back plate 320 adapted to run along free edges 321 on the upper ends of the sections of the flange portions 308 and 309 as shown in the drawing. (U. S. Patent 3,806,998, Col. 2, lines 41-46).

Integrally formed with the back plate 320 and extending in the same direction (downwardly as shown) therefrom are respective coextensive side walls 322 with an intermediate spreader finger 323 extending in the same direction as the side walls at one end of the slider. (U. S. Patent 3,806,998, Col. 2, lines 46-51). The side walls 322 are in the form of panels which are laterally divergent from a narrower end of the slider. (U. S. Patent 3,806,998, Col.

2, lines 51-55). The slider walls 322 are each provided with an inwardly projecting shoulder structure 324 flange adapted to engage respective shoulder ribs 325 and 327 on respectively outer sides of the lower section of the flange portions 308 and 309. (U. S. Patent 3,806,998, Col.

2, line 66 to Co. 3, line 3).

Additionally, the interlocking fastening strips may comprise"profile"fastening strips, as shown in Fig. 13 and described in U. S. Patent 5,664,299. As shown in FIG.

13, the first profile 416 has at least an uppermost closure element 416a and a bottommost closure element 416b. (U. S. Patent 5, 664, 299, Col. 3, lines 25-27). The closure elements 416a and 416b project laterally from the inner surface of strip 414. (U. S. Patent 5,664,299, Col.

3, lines 27-28). Likewise, the second profile 417 has at least an uppermost closure element 417a and a bottommost closure element 417b. (U. S. Patent 5,664,299, Col. 3, lines 28-30). The closure elements 417a and 417b project laterally from the inner surface of strip 415. (U. S.

Patent 5,664,299, Col. 3, lines 30-32). When the bag is closed, the closure elements of profile 416 interlock with the corresponding closure elements of profile 417. (U. S.

Patent 5,664,299, Col. 3, lines 32-34). As shown in FIG.

13, closure elements 416a, 416b, 417a and 417b have hooks on the ends of the closure elements, so that the profiles remain interlocked when the bag is closed,. thereby forming a seal. (U. S. Patent 5,664,299, Col. 3, lines 34-37).

The straddling slider 410 comprises an inverted U- shaped member having a top 420 for moving along the top edges of the strips 414 and 415. (U. S. Patent 5,664,299, Col. 4, lines 1-3). The slider 410 has side walls 421 and 422 depending from the top 420. (U. S. Patent 5,664,299, Col. 4, lines 3-4). A separating leg 423 depends from the top 420 between the side walls 421 and 422 and is located between the uppermost closure elements 416a and 417a of profiles 416 and 417. (U. S. Patent 5,664,299, Col. 4, lines 26-30). The fastening assembly includes ridges 425 on the outer surfaces of the fastening strips 414 and 415, and shoulders 421b and 422b on the side walls of the slider. (U. S. Patent 5, 664,299, Col. 4, lines 62-65).

The shoulders act as means for maintaining the slider in straddling relation with the fastening strips by grasping the lower surfaces of the ridges 425. (U. S. Patent 5,664,299, Col. 5, lines 4-7).

Also, the interlocking fastening strips may be "rolling action"fastening strips as shown in Fig. 14 and described in U. S. Patent 5,007,143. The strips 514 and

515 include profiled tracks 518 and 519 extending along the length thereof parallel to the rib and groove elements 516 and 517 and the rib and groove elements 516,517 have complimentary cross-sectional shapes such that they are closed by pressing the bottom of the elements together first and then rolling the elements to a closed position toward the top thereof. (U. S. Patent 5,007,143, Col. 4, line 62 to Col. 5, line 1). The rib element 516 is hook shaped and projects from the inner face of strip 514.

(U. S. Patent 5,007,143, Col. 5, lines 1-3). The groove element 517 includes a lower hook-shaped projection 517a and a relatively straight projection 517b which extend from the inner face of strip 515. (U. S. Patent 5,007,143, Col. 5, lines 3-6). The profiled tracks 518 and 519 are inclined inwardly toward each other from their respective strips 514 and 515. (U. S. Patent 5,007,143, Col. 5, lines 6-8).

The straddling slider 510 comprises an inverted U- shaped plastic member having a back 520 for moving along the top edges of the tracks 518 and 519 with side walls 521 and 522 depending therefrom for cooperating with the tracks and extending from an opening end of the slider to a closing end. (U. S. Patent 5,007,143, Col. 5, lines 26- 31). A separator finger 523 depends from the back 520 between the side walls 521 and 522 and is inserted between the inclined tracks 518 and 519. (U. S. Patent 5,007,143, Col. 5, lines 34-36). The slider 510 has shoulders 521a and 522a projecting inwardly from the depending side walls 521 and 522 which are shaped throughout the length thereof for cooperation with the depending separator finger 523 in creating the rolling action in opening and closing the reclosable interlocking rib and groove profile elements 516 and 517. (U. S. Patent 5,007,143, Col. 5, lines 43- 49).

Although several interlocking fastening strip embodiments have been specifically described and illustrated herein, it will be readily appreciated by those skilled in the art that other kinds, types, or forms of fastening strips may be used without departing from the scope or spirit of the present invention.

The interlocking fastening strips may be manufactured by extrusion through a die and may be formed from any suitable thermoplastic material including, for example, polyethylene, polypropylene, nylon, or the like, or from a combination thereof. Thus, resins or mixtures of resins such as high density polyethylene, medium density polyethylene, and low density polyethylene may be employed to prepare the interlocking fastening strips.

When the fastening strips are used in a salable bag, the fastening strips and the films that form the body of the bag may be conveniently manufactured from heat salable material. In this way, the bag may be economically formed by using an aforementioned thermoplastic material and by heat sealing the fastening strips to the bag. For example, the bag may be made from a mixture of high pressure, low density polyethylene and linear, low density polyethylene.

The fastening strips may be manufactured by extrusion or other known methods. For example, the closure device may be manufactured as individual fastening strips for later attachment to the bag or may be manufactured integrally with the bag. In addition, the fastening strips may be manufactured with or without flange portions on one or both of the fastening strips depending upon the

intended use of the fastening strips or expected additional manufacturing operations.

The fastening strips can be manufactured in a variety of forms to suit the intended use. The fastening strips may be integrally formed on the opposing sidewalls of the container or bag, or connected to the container by the use of any of many known methods. For example, a thermoelectric device may be applied to a film in contact with the flange portion of the fastening strips or the thermoelectric device may be applied to a film in contact with the base portion of fastening strips having no flange portion, to cause a transfer of heat through the film to produce melting at the interface of the film and a flange portion or base portion of the fastening strips. Suitable thermoelectric devices include heated rotary discs, traveling heater bands, resistance-heated slide wires, and the like. The connection between the film and the fastening strips may also be established by the use of hot melt adhesives, hot jets of air to the interface, ultrasonic heating, or other known methods. The bonding of the fastening strips to the film stock may be carried out either before or after the film is U-folded to form the bag. In any event, such bonding is done prior to side sealing the bag at the edges by conventional thermal cutting. In addition, the first and second fastening strips may be positioned on opposite sides-of the film.

Such an embodiment would be suited for wrapping an object or a collection of objects such as wires. The first and second fastening strips should usually be positioned on the film in a generally parallel relationship with respect to each other, although this will depend on the intended use.

From the foregoing it will be understood that modifications and variations may be effectuated to the disclosed structures-particularly in light of the foregoing teachings-without departing from the scope or spirit of the present invention. As such, no limitation with respect to the specific embodiments described and illustrated herein is intended or should be inferred. In addition, all references and copending applications cited herein are hereby incorporated by reference in their entireties.