Field of the Invention
The present invention generally relates to plastic sliders for opening and closing zippers of reclosable plastic bags and, more particularly, relates to a one-piece "gull wing" type foldable plastic slider having an improved compression-type latch for securely locking the slider in a folded position.
Background of the Invention
Plastic zippers with sliders are well known in the art. The plastic zipper includes male and female tracks forming respective interlocking profiles. In the manufacture of a thermoplastic bag, the male and female tracks extend along the mouth of the bag and are adapted to be secured in any suitable manner to opposing flexible panels of the bag. The male and female tracks may be integral marginal portions of these flexible panels or they may be extruded separately and thereafter attached to the flexible panels along the mouth of the bag. The slider, which is mounted to the zipper, is used to open and close the zipper. When the slider is in a closed position, the profiles are interlocked with each other. In response to moving the slider to an open position, the profiles are disengaged from each other.
A foldable zipper slider with compression-type latch is disclosed in U.S. Pat. No. 5,063,644. This slider locks into place over the reclosable zipper using a flexible tongue compression-type latch. This flexible tongue style latch is effective on larger sliders, but when the size of the slider is reduced it becomes difficult and expensive to mold such an apparatus. Accordingly, there is a need to improve the compression-type latch so it can be effectively used on a smaller scale. The present invention seeks to achieve this result.
Summary of the Invention
It is an object of the present invention to provide a new and improved one-piece foldable plastic zipper slider with compression-type latch.
The present invention relates to a foldable plastic slider for straddling relation with a profiled plastic zipper. The straddling slider for closing or opening the zipper by movement therealong comprises a transverse support member with opposing sides, a pair of depending legs, and a pair of wings hingedly attached to the opposing sides of the support member. The wings have openings for receiving the respective legs and each has a cored out cross piece. Each cored out cross piece has a solid sloped latch. The wings are folded relative to the support member and each solid sloped latch engages its respective leg. This locks the slider on the zipper.
Brief Description of the Drawings
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:
FIG. 1 is a perspective view of a foldable plastic slider embodying the present invention prior to being mounted on a zipper;
FIG. 2 is a top view of the foldable plastic slider in FIG. 1;
FIG. 3 is a perspective view of the foldable plastic slider in the process of being mounted on the zipper;
FIG. 4 is a perspective view of the foldable plastic slider after it has been mounted on the zipper;
FIG. 5 is a side view of the foldable plastic slider just prior to latching the slider wings;
FIG. 6 is a sectional view taken generally along the lines 6--6 in FIG. 5;
FIG. 7 is a side view of the foldable plastic slider in the process of latching the slider wings;
FIG. 8 is a sectional view taken generally along the lines 8--8 in FIG. 7;
FIG. 9 is a side view of the foldable plastic slider after the slider wings have been latched in a closed sidewall position;
FIG. 10 is a sectional view taken generally along the lines 10--10 of FIG. 9;
FIG. 11 is a top view of a foldable plastic slider in accordance with an alternative embodiment of the present invention;
FIG. 12 is a bottom view of the foldable plastic slider in FIG. 11; and
FIG. 13 is a perspective view of the foldable plastic slider in FIG. 11.
While the invention is susceptible to various modifications and alternative forms, a specific embodiment thereof has been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
Detailed Description of Preferred Embodiments
FIGS. 1, 3 and 4 depict a mouth portion of a reclosable plastic bag embodying the present invention. The plastic bag comprises first and second opposing panels 4 and 5 fixedly connected to each other along a pair of sides (not shown) and a bottom (not shown) bridging the pair of sides. The bag is provided with a reclosable zipper 6 extending along the mouth portion, which is formed opposite the sealed bottom of the plastic bag.
The zipper 6 includes a male track 14 and a female track 16. The male track 14 includes a male profile 18 and a first depending fin or flange 22 extending downward from the male profile 18. Likewise, the female track 16 includes a female profile 20 and a second depending fin or flange 24 extending downward from the female profile 20. If the zipper 6 is formed separately from the panels 4 and 5 of the bag, the first and second fins 22 and 24 are thermally fused to inner surfaces of the respective first and second panels 4 and 5. Alternatively, the zipper 6 may be integrally formed with the panels 4 and 5 such that the first fin 22 is integrally formed with the first panel 4 and the second fin 24 is integrally formed with the second panel 5.
To assist in opening the plastic bag, a foldable plastic slider 10 is slidably mounted to the zipper 6 for movement between a closed position and an open position. FIG. 1 illustrates the slider 10 prior to being mounted on the zipper 6, while FIG. 4 illustrates the slider 10 after it has been mounted to the zipper 6. The slider 10 in its assembled position shown in FIG. 4 forces the male and female profiles 18 and 20 into engagement. The slider 10 has an opening end and a closing end, the slider 10 is wider at the opening end to allow separation of the male and female profiles 18 and 20. The slider is sufficiently narrow at the closing end to press the male and female profiles 18 and 20 into an interlocking relationship as the slider 10 is moved in the closing direction.
The slider 10 is formed from a single piece of molded plastic such as, for example, nylon, polypropylene, polystyrene, Delrin or ABS. The slider 10 is particularly suited for use with profiled plastic reclosable fasteners or zippers and thermoplastic bags. The examples of the bag and zipper, and construction of the slider and zipper are more fully described in U.S. Pat. Nos. 5,063,644, 5,067,208 and 5,007,143 which are incorporated herein by reference in their entirety.
Referring to FIG. 1, the foldable plastic slider structure comprises an inverted U-shaped member including a transverse support member or body 12 from which a separating finger 11 depends. The body 8 also includes two integral depending legs 31, 32 and two hinged "wings" 25, 26. The lower ends of legs 31, 32 are provided with respective engaging shoulders 31a, 32a and respective angled surfaces 31b, 32b adjacent to the respective engaging shoulders 31a, 32a. The wings 25, 26 have respective cross pieces 25c, 26c forming respective solid sloped/ramp latches 25a, 26a, and respective cored out regions 25b, 26b. The wings 25, 26 also have respective wing shoulders 29,30. Referring to FIG. 2, the wings 25, 26 are connected to the body 12 by means of respective hinge structures 27, 28 located on opposite sides of the body 12. The hinge structures 27, 28 are relatively thin sections of plastic material as compared to the wall thicknesses of the wings 25, 26 and the flexibility of the plastic material makes possible the use of the integral hinge structures 27, 28 which are sometimes referred to as "living" hinges. The wings 25, 26 form central openings to receive the respective legs 31, 32 when the wings 25, 26 are folded down to the closed sidewall position, to be described later.
FIG. 3 depicts the slider 10 undergoing the process of assembly. The slider 10 is mounted on the tracks 14, 16 of the zipper 6 in such a way that the depending separating finger 11 is between the male and female profiles 18, 20 of the respective tracks 14, 16. The depending legs 31, 32 are positioned on the outside of the tracks 14, 16 in such a way that the tracks 14, 16 of the zipper 6 separate the depending separating finger 11 from the respective depending legs 31, 32. The wings 25, 26 are then rotated downward toward the bottom of the bag with the "living" hinges acting as the axis of rotation. FIG. 4 shows the slider in an assembled condition, the wings 25, 26 have been folded down to their closed sidewall state. The body 12 is adapted to move along the top edges of the zipper tracks 14, 16. The wings 25, 26 having wing shoulders 29, 30 that are positioned beneath the tracks 14, 16 to prevent the slider 10 from being lifted off the top of the zipper 6.
When the wings 25, 26 are folded down from their open position to their closed sidewall position, the wings 25, 26 are held in place by an improved compression-type latch. As shown in FIGS. 5 and 6, when the wing 25 is rotated to the closed sidewall position the solid latch 25a will come into contact with the angled surface 31b adjacent to the latching shoulder 31a. When the wing 25 is moved toward the closed sidewall position the angled surface 31b exerts a force on the solid sloped latch 25a shown in FIGS. 7 and 8. The angles of the sloped latch 25a and the angled surface 31b cause the vector of the force to be in the downward direction. This causes the upper edge 25d of cored out region 25b to flex or depress. The cored out region 25b allows the upper edge 25d of the cross piece 25c to be a thinner piece of plastic. This allows the upper edge 25d to have the flexibility necessary to deflect down when the solid latch 25a comes into contact with leg 31. The upper edge 25d remains depressed until the leg 31 has completely passed over the solid sloped latch 25a. Then, the upper edge 25d returns to its original shape forcing the solid sloped latch 25a into engagement with shoulder 31a shown in FIGS. 9 and 10, thereby locking the wing 25 and leg 31 into the closed sidewall position.
The improved compression-type latch offers many advantages. It allows for easier installation of the slider 10 and increases the difficulty in removing the slider from the bag. The cored out region 25c, when depressed, acts similar to a spring in compression and once released forces the solid sloped latch 25a upward into a locked condition with the shoulder 31a of leg 31. As the wing 25 is being latched the angles of the solid sloped latch 25a and the angled surface 31b are able to work together to depress the upper edge 25d. However, when attempting to disengage the wing 25 from the leg 31 the direction in which the force acts is unable to depress the upper edge 25d; rather, it forces the leg 31 more strongly into engagement with the wing 25. This increases the difficulty in disassembling the slider. The old compression-type latch design using a flexible tongue latch without a cored out region as described more fully in U.S. Pat. No. 5,448,808 required an opening force to unlatch the wing from the leg ranging from 3.7 lbs., std. dev. 0.10 to 5.7 lbs., std. dev. 0.19. While this is impressive, the improved compression-type latch comprising a solid sloped latch and cored out region requires an opening force ranging from 8.3 lbs., std. dev. 0.26 to 9.9 lbs., std. dev. 0.17. This opening force greatly inhibits a user from removing the slider from the zipper.
It is to be understood that the other wing 26 has a solid sloped latch 26a, a s cored out region 26b, a cross piece 26c, and an upper edge 26d shown in FIG. 2, which allow the solid sloped latch 26a to engage the shoulder 32a of the leg 32. This provides a compression-type latch to lock wing 26 in place with leg 32. All of which functions in the same manner as for the wing 25 as described above.
As shown in FIG. 4, the cored out regions 25b, 26b are on the exterior of the respective cross pieces 25c, 26c, face away from the respective bag panels 4, 5, and can be seen when the slider 10 is fully installed on the zipper 6. In an alternative embodiment depicted in FIGS. 11-13, where like reference numerals are used to designated analogous parts, the cored out regions 25b, 26b are on the interior of the respective cross pieces 25c, 26c and would face toward the bag panels and be hidden is from view when the slider is fully installed on a zipper. The compression-type latch on the slider in FIGS. 11-13 functions in substantially the same way as the compression-type latch on the slider in FIGS. 1-10.
While the present invention has been described with reference to one or more particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the claimed invention, which is set forth in the following claims.