A zipper is provided wherein at least one stringer has a row of coupling elements presenting a variable visual appearance along the coupled length of the zipper. The zipper has improved aural, tactile or visual aesthetics, and is more difficult to counterfeit.
While the major function of a zipper assembly is mechanical--to reversibly couple two generally flexible panels or strips, aesthetic considerations also arise which may dictate when and how a zipper may be used in a given application. The aesthetic considerations may be aural, tactile and/or visual. The present invention alters the visual aspect of the zipper assembly to provide a less mechanical appearance, and may also alter the sound and feel of the zipper when it is opened and closed.
The present invention provides for a zipper stringer or zipper assembly comprising two stringers. At least one stringer has a row of coupling elements presenting a variable visual appearance along the coupled length of the zipper.
The following terms are defined as follows:
'Color' is taken to mean any color, including black, white and gray, and the phrase 'distinguishable colors' means any two colors that are distinguishable by the human eye, and preferably exhibit a delta E* of at least one, more preferably five, and most preferably ten. Colors include those produced by any pigment or dye, and those that may be accentuated by UV light, such as fluorescent or phosphorescent pigments or dyes.
'Coupling element' means a substantially rigid projection (tooth), independently arrayed along a tape in a spaced fashion with other substantially rigid projections to form a stringer, the rigid projection having surface geometry for reversible mechanical interlocking with mating surface geometry of two adjacent projections on a mating stringer.
'Coupling element projected area' means the total area bounded by the outline of the face of a coupling element when projected perpendicularly upon the zipper plane when the zipper stringer is parallel to the zipper plane.
'Height' for a coupling element means, relative to the coupling element head (the portion of the coupling element with interlocking geometry), the distance from the proximal edge of the stringer tape to the distal edge of the coupling element. The height is measured in a direction perpendicular to the pitch line. 'Face height' is the height of the coupling element above the stringer tape (generally towards the outside of a garment, bag, or other item), while 'back height' is the height of the coupling element below the stringer tape.
'Information sequence' means the consecutive listing of one or more properties (such as pitch, color, reflectivity, or projected coupling area) that vary along the stringer or closed zipper.
'Pitch width', and also 'coupling element spacing', means the distance along the pitch line and between the centerline of a coupling element to the centerline of the next adjacent coupling element on the same stringer.
'Pitch line' means the line that bisects the coupling elements of a closed zipper.
'Pitch sequence' means the consecutive listing of the coupling element widths of a stringer or zipper when closed.
'Reversible' means that the zipper or a segment thereof may be repeatedly closed and opened without damage to the coupling elements, except for normal wear.
'Self-interlocked' means that single coupling elements on one stringer are geometrically locked to two adjacent coupling elements on a mating stringer without the use of pins or other additional elements.
'Slider' means a moveable element for reversibly joining two stringers. Generally, a slider comprises a pair of converging channels for reversibly directing the two arrays of non-interlocked coupling elements of the stringers through a curved coupling path and into a parallel self-interlocked relationship. The use and construction of sliders is well known to those versed in the art.
'Stringer' means a flexible zipper half comprising a linear array of coupling elements independently and flexibly mounted to a tape, capable of coupling to a second stringer (e.g., by means of a slider, whereby the coupling elements on the stringers are temporarily rotated to allow them to be interleaved, then straightened to geometrically interlock them with adjacent mating coupling elements).
The coupling elements may be metallic or polymeric, but are preferably molded from thermoplastic materials. A zipper may be individually molded as discreet stringers, or more efficiently by continuous injection molding on a mold wheel with one or more mold bands. Such a manufacturing method is described in U.S. Pat. Nos. 4,268,474 and 4,350,656 to Moertel, the teachings therein entirely incorporated herein by reference. The surface geometry that interlocks a given coupling element with adjacent coupling elements may comprise male and female projections that prevent relative movement in both the zipper plane and in the direction orthogonal to the zipper plane.
Alternatively, mating projections may be used to prevent movement in the zipper plane, with separate projections to prevent motion orthogonal to the plane. Known modifications such as end stops and/or pin members (for aligning a slider and the ends of two mating stringers) can be provided at the ends of the stringers.