Abstract:
A clasp for use in making jewelry comprises an elongated hollow tube having an opening at least at one of its ends and an elongated, Z-shaped slot having a first section extending from the open end of the tube to a first intermediate location, a second section extending approximately circumferentially from the first intermediate location to a second intermediate location, and a third section extending from the second intermediate location to a third intermediate location. Flexible decorative strands of material, having enlarged ends larger than the slot, can be slid into the opening of the slot and into the third section, where they remain unless deliberate manipulations are undertaken to remove the strands.

Description:
FIELD OF THE INVENTION 
     This invention relates to jewelry, and more specifically to a clasp for use in making articles of jewelry such as bracelets, from flexible strands of decorative cord or like material. 
     BACKGROUND OF THE INVENTION 
     Making home-made jewelry has become popular among young women, especially those in their teens and pre-teens. Bracelets, and necklaces, for example, can be made from various materials, such as strands of beads, cords of yarn or plastics, metal chains, and many other materials. Typically, the bracelet or necklace is made up of several, e.g., three or more, such strands arranged in parallel to one another. To connect the opposite ends of the parallel array of strands to each other, each end of the parallel array of strands is typically fastened to a clasp. The two clasps are releasably connectible to each other so that the bracelet or necklace can be conveniently worn and removed. 
     Typical jewelry clasps are described in the following U.S. Pat. Nos:
     U.S. Pat. No. 2,266,074, granted Dec. 16, 1941,   U.S. Pat. No. 2,586,758, granted Feb. 19, 1952,   U.S. Pat. No. 3,120,042, granted Feb. 4, 1964,   U.S. Pat. No. 3,247,560, granted Apr. 26, 1966,   U.S. Pat. No. 3,247,561, granted Apr. 26, 1966,   U.S. Pat. No. 4,527,316, granted Jul. 9, 1985,   U.S. Pat. No. 6,880,363, granted Apr. 19, 2005, and   U.S. Pat. No. 8,499,582, granted Aug. 6, 2013.   

     These clasps provide for connection of the ends of necklaces and bracelets composed of plural strands, but are more suitable for use by adults, and generally lack the ability to accommodate a broad variety of kinds of strands. 
     There is a need for an inexpensive, versatile, and easy to use clasp to enable young persons to make their own bracelets, necklaces and similar articles. 
     SUMMARY OF THE INVENTION 
     The clasp in accordance with the invention comprises an elongated hollow tube having first and second ends, and an opening at least at the first end. The tube is defined by a cylindrical wall having a circumferential outer surface and a Z-shaped slot forming an opening from the interior of the tube to the exterior thereof. The slot extends from the first end of the tube to a location adjacent the second end of the tube. 
     More specifically, the hollow tube is elongated along a longitudinal direction, and its first and second opposite ends are separated from each other along the longitudinal direction. The tube comprises a circumferential wall having internal and external surfaces, and a longitudinal internal bore defined by the internal surface. The bore has an opening at the first end of the tube, and the bore extends longitudinally from the opening at least to a location adjacent the second end. The slot forms a continuous elongated opening through the wall from the internal surface to the external surface of the wall, and extends from the first end of the tube at least to a location adjacent the second end. The slot has minimum and maximum widths and an entry formed at the first end of the tube. The slot comprises a first slot section extending longitudinally from the entry to a first intermediate location between the first and second ends of the tube, a second section extending from the first intermediate location to a second intermediate location between the first and second ends. The first and second intermediate locations are both closer to the first end than to the second end. A third section of the slot extends longitudinally from the second intermediate location to an end surface at a third intermediate location. The third intermediate location is closer to the second end than to the first end, and the first and third sections are circumferentially displaced from each other. 
     Plural flexible strands, each having a thickness smaller than the minimum width of the slot and an enlarged end having a thickness larger than the maximum width of the slot, can be slid through the first and second sections into positions in which they extend through the third section of the slot, while their enlarged ends are passed through the opening at the first end of the tube and brought to positions inside the longitudinal internal bore of said tube and adjacent the third section of the slot. 
     The second intermediate location is preferably at least as close as the first intermediate location to the first end of the hollow tube, and can be closer than the first intermediate location to the first end of the hollow tube so that the second section forms acute angles with the first and third sections. 
     Preferably each of the three section of the slot is elongated, and the slot has a uniform width. 
     The end surface of the third section of the slot can be constituted by a closed end of the third section. 
     A fastening loop can be attached to the external surface of the circumferential wall at a location midway between the first and second ends and diametrically opposite the third section of the slot. 
     An article of jewelry can be made using two of the above-described elongated hollow tubes and a plurality of flexible strands each having enlargements at both ends for connection to the third slot section of the respective tubes. A releasable connection can be provided to connecting the two tubes to each other in parallel relationship, so that the clasps, the releasable connection and the flexible strands form a closed loop. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an oblique perspective view of a clasp according to the invention, showing a side and one end thereof; 
         FIG. 2  is an oblique perspective view of the clasp showing the opposite end thereof; 
         FIG. 3  is an oblique perspective view corresponding to  FIG. 2 , illustrating the manner in which a flexible strand is attached to the clasp; and 
         FIG. 4  is a perspective view showing an assembly composed of two clasps linked together in parallel relationship and an array of flexible strands extending from one clasp to the other to form a bracelet. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in  FIGS. 1 and 2 , the clasp  10  comprises a hollow tube  12 , elongated along a longitudinal direction and having first and second opposite ends,  14  and  16  respectively, separated from each other along the longitudinal direction. The tube comprises a circumferential wall having and internal surface  18  and an external surface  20 , and a longitudinal internal bore  22  defined by the internal surface. The internal bore  22  has an opening at the first end  14  of the tube and extends longitudinally from the opening at least to a location  24  adjacent the second end  16 . In the embodiment shown, the bore  2  extends all the way through the tube, and has openings at both ends. A slot  26  forms a continuous elongated opening through the wall from the internal surface to the external surface. This opening extends from the first end  14  of the tube at least to location  24  adjacent the second end  16  of the tube. 
     The slot can be of uniform width, but the width of the slot does not need to be strictly uniform. Thus, the slot may have a minimum width and a maximum width. The slot has an entry  28  formed at the first end  14  of the tube, and comprises a first slot section  30 , extending longitudinally from the entry  28  to a first intermediate location  32  between the first and second ends of the tube, a second section  34 , extending from the first intermediate location  32  to a second intermediate location  36  between the first and second ends of the tube, and a third section  38 , extending longitudinally from the second intermediate location  36  to an end surface at location  24 , which is a third intermediate location. 
     The first and second intermediate locations  32  and  36  are both closer to the first end  14  of the tube than to the second end  16 , and the third intermediate location  24  is closer to the second end  16  of the tube than to the first end  14 . 
     Because the first and third sections of the slot  30  and  38  are circumferentially displaced from each other and connected by the second section  34 , the slot is Z-shaped. Preferably the shape of the slot is such that the second intermediate location  36  is at least as close as the first intermediate location  32  to the first end  14  of the tube. If the distance from intermediate location  32  to end  14  of the tube exceeds the distance from intermediate location  36  to the end  14  of the tube by the width of the second slot section  34 , the intermediate section  34  of the slot can be strictly circumferential. Ideally, however, the second intermediate location  36  is still closer than the first intermediate location  32  to said first end  14  of the tube, so that the first and third sections  30  and  38  form acute angles, e.g., angles of about 80°, with the second section  34 , as shown in  FIGS. 1 and 2 . 
     In  FIG. 2 , a flexible strand  40 , is shown being engaged with the slot  26 . In this case, the flexible strand  40  is a length of flexible plastics material having an oblong rectangular cross-sectional shape and a width, measured in the direction of smaller dimension of the rectangular cross-section, that is smaller than the minimum width of the slot  26 . A simple overhand knot  42  is formed at an end of the flexible strand  40  so that the strand has an enlarged end with a thickness larger than the maximum width of the slot  26 . As shown in  FIG. 3 , the strand is slid through the entry  28  and through the first section of the slot into the second section, with the enlarged end formed by the knot positioned so that the strand extends from the exterior of the tube, inwardly through the slot, to the enlarged end. The strand can then be moved into the third section of the slot, and the enlarged end can be pulled inward through the opening at the first end  14  of the tube. By manually bending the strand  40  so that it passes around the acute angles of the slot, the strand  40  can be slid into a position adjacent a similar strand  44  previously engaged with the tube in a similar manner. A series of strands can be engaged with the tube until the third section  38  of the slot is filled, or nearly filled. The enlarged ends of the strands, which are larger than the maximum width of the third section  38  of the slot, are positioned inside the bore of the tube adjacent the third slot section  38 , and prevent the strands from being pulled out through the third slot section. 
     The second slot section  34 , which extends from slot section  38  to slot section  30 , which is circumferentially displaced from slot section  34 , prevents inadvertent disengagement of the strands from the tube by requiring, for removal, a special manipulation of the strands in which they are moved longitudinally from slot section  38  into slot section  34 , and then through slot section  34  to slot section  30  in a direction having a circumferential component. Thus when the strands are in place, they are confined between the second section  34  of the slot, and the closed end surface of the third slot section at the third intermediate location  24 , and inadvertent removal of the strands form the slot is effectively prevented. 
     The strands, of course, need not be plastic strands having elongated rectangular cross-sectional shapes. Lengths of yarn having knotted ends, or any of various other kinds of strands, for example, beaded strings or beaded chains, can be used. In the case of a beaded string or chain, an endmost bead can serve as the enlargement at the end of the strand, that prevents the strand from being pulled out through the third slot section  38 . The Z-shape of the slot will prevent accidental disengagement of the strands from the tubular clasps. 
     Although the third section  38  of the slot in the embodiment shown in  FIGS. 1-4  has a closed end at location  24 , the advantages of the invention can be realized in alternative embodiments in which the slot has entries at both ends of the tube, two first slot sections corresponding to slot section  30  adjacent the opposite ends of the tube, two second slot sections corresponding to slot section  34 , and a single third slot section corresponding to slot section  38 . In this case, the end surfaces that limit longitudinal sliding of the strands, are side walls of the two second slot sections instead of closed ends corresponding to the closed end of slot section  38  at location  24 . 
       FIG. 3  also shows a fastening loop  46  attached to the external surface of the circumferential wall of the tube at a location preferably midway between the first and second ends  14  and  16  of the tube and diametrically opposite the third slot section  38 . 
     As shown in  FIG. 4 , two clasps  48  and  50 , of the kind illustrated in  FIGS. 1-3 , can be utilized to make a bracelet. The fastening loops  52  and  54  of the respective clasps can be connected to each other by a link  56  composed of two integrally connected, resilient, wire loops  58  and  60 , having gaps  62  and  64 , which have a width slightly smaller than the width of the wire of the loops. The resilience of the link and the dimensional relationship of the gaps to the loop wire allow the link to be snapped onto the loops, and to be disengaged from the loops manually. 
     As mentioned above, the slotted tubular clasps as described above can be used to make bracelets from a wide variety of materials. The size of the bracelet depends on the lengths of the strands that extend from one clasp to the other. With sufficiently long strands of material, the clasps can also be used to make necklaces and even decorative belts. The clasps can be used to make an article of jewelry using two or more strands of different kinds of material, for example a bracelet made from strands of beads and yarns disposed side-by-side in an alternating arrangement. 
     The clasps can also be re-used. For example, if the strands of an article of jewelry made from a pair of clasps are damaged, or the user simply desires to make a new article of jewelry, she can easily remove the existing strands and replace them with new strands, strands of other materials, or strands of a different length.