Patent Publication Number: US-2017347758-A1

Title: Locking slider assembly and a method for its manufacture

Description:
TECHNICAL FIELD 
     The device and methods disclosed herein relate generally to fasteners, and particularly to a locking slider assembly. 
     BACKGROUND ART 
     Slide fasteners such as zippers are used everywhere, on backpacks, handbags, luggage and clothing, as a versatile and reliable way to join two edges of fabric together. Hitherto, however, the convenience of zippers has come at a price: security. Zippers are difficult to lock, and the solutions presented thus far for securing zippers leave a lot to be desired. For instance, one popular way method for locking zippers on luggage is to padlock two sliders of a zipper together, which requires closing the zipper to the point of placing the sliders in close proximity, and attaching a padlock, presumably carried about the person of the user or in a pocket of the luggage item. This is quite inconvenient compared to the process of securing luggage with a latch, which can be performed in a single step without attaching any external equipment. 
     Therefore, there remains a need for a slide fastener that can be locked quickly and effectively. 
     SUMMARY 
     In one aspect, a locking slider assembly includes a slider having a slot. The assembly includes a rail slidably inserted through the slot of the slider, the rail having at least one tooth movable between an extended state in which the tooth prevents the slot from moving in at least one direction along the rail, and a retracted state in which the slot can slide past the at least one tooth. 
     In a related embodiment, the slot is formed by a substantially C-shaped projection attached to the slider. In another embodiment, the slot fits snugly over the rail. In an additional embodiment, the slider further includes a cavity into which the at least one tooth inserts when in the extended position. 
     In another related embodiment, the rail also includes an elongated member on which the at least one tooth is mounted, the elongated member slidably engaged to the rail, so that when the elongated member slides in a first direction the at least one tooth is forced into the extended position, and when the elongated member slides in a second direction the at least one tooth is forced into the retracted position. In another embodiment, the at least one tooth is mounted on the elongated member by a biasing means, the biasing means having a bias that urges the at least one tooth into the extended state. In a further embodiment, the rail also includes at least one surface against which the tooth is forced when the elongated member is moved in the second direction, the at least one surface and at least one tooth formed so that forcing the at least one tooth against the at least one surface moves the tooth into the retracted position. 
     In another embodiment, the elongated member is flexible. Yet another embodiment includes a spool to which one end of the elongated member is fixed, so that rotating the spool to a locking position causes the elongated member to slide in the first direction. A further embodiment still also includes a latch that secures the spool in the locking position. An additional embodiment also includes a second locking assembly having a second elongated member, and the second elongated member is also wound on the spool. Still another embodiment includes a splitter dividing the elongated member and the second elongated member. In another embodiment, a portion of the elongated member projects away from the rail. An additional embodiment includes a sheath that contains the portion of the elongated member that projects away from the rail. In another embodiment, the sheath is flexible. In another related embodiment, the at least one tooth includes a plurality of teeth. In an additional embodiment, the rail further includes a tube having a plurality of openings, and each of the plurality of teeth extends through one of the plurality of openings. 
     In another aspect, a slide fastener incorporating a locking slider assembly includes a fastener having two flexible strips and a set of interlocking teeth alternately attached to the two flexible strips. The slide fastener includes a slider slidably engaged to the fastener, the slider having a mechanism that separates the interlocking teeth when the slider slides in a first direction and interlocks the interlocking teeth when the slider slides in a second direction, the slider further including a slot. The slide fastener includes a rail slidably inserted through the slot of the slider, the rail having at least one tooth movable between an extended state in which the tooth prevents the slot from moving in at least one direction along the rail, and a retracted state in which the slot can slide past the at least one tooth. 
     In another aspect, method for manufacturing a locking slider assembly includes obtaining a slide fastener. The method includes incorporating in the slide fastener a slider slidably engaged to the fastener, the slider having a mechanism that separates the interlocking teeth when the slider slides in a first direction and interlocks the interlocking teeth when the slider slides in a second direction, the slider further having a slot. The method further includes attaching to the slide fastener a rail slidably inserted through the slot of the slider, the rail having at least one tooth movable between an extended state in which the tooth prevents the slot from moving in at least one direction along the rail, and a retracted state in which the slot can slide past the at least one tooth. 
     These and other features of the present invention will be presented in more detail in the following detailed description of the invention and the associated figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The preceding summary, as well as the following detailed description of the disclosed system and method, will be better understood when read in conjunction with the attached drawings. It should be understood that the invention is not limited to the precise arrangements and instrumentalities shown. 
         FIG. 1A  is a schematic diagram illustrating an embodiment of a locking slider assembly as disclosed herein; 
         FIG. 1B  is a schematic diagram illustrating an embodiment of a locking slider assembly as disclosed herein; 
         FIG. 1C  is a schematic diagram illustrating an embodiment of a slider as disclosed herein; 
         FIG. 1D  is a schematic diagram illustrating an embodiment of a partially cross-sectioned locking slider assembly as disclosed herein; 
         FIG. 1E  is a schematic diagram illustrating an embodiment of a partially cross-sectioned locking slider assembly as disclosed herein; 
         FIG. 1F  is a schematic diagram illustrating an embodiment of a partially cross-sectioned slider as disclosed herein; 
         FIG. 2A  is a schematic diagram illustrating an embodiment of a rail as disclosed herein; 
         FIG. 2B  is a schematic diagram illustrating an embodiment of a rail as disclosed herein; 
         FIG. 2C  is a schematic diagram illustrating an embodiment of a rail as disclosed herein; 
         FIG. 2D  is a schematic diagram illustrating an embodiment of a rail as disclosed herein; 
         FIG. 2E  is a schematic diagram illustrating an embodiment of a rail as disclosed herein; 
         FIG. 2F  is a schematic diagram illustrating an embodiment of a rail as disclosed herein; 
         FIG. 2G  is a schematic diagram illustrating an embodiment of a rail as disclosed herein; 
         FIG. 2H  is a schematic diagram illustrating an embodiment of a rail as disclosed herein; 
         FIG. 3  is a schematic diagram illustrating an embodiment of a portion of a sheath and elongated member as disclosed herein; 
         FIG. 4A  is a schematic diagram illustrating an embodiment of a spool as disclosed herein; 
         FIG. 4B  is a schematic diagram illustrating an embodiment of a spool as disclosed herein; 
         FIG. 4C  is a schematic diagram illustrating an embodiment of a spool as disclosed herein; 
         FIG. 4D  is a schematic diagram illustrating an embodiment of a spool as disclosed herein; 
         FIG. 5A  is a schematic diagram illustrating an embodiment of a backpack incorporating an embodiment of the locking slider assembly as disclosed herein; 
         FIG. 5B  is a schematic cutaway diagram illustrating an embodiment of a backpack incorporating an embodiment of the locking slider assembly as disclosed herein; 
         FIG. 5C  is a schematic diagram illustrating an embodiment of a backpack incorporating an embodiment of the locking slider assembly as disclosed herein; 
         FIG. 5D  is a schematic diagram illustrating an embodiment of a slide fastener incorporating an embodiment of the locking slider assembly as disclosed herein; 
         FIG. 5E  is a schematic diagram illustrating an embodiment of a slide fastener incorporating an embodiment of the locking slider assembly as disclosed herein; 
         FIG. 5F  is a schematic diagram illustrating an embodiment of a slide fastener incorporating an embodiment of the locking slider assembly as disclosed herein; 
         FIG. 5G  is a schematic diagram illustrating an embodiment of a slider mechanism as disclosed herein; 
         FIG. 5H  is a schematic diagram illustrating an embodiment of a slider mechanism as disclosed herein; 
         FIG. 6  is a flow diagram illustrating one embodiment of a method for manufacturing a slide fastener incorporating an embodiment of the locking slider assembly as disclosed herein; 
         FIG. 7A  is a schematic diagram illustrating an embodiment of a locking slider assembly as disclosed herein; 
         FIG. 7B  is a schematic diagram illustrating an embodiment of a locking slider assembly as disclosed herein; 
         FIG. 8  is a schematic diagram illustrating an embodiment of a locking slider assembly as disclosed herein; 
         FIG. 9A  is a schematic diagram illustrating an embodiment of a rail as disclosed herein; 
         FIG. 9B  is a schematic diagram illustrating an embodiment of a rail as disclosed herein; 
         FIG. 10  is a schematic diagram illustrating an embodiment of a locking slider assembly as disclosed herein; and 
         FIG. 11  is a flow diagram illustrating one embodiment of a method for manufacturing a slide fastener incorporating an embodiment of the locking slider assembly as disclosed herein. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     Embodiments of the disclosed locking slider assembly enable a user to secure one or more sliders in place on a slide fastener or similar device; the locking mechanism may lock the sliders in place regardless of the sliders&#39; position along the slide fastener. Some embodiments enable the user to engage the locking mechanism by turning a toggle; the user may be able to lock the toggle in place, and may be able to lock multiple zippers with a single toggle. 
       FIGS. 1A-F  depict some embodiments of a locking slider assembly  100 . As an overview, the locking slider assembly includes a rail  101  having a travel direction  102 . The rail  101  has a cross-sectional dimension  107 , as shown in  FIGS. 1D-E . The rail  101  is switchable between a first state in which the cross-sectional dimension  107  has a first value, as shown for example in  FIGS. 1A and 1D  and a second state in which the cross-sectional dimension  107  has a second value, as shown for instance in  FIGS. 1B and 1E , the second value greater than the first value. The assembly includes a slider  103 . The slider  103  includes a slot  104  that fits over the rail  101 . The slot has a first surface  105  and a second surface  106 . The first surface  105  and second surface  106  are separated by a distance aligned with the cross-sectional dimension that is greater than the first value of the cross-sectional dimension and less than or equal to the second value of the cross-sectional dimension. As a result, the slot  104  may be able to slide over the rail  101  when the rail  101  is in the first state, and the slot  104  may be unable to slide over the rail  101  when the rail  101  is in the second state. 
     Viewing  FIGS. 1A-C  in greater detail, the rail  101  may be an elongated structure along which the slider  103  can travel by sliding. The rail  101  may have a substantially uniform width and depth throughout its length, when in the first state. The rail  101  in the first state may have any suitable cross-sectional form. The cross-section of the rail  101  may have a substantially polygonal perimeter, which may be regular or irregular; for instance, the perimeter of the cross-section of the rail  101  may be substantially rectangular. The perimeter of the cross-section of the rail  101  may have a substantially curved form; for instance the perimeter may have a substantially circular or elliptical shape. The perimeter may combine straight and curved forms; for instance the perimeter may be substantially rectangular with rounded corners, or combine parts of an elliptical curve with polygonal straight portions. The length of the rail  101  may be arbitrarily great: for instance, the rail  101  may be as long as any slide fastener in which the locking slider assembly  100  is incorporated as described below. 
     The rail  101  may be composed of any suitable material or combination of materials. The rail  101  may be composed at least in part of substantially flexible material; for instance, the rail  101  may exhibit similar flexibility to a slide fastener in which the locking slider assembly  100  is incorporated as described in further detail below. The flexible material may include a natural polymer such as rubber or an artificial polymer such as a flexible or elastomeric plastic. The flexible material may include a natural or artificial textile material. The flexible material may include a natural or artificial membranous material, such as leather. The rail  101  may be composed in part of rigid material; for instance, the rail  101  may include one or more rigid sections. The rigid material may include without limitation metal, rigid plastic, wood, or fiberglass. 
     The rail  101  has a cross-sectional dimension  107 . The cross-sectional dimension may be any dimension substantially orthogonal to the travel direction  102 ; for instance, the cross-sectional dimension may be a height of the rail  101 , for instance as illustrated in  FIGS. 1A-B  and  1 D-E, a width of the rail  101 , a diameter across the rail  101  as illustrated in  FIGS. 2E-2H  or any other dimension measurable between two points on a cross-section of the rail  101  where the cross-section is taken to be substantially orthogonal to the travel direction  102 . The rail  101  may be switched between two states, as illustrated in  FIGS. 1A-B  and  FIGS. 1D-E . The dimension  107  is greater in the second state, as illustrated for instance in  FIGS. 1B and 1E  than in the first state, as illustrated for example in  FIGS. 1A and 1D ; in other words, in the direction of measurement of the dimension  107  the rail  101  may expand when switching from the first state to the second state. The expansion may not be uniform along the length of the rail  101 ; for instance, the expansion may occur at a series of substantially evenly spaced locations along the rail  101 , leaving the area between those locations relatively unchanged. In some embodiments, as illustrated for instance in FIGS.  2 E-F, the dimension  107  expands without increasing the total circumference of the cross-section of the rail  101  where the expansion occurs; in other words, the increase in the dimension  107  is matched by a decrease in a second dimension, for instance turning the circular cross-section of a cylindrical tubular rail  101  into an elliptical cross-section, at least where the dimension  107  is being modified. In other embodiments, as illustrated for instance in  FIGS. 2G-H , the total circumference of the cross-section increases when the dimension  107  increases; in other words, a second dimension may stay the same or increase as well. 
       FIGS. 2A-D  depict side views of an embodiment of the rail  101  in the first and second states, respectively. In some embodiments, as shown in, the rail  101  includes a top surface  200 . The rail  101  may include a bottom surface  201 . In some embodiments, the height of the rail  101  is the distance from the bottom surface  201  to the top surface  200 . The rail  101  may change its height from the first state to the second using a mechanism  202  disposed between the top surface and bottom surface that pushes the top and bottom surfaces apart to change the rail to the second state. In some embodiments, as shown in  FIGS. 1A-B , the rail includes a tube having an exterior including the top surface and bottom surface and an interior containing the mechanism  202 . In some embodiments, at least one of the top surface  200  and the bottom surface  201  is composed at least in part of flexible material. Returning to  FIGS. 2A-B , the mechanism  202  may include at least one wedge cam  203 . The wedge cam  203  may have a cam face  204  forming an angle with the top surface  200 . The cam face  204  may alternatively form an angle with the bottom surface  201  or the bottom surface. The at least one wedge cam  203  may be constructed of substantially rigid material. The at least one wedge cam  203  may be attached to the rail  101  or may rest inside the rail  101 . For instance, where the rail  101  is a tube, the at least one wedge cam  203  may rest inside the tube; the at least one wedge cam  203  may be attached to a surface of the interior of the tube. The at least one wedge cam  203  may be a part of an elongated structure such as a strip that sits inside the tube; the elongated structure may be attached to a surface of the interior of the tube. The at least one wedge cam  203  include a plurality of wedge cams; for instance, the at least one wedge cam  203  may include a plurality of wedge cams incorporated in a long strip of material that is placed inside the tube. The at least one wedge cam  203  may be a flat planar wedge; in other embodiments, the at least one wedge cam  203  has a conical or otherwise curved cam face  204 ; the cam face  204  may extend all the way around the wedge cam  203  when the wedge cam  203  is conical. 
     The mechanism  202  may include an elongated member  205 . The elongated member  205  may be slidable over the at least one wedge cam  203 ; for example, the elongated member may rest on top of the at least one wedge cam  203 . In some embodiments, the elongated member  205  is flexible; for instance, the elongated member  205  may be or include a wire, such as a plastic or metal wire. The elongated member  205  may include or be a string or yarn. The elongated member  205  may include or be a cable, such as a cable suitable for use in bicycle brakes or similar devices. 
     The elongated member  205  may have at least one bead  206 . In some embodiments, a bead  206  is a physical object, attached to the elongated member  205 , that has a greater cross-sectional area than the elongated member  205 . In some embodiments, the elongated member passes through the bead  206 ; for instance, the bead  206  may have a hole through it, through which the elongated member  205  is strung, similarly to a necklace. The bead  206  and elongated member  205  may also be manufactured together; for instance, the bead  206  and elongated member  205  may be extruded or molded together. In some embodiments, the at least one bead  206  is affixed to the elongated member  205 ; in other words, the bead  206  may not slide along the elongated member  205 . The at least one bead  206  may have any shape, including a substantially spherical shape, a spheroidal shape, a regular or irregular polyhedral shape, or any combination of curved and polyhedral forms; for instance, the at least one bead  206  may have a form that presents a concave surface to a convex cam face  204 , or the bead  206  may have a form that presents a convex surface to a concave cam face  204 . The at least one bead  206  may be a plurality of beads; there may be a bead resting near each wedge cam  203 . In some embodiments, sliding the elongated member  205  in a first direction  207  causes the at least one bead  206  to travel up the wedge cam  203  and push the upper surface  200  and lower surface apart  201 . The upper surface  200 , lower surface  201  or both may deform where each bead  206  is riding up the cam surfaces  203 , increasing the height of the rail  101  at that point; in some embodiments, increasing the height of the rail  101  at least at one point along the rail  101  is increasing the height of the rail. The result of the elongated member  205  being pulled or pushed in the first direction  207  thus may be to create a series of lumps or similar protrusions in the top surface  200  or bottom surface  201  of the rail, blocking the slot  104  from sliding over the rail, for instance as illustrated in  FIG. 1B . In some embodiments, the mechanism  202  includes more than one elongated member  205  with beads  206 ; the plurality of elongated members  202  may be coupled in parallel so that a force pulling one in the first direction pulls the others as well. As a result, the rail  101  may expand in more than one dimension at the same time. 
     As shown in  FIGS. 2C-D , the mechanism  202  may include a biasing means  208  having a bias that tends to resist movement of the elongated member  205  in the first direction  207 . The biasing means  208  may be a spring, or a piece of elastic material. The biasing means  208  may act as a return spring, so that when a force pulling the elongated member  205  in the first direction  207  is released, the biasing means  208  will pull the elongated member  205  in a second direction that is the opposite direction from the first direction; as a result, the at least one bead  206  may travel back down the at least one wedge cam  203  and the rail  101  may return to the first state. 
     In some embodiments, as shown for instance in  FIGS. 2A-B , a portion of the elongated member  205  projects away from the rail  101 ; for instance, where the rail  101  is a tube, the elongated member may exit the tube. The locking slider assembly  100  may include a sheath  209  containing the portion of the elongated member  205  that projects away from the rail  101 . The sheath  209  may be constructed from any material or combination of materials suitable for the construction of the rail  101 . The sheath  209  may be flexible. The sheath  209  may be flexible but inelastic; the sheath  209  may function similarly to the sheath of a Bowden cable. For instance, as shown in  FIG. 3 , the sheath may include an outer layer  209   a;  the outer layer may be flexible, but sufficiently inelastic to resist longitudinal compression, so that when a mechanism attached to an end of the outer layer  209   a  pulls or pushes the elongated member  205  while pulling or pushing the outer layer  209   a  in the other direction, in a manner analogous to a bicycle brake. The outer layer  209   a  may contain winding or twined wires, or polymer material having similar properties, to add stiffness to the outer layer  209   a.  Viewing  FIGS. 2A-B  again, the outer layer  209   a  may be attached to the end of the rail  101  by a nut  210 . The nut  210  may be adjustable to move the end of the outer layer  209   a,  modifying the length of the outer layer  209   a;  lengthening the outer layer  209   a  may have the effect of adding tension to the elongated member  205 , while shortening the outer layer  209   a  may have the effect of reducing tension on the elongated member  205 . The sheath  209  may also include an inner layer  209   b.  The inner layer  209   b  may have low friction, to make the elongated member move more easily within the sheath  209 . 
     Turning now to  FIGS. 4A-B , the assembly  100  may include a spool  400  to which one end of the elongated member  205  is fixed, so that rotating the spool to a locking position causes the elongated member  205  to slide in the first direction. The spool  400  may be substantially cylindrical, so that the elongated member  205  winds onto the spoon in a similar manner to a cable on a winch or a sewing thread on a sewing thread spool. In some embodiments, rotating the spool from the unlocked position shown in  FIG. 4A  to the locked position shown in  FIG. 4B  causes the elongated member  205  to wind onto the spool, pulling the elongated member  205  in the first direction, and putting the rail  101  in the second state. This is illustrated for example in  FIGS. 4C-D :  FIG. 4C  illustrates an embodiment of the spool  400  as seen from the side with an end the elongated member  205  attached to it, and  FIG. 4C  illustrates the same embodiment with the spool  400  rotated, and the elongated member  205  wound around the substantially cylindrical spool, pulling the elongated member  205  in the desired direction. A user may turn the spool  400  to the locking position or the unlocking position by manipulating a lever  401  or similar manual interface device. In some embodiments, the assembly  100  includes a latch  402  that secures the spool  400  in the locking position. The latch  402  may attach to a projection from the lever  401 . The latch  402  may be opened by a button or switch; alternatively the latch  402  may include a lock, which may function in any suitable way, and may include, without limitation, a combination lock or a lock that accepts a key. 
     In some embodiments, a second elongated member  403  is also attached to the spool  400 ; the second elongated member  403  may be attached so that turning the spool to the locking position pulls the second elongated member toward the spool. In some embodiments, as shown for example in  FIGS. 5A-B , the second elongated member  403  may be part of a second assembly  500 ; for instance, the first assembly  100  may be included in a first zipper  501  on a backpack  502 , and the second assembly  500  may be included in a second zipper  503 . As shown in  FIG. 5C , the spool  400  may be mounted on a shoulder strap of the backpack  502 , with the sheathed cable or cables  209  running through the strap into the backpack  502 , for instance to connect with slide fasteners that close the backpack.  FIGS. 5D-E  illustrate how the assembly  100  or the second assembly  500  may be incorporated in a slide fastener, such as a zipper, as set forth in further detail below. The second assembly  500  may any assembly suitable for use as the first assembly  100  as described above in connection with  FIGS. 1A-4D . The spool may have three or more elongated members attached to it. Returning to  FIGS. 4A-B , the assembly  100  may include a splitter  404  that divides the elongated member and the second elongated member. The sheath  209  may attach to the splitter; a second sheath  405  may attach to the splitter, containing the second elongated member  403  as described above. Each sheath may attach to the splitter by way of a nut  406 ; as described above in connection with  FIGS. 2A-3 , the nuts  406  may be tightened or loosened to adjust the tension on the elongated members  205 ,  403 . 
     Returning to  FIGS. 1A-F , the assembly includes a slider  103 . The slider may be made of any rigid material; for instance, the slider  103  may be constructed from metal. The slider  103  includes a slot  104  that fits over the rail  101 . The slot  104  may have a cross-sectional shape that is substantially the same as the cross-sectional shape of the rail  101 . For instance, where the rail  101  has a substantially rectangular cross-sectional shape as described above in reference to  FIGS. 1A-2D , the slot  104  may be substantially rectangular; that is, the slot  104  may have a substantially rectangular shape that is open at one end, such as a substantially rectangular C-shaped profile, with the upper surface  105  forming the underside of the top of the C, and the lower surface  106  forming the top side of the bottom of the C. The slot  104  may fit snugly over the rail  101  when the rail is in the first state. The slot has a first surface  105  and a second surface  106 . The first surface  105  and second surface  106  are separated by a distance aligned with the cross-sectional dimension  107  that is greater than the first value of the cross-sectional dimension and less than or equal to the second value of the cross-sectional dimension; for example, the distance between the first surface  105  and second surface  106  may be almost the same height as the first height of the rail  101 , when in the first state. When the rail  101  is in the second state, the slot  104  may be stuck between two lumps in the rail; in other embodiments, the rail may hold the slot  104  by creating friction between the slot and the upper and lower surfaces of the rail  101  by expanding within the slot  104  when the rail is in the second state. 
     Returning to  FIGS. 5A-5H , the slider locking assembly  100  may be incorporated in a slide fastener  501 . As an example,  FIGS. 5C-E  illustrate an embodiment of a slide fastener  501  incorporating a slider locking assembly. The slide fastener  501  may include a fastener  504  having two flexible strips  505  and a set of interlocking teeth  506  alternately attached to the two flexible strips. The fastener  504  may be any fastener suitable for use in a slide fastener or zipper. The flexible strips  505  may be constructed from any flexible material as described above in reference to  FIGS. 1A-2D . The flexible strips may have any suitable shape for use in a slide fastener. In some embodiments, the flexible strips  505  are attached to two sheets or panels  507 ; the sheets or panels  507  may be part of a garment, bag, backpack, luggage item, or other product on which a slide fastener of zipper is useful for joining the edges of two sheets or panels. The sheets or panels may be constructed of any flexible or rigid materials as described above in reference to  FIGS. 1A-2D . The teeth  506  may have any form suitable for use in a slide fastener; the teeth may be substantially rectangular. The teeth  506  may have interlocking projections and indentations. The teeth  506  may have regular or irregular polyhedral forms that interlock. The teeth  506  may be formed individually from rigid material such as metal or plastic and attached independently to the flexible strips  505 . In other embodiments, the teeth  506  are formed from a coiled filament or wire of material such as nylon, and flattened at certain points to enable them to interlock. Persons skilled in the art will be aware of many ways to construct fasteners having interlocking teeth attached to strips of flexible material. 
     The slide fastener  501  may include a rail  101  having a travel direction, the rail switchable between a first state in which the rail has a first height substantially orthogonal to the travel direction and a second state in which the rail has a second height substantially orthogonal to the travel direction, the second height greater than the first height. The rail  101  may be any rail as described above in reference to  FIGS. 1A-2D . The rail  101  may be manufactured separately from the fastener  504 , and subsequently attached to the fastener  504 ; for instance, as shown in  FIG. 5E , the rail  101  may have a projecting strip  101   a  that may be attached to one of the flexible strips or to one of the sheets or panels  507  to which the flexible strips are attached. The projecting strip  101   a  may be attached by any suitable process, including without limitation adhesion, heat sealing, or sewing. The rail  101  may be attached on the underside of the slide fastener  501 ; that is, where the slide fastener  501  closes an opening in an object, such as a backpack, luggage item, pocket, or garment, which has an interior or exterior, the rail  101  may be attached on the interior side of the slide fastener  501 . The rail  101  may be attached to run parallel to the fastener  504  when the teeth of the fastener  504  are interlocked, as shown in  FIGS. 5C-D . 
     The slide fastener  501  may include a slider  103 . The slider  103  may include a slot  104  that fits over the rail  101 , the slot  104  having an upper surface over the rail and a lower surface under the rail, the slot having a distance between the upper surface and lower surface, the distance being greater than the first height and less than the second height, as described above in reference to  FIGS. 1A-2D . The slider  103  may be slidably engaged to the fastener  504 . The slider  103  may have a mechanism  508  that separates the interlocking teeth when the slider slides in a first direction and interlocks the interlocking teeth when the slider slides in a second direction. As illustrated in  FIGS. 5F-G , the mechanism  508  may combine a wedge  509  with a y-shaped junction  510 . When the slider, and therefore the mechanism  508 , travels in the first direction  511 , the teeth may move in the opposite direction as illustrated in  FIG. 5F ; the wedge  509  may part the teeth so that they pass through the two parted branches of the Y-junction  510 . When the slider, and therefore the mechanism  508 , travel in the second direction  512 , the teeth may travel through the slider in a direction opposite to the second direction  512 , and the Y-junction  510  may force the teeth to intermesh as they enter the stem of the Y-shaped passage  510 . Persons skilled in the art will be aware of various ways to implement such a mechanism. 
     In some embodiments, the incorporation of the locking slider assembly  100  in the slide fastener  501  results in a slide fastener  501  that may be locked, preventing the slider  103  from moving along the fastener  504  and parting or enmeshing the teeth, when the rail  101  is in the second state. Thus, a user may be able to lock the slide fastener  504  when it is entirely or partially closed; the user may do so using the spool  400  and handle  401  as illustrated in  FIGS. 4A-B  and  5 A-B. The user may latch the spool  400  so that the slide fastener  501  cannot be opened until the spool  400  is unlatched; where the latch incorporates a lock, the slide fastener  501  may be impossible to open in the conventional way until the spool is unlocked. As a result, the user may be able to secure the slide fastener  501  thoroughly, quickly, and easily, protecting any valuable object enclosed by the slide fastener  501 . 
       FIG. 6  illustrates some embodiments of a method  600  for manufacturing a slide fastener having a locking slider assembly. The method  600  includes obtaining a slide fastener ( 601 ). The method  600  includes attaching to the slide fastener a rail, the rail having a travel direction, the rail switchable between a first state in which the rail has a first height substantially orthogonal to the travel direction and a second state in which the rail has a second height substantially orthogonal to the travel direction, the second height greater than the first height ( 602 ). The method  600  includes incorporating in the slide fastener a slider slidably engaged to the fastener, the slider having a mechanism that separates the interlocking teeth when the slider slides in a first direction and interlocks the interlocking teeth when the slider slides in a second direction, the slider further comprising a slot that fits over the rail, the slot having an upper surface over the rail and a lower surface under the rail, the slot having a distance between the upper surface and lower surface, the distance being greater than the first height and less than the second height. 
     Referring to  FIG. 6  in greater detail, and by reference to  FIGS. 1A-5G , the method  600  includes obtaining a slide fastener ( 601 ). The slide fastener may be any slide fastener as described above in connection with  FIGS. 5A-G . In some embodiments, obtaining the slide fastener involves purchasing or otherwise sourcing a slide fastener from another party; the slide fastener thus obtained may include the fastener  504 . In some embodiments, the slide fastener thus sourced includes a slider having a mechanism  508  as described above for parting or enmeshing the interlocking teeth; in other embodiments the slide fastener  501  includes only the fastener  504 . In other embodiments, obtaining the slide fastener  501  includes manufacturing the slide fastener  501  or one or more components of the slide fastener. The method  600  may include incorporating the slide fastener  501  in a product such as a backpack, luggage item, handbag, or article of clothing; the flexible strips  505  may be sewn or otherwise attached to the product. 
     The method  600  includes attaching to the slide fastener a rail, the rail having a travel direction, the rail switchable between a first state in which the rail has a first height substantially orthogonal to the travel direction and a second state in which the rail has a second height substantially orthogonal to the travel direction, the second height greater than the first height ( 602 ). The rail  101  may be any rail  101  as described above in reference to  FIGS. 1A-5G . In some embodiments, this includes manufacturing the rail  101 . The rail  101  may be extruded or otherwise formed from polymer material in a manner analogous to the formation of plastic or rubber tubing. The rail  101  may be attached to the slide fastener  501  as shown in  FIGS. 5A-G ; the rail  101  may be attached before or after the slide fastener  501  is incorporated in the product. 
     The method  600  may include incorporating the mechanism  202  in the rail; where the rail  202  includes a tube, this may include inserting the wedge cams  203  in the rail  101 . This may include inserting a strip bearing the wedge cams  203  inside the rail; the strip or individual wedge cams  203  may be adhered or otherwise attached to the interior surface of the tube. The elongated member  205  may be inserted over the wedge cams  203  in the tube; in some embodiments the elongated member  205  and wedge cams  203  are inserted together. The method  600  may include placing the biasing means  208  at one end of the rail; an end cap or other element bearing the biasing means may be attached. 
     The method  600  includes incorporating in the slide fastener a slider slidably engaged to the fastener, the slider having a mechanism that separates the interlocking teeth when the slider slides in a first direction and interlocks the interlocking teeth when the slider slides in a second direction, the slider further comprising a slot that fits over the rail, the slot having an upper surface over the rail and a lower surface under the rail, the slot having a distance between the upper surface and lower surface, the distance being greater than the first height and less than the second height. The slider  103  may be any slider  103  as described above in reference to  FIGS. 1A-5G . In some embodiments, incorporating the slider  103  involves attaching a slot  104  to an existing slider  103 , such as a slider that came with the slide fastener  501  if the slide fastener is sourced from another party; in other embodiments, the slider  103  with the slot  104  is manufactured by methods that may include without limitation molding, machining, or rapid prototyping. Incorporating the slider  103  may include inserting the teeth  506  of the fastener  504  in the mechanism of the slider  103 . Incorporating the slider  103  may include inserting the rail  101  in the slot of the slider  103 . 
     The method may include attaching the end of the elongated member to the spool  400 ; in some embodiments, the spool is manufactured, for instance by molding, machining, or rapid prototyping. The spool  400  and latch  402  may be assembled together; the spool  400  and latch  402  may be incorporated in the product before or after they are assembled together. The spool  400  and latch  402  may be incorporated in the product before or after the end of the elongated member  205  is attached to the spool. 
     The method may include inserting the elongated member in a sheath  209 . The elongated member may be tensioned as described above by adjusting one or more nuts on the ends of the sheath. The sheath  209  may be attached to the rail by a nut. The sheath  209  may be attached to the spool  400  by way of a splitter  500  as described above. 
       FIGS. 7A-B  depict some embodiments of a locking slider assembly  700 . As an overview, the locking slider assembly includes a slider  701 . The slider includes a slot  702 . The locking slider assembly includes a rail  703  slidably inserted through the slot  702  of the slider  701 . The rail  703  includes at least one tooth  704 . The at least one tooth  704  is movable between an extended state in which the tooth prevents the slot  702  from moving in at least one direction  705  along the rail, as illustrated in  FIG. 7A , and a retracted state in which the slot  702  can slide past the at least one tooth  704 , as illustrated in  FIG. 7B . 
     Viewing  FIGS. 7A-B  in greater detail, the locking slider assembly  700  includes a slider  701 . The slider  701  may be any item suitable for use as a slider  103  as described above in connection with  FIGS. 1A-6 . The slider  701  includes a slot  702  into which the rail  703  is slidably inserted; the slot  701  may be any feature suitable for use as a slot  104  as described above in relation to  FIGS. 1A-6 . For instance, the slot  702  may be formed by a substantially C-shaped projection attached to the slider  701 . In some embodiments the slot  701  fits snugly over the rail  703 . In some embodiments, as illustrated in  FIG. 8 , the slider  701  further includes a cavity  801  into which the at least one tooth  704  inserts when in the extended position; the cavity  801  may be a hole straight through the projection forming the slot, or may be formed by a depression in an internal surface of the slot  702 . The cavity  800  may have any shape suitable for accepting the portion of the at least one tooth  704  that inserts into the cavity  800  when the at least one tooth  704  is in the extended position; for example, the cavity may have any cross-sectional form usable for the cross-sectional form of the at least one tooth  704  as described in further detail below. 
     The assembly  700  includes a rail  703 . The rail  703  may be any feature suitable for use as a rail  101  as described above in connection with  FIGS. 1A-6 . The rail  703  is slidably inserted in the slot  702 ; the slot  702  and slider  701  may be free to slide along the rail in a longitudinal direction  705  or its opposite direction. The rail  703  includes at least one tooth  704 . The at least one tooth  704  is movable between an extended state in which the tooth prevents the slot  702  from moving in at least one direction  705  along the rail, as illustrated in  FIG. 7A , and a retracted state in which the slot  702  can slide past the at least one tooth  704 , as illustrated in  FIG. 7B . 
     The at least one tooth  704  may be any member that projects into the path of travel of the slider  701 , when in the extended position, to prevent the slider  701  from traveling in at least one direction. The at least one tooth  704  may be constructed of any material or combination of materials suitable for the construction of the slider  701  or the rail  703 . The at least one tooth  704  may have any three-dimensional shape, including any polyhedral or spheroidal shape, or any combination of such forms. The at least one tooth  704  may have a cross-section transverse to the direction of motion of the tooth between the first and second positions; the cross-section may have any polygonal form, curved form, or combination thereof, including without limitation rectangular, square, circular, or elliptical forms, with rounded corners, straight sections, and the like. Although in the exemplary illustrations provided in the figures, the at least one tooth  704  projects in only one direction, the at least one tooth  704  may include teeth that project in two or more directions; moreover, the at least one tooth  704  may project in any direction from the rail  703 , including upward, downward, sideways, and so forth. 
     In some embodiments, as illustrated for example in the partial longitudinal cross-section in  FIGS. 9A-B  the rail  703  also includes an elongated member  900 . The elongated member  900  may be any component suitable for use as an elongated member  205  as described above in reference  FIGS. 1A-6 . In some embodiments, the at least one tooth  704  is mounted on the elongated member  205 ; for instance, the at least one tooth  704  may be attached directly or indirectly to the elongated member  205  so that when the elongated member moves in one or more directions the at least one tooth  704  also moves in those directions. The rail  703 , at least one tooth  704 , and elongated member  900  may be formed that when the elongated member  900  slides in a first direction  901  the at least one tooth  704  is forced into the extended position, as shown for example in  FIG. 9B , and when the elongated member  900  slides in a second direction, which may be opposite to the first direction  901 , the at least one tooth  704  is forced into the retracted position, as illustrated for instance in  FIG. 9A . The mechanism whereby the at least one tooth  704  is forced into the extended position may be a wedge cam mechanism such as that described above in reference to  FIGS. 1A-6 . In other embodiments, at least one tooth  704  is mounted on the elongated member  900  by a biasing means  902 ; for instance, the at least one tooth  704  may be attached to at least one biasing means  902  that is attached in turn to the elongated member. The biasing means  902  may be any kind of spring or other elastic component. The biasing means  902  may have a bias that urges the at least one tooth into the extended state; for instance, the biasing means  902  may be inserted into the rail by deforming the biasing means  902 , causing the biasing means  902  to exert a recoil force tending to urge the at least one tooth  704  away from the rail  703  and into the extended position. 
     The mechanism to force the at least one tooth  704  into the retracted position when the elongated member  900  is moved in the second direction may include a biasing means (not shown); for instance, where the at least one tooth  704  is forced into the extended position by traveling up a wedge cam, a biasing means may force the at least one tooth  704  back into the retracted position when the at least one tooth  704  is moved in the second direction. In other embodiments, the rail  703  also includes at least one surface  903  against which the at least one tooth  704  is forced when the elongated member  900  is moved in the second direction, the at least one surface  903  and at the least one tooth  704  are formed so that forcing the at least one tooth  704  against the at least one surface  903  moves the at least one tooth  704  into the retracted position. For example, as shown in  FIGS. 9A-B , the at least one tooth  704  may have an angled surface that when forced against a surface  903  of the rail  703 , causes the surface  903  of the rail  703  to exert a force on the at least one tooth  704  toward the retracted position. The at least one surface  903  may be the edge of an opening in the rail  703  out of which the tooth  704  projects when in the extended position. 
     The elongated member  900  may be moved in the first or second direction using a spool to which one end of the elongated member  900  is fixed, so that rotating the spool to a locking position causes the elongated member to slide in the first direction, as illustrated and described in reference to  FIGS. 4A-5C  above. The spool may have a latch that secures the spool in the locking position, as described above in reference to  FIGS. 4A-5C . Likewise, as described above in reference to  FIGS. 4A-5C , the assembly  700  may include a second locking assembly having a second elongated member, and wherein the second elongated member is also wound on the spool. The assembly  700  may include a splitter dividing the elongated member and the second elongated member. 
     As described in further detail above in reference to  FIGS. 3-5C , a portion of the elongated member  900  may project away from the rail  703 ; the assembly  700  may include a sheath  209  containing the portion of the elongated member that projects away from the rail  703 . The sheath  209  may be flexible. 
     Returning now to  FIGS. 7A-B , the at least one tooth  704  may include a plurality of teeth. For instance, the plurality of teeth may be regularly spaced so that, when in the extended position, the plurality of teeth can prevent the slider  701  from moving away from whatever position the slider  701  currently occupies along the rail  703 . In some embodiments, the rail  703  forms a tube with a plurality of openings  706 . Each of the plurality of teeth  704  may project through one opening of the plurality of openings  706 ; in other words, each tooth  704  may retract into an opening  706  when the tooth  704  moves into the retracted position, and may extend out of the opening when in the extended position. An edge of the opening  706  may form a surface against which the tooth is pushed when the elongated member  900  moves in the second direction, as described above. 
       FIG. 10  illustrates a slide fastener  1000  incorporating a locking slider assembly  700  as described above in reference to  FIGS. 7A-9B . The slide fastener  1000  includes two flexible strips  1001 . The slide fastener  1000  includes a set of interlocking teeth  1002  alternately attached to the two flexible strips  1001 . The slide fastener  1000  includes a slider  701  slidably engaged to the fastener  1000 , the slider  701  having a mechanism  1003  that separates the interlocking teeth  1002  when the slider  701  slides in a first direction and interlocks the interlocking teeth  1002  when the slider  701  slides in a second direction. The interlocking teeth,  1002  flexible strips  1001 , slider  701 , and mechanism  1003  may function as described above in connection with  FIGS. 1A-6 . The slider  701  includes a slot  702  as described above in reference to  FIGS. 7A-9B . The fastener  1000  includes a rail  703  slidably inserted through the slot of the slider, the rail having at least one tooth movable between an extended state in which the tooth prevents the slot from moving in at least one direction along the rail, and a retracted state in which the slot can slide past the at least one tooth; this may be implemented as described above in reference to  FIGS. 7A-9B . 
       FIG. 11  illustrates some embodiments of a method  1100  for manufacturing a slide fastener having a locking slider assembly. The method  1100  includes obtaining a slide fastener ( 1101 ). The method  1100  includes incorporating in the slide fastener a slider slidably engaged to the fastener, the slider having a mechanism that separates the interlocking teeth when the slider slides in a first direction and interlocks the interlocking teeth when the slider slides in a second direction, the slider further comprising a slot ( 1102 ). The method  1100  includes attaching to the slide fastener a rail slidably inserted through the slot of the slider, the rail having at least one tooth movable between an extended state in which the tooth prevents the slot from moving in at least one direction along the rail, and a retracted state in which the slot can slide past the at least one tooth ( 1103 ). 
     Referring to  FIG. 11  in greater detail, and by reference to  FIGS. 7A-10 , the method  1100  includes obtaining a slide fastener ( 1101 ). This may be implemented as described above in reference to  FIG. 6 . 
     The method  1100  includes incorporating in the slide fastener a slider slidably engaged to the fastener, the slider having a mechanism that separates the interlocking teeth when the slider slides in a first direction and interlocks the interlocking teeth when the slider slides in a second direction, the slider further comprising a slot ( 1102 ). This may be implemented as described above in reference to  FIG. 6   
     The method  1100  includes attaching to the slide fastener a rail slidably inserted through the slot of the slider, the rail having at least one tooth movable between an extended state in which the tooth prevents the slot from moving in at least one direction along the rail, and a retracted state in which the slot can slide past the at least one tooth ( 1103 ). This may be implemented as described above in reference to  FIGS. 6-10 . 
     It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.