Abstract:
A length-adjustable strap has two plies joined together to form a channel therebetween. The channel generally does not extend the entire length of the strap. At least one extender slidably engages in the channel. The extender may have holes therethrough or recesses that engage elements of one or more fasteners at or near the proximal end of the strap in an adjustment region outside of the channel. Mating screws are joined to the fastener(s) to secure the extender in place. Optionally, the fastener(s) and mating screws are replaced by a tie that threads through holes formed through the first ply and optionally the second ply as well as the hole(s) formed through the extender to secure the extender in place. Multiple fastening connections more evenly distribute the load.

Description:
BACKGROUND 
     The field of the present invention relates to length-adjustable leather straps for guitars. 
     Guitar straps are made to hold a guitar via the shoulders at an adjustable length to suit the position favored by the musician. Guitars have different mechanisms for permitting strap attachment. Most guitars have strap nuts anchored to the guitar with screws. Generally, two strap nuts are pre-attached to electric guitars. The lower strap nut usually is located at the bottom (bridge end) of the guitar body. The upper strap nut usually is located at or near the top (neck end) of the guitar body, such as on the upper body curve, at the tip of the upper horn on a double cut-away, or at the neck joint (heel), or sometimes at the lower body end. Some acoustic and classical guitars have only a single strap nut at the bottom of the body. The other end must be tied onto the headstock, above the nut and below the machine heads. 
     While some guitar straps are formed with lengths of fabric and have protruding buckles at one or both ends for length adjustment, most professional musicians favor leather guitar straps, and particularly those with ladder lock or “H” lock attachment. For leather straps with ladder lock attachment, the strap has a series of slots at each end. A separate length leather strap having a width comparable to the slot opening is provided with one end having a clasp or hole therein. Once a desired guitar strap length is determined, the separate length leather strap is threaded through the slots above and below the face surfaces of the main strap. The separate length leather strap also is threaded through the clasp or hole to engage the leather strap in place. The separate length of the leather strap is provided with one or more openings to engage strap buttons. 
     One disadvantage of existing leather guitar straps with ladder lock attachment is that length adjustment cannot be completed rapidly. Moreover, it is not intuitive how best to adjust for a desired length. The separate length leather strap has to be removed and repositioned and re-threaded through the slots of the main strap. A third disadvantage of existing leather guitar straps is that the separate length leather strap has portions seated on each face surface of the guitar strap. These raised portions increase the thickness of the guitar strap, make the outer faces of the strap not smooth, and tend to rub against the user&#39;s shoulder or back causing discomfort. 
     U.S. Pat. No. 7,507,889 shows a compression adjustable strap that has a first portion defining a tunnel along substantially the entire length of the first portion to slidingly receive a second strap portion. The compression or frictional engagement between the first strap portion and second strap portion is sufficient to secure the position of the second strap portion. Optionally, the second strap portion may define a row of holes to engage with a post or button on the first portion to maintain the second strap portion in a desired position with respect to the first portion (which the patent calls an “adjustment keeper”). The compression adjustable strap may be used as a guitar strap. 
     U.S. Pat. No. 4,858,801 discloses a guitar strap that is a band with an end belt coupled to one side of the band by slidably inserting the end belt into a tunnel. The anchor member to hold the end belt to the band may be a hook and loop fastener. One fastener strip is on the external face of the band. 
     A disadvantage of existing guitar straps with tunnels to hold extenders is that compression or frictional engagement is not sufficient to maintain the position of the slidable portion in a tunnel. A single hole seated over a single point post or button used as an “adjustment keeper” forms an early failure zone for the strap, shortening the useful life of the strap. A second disadvantage is that hook and loop fasteners increase the thickness of the guitar strap and lead to surface wear or cause bulges to form on the strap leading to user discomfort. 
     Improvements to length adjustable leather straps for guitars continue to be sought. Golf bags and rifle carry slings also would benefit from unencumbered, smooth-surfaced length-adjustable leather straps. 
     SUMMARY 
     In one aspect of the invention, a length-adjustable strap has a first ply joined to a second ply and defining a channel between the first ply and the second ply. A fastener is positioned at or near the proximal end of the first ply. An extender is slidably engageable into the channel from the proximal end of the first ply. The extender defines a plurality of spaced apart holes therethrough or recesses. Each of said holes or recesses is adapted to mate with an element of the fastener, such as an internally threaded opening or an upstanding threaded post. Preferably, the holes or recesses are aligned such that a respective hole of the extender is matched with a respective element of the fastener. Such holes then may engage the respective elements of the fastener to set the length of that portion of the extender that extends out from the channel. In one embodiment, the fastener has one element to engage with a respective hole of the extender, and in another embodiment, the fastener has more than one element to engage, with each element adapted to engage with a respective hole of the extender. The fastener is in an adjustment region that is in a nonencumbered area of the strap outside of the channel. 
     A hole closer to the proximal end of the extender is adapted to engage a guitar nut. Mating screws may engage or mate with the elements of the fasteners to secure the extender in place. 
     In a second aspect of the invention, a fastener is positioned at or near the proximal end of the first ply and the fastener has elements disposed in a line that is parallel to the center line along the length of the strap. The extender defines a plurality of spaced apart holes or recesses that are disposed in a single row extending in a line that is parallel to the center line along the length of the extender. Two of such holes or recesses may engage the elements of the fastener to set the length of that portion of the extender that extends out from the channel. The fastener is in an adjustment region that is in a nonencumbered area of the strap outside of the channel. 
     In another aspect of the invention, the length-adjustable strap has a second fastener or pair of fasteners at or near the distal end of the first ply. A second extender is slidably engageable into the channel, so that the first extender extends from one end and the second extender extends from the other end of the strap. The second extender defines a plurality of spaced apart holes therethrough or recesses, with said holes or recesses adapted to mate with the second fastener or pair of fasteners. Additional mating screws may engage or mate with the second fastener(s) to secure the second extender in place. 
     In another aspect of the invention, the first ply defines first and second slot openings at or near its proximal end and its distal end, respectively. The extender(s) slidably engage into the channel via the first and second slot openings. 
     In still another aspect of the invention, the length-adjustable strap has a first ply joined to a second ply to define a channel therebetween. However, fastener(s) are not joined to the strap. Instead, the first ply and optionally the second ply further define two or more holes therethrough at or near the proximal end, and optionally two or more additional holes therethrough at or near the distal end. An extender is slidably engageable into the channel. The extender defines a plurality of holes along at least a portion of its length. A tie is threaded through at least some of the holes through the first ply and the holes through the extender to join the extender to the first ply. If the second ply has holes therethrough, the tie may be threaded also through those holes so that the extender is joined to the first ply and the second ply. The holes may be disposed in either one row or in two rows along the length of the extender. The tie is threaded through at least two of the holes, such as two of the holes in the single row where the extender has a single row of holes, or such as one hole from each row in the two rows where the extender has two rows of holes. The holes through the first ply are in an adjustment region that is in a nonencumbered area of the strap outside of the channel. 
     The length-adjustable straps have particular application for attachment to a nut projecting outwardly from a guitar. The extenders have holes, slots, openings or engagement mechanisms adapted to attach to the nut on a guitar. 
     There are several advantages of the length-adjustable straps of the current invention for guitar straps. The length-adjustment is made in an adjustment region, which is a free-floating area that is not in contact with the guitar body or the user&#39;s shoulder. The extender does not increase bulk or encumber the shoulder-contacting area of the user. The second ply of the length-adjustable strap has a surface facing away from the first ply that is substantially smooth. This substantially smooth surface allows the strap to slide along the user&#39;s shoulder without encumbering the shoulder or having raised portions or bulges that rub the user&#39;s shoulder. In addition, the substantially smooth surface won&#39;t scuff or mar guitar surfaces. Moreover, the length adjustment is more intuitive because the holes in the extender are spaced apart at uniform spacing distances and are engageable with elements of fasteners or with holes in the first/second ply that are spaced apart at the same uniform spacing distances. This design is particularly advantageous when the first ply and second ply are formed of leather. 
     The length-adjustable straps also can be used in association with Sunday golf bags and rifle carry slings, among other things. 
     A more complete understanding of the invention, including an understanding of the various configurations of length-adjustable straps, will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by consideration of the followed detailed description. Reference will be made to the appended drawing sheets which will first be described briefly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure. In the drawings, wherein like reference numerals refer to similar components: 
         FIG. 1  is a right front perspective view of a first embodiment of a length-adjustable strap according to the invention shown attached to a guitar; 
         FIG. 2  is a right front perspective view of the first embodiment of a length-adjustable strap according to the invention; 
         FIG. 3  is a partial exploded view of a proximal end of the length adjustable strap of  FIG. 2 ; 
         FIG. 4  is a partial right front perspective view of the proximal end of the length adjustable strap of  FIG. 1  as assembled; 
         FIG. 5  is a top plan view of a second embodiment of a length-adjustable strap according to the invention; 
         FIG. 6  is a bottom plan view of the length-adjustable strap of  FIG. 6 ; 
         FIG. 7  is a cross-sectional view taken along line  7 - 7  of  FIG. 6 ; 
         FIG. 8  is a top plan view of a third embodiment of a length-adjustable strap according to the invention; 
         FIG. 9  is a bottom plan view of the length adjustable strap of  FIG. 8 ; 
         FIG. 10  is a top plan view of the first ply portion of the length-adjustable strap of  FIG. 8  without an extender; 
         FIG. 11  is a cross-sectional view taken along line  11 - 11  of  FIG. 8 ; 
         FIG. 12  is a top plan view of the first ply portion of a fourth embodiment of a length-adjustable strap according to the invention without an extender; and 
         FIG. 13  is a cross-sectional view of a length-adjustable strap with an extender joined by customary screw fasteners. 
     
    
    
     DETAILED DESCRIPTION 
     Turning in detail to the drawings,  FIGS. 1-4  show a first embodiment of a length-adjustable strap  10 . The strap  10  may be a guitar strap. The strap  10  is shown attached to a guitar  200  in  FIG. 1 . One end of an extender  30  is joined to a guitar nut (not shown), and one end of the strap  10  is joined to another guitar nut  202 . 
     The strap  10  has an upper ply or first ply  12  joined to a lower ply or second ply  14 . Preferably, the two plies  12 ,  14  are leather. A central channel  20  is formed between the facing surfaces of the upper ply  12  and the lower ply  14 . The upper ply  12  defines a slot opening  16  that communicates with the central channel  20 . The central channel  20  preferably does not extend along the entire length of the strap  10 . 
     A first upstanding threaded screw, t-nut or PAL nut  22  is provided at or near the proximal end of the upper ply  12  and extends outwardly from the outer face surface of the upper ply  12 . The first upstanding threaded screw or nut  22  in this embodiment is positioned adjacent to the slot opening  16  leading to the channel  20 . 
     A first extender  30  has a width suitable for slidable engagement through the slot  16  and into the channel  20  at the proximal end of the strap  10 . The first extender  30  has a plurality of holes  32  therethrough or recesses extending along its length. A first end of the first extender  30  is inserted into the channel  20  through the slot  16 . A portion of the length of the first extender  30  remains extended outside of the channel  20 . The first upstanding threaded screw, t-nut or PAL nut  22  mates with one of the holes  32  to establish a desired length of the extender outside of the channel  20 . A mating screw  34  is joined to the first upstanding threaded screw, t-nut or PAL nut  22  to fasten the screws together and join the extender  30  to the first ply  12  of the strap  10 . 
     Optionally, a second extender (not shown) has a width suitable for slidable engagement through an opposite slot and into the channel  20  at the distal end of the strap  10 . A first end of the second extender is inserted into the channel  20  through the opposite slot. A portion of the length of the second extender remains extended outside of the channel  20 . The second extender may have a plurality of holes therethrough or recesses extending along its length. A second upstanding threaded screw, t-nut or PAL nut mates with one of the holes to establish a desired length of the optional second extender outside of the channel  20 . A second mating screw is joined to the second upstanding threaded screw, t-nut or PAL nut to fasten the screws together and join the second extender to the first ply  12  of the strap  10 . 
     A significant advantage of this second embodiment of the length-adjustable strap  10  is that the outwardly facing surface of the second ply  14  remains smooth, without raised portions that may scuff or mar equipment surfaces. A second significant advantage is that the extender(s)  30  are readily adjusted very quickly to have different length portions exposed outside of the channel  20 . The strap need not be separated from the equipment to which it is attached, such as a guitar, when the positions of the extender(s) is/are adjusted to lengthen or shorten the overall length of the length-adjustable strap. 
     Referring next to  FIGS. 5 to 7 , an alternative embodiment of the length-adjustable strap  100  has an upper ply or first ply  112  joined to a lower ply or second ply  114 . Preferably, the two plies  112 ,  114  are leather. A central channel  120  is formed between the facing surfaces of the upper ply  112  and the lower ply  114 . The upper ply  112  defines a slot opening  120   b  that communicates with the central channel  120 . 
     A pair of holes  164 ,  166  is formed through the first ply  112 . The holes  164 ,  166  are spaced apart in a line along a center axis of the first ply along its length. The holes  164 ,  166  are generally near the proximal end of the strap in the adjustment region  180 . A pair of holes  167 ,  169  is formed through the second ply  114 . The holes  167 ,  169  are spaced apart in a line along a center axis of the second ply along its length. The holes  167 ,  169  substantially align with holes  164 ,  166 . 
     A first extender  170  shown in  FIGS. 5 to 7  has a row of holes  172  therethrough along its length. As shown in  FIG. 6 , the holes  172  extend in a row along the center axis along the length of the extender  170 . A raw hide string or other tie  174  is threaded through a first hole of the row of holes in the extender  170 , and through the hole  164  formed in the first ply  112 , and through the hole  167  formed in the second ply  114 , then the tie  174  is threaded through a second hole  169  in the second ply  114  and through the second hole  166  in the first ply  112 . The ends of the string or tie  174  are then tied or knotted together to join the extender  170  to the first ply  112  and second ply  114 . 
     The central channel  120  preferably does not extend along the entire length of the strap  100 . Preferably, the central channel  120  does not extend more than about 20 inches from the proximal end of the strap. With such preferred embodiment, the user&#39;s shoulder comes into contact with only the second ply  114  of the strap  100  without the bulk of the extender  170  inside the strap. The entire width of strap  100  then lays on the user&#39;s shoulder as intended without bulging and without otherwise encumbering the user. I have found that there is improved comfort for the user if there are no encumbrances to the strap for from two-thirds to three-fourths of the guitar strap. Thus, it is preferred that the extender ( 170 ) does not extend into the central channel  120  beyond about one-fourth to one-third the length of the guitar strap. Hence, there is less bulk along that portion of the strap  100  that is in contact with a user&#39;s shoulder. 
     A significant advantage of this embodiment of the length-adjustable strap  100  is that the outwardly facing surface of the second ply  114  remains relatively smooth, either without raised portions that may scuff or mar equipment surfaces, or with only leather tie at the outwardly facing surface, which does not scuff or mar equipment surfaces. A second significant advantage is that the slidably engageable extender(s)  170  are readily adjusted very quickly at the adjustment region  180  to have different length portions exposed outside of the channel  120 . The strap need not be separated from the equipment to which it is attached, such as a guitar, when the positions of the extender(s) is/are adjusted to lengthen or shorten the overall length of the length-adjustable strap. The length adjustment in the adjustment region  180  is made in a free-floating area spaced apart from the guitar and from that part of the strap that rests on the user&#39;s shoulder. A third significant advantage is that the extender is secured to the first and second plies at two points of connection to better distribute the load on the tie  174 . 
     Referring next to  FIGS. 8 to 11 , an alternative embodiment of the length-adjustable strap  200  has an upper ply or first ply  212  joined to a lower ply or second ply  214 . Preferably, the two plies  212 ,  214  are leather. A central channel  220  is formed between the facing surfaces of the upper ply  212  and the lower ply  214 . The upper ply  212  defines a slot opening  220   b  that communicates with the central channel  220 . The central channel  220  preferably does not extend along the entire length of the strap  200 . Hence, there is less bulk along that portion of the strap  200  that is in contact with a user&#39;s shoulder. 
     A fastener  226 , such as a double t-nut fastener, is embedded between the first and second plies  212 ,  214 . A first internally threaded portion  222  is provided in the fastener  226  at or near the proximal end of the upper ply  212  and is accessed through a hole formed in the outer face surface of the upper ply  212 . The first internally threaded portion  222  in this embodiment is positioned adjacent to the slot opening  220   b  leading to the channel  220 . A second internally threaded portion  224  is provided in the fastener  226  and is spaced apart from the first threaded portion  222 , preferably along a center line of the upper ply  212 . The second internally threaded portion  224  is accessed through a hole formed in the outer face surface of the upper ply  212 . The fastener  226  is located in the adjustment region  280  that is between the proximal end of the first ply  212  and the slot opening  220   b  of the channel  220 . 
     A first extender  230  has a width suitable for slidable engagement through the slot  220   b  and into the channel  220  at the proximal end of the strap  200 . The first extender  230  has a plurality of holes  232  therethrough or recesses extending along its length. A first end of the first extender  230  is inserted into the channel  220  through the slot  220   b . A portion of the length of the first extender  230  remains extended outside of the channel  220 . Holes  232  of the first extender  230  are matched with the holes in the upper ply  212  to access the internally threaded portions  222 ,  224  of the fastener  226  to establish a desired length of the extender outside of the channel  220 . A mating screw, t-nut or PAL nut  234  is joined to the first internally threaded portion  222  to fasten the screw to the fastener  226  and join the extender  230  to the first ply  212  of the strap  200 . A second mating screw  236  is joined to the internally threaded portion  224  of the fastener  226  to fasten the screw to the fastener and join the extender  230  to the first ply  221  of the strap  200 . 
     A significant advantage of this embodiment of the length-adjustable strap  200  is that the outwardly facing surface of the second ply  214  remains smooth, without raised portions that may scuff or mar equipment surfaces. A second significant advantage is that the slidably engageable extender(s)  230  are readily adjusted very quickly to have different length portions exposed outside of the channel  220 . The strap need not be separated from the equipment to which it is attached, such as a guitar, when the positions of the extender(s) is/are adjusted to lengthen or shorten the overall length of the length-adjustable strap. The length adjustment occurs at the adjustment region  280  which is outside of the channel  220  and is in a free-floating region of the strap that is not in contact with the guitar or with the user&#39;s shoulder when the strap is worn. A third significant advantage is that the extender is secured to the first and second plies at two points of connection to better distribute the load on each fastener. Moreover, it is again desired to have the length of the extender  230  be limited to about one-fourth to one-third the length of the guitar strap to minimize bulk in the majority of the length of the guitar strap for increased user comfort. 
     An alternative arrangement is shown in  FIGS. 12 and 13 . Instead of fastener  226  that is present in the embodiment of  FIGS. 8-11 , it would be possible to use more customary fastening hardware, such as mating screws, t-nuts or PAL nuts  242 ,  244  to receiving mating screws  234 ,  236 . In such an embodiment, the screw heads of the mating screws, t-nuts or PAL nuts  242 ,  244  would be visible at the outer surface of the lower ply  214 . In such case, it may be more desirable to have plastic screw heads so as to minimize scratching or marring of guitars or other instruments or equipment connected to the strap. The holes  232  in the extender  230  seat around the upstanding portions of the mating screws, t-nuts of PAL nuts  242 ,  244 . Then mating fasteners  234 ,  236  are joined to secure the extender to the first ply  212  of the strap  200 . 
     Optionally, if the channel  220  extends along the entire length of the strap, a second extender (not shown) has a width suitable for slidable engagement through an opposite slot and into the channel  220  at the distal end of the strap  200 . A first end of the second extender is inserted into the channel  220  through the opposite slot. A portion of the length of the second extender remains extended outside of the channel  220 . The second extender may have a plurality of holes therethrough or recesses extending along its length. A second double fastener comparable to fastener  226  is embedded between the plies  212 ,  214  (or customary fasteners  242 ,  244  are provided). Once the holes of the optional second extender are aligned with the fastening elements of the double fastener to establish a desired length of the optional second extender outside of the channel  220 , mating screws may be joined to receiving elements of the double fastener to join the second extender to the first ply  212  of the strap  200 . 
     Adjusting the length of the guitar straps  10 ,  100 ,  200  of the invention can be accomplished quickly and accurately. The joining mechanisms are easy for a user to detach and reattach when extending a greater or lesser portion of the length of the extenders  70 ,  170 ,  230  out of the central channels  20 ,  120 ,  220 . Preferably, the spacing between holes  172 ,  232  of the extenders is consistent, such as one-inch from the center of a first hole to the center of an adjacent hole, and so on. The extenders  70 ,  170 ,  230  preferably may have a length from end to end of between about 12 inches and about 20 inches, most preferably about 18 inches. 
     Thus, various configurations of length-adjustable straps are disclosed. While embodiments of this invention have been shown and described, it will be apparent to those skilled in the art that many more modifications are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the following claims.