Abstract:
A variable length shaft assembly comprising a shaft, a shaft adapter, a grip sleeve, an actuator screw, a grip, and a screw is disclosed herein. The grip is bonded to the grip sleeve, the shaft adapter is bonded to the shaft, and the shaft adapter comprises a keyed portion that mates with a keyed structure inside of the grip sleeve. The actuator screw comprises external threads that mate with internal threads inside the grip sleeve, and the location of the actuator screw within the grip sleeve can be adjusted with a wrench. Once the actuator screw is at a desired location within the grip sleeve, the shaft is semi-permanently fixed to the grip sleeve by releasable affixing the keyed structure of the shaft adapter to the actuator screw with the screw. The overall length of the assembly can be adjusted and fine-tuned using these structures.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Provisional Patent Application No. 61/721,348, filed on Nov. 1, 2012, the disclosure of which is hereby incorporated by reference in its entirety herein. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     None 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a variable length shaft assembly that allows for quick, semi-permanent length adjustments. More specifically, the present invention relates to a variable length shaft that conforms to USGA rules, and whose length can be adjusted without the use of multiple shaft extension components. 
     2. Description of the Related Art 
     Customization of golf clubs to help golfers attain better shots has become a popular and more prevalent practice in recent years. Golf club manufacturers and designers have devised various features to allow club fitters and golf club players to adjust certain characteristics of their clubs. Such characteristics include loft, lie, face angle, center of gravity (CG) location, and club length. 
     Current technology provides two methods to adjust overall club length. One such method involves the destruction and removal of the grip on a shaft. Upon removal of the grip by peeling or tearing, the end portion of the shaft is trimmed to decrease the club length or an extension piece is affixed to the end of the shaft to increase its length. Aftermarket extensions are available specifically for this purpose; alternatively, extensions can be made from portions of other golf club shafts that are cut to the desired length and then inserted into the end of the first club&#39;s shaft. The extension piece must match the diameter of the existing shaft, so it is necessary at times to build up the diameter of the extension or existing shaft by adding layers of tape. This method requires that the user making the adjustments have access to potentially expensive new components and tools as well as having a high level of skill. It also causes damage to the original shaft and grip. 
     The second method of adjusting club length involves replacing the entire shaft and grip using a semi-permanent head-shaft connection device that some manufacturers offer with their clubs, particularly with drivers. The existing shaft may be removed from the driver head and replaced with a different shaft that has either a shorter or longer length. This method is not possible on all clubs, however, as the head must have hardware that allows for removal of the shaft and replacement with a new shaft without damaging the head. 
     A golfer who does not possess club altering skills or the necessary disposable income to purchase new components likely will be daunted by these two methods of adjusting club length. The first method requires the golfer to make use of several tools to remove the grip and cut the shaft if he or she desires a shorter length, and also to have materials such as tape and a replacement grip on hand to replace the grip and mend any damage caused to the shaft and grip. The skill set required to change the shaft length using this method is usually beyond the abilities of the average golfer, so the golfer would need to seek the services of a golf club fitter or technician to have their club length changed. The second method requires the golfer to buy an entirely new shaft at a different length, which can be very expensive, and also may require the golfer to retain a golf club fitter or technician to replace the shaft. 
     Ultimately, the two methods described above require an inventory of spare components and above average technical skill, particularly with regard to the first method. It is therefore desirable to facilitate the change of a club&#39;s length using a faster, easier, and less expensive system and method than is currently available. 
     BRIEF SUMMARY OF THE INVENTION 
     One aspect of the present invention is a shaft assembly comprising first shaft comprising an internal surface, a second shaft, a mechanical fastener, and an actuator screw comprising a threaded external surface, a first cavity, and a through-bore sized to receive at least part of the mechanical fastener, wherein the second shaft comprises a tip end sized to fit within the first cavity and a first keyed structure, wherein the internal surface comprises threads and a second keyed structure sized to mate with the first keyed structure, wherein the threaded external surface of the actuator screw mates with the threads on the internal surface of the first shaft, and wherein fixing the actuator screw to the tip end with the mechanical fastener releasably affixes the first shaft to the second shaft. In some embodiments, the mechanical fastener may be a screw having a head and a threaded portion, and the tip end may comprise a threaded bore sized to receive the threaded portion of the mechanical fastener. In other embodiments, the actuator screw may comprise a second cavity sized to mate with an adjustment tool. In one embodiment, the second shaft may comprise an unthreaded external surface, which may comprise length markings. In other embodiments, the grip may be disposed on an external surface of the first shaft. 
     Another aspect of the present invention is a variable length shaft assembly comprising a shaft, a shaft adapter, and a grip sleeve, wherein the grip sleeve comprises a threaded internal surface, wherein the shaft adapter comprises a threaded external surface sized to engage with the threaded internal surface of the grip sleeve, and wherein the shaft adapter is affixed to the shaft. In some embodiments, the shaft adapter may comprise an adapter portion and an actuator screw portion, the threaded external surface may be disposed on the actuator screw portion, and the actuator screw portion may be releasably attached to the adapter portion. In some embodiments, the shaft assembly may further comprise a mechanical fastener, and attaching the actuator screw portion to the adapter portion with the mechanical fastener may fix the shaft adapter to the grip sleeve. In further embodiments, the mechanical fastener may be a screw comprising ahead and a threaded extension, and the screw may reversibly fix the shaft adapter to the grip sleeve. In other embodiments, the adapter portion may comprise a first keyed structure, the grip sleeve may comprise a second keyed structure, and the first keyed structure may mate with the second keyed structure to prevent the shaft adapter from rotating when the adapter portion is inserted into the grip sleeve. 
     In other embodiments, the shaft assembly may further comprise a retention o-ring, the actuator screw portion may comprise a flange having a through bore, the threaded extension of the screw may be disposed within the through bore, and the retention o-ring may prevent the screw from disengaging from the actuator screw. In some embodiments, the shaft may comprise an external surface having a plurality of length markings, the grip sleeve may comprise a grip portion composed of a rubber material, and the shaft adapter may be permanently affixed to the shaft. 
     Yet another aspect of the present invention is a variable length golf dub comprising a golf club head, a shaft comprising a through bore and an external surface, a grip sleeve comprising a through bore, a receiving section, and a body, a shaft adapter comprising a base, a keyed extension, and a tip portion, an actuator screw comprising a first cavity, a second cavity, a flange having a through bore, and a threaded external surface, a mechanical fastener, and a grip, wherein first end of the shaft is affixed to the golf club head, wherein the base of the shaft adapter is permanently affixed to second end of the shaft, wherein the grip is affixed to an external surface of the body of the grip sleeve, wherein each of the actuator screw, the keyed extension, and the tip portion is sized to fit within the body of the grip sleeve, wherein the body of the grip sleeve comprises a threaded internal surface sized to engage with the threaded external surface of the actuator screw and an internal keyed geometry sized to mate with the keyed extension of the shaft adapter, wherein the tip portion fits within the second cavity of the actuator screw, and wherein the mechanical fastener releasably affixes the actuator screw to the tip portion of the shaft adapter. 
     In some embodiments, the variable length golf club may be capable of increasing and decreasing in length by at least 0.50 inch. In other embodiments, the receiving section of the grip sleeve may have a first diameter sized to receive the entire shaft adapter and the shaft, and the body of the grip sleeve may have a second diameter sized to receive the keyed extension and the tip portion of the shaft adapter but not the shaft. In still other embodiments, the mechanical fastener may be a screw comprising a head and a threaded extension, the tip portion of the shaft adapter may comprise a threaded bore sized to receive the threaded extension of the screw, and the threaded bore in the tip portion of the shaft adapter may align with the through bore in the flange of the actuator screw when the tip portion is disposed within the second cavity of the actuator screw. 
     In further embodiments, the variable length golf club may further comprise a retention o-ring, the threaded extension of the screw may extend through the through bore in the flange of the actuator screw, and the retention o-ring may prevent the screw from disengaging from the actuator screw. In some embodiments, the first cavity of the actuator screw may comprise a keyed geometry sized to mate with an adjustment tool, and the actuator screw may be disposed at any point along the threaded internal surface of the body of the grip sleeve. In further embodiments, the keyed geometry of the first cavity of the actuator screw may comprise a hexagonal structure, and each of the keyed extension of the shaft adapter and the internal keyed geometry of the grip sleeve body may comprise an octagonal structure. In still other embodiments, the grip sleeve, the shaft adapter, and the shaft may be composed of a composite material, the actuator screw may be composed of a plastic material, the screw may be composed of a metal alloy material, the grip may be composed of a polymeric material, and the external surface of the shaft may comprise a plurality of length markings. 
     Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a side perspective view of a first embodiment of the invention in assembled form. 
         FIG. 2  is another side perspective view of the embodiment shown in  FIG. 1 . 
         FIG. 3  is a side perspective view of the embodiment shown in  FIG. 1  in exploded form. 
         FIG. 4  is a cross-sectional view of the embodiment shown in  FIG. 3  along lines  4 - 4 . 
         FIG. 5  is a cross-sectional view of the embodiment shown in  FIG. 1  along lines  5 - 5 . 
         FIG. 6A  is a side perspective view of the grip sleeve of the first embodiment shown in  FIG. 1 . 
         FIG. 6B  is a top plan view of the grip sleeve shown in  FIG. 6A . 
         FIG. 6C  is a bottom plan view of the grip sleeve shown in  FIG. 6A . 
         FIG. 6D  is a cross-sectional view of the grip sleeve shown in  FIG. 6A  along lines  6 D- 6 D. 
         FIG. 7A  is a side perspective view of the shaft adapter of the first embodiment shown in  FIG. 1 . 
         FIG. 7B  is a top plan view of the shaft adapter shown in  FIG. 7A . 
         FIG. 7C  is a bottom plan view of the shaft adapter shown in  FIG. 7A . 
         FIG. 7D  is a cross-sectional view of the shaft adapter shown in  FIG. 7A  along lines  7 D- 7 D. 
         FIG. 8A  is a side perspective view of the actuator screw of the first embodiment of the present invention shown in  FIG. 1 . 
         FIG. 8B  is a top plan view of the actuator screw shown in  FIG. 8A . 
         FIG. 8C  is a bottom plan view of the actuator screw shown in  FIG. 8A . 
         FIG. 8D  is a cross-sectional view of the actuator screw shown in  FIG. 8A  along lines  8 D- 8 D. 
         FIG. 8E  is a side perspective view of the cross-sectional vim shown in  FIG. 8D . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is directed to a variable length shaft that provides club length adjustability. Club length adjustability is an advantageous feature for golf clubs because, for example, extending the length of a club can have the desired effect of increasing club head speed, which results in longer driving distances. Conversely, shortening the length of a club can provide a golfer with more control and accuracy in driving the golf ball. Golf course conditions often require accurate driving due to hazards, including but not limited to water, rough, and out of bounds markers, and driving accuracy can be more preferred than driving distance in competitive situations. 
     The present invention is also valuable because a golfer&#39;s swing may change over time, thus requiring alterations to his or her clubs. A golfer may improve his or her game through lessons and may gain greater flexibility and strength through practice and exercise. As such, it is reasonable for a golfer to wish to change his or her club&#39;s shaft and/or grip length to help improve his or her accuracy, distance, and feel as needed or desired. 
     The present invention provides golfers with a system and method to easily, quickly and inexpensively modify the length of their golf club shafts and/or grips to have them perform in a desired manner. This invention enables golfers to change their club length wherever they wish, including, but not limited to, at the practice range, the golf course, and their home. The present invention also is designed to avoid altering a club&#39;s swing weight its “feet.” The tool and components that are used to alter a club&#39;s length are small and can be carried in a pocket of the user&#39;s golf bag. Furthermore, the technical ability required to modify the golf club length according to this invention is minimal and its approach is intuitive and easy for a golfer to understand. The present adjustable shaft invention can be used with any golf club head, including driver, putter, and iron heads, and may also be used with any type of equipment or structure (including, but not limited to, sporting equipment) that could benefit from a variable-length shaft. 
     A preferred embodiment of the present variable length shaft and grip system  10  is shown in  FIGS. 1-8E , and comprises a shaft adapter  20 , a shaft  30 , a grip sleeve  40 , a grip  50 , an actuator screw  60 , a screw  70  having a head  72  and a threaded extension  74 , and an o-ring  90 . In alternative embodiments, the screw  70  may be replaced with any type of mechanical fastener known to a person skilled in the art. Still other embodiments may not include the o-ring  90 . 
     As shown in  FIG. 3 , the shaft  30  preferably has a first end  31 , a second end (not shown) that is bonded to a golf club head (not shown), a through bore  34 , and length markings  35 . The length markings  35  preferably are disposed on an external surface  36  of the shaft  30  proximate the first end  31  to assist a user when he or she wishes to precisely adjust the length of the golf shaft and/or grip along a shaft axis  32 . The length markings  35  may be engraved into the shaft  30  or may be applied via paint or a decal. The shaft  30  preferably is composed of a thin, lightweight, sturdy composite material, but in alternative embodiments may be composed of plastic or a metal alloy, or any other material known to a person skilled in the art. In other embodiments, the shaft may have only a partial bore that does not extend all the way from the first end  31  to the second end, but instead is sized only to receive the base  210  of the shaft adapter  20 . 
     As shown in  FIGS. 3-5  and  7 A- 7 D, the shaft adapter  20  comprises abuse  210 , a keyed extension  220 , and a tip portion  230 . The base  210  is sized to fit snugly within the first end  31  of the shaft  30 , and preferably is permanently affixed to the shall  30  with a permanent adhesive, one or more mechanical fasteners, or any other means known to a person skilled in the art. In alternative embodiments, the base  210  may be affixed to an external surface  36  or an edge surface  38  of the shaft  30 . The shaft adapter  20  may be sized to fit into any desired shaft, so that an otherwise non-adjustable shaft  30  may be retrofitted to benefit from the variable length shaft and grip system  10  disclosed herein. The shaft adapter  20  preferably is hollow, as shown in  FIGS. 4 and 7D , and preferably is composed of a lightweight composite material, though in alternative embodiments the shaft adapter  20  may be composed of plastic, metal alloy, or any other material preferred by a person skilled in the art, and may be partially or completely solid. 
     The keyed extension  220  extends longitudinally from the base  210 , and in the preferred embodiment has an octagonal external geometry  225  that mates with an octagonal internal keyed geometry  422  of the grip sleeve  40  and prevents the shaft adapter  20 , and thus the shaft  30 , from rotating when the shaft adapter  20  is disposed within the grip sleeve  40 . In alternative embodiments, however, the keyed extension  220  may have any cross-sectional shape that, when mating with a corresponding shape within the grip sleeve  40 , prevents rotation of the shaft adapter  20  within the grip sleeve  40 . The tip portion  230  extends longitudinally from the keyed extension  220  and includes a threaded bore  235  sized to receive the threaded extension  74  of the screw  70 . In the preferred embodiment, the tip portion  230  has a cylindrical shape, and has a smaller diameter than that of the keyed extension  220  and the base  210 . As shown in  FIGS. 5  and  7 A- 7 D, the base  210  is divided from the keyed extension  220  with a raised ring  215 , which creates a first ledge  216  that serves to prevent the base  210  of the shaft adapter  20  from moving too far within the grip sleeve  40  and a second ledge  217  against which the edge surface  38  of the shaft  30  abuts. The shaft adapter  20  may have any length desired by the user, and preferably allows the variable length shaft and grip system  10  to increase and/or decrease in length by at least 1 inch. 
     As shown in  FIGS. 1-6D , the grip sleeve  40  comprises a receiving section  410 , which, as shown in  FIG. 5 , is sized to receive both the shaft adapter  20  and the shaft  30 , and a body  420 , which comprises an internal keyed geometry  422  and a threaded internal surface  426  with threads having a pitch of approximately 0.125-0,500 inch, more preferably 0.20-0.30 inch, and most preferably 0.25 inch. As noted herein, the internal keyed geometry  422  preferably is octagonal, and is sized to mate with the octagonal external geometry  225  of the keyed extension  220 . In other embodiments, however, the internal keyed geometry  422  may have any cross-sectional shape that, when mating with a corresponding shape on the keyed extension  220 , prevents rotation of the shaft adapter  20  within the grip sleeve  40 . For example, the internal keyed geometry  422  of the grip sleeve  40  and the external geometry  225  of the shaft adapter  20  may include splines, projections, different polygonal shapes, or other mating features known to a person skilled in the art. 
     As shown in  FIGS. 3-6A  and  6 D, the receiving section  410  has a larger diameter than the body  420 , and the point at which the receiving section  410  intersects with the body  420  forms a first, exterior ledge  415  and a second, interior ledge  416 . The grip sleeve  40  is hollow and has a through bore  430  that extends from a first end  42  to a second end  44  at the mouth of the receiving section  410 , and preferably is composed of a lightweight composite material, though in alternative embodiments the grip sleeve  40  may be composed of plastic, metal alloy, or any other material preferred by a person skilled in the art. 
     The preferred embodiment of the present invention also includes a grip  50 , shown in  FIGS. 1-5 , which is hollow and is sized to fit over the body  420  of the grip sleeve  40 . As shown in  FIGS. 3 and 4 , the grip  50  comprises a top end  52  with an opening  54  that is large enough to give an adjustment tool (not shown) access to the interior structure of the variable length shaft and grip system  10 , and a bottom end  56  with an opening  58  sized to receive the body  420  of the grip sleeve  40 . In the preferred embodiment, the grip  50  is permanently affixed to the external surface of the grip sleeve  40  body  420  with an adhesive, and the bottom end  56  of the grip  50  abuts the first, exterior ledge  415  of the grip sleeve  40  as shown in  FIGS. 1 ,  2 , and  5 . In embodiments in which the variable length shaft and grip system  10  disclosed herein is not used in connection with sporting goods or a structure that requires a grip, the grip  50  need not be used. The grip  50  is preferably composed of a rubber material, hut in other embodiments may be composed of any material and have any characteristics, such as elasticity, thickness, and length, known to a person skilled in the art. 
     The actuator screw  60  of the present invention provides the releasable locking and adjustment mechanism for the variable length shaft and grip system  10  disclosed herein. As shown in  FIGS. 3-5  and  8 A- 8 E, the actuator screw  60  is a tubular structure with a consistent external diameter that is sized to fit within the body  420  of the grip sleeve  40 . The actuator screw  60  has a threaded external surface  610 , a first end  620  with a first cavity  625 , a second end  630  with a second cavity  635 , and a flange  640  disposed between the first and second cavities  625 ,  635  with a through bore  645  sized to receive the threaded extension  74  of the screw  70 . The threads on the threaded external surface  610  preferably have a pitch that matches the pitch of the threads of the threaded internal surface  426 , (approximately 0.125-0.500 inch, more preferably 0.20-0.30 inch, and most preferably 0.25 inch), and preferably allow for 0.25 inch of length adjustment per turn of the actuator screw  60  within the grip sleeve  40  body  420 . As shown in  FIG. 5 , the o-ring  90  sits within the first cavity  625  and abuts the flange  640 , cushioning the head  72  of the screw  70  when the threaded extension  74  is fully threaded through the through bore  645 . 
     As shown in  FIGS. 8D and 8E , the first cavity  625  of the actuator screw  60  has a hexagonal internal geometry  626  which is sized to mate with a hex wrench (not shown), white the second cavity  635  has a cylindrical internal geometry sized to receive the tip portion  230  of the shaft adapter  20 . As shown in  FIG. 5 , the through bore  645  is located within the actuator screw  60  to line up with the threaded bore  235  in the tip portion  230  of the shaft adapter  20  when the tip portion  230  is disposed within the second cavity  635 . In alternate embodiments, the first cavity  625  may have any type of structural configuration that receives a wrench or other tool having mating geometry. 
     In the preferred embodiment, the o-ring  90  and the screw  70  are inserted into the first cavity  625  of the actuator screw  60  such that the o-ring  90  is disposed between the screw head  72  and the flange  640 . The screw  70  preferably is prevented from becoming disengaged from the actuator screw  60  with a second, retention o-ring  95  that is affixed to the tail end of the threaded extension  74  of the screw  70  so that the flange  640  is trapped between the screw head  72 , which cannot fit through the through bore  645 , and the retention o-ring  95 . In alternative embodiments, a clip may be attached to the threaded extension  74 , or any other means known to a person skilled in the art to prevent the screw  70  from disengaging from the actuator screw  60 . 
     Once the actuator screw  60  is assembled with the o-ring  90 , screw  70 , and retention o-ring  95  as described, this assembly  80  is inserted into the body  420  of the grip sleeve  40  such that the threaded external surface  610  mates with the threaded internal surface  426  of the grip sleeve  40 . The actuator screw  60  may be inserted into either end  42 ,  44  of the grip sleeve  40 , but (preferably is inserted into the first end  42  where the threaded internal surface  426  begins. The grip  50  may then be bonded to the exterior surface of the body  420  of the grip sleeve  40 . The actuator screw  60  can be moved within the through bore with a hex wrench (not shown), which has a hexagonal end that mates with the hexagonal internal geometry  626  of the first cavity  625 . Turning the hex wrench causes the actuator screw  60  to move through the through bore  430  towards either end  42 ,  44  of the grip sleeve  40  until it is located at a desired location within the body  420  of the grip sleeve  40 . 
     Once the actuator screw  60  is at a desired location, the shaft adapter  20 , which preferably is permanently bonded to the shaft  30 , is inserted through the receiving section  410  of the grip sleeve  40  so that the keyed extension  220  fits within the body  420  of the grip sleeve  40  and the tip portion  230  engages with the second cavity  635  of the actuator screw  60 , as shown in  FIG. 5 . The shaft adapter  20 , and thus the shaft  30 , is semi-permanently fixed to the actuator screw  60  by screwing the screw  70  into the threaded bore  235  of the tip portion  230 . The screw  70  can be accessed with a screwdriver via the opening  54  in the grip  50  and the through bore  430  of the grip sleeve  40 . Fixing the actuator screw  60  to the shaft adapter  20  in this way serves to anchor the actuator screw  60  within the grip sleeve  40 , as the shaft adapter  20  cannot rotate within the body  420  of the grip sleeve  40  due to the internal keyed geometry  422 , and prevents the shaft adapter  20  from being removed from the grip sleeve  40  because the actuator screw  60  cannot turn or move within the grip sleeve  40 . 
     If a user is not satisfied with the overall length of the variable length shaft and grip system  10  described herein after fixing the actuator screw  60  to the shaft adapter  20 , he or she can simply unscrew the screw  70  from the tip portion  230  of the shaft adapter  20 , move the actuator screw  60  to a new location within the grip sleeve  40  with the hex wrench or other tool, and then reattach the actuator screw  60  to the shaft adapter  20  with the screw  70 . The length L 2  of the keyed extension  220  of the shaft adapter  20  determines the overall length adjustability of the variable length shaft and grip system  10  disclosed herein, as the first ledge  216  on the raised ring  215  of the shaft adapter  20  abuts the second, interior ledge  416  of the grip sleeve  40  when the keyed extension  220  is fully disposed within the body  420  of the grip sleeve  40  and prevents the base  210  of the shaft adapter  20  from being inserted into the body  420  of the grip sleeve  40 . 
     Preferably, the threaded internal surface  426  of the grip sleeve  40  does not extend along the entire length of the body  420 , with a gap  425  having a length L 3  located between the second, interior ledge  416  and the threads of the threaded internal surface  426 . The receiving section  410  of the grip sleeve  40  preferably has a length L 4  that, when added to the length L 3  of the gap, is equivalent to the length L 5  of the tip portion  230  and keyed extension  220  of the shaft adapter  20 , so that when the variable length shaft and grip system  10  is at its most extended configuration, with the actuator screw  60  located at the second end  44 —most point of the threaded internal surface  426 , the shaft adapter  20  is completely hidden within the grip sleeve  40  and only the grip  50 , grip sleeve  40 , and shaft  30  are visible, as shown in  FIGS. 1 and 2 . 
     The disclosure of each of U.S. patent application Ser. Nos. 13/286,791 and 13/544,536 is hereby incorporated by reference in its entirety herein. The disclosure of each of U.S. Patent Application Publication Numbers 20120149486, 20120149487, 20120149488, 20120149489, and 20120184389 is also hereby incorporated by reference in its entirety herein. 
     From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and wilt readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention which an exclusive property or privilege is claimed are defined in the following appended claims.