Patent Publication Number: US-2005138824-A1

Title: Fiber optic sight pin

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This document claims priority to and incorporates by reference all of the subject matter included in the provisional patent application filed on Dec. 24, 2003, and having Ser. No. 60/532,655. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates generally to sights for archery bows employing fiber optic elements and, more specifically, to sight pin constructions which provide increased stability to the fiber optic element and which provide illuminated sight capabilities in environments where ambient light is reduced or absent.  
      2. Description of the Art  
      Archery bow sights utilizing a plurality of sight pins have been known in the art for many years. Typically, these sights use a bracket or other mounting structure for mounting the sight to a bow. The sight is commonly comprised of a pin plate, a pin guard, and a plurality of sight pins which are secured to the pin plate and extend into a sight window formed by the pin guard. The sight is mounted to a bow in a manner so that when the bow string is drawn, the archer can look through a peep sight provided in the bow string and align the tip of a pin attached to the sight with a target. For sights utilizing a plurality of sight pins having their tips vertically aligned, each individual sight pin is typically provided for aiming the bow at a target at a particular distance from the archer. For example, one pin may be positioned in the sight for aiming the bow at a target 50 yards from the archer while another pin may be positioned for a target that is at 100 yards distance.  
      It is also known in the art to construct sight pins with a light-gathering fiber optic element to enable use of the sighting device in low light environments. Various configurations of sight pins using fiber optic members have been proposed.  
      It is also well-known in the art that despite the light-gathering capabilities of fiber optic elements which render sighting devices more useful in low-light conditions (e.g., dusk), there is a point at which the ambient light is so low that the fiber optic element is no longer capable of gathering sufficient light to provide any illumination. While others in the art have disclosed the use of electronic means for providing a light source to the fiber optic elements of the sighting device, the use of such devices add weight to the device, may fail electrically and may be vulnerable to damage by contact with bushes or the like.  
      It has also been proposed to provide a self illuminating substance such as tritium at one end of a fiber optic element in order to illuminate the opposite end. Because of the surface area of the ends of such fiber optic elements, the amount of light provided in such a small surface area is relatively low.  
      Thus, it would be advantageous to provide a relatively large amount of fiber for each sight pin to provide increased light gathering capabilities by increasing the exposed surface area of the fiber.  
      It would also be advantageous in the art to provide a non-electrical source of light that can illuminate the fiber optic element of the sight pin to provide sufficient illumination to the fiber optic element to enhance the usefulness of the device in very low or no ambient light conditions.  
     SUMMARY OF THE INVENTION  
      In accordance with the present invention, a sight pin for use with a bow sight includes an elongate segment of fiber optic material used to form a sighting indicia at one of its terminal ends. The other end of the fiber optic member is wound upon a spool to increase the exposed surface area of the fiber optic material to increase light absorption and thus the brightness of the sight indicia.  
      The sight pin includes an elongate pin arm defining a sight point at a first end and configured for attachment to a bow sight proximate a second end. A fiber optic member has a first terminal end adjacent the sight point of the sight pin for providing a sight indicia. A spool in the form of a cylindrical member is positioned proximate the second end of the sight pin. The fiber optic member is wound upon the spool with a plurality of windings so as to maximize the amount of fiber optic material that is exposed to ambient light.  
      In one embodiment the spool is coupled directly to the sight pin itself so that the sight pin can be adapted to an existing bow sight for use therewith.  
      In another embodiment the spool is coupled to the bow sight and the fiber optic member from the sight pin is wound upon the spool.  
      In another embodiment, more than one fiber optic member from more than one sight pin is wound upon a single spool.  
      In still another embodiment, a plurality of sight pins with spools integrally formed therewith are configured to be used together on a single bow sight.  
      In yet another embodiment, each spool is provided with a luminescent material, such as glow-in-the-dark material, that is wrapped around the spool. The fiber optic member is then wound over the luminescent material. By charging the luminescent material for a period of time with a light source, the fiber optic member will remain illuminated for a period of time while the luminescent material radiates light.  
      Thus, a non-electric light source is provided along a length of the fiber optic member in order to brighten the fiber optic element as a result of the light being emitted from the non-electric light source.  
      The non-electric light source is a material which naturally emits light, such as a radioactive or chemically activated material commonly used in such devices as illuminated watches and “glow-in-the-dark” signage. In addition, zinc sulfide and copper mixed phosphorescent pigments and powder materials can be incorporated into many materials such as plastics. Such luminescent plastic materials may be formed by mixing luminescent pigment powder with transparent plastic resin. The luminescent plastic can then be formed into the desired shape or applied to the product by casting, molding, extruding, dipping and/or coating. The luminescent pigment is compatible with acrylics, polyester, epoxy, polyvinyl chloride, polypropylene and polyethylene polymers.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of a first embodiment of an archery sight and sight pins in accordance with the principles of the present invention;  
       FIG. 2A  is a side view in elevation of a sight pin shown in  FIG. 1 ;  
       FIG. 2B  is a side view in elevation of a cap in accordance with the principles of the present invention;  
       FIG. 2C  is an end view in elevation of the sight pin shown in  FIG. 2A ;  
       FIG. 3  is a perspective view of a second embodiment of an archery sight and sight pins in accordance with the principles of the present invention;  
       FIG. 4  is a perspective view of a third embodiment of an archery sight and sight pin in accordance with the principles of the present invention; and  
       FIG. 5  is an view in elevation of a fourth embodiment of an archery sight and sight pins in accordance with the principles of the present invention.  
       FIG. 6A  is a side perspective view of the sight pin shown in  FIG. 3 ;  
       FIG. 6B  is a front side view of the sight pin shown in  FIG. 6A ;  
       FIG. 6C  is a back side view of the sight pin shown in  FIG. 6A .  
       FIG. 7A  is a side perspective view of the sight pin shown in  FIG. 1 ;  
       FIG. 7B  is a front side view of the sight pin shown in  FIG. 7A ;  
       FIG. 7C  is a back side view of the sight pin shown in  FIG. 7A ;  
       FIG. 8  is a representative top side view of the sight pins shown in  FIGS. 6A and 7A ;  
       FIG. 9  is a representative bottom side view of the sight pins shown in  FIGS. 6A and 7A ;  
       FIG. 10  is a representative left side view of the sight pins shown in  FIGS. 6A and 7A ; and  
       FIG. 11  is a representative right side view of the sight pins shown in  FIGS. 6A and 7A . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       FIG. 1  illustrates a bow sight device, generally indicated at  10  in accordance with the principles of the present invention. The sighting device  10  is comprised of an integrated pin plate  14 , a pin guard  16 , which defines a sight window  18 , and a mounting portion  19 . A plurality of sight pins  20 ,  21  and  22  are secured to the pin plate  14  by attachment members  23 , such as screws, each of which engage one of the sight pins  20 ,  21  and  22  and extend through a slot  24  formed in the pin plate  14 . The sight pin  20  includes an elongate segment of fiber optic material  34  used to form a sighting indicia at one of its terminal ends. The other end of the fiber optic member  34  is wound upon a spool  38  to increase the exposed surface area of the fiber optic material  34  to increase light absorption and thus the brightness of the sight indicia.  
      The slot  24  is provided with a recessed portion  25  that circumscribes an elongate channel that extends through the pin plate  14 . As will be described in more detail, the sight pin  20  engages with this recessed portion  25  to prevent rotation of the pin  20  relative to the pin plate, essentially mating together in a male/female or tongue and groove relationship. The channel allow for passage of the shaft of an elongate fastener therethrough. The sight pins  20 ,  21  and  22  extend transversely from the pin plate  14  into the sight window  18 . The sighting device  10  is attached to a first bracket  28  by securing members  30 , such as threaded bolts. The first bracket  28  may be adjustably connected to a second bracket  29  by additional securing members. The second bracket  29  may then be coupled or directly attached to the riser of a bow as is known in the art.  
      In use, the archer typically aligns a peep sight positioned on or secured within a bowstring with one of the sight pins  20 ,  21  or  22 . Each of the sight pins  20 ,  21  and  22  is positioned and adjusted to correspond to a given distance (e.g., 50 yards, 100 yards, 150 yards, etc.) from the bow. The sight pins  20 ,  21  and  22  allow the archer to better position the aim of the arrow to compensate for target distance and trajectory. Sight pins  20 ,  21  and  22  relevant to the present invention are those which employ fiber optic members  34 ,  35  and  36 , respectively, to provide an illuminated point or sight tip at the terminal end of each fiber optic member  34 ,  35  and  36 . While the sight pins  21  and  22  are generally of a traditional configuration, the sight pin  20  includes a substantially longer length of fiber optic material that is wound upon a cylindrical member  38  to form a spool of wound fiber optic material. The width of the spool  38  may be varied to accept more or less fiber optic material thereon. By winding the fiber optic material  34  onto the spool  38 , an increased amount of fiber optic material is employed for the sight pin  20 , as compared to sight pins  21  and  22 . This increased length of the fiber optic member  34  increases the exposed surface area of the fiber optic member  34  to increase the light gathering ability of the fiber optic member  34  to, in turn, increase the illumination of the sight tip. Moreover, by coupling the spool  38  to the individual sight pin  20 , the sight pin  20  can be adapted to virtually any existing bow sight regardless of configuration. That is, the sight pin  20  of the present invention could be easily adapted to virtually any existing bow sight without requiring modification to the design or configuration of the bow sight.  
      As shown in  FIG. 2A , the sight pin  20  is comprised of a pin arm  40  for supporting the proximal or terminal end  42  of the fiber optic member  34 . The proximal end  43  of the pin arm  40  includes an enclosed channel  44  for receiving and retaining a portion of the fiber optic member  34  proximate its terminal end  42 . The terminal end  42  of the fiber optic member is enlarged as by melting the terminal end  42  to form a dome-shaped end. The size of the terminal end  42  is greater than the diameter of the channel  44  to prevent the terminal end from being pulled through the channel. Thus, the terminal end  42  abuts against the proximal end  43  of the pin arm  40 . The terminal end of the fiber optic member  34  forms a sighting indicia or tip from which light gathered by the fiber optic member  34  is emitted. The pin arm  40  forms an arc to position the sight tip  42  at the appropriate location within the sight window  18  of the sight  10  and to form a gentle curve form bending the fiber optic member  34  along its arc to prevent the fiber optic member  34  from being kinked or otherwise bending too severely in a manner that could cause the fiber optic member  34  to fracture. The fiber optic member  34  is then wound upon the spool  38  with a plurality of windings  46 . The ends  48  and  50  of the spool  38  have a diameter that is larger than the body  52  of the spool  38 , such as a typical spool of thread. A layer  54  of glow-in-the-dark material, such as luminescent-type, efflorescent-type or self-illuminating tape, underlies the windings  46  to illuminate the fiber optic member  34  in low light conditions. Because the fiber optic material  34  is a relatively translucent plastic that can be penetrated by light, the glow-in-the-dark material can be charged through the windings  46  and then illuminate the fiber optic member  34  along the windings  46 . It should be noted that such fiber optic material  34  is available in various colors (e.g., yellow, red, green, etc.). A transparent layer of tape  56  or other suitable material is applied over the windings  46  to prevent unwinding of the fiber optic member  34  while allowing light to illuminate the fiber optic member  34  along the windings  46  and to charge the glow-in-the-dark tape  54 .  
      The sight pin  20  also includes an engagement portion  60  for engaging with the slot  24  (see  FIG. 1 ). The engagement portion  60  is comprised of a rectangularly-shape protrusion that allows the sight pin  20  to be adjusted vertically relative to the slot while preventing rotation of the pin  20  relative to the slot  24  to keep the pin arm  40  in a substantially horizontal orientation relative to the sight window  18 .  
      As shown in  FIG. 2B , because of the large exposed surface area of the fiber optic member  34  in the windings  46 , an opaque cap  62  may be provided to cover all or a portion of the windings  46  when ambient light is high. By placing the cap  62  over all or a portion of the windings  46 , the brightness of the sight tip  42  can be controlled as desired. The cap  62  has a generally cylindrical shape to substantially match the shape and size of the spool  38 . The cap  62  may be comprised of a rubber or latex material that is flexible and resilient to form a friction fit over the spool  38  to prevent the cap from falling off of the spool  38  while allowing the cap  62  to be easily removed or slid relative to the spool  38 .  
      As further illustrated in  FIG. 2C , the sight pin  20  as shown from the proximal end  48  includes an internal bore  66  that extends into the spool  38  to decrease the weight of the spool  38  and thus the sight pin  20 . The pin arm  40  and spool  38  of the sight pin  20  may be formed from plastic or metal. The engagement portion  60  defines a threaded bore  68  for receiving an externally threaded fastener for attaching the sight pin  20  to the pin plate  14  (see  FIG. 1 ).  
      Referring now to  FIG. 3 , an alternative embodiment of a bow sight, generally indicated at  100 , and associated sight pins  102 ,  103  and  104  are illustrated in accordance with the principles of the present invention. The sight pin  104  is configured similarly to the sight pin  20  illustrated in  FIG. 1 . Likewise the sight pin  102  is configured similar to the sight pin  20  but provides is pin arm  106  on the opposite side of the spool  108 . The sight pin  103  is configured with an elongated pin arm  110  that allows the spool  112  to be positioned behind the spool  108  while maintaining the sight tips  114 ,  116  and  118  of the sight pins  102 ,  103  and  104 , respectively, in relative vertical alignment. In this embodiment, the sight pin  103  is configured similarly to the sight pin  102 , but by having an elongated pin arm  110  of sufficient length, the sight pin  103  can be seated behind the sight pin  102  to allow the pin arms  106  and  110  to be positioned as close together as desired by a user, even touching. Each of the sight pins  102 ,  103  and  104  are coupled to the bow sight body  118  by attachment to a respective slot. Because the spools  108  and  113  of the sight pins  102  and  104  are substantially vertically aligned, they can be coupled to the same slot, such as the slot similar to slot  24  shown in  FIG. 1 . An additional slot  120  is provided for the sight pin  103  and has a similar configuration as the slot  24  shown in  FIG. 1  to allow mating engagement of the pin  103  with the slot  120  to allow vertical adjustability of the sight pin  103  relative to the sight body  118  while preventing rotational movement.  
      Referring now to  FIG. 4 , the sight pins in accordance with the principles of the present invention can be adapted to bow sight, generally indicated at  200  which employs a vertically oriented sight pin  202 . The sight pin  202  is configured in a similar manner as the sight pin  20  shown in  FIG. 1 , but can be fixed relative to the sight body  204  since the configuration of the bow sight  200  allows for vertical adjustment of the sight window  206  and thus the sight pin  202  relative to the bow (not shown). The bow sight  200  is configured with a lever  208  which when slid relative to the arched slot  210  rotates about a pivot point  212  to cause translating movement of the sight body  204  relative to the bracket  214 .  
      Referring now to  FIG. 5 , another embodiment of a bow sight, generally indicated at  300 , is illustrated. While various other embodiments illustrated herein have shown a single spool associated with a single sight pin for winding the fiber optic material from that pin thereon, it is further contemplated that fiber optic members  302 ,  303  and  304  from other sight pins  306 ,  307  and  308 , respectively, may be wound upon a single spool  310 . The spool  310  may be associated with one of the sight pins, such as sign pin  308 , as has been heretofore described, or may be a separate component coupled to the sight body  312  in a manner that allows the individual sight pins  306 ,  307  and  308  to be independently adjusted relative to the sight body  312 , while the spool  310  remains in a fixed location.  
      Referring now to  FIGS. 6A, 6B ,  6 C,  7 A,  7 B,  7 C, and  8 - 11  there is shown in various views the sight pins  104  illustrated in  FIG. 3  and sight pin  20  illustrated in  FIG. 1 . In particular,  FIG. 6A  shows a side perspective view of the sight pin  104  shown in  FIG. 3 .  FIG. 6B  shows a front side view of the sight pin  104  shown in  FIG. 6A  and  FIG. 6C  illustrates a back side view of the sight pin  104 .  FIG. 7A  is a perspective side view of the sight pin  20  shown in  FIG. 1 .  FIG. 7B  is a front side view of the sight pin  20  and  FIG. 7C  is a back side view of the sight pin  20 .  FIG. 8  is a representative top side view of the sight pins  104  and  20 ,  FIG. 9  is a representative bottom side view of the sight pins  104  and  20 ,  FIG. 10  is a representative left side view of the sight pins  104  and  20  and  FIG. 11  is a representative right side view of the sight pins  104  and  20 .  
      While the present invention has been described with reference to certain embodiments, it is contemplated that upon review of the present invention, those of skill in the art will appreciate that various modifications and combinations may be made to the present embodiments without departing from the spirit and scope of the invention as recited in the claims. It should be specifically noted that reference to the term “spool” in the specification and claims is not intended to include only a cylindrical structure, but any structure upon which the fiber optic member can be wound. The principles of the present invention may be adapted to any type of sight pin including those illustrated as well as sight pins used on pendulum type sights and the like. The claims provided herein are intended to cover such modifications and combinations and all equivalents thereof. Reference herein to specific details of the illustrated embodiments is by way of example and not by way of limitation.