Abstract:
A crossbow sighter is used to align the sight used on a crossbow to the axis of the groove on the crossbow. In this manner, the cross bow bolt will strike close to, or at, the location sighted by the sight. The crossbow sighter fits into the groove and has a body with a length that extends past the bow string when the bow string is in its fully relaxed position. The bow string rests against the body and applies cross-axial pressure to the crossbow sighter and helps retain it in the groove while aligning the crossbow sight.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application No. 62/136,316, filed on Mar. 20, 2015. U.S. Pat. No. 6,421,947 is incorporated herein by reference to the extent its disclosure is not inconsistent with the present disclosure. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a sighter for aligning the sight on a crossbow to at least approximately the location where the crossbow bolt strikes after being fired. 
       BACKGROUND OF THE INVENTION 
       [0003]    This invention relates to a sighter for calibrating a crossbow sight to align with the groove axis of a crossbow for the purpose of calibrating the crossbow sight. The calibration process of a crossbow scope to align the sight with the crossbow groove axis now requires that several bolts be fired so that the sight can be gradually adjusted to align with a target point that the bolts strike. The crossbow sight can be a physical sight or an optical scope. Crossbow sights and crossbow structures are known to those skilled in the art. 
       SUMMARY OF THE INVENTION 
       [0004]    A crossbow sighter for projecting an axis of a crossbow groove is used to align a crossbow&#39;s sight with the groove axis. The crossbow sighter (or “sighter”) comprises a body that minimizes errors in alignment. The body is extended so it is long enough to be positioned in the crossbow groove and to have the bow string, when in its relaxed position, rest upon the body to help retain the sighter in the groove. The body has a proximal (or first) section, in which a laser is mounted, and that is received in the groove, and a distal (or second) section, which extends past the bow string, when the string is in its relaxed position. The bow string is positioned against the side of the second section to apply cross-axial force to the sighter and help retain it in the groove. 
         [0005]    A sighter according to the invention may have a one-piece body, or a multi-piece body. Either way, it is designed to be axially aligned with the crossbow groove when positioned in the groove. In this manner, a beam of laser light emitted from the sighter travels in a straight path along the axis of the crossbow groove. The crossbow sight is then calibrated to the point at which the laser beam strikes. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is an exploded, perspective view of the crossbow sighter according to aspects of the invention. 
           [0007]      FIG. 2  is a side, exploded view of the crossbow sighter of  FIG. 1 . 
           [0008]      FIG. 3A  is a partial, side perspective view of the crossbow sighter of  FIG. 1  showing one alternative switch. 
           [0009]      FIG. 3B  is a partial, side perspective view of the crossbow sighter of  FIG. 3  showing the beginning of removal of the switch assembly. 
           [0010]      FIG. 3C  is a side view of the removed switch assembly of the crossbow sighter of  FIGS. 3A and 3B  showing how batteries can be removed and replaced. 
           [0011]      FIG. 3D  is a partial, side perspective view of the crossbow sighter of  FIGS. 3A-3C  showing the switch assembly being reinstalled. 
           [0012]      FIG. 4  is a top view of a crossbow sighter in accordance with aspects of the invention. 
           [0013]      FIG. 5  is a side, partial cross-sectional view of the crossbow sighter of  FIG. 4 . 
           [0014]      FIG. 6  is an enlarged view of the section marked as  FIG. 6  on  FIG. 5 . 
           [0015]      FIG. 7  is an enlarged view of the section marked as  FIG. 7  on  FIG. 5 . 
           [0016]      FIG. 8  is a side view of a crossbow sighter in accordance with aspects of the invention, mounted in a crossbow groove. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0017]    Turning now to the drawings where the purpose is to describe preferred embodiments of the invention and not to limit same,  FIGS. 1 and 2  show exploded views of a preferred embodiment of a crossbow sighter  10  according to the invention. 
         [0018]    The crossbow sighter  10  comprises an elongated body  12  having a body axis  14 . The body  12  has a proximal (or first) section  16  and a distal (or second) section  18 . The proximal section  16  and distal section  18  may have the same diameter, or (as shown) the diameter of the proximal section  16  may be different from, and greater than, the diameter of the distal section  18 . 
         [0019]      FIGS. 5-7  are partial cross-sectional illustrations of the crossbow sighter  10  of  FIGS. 1 and 2 , depicting the first cylindrical cavity. A first cavity  60  has an axis that is preferably aligned with body axis  14 , and is located in the proximal end  16 . The first cavity  60  houses a light source  62 , typically a laser, an electrically conductive spring  64 , and a rotary switch  66 . The light source  62  is permanently mounted in the housing so that it need not be removed to change batteries or to make support adjustments. The light source  62  emits a beam that is in alignment with the body axis  14 . The switch  66  is rotated to selectively connect the light source  62  to a power supply  68 . The spring  64  keeps switch  66  locked into a position, either on or off, and provides an electrical path to the laser light  62 . Proximal end  16  includes a channel  70  formed between the body surface and the first cavity  60  to expose the switch  66 . The switch  66  can be accessed for rotation through channel  70 . 
         [0020]    Also shown in  FIGS. 1 and 2 , the body proximal end  16  includes a second cylindrical cavity  60 A connected to channel  70 . The second cavity  60 A is preferably aligned with the body axis  14  to form an opening from which the light source beam is projected. 
         [0021]    The first cavity  60  has a cavity diameter. The switch  66  is cylinder with a switch diameter that is less than the cavity diameter, so that switch  66  has the freedom to rotate (see e.g.,  FIG. 3A ). The switch  66  has an axis preferably substantially aligned along the body axis  14 . The switch  66  rotates to selectively connect the power source  68  to the light source  62 . 
         [0022]    The switch  66  has a top, or first outside surface  80  which is radially disposed around the switch axis. The first surface  80  has a conductive area  84 . The first surface  80  also includes a cam  86 . 
         [0023]      FIG. 5  is a partial cross-sectional view of the body  12  of  FIG. 4 . The first cavity  60  (see  FIG. 5 ) has a second surface  88  which interfaces with the switch first surface  80 , which is radially disposed inside proximal section  16 . The second surface  88  includes a second conductive area. An electrical connection is made between the body  12  and the switch  66  when the second conductive area interfaces with the first conductive area  84 . The second surface  88  is preferably cylindrical. When the second surface  88  receives the switch conductive area  84 , an electrical connection is made between first conductive area  84  and second conductive area  90 . The conductive areas are not limited to any special shape or position. As shown, the conductive areas can be centered around the axis  14 . When the switch  66  is not in the channel  70 , the first surface  80  and second surface  88  are forced apart, and no electrical connection is made. 
         [0024]    The switch  66  has a third outside surface preferably radially disposed around the switch axis  82 , having a third conductive area. When the switch  66  operates as a passive electrical conductor, the third conductive area can be a conductive rod. In some aspects, the conductive rod may pass all the way through switch  66  from the first surface  90  to the third surface. Alternately, the switch  66  can be a metal, such as aluminum, which may be anodized or coated with an insulator, except for areas on the first surface  80  and third surface which act as conductive areas  84  and the third conductive area, so that the switch  66  may be a conductor. As explained in more detail below, the switch  66  may be a battery housing in some aspects of the invention, and the third conductive area can be the battery terminal  110 , the spring  64 , or the combination of battery and spring  64 . 
         [0025]    The first cavity  60  may have a fourth surface preferably radially disposed around the body axis  12 , having a fourth conductive area which is not explicitly shown. The fourth surface can be a part of the inside surface of proximal end  16 , as is the second surface  88 . However, the fourth surface is actually the light source  62  electrical terminal. Also as shown, the electrically conductive spring  64  is preferably substantially aligned along the body axis  12  between the third surface and fourth surface. Therefore, when the switch  66  is in the “on,” position, the second conductive area (if used) is connected to the fourth conductive area through the switch  66  and spring  64 . 
         [0026]    In some aspects of the invention the power supply  68  is housed elsewhere in the body  12  (not shown), but in the preferred embodiment power source  68  is housed in switch  68 . The switch  66  then acts as a selectively engagable passive conductor which completes an electrical circuit between the second conductive area and fourth conductive area from power source  68 , to the light source  62 , with the return ground path from the light source  62  through the electrically conductant inside surface of proximal end  16 . In a preferred aspect of the invention the batteries are housed in the switch  66 , as shown in  FIGS. 1, 2 and 3C . Switch  66  is removable from cavity  60  through slot  70  as shown in Figures to replace batteries does not affect the accuracy of crossbow sighter  10 . The switch  66  is easily removed through channel  70 . 
         [0027]    Power source  68  is preferably a number of (three are shown) coin batteries arranged end-to-end in a battery cavity  112 . The power source  68  can also be any other suitable source. Power source  68  has a first polarity (+) connected to the switch&#39;s first conductive area  84  and a second polarity (−) connected to the switch&#39;s third conductive area in one preferred embodiment. An axial plug  114 , with a center hole to admit spring  64 , may be used to seal the end of battery cavity  112 . 
         [0028]    Turning again to  FIGS. 1 and 2 , a brace (or cushioning device)  72  fits over distal end  62 A of laser  62 . Laser light is emitted through end  62 A. A cap  74  with a lens, which may be clear or refractory to refract the laser light into a shape such as a crosshair, or multiple projections forming an area between them, is received in cavity  60  to seal cavity  60  and the internal components. As shown, cap  74  is threadingly received in cap  60 . 
         [0029]    Proximal end  18  has two openings  18 A that receive fasteners  19 , which are preferably thread screws. Fasteners  19  can be tightened against, or retracted from, laser  62  to move it up and down, or side to side. 
         [0030]      FIG. 6  illustrates the crossbow sighter  10  mounted in a crossbow groove whose axis is projected by the laser light. The extended body  12  permits it to extend beyond the bow string  200 , so the bow string  200  can be positioned on the side of the distal section  18 , to press against the side of distal end  18  and help retain sighter  10  in the groove. 
         [0031]    In a preferred embodiment, proximal end  16  has approximately the same diameter as a crossbow bolt and is received in the crossbow groove in the same manner as a bolt. Extended distal end  18 , as shown, has a diameter slightly smaller than the diameter of proximal end  16 . Body  12  can be one piece, or more than one piece, as long as it is sufficiently aligned along axis  14  so laser light emitted from laser  62  aligns with the axis  14  ad the axis of the crossbow groove. The length of body  12  is preferably 7″, or at least 5″, at least 6″, or at least 7″, or between 6½″ and 7½″. Body  12  preferably has a length that permits it to function with most, if not all, crossbows. 
         [0032]    Some exemplary, specific examples of the invention are set forth below: 
       EXAMPLE 1 
       [0033]    A crossbow sighter for projecting a beam of light along the axis of a groove used to retain a crossbow bolt, the crossbow sighter comprising a body with a length greater than the distance between the groove and the crossbow string when the string is in a relaxed position, an outer surface dimensioned to be received in the groove, and a light source to emit a beam aligned with the groove axis. 
       EXAMPLE 2 
       [0034]    The crossbow sighter of example 1 wherein the body is cylindrical and has a uniform diameter. 
       EXAMPLE 3 
       [0035]    The crossbow sighter of example 1 wherein the diameter of the body varies. 
       EXAMPLE 4 
       [0036]    The crossbow sighter of example 3 wherein the light source is inside the body and there is an opening in an end of the body through which the light is emitted. 
       EXAMPLE 5 
       [0037]    The crossbow sighter of example 4 wherein the opening is covered by a lens. 
       EXAMPLE 6 
       [0038]    The crossbow sighter of any of examples 1-5 further comprising a power source connected to the light source. 
       EXAMPLE 7 
       [0039]    The crossbow sighter of example 6 further comprising a switch to selectively connect the power source to the light source. 
       EXAMPLE 8 
       [0040]    The crossbow sighter of example 7 wherein the body includes a first cavity to house the light source, the switch, and the power source. 
       EXAMPLE 9 
       [0041]    The crossbow sighter of example 8 wherein the body includes a second cavity connected to the first cavity to form an opening from which the light source beam is projected. 
       EXAMPLE 10 
       [0042]    The crossbow sighter of example 7 wherein the body includes a channel formed between the body surface and the first cavity to expose the switch. 
       EXAMPLE 11 
       [0043]    The crossbow sighter of example 10 wherein the switch is a partial cylinder, and wherein the switch is rotatable to selectively connect the power source to the light source. 
       EXAMPLE 12 
       [0044]    A The crossbow sighter of example 11 wherein the switch includes a first outside surface radially disposed around a switch axis and having a first conductive area and cam; wherein a first cavity of the body has a second surface radially disposed around the body axis, having a second conductive area and a channel to receive the switch cam; and wherein the switch cam cooperates with the second surface channel to selectively connect the first and second conductive areas. 
       EXAMPLE 13 
       [0045]    The crossbow sighter of example 12 wherein the switch has a third outside surface radially disposed around the switch axis, having a third conductive area, and wherein the first and third conductive areas are connected through the switch; wherein the first cavity has a fourth surface radially disposed around the body axis, having a fourth conductive area; and further comprising: an electrically conductive spring substantially aligned along the body axis between the third and fourth surfaces; and wherein the second and fourth conductive areas are selectively connected through the switch and spring. 
       EXAMPLE 14 
       [0046]    The crossbow sighter of example 13 wherein the body includes a conductive path, through the light sources, between the second and fourth conductive surfaces; wherein the switch includes a battery cavity; wherein the power source includes at least one battery, housed in the switch&#39;s battery cavity, having a first polarity connected to the switch&#39;s first conductive area and a second polarity connected to the switch&#39;s third conductive area; and wherein the light source is selectively powered with the battery. 
       EXAMPLE 15 
       [0047]    The crossbow sighter of example 1 wherein the light source is a laser. 
       EXAMPLE 16 
       [0048]    The crossbow sighter of any of examples 1-15 wherein the body is at least 5″ long, or at least 6″ long or at least 7″ long. 
       EXAMPLE 17 
       [0049]    The crossbow sighter of any of examples 1-16 wherein the body is comprised of multiple sections. 
       EXAMPLE 18 
       [0050]    The crossbow sighter of any of examples 1-16 wherein the body is formed of a single section. 
       EXAMPLE 19 
       [0051]    The crossbow sighter of any of examples 1-18 wherein the body is comprised of aluminum, steel or plastic. 
         [0052]    Having thus described some embodiments of the invention, other variations and embodiments that do not depart from the spirit of the invention will become apparent to those skilled in the art. The scope of the present invention is thus not limited to any particular embodiment, but is instead set forth in the appended examples and the legal equivalents thereof. Unless expressly stated in the written description or examples, the steps of any method recited in the examples may be performed in any order capable of yielding the desired result.