Patent Publication Number: US-2023152069-A1

Title: High impact strength lighted nock assembly

Description:
REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. application Ser. No. 17/366596, filed on Jul. 2, 2021, which is a continuation of U.S. application Ser. No. 16/237034, filed on Dec. 31, 2018, now U.S. Pat. No. 11,054,227, which is a continuation of U.S. application Ser. No. 15/631016, filed Jun. 23, 2017, now U.S. Pat. No. 10,203,186, which claims the benefit of U.S. Provisional Application No. 62/459421, filed Feb. 15, 2017 and U.S. Provisional Application. No. 62/492671, filed May 1, 2017, the entire disclosures of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure is directed to a lighted nock constructed from a transparent or semi-transparent, reinforced, high impact strength polymeric material (or blend of polymeric materials) for use in bows and crossbows. 
     BACKGROUND 
     Lighted arrow nocks, such as disclosed in U.S. Pat. No. 8,777,786 (Bay) and U.S. Pat. No. 9,279,649 (Bay), allow an archer to be able to more easily see the arrow in flight, see the point of arrow impact, and recover the arrow after a shot. Being able to observe the arrow in flight and see the point of impact helps the archer to diagnose problems with shooting form or bow setup and make appropriate adjustments. Perhaps more importantly, a lighted arrow nock allows an archer to more easily recover the arrow. 
     Bow hunters can especially benefit from using an arrow with a lighted nock device. Recovering an arrow that was shot at an animal is critical in the ethical harvest of animals, and a lighted nock device allows a bow hunter to recover the arrow and animal more easily. Upon recovering the arrow, the bow hunter can diagnose many things about the shot by inspecting the arrow. 
     As vertical bows and crossbows (referred to collectively herein as “bows”) have gotten more powerful current lighted nock products have demonstrated an inability to handle the forces generated during launch. If a nock breaks on launch the energy stored in the bow is not absorbed (or is only partially absorbed) by the arrow, resulting in a fill or partial “dry fire” event. In a dry fire event some or all of the energy stored by the bow is absorbed by the bow itself, especially the limbs and the riser. Shattered limbs and crack risers are common outcomes of a dry fire event. Dry fire events are often catastrophic for the bow. 
     Many existing lighted nock systems have components that transfer forces to the inside surface of the arrow shaft, causing arrow shaft fractures, such as U.S. Pat. No. 7,021,784 (DiCarlo) and U.S. Pat. No. 9,546,851 (Kim). Some lighted nock systems that rely on nock translation to activate the light also require the entire light assembly to be removed from the arrow to deactivate the light. Most of the lighted nock systems suffer from unintended activation of the light, such as during transport, which can drain the battery. 
     SUMMARY 
     One embodiment relates to matched arrow set that includes a first arrow and a second arrow. The first arrow including: a first shaft, a first bushing coupled to the first shaft, and a first nock received in the first bushing. The second arrow including: a second shaft, a second bushing coupled to the second shaft, and a second nock received in the second bushing. The first shaft and the first bushing define a first weight, the second shaft and the second bushing define a second weight greater than the first weight, and a first arrow weight is substantially the same as a second arrow weight. 
     Another embodiment relates to a matched weight arrow set that includes a first arrow including a lighted nock assembly and defining a first weight, and a second arrow including a non-lighted nock assembly and defining a second weight. The lighted nock assembly weighs more than the non-lighted nock assembly, and the first weight is within two percent of the second weight. 
     Another embodiment relates to a matched weight arrow set that includes a first arrow and a second arrow. The first arrow defines a first arrow weight and includes: a first shaft, a first bushing coupled to the first shaft, wherein the first shaft and the first bushing define a first base weight, and a lighted nock received in the first bushing. The lighted nock includes: a head configured to engage a drawstring, a shank formed with the head and sized to be received within the first bushing and defining a cavity, and a light assembly received in the cavity. The second arrow defines a second arrow weight and includes: a second shaft, a second bushing coupled to the second shaft, wherein the second shaft and the second bushing define a second base weight, and a non-lighted nock received in the second bushing. The first arrow weight is within five percent of the second arrow weight, and the first base weight is less than the second base weight. 
     This summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices or processes described herein will become apparent in the detailed description set forth herein, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG.  1    is a perspective view of a nock for an archery arrow in accordance with an embodiment of the present disclosure. 
         FIG.  2    is a top view of the nock of  FIG.  1   . 
         FIG.  3    is a side view of the nock of  FIG.  1   . 
         FIG.  4    is an end view of the nock of  FIG.  1   . 
         FIG.  5    is an end view of the nock of  FIG.  1   . 
         FIGS.  6 A and  6 B  are sectional views of a lighted nock assembly in accordance with an embodiment of the present disclosure. 
         FIGS.  7 A and  7 B  are sectional views of a light assembly in accordance with an embodiment of the present disclosure. 
         FIG.  7 C  is a sectional view of an alternate light assembly with multiple acceleration switches in accordance with an embodiment of the present disclosure. 
         FIG.  8 A  is a sectional view of a combination lighted nock assembly and bushing in accordance with an embodiment of the present disclosure. 
         FIG.  8 B  is a perspective view of the bushing of  FIG.  8 A . 
         FIG.  9    is a sectional view of a lighted nock assembly for a half-moon nock in accordance with an embodiment of the present disclosure. 
         FIG.  10    is a sectional view of a lighted nock assembly for a V-nock in accordance with an embodiment of the present disclosure. 
         FIG.  11    is a sectional view of a lighted nock assembly for a flat nock in accordance with an embodiment of the present disclosure. 
         FIG.  12 A  is a perspective view of an alternate lighted nock assembly used with a bushing in accordance with an embodiment of the present disclosure. 
         FIG.  12 B  is cross-sectional view of the lighted nock assembly of  FIG.  12 A  in a deactivated configuration in accordance with an embodiment of the present disclosure. 
         FIG.  12 C  is cross-sectional view of the lighted nock assembly of  FIG.  12 A  in an activated configuration in accordance with an embodiment of the present disclosure. 
         FIG.  13 A  is an exploded view of the lighted nock assembly of  FIG.  12 A . 
         FIG.  13 B  is a sectional view of the lighted nock assembly of  FIG.  12 A  without the bushing. 
         FIGS.  14 A and  14 B  illustrate an interface of the bushing and the nock of  FIG.  12 A . 
         FIG.  15    illustrates the light assembly of  FIG.  12 A . 
         FIGS.  16 A and  16 B  illustrate the battery stop of  FIG.  12 A . 
         FIGS.  17 A and  17 B  illustrate a tab stop for use with a lighted nock assembly in accordance with an embodiment of the present disclosure. 
         FIG.  18    illustrates a matched weight arrow that can be used with or without a lighted nock assembly in accordance with an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Following below are more detailed descriptions of various concepts related to, and implementations of, methods, apparatuses, and systems for nocks. Before turning to the figures, which illustrate certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting. 
       FIGS.  1  through  5    illustrate various views of an exemplary nock  21  in accordance with an embodiment of the present disclosure. The nock  21  is molded from a reinforced polymeric material (or blend of polymeric materials). The nock  21  can be used with or without a light assembly, as will be discussed herein. 
     For lighted nock applications, the reinforced polymeric material is preferably transparent, but may also be semi-transparent or translucent. Light transmittance of the polymeric material is preferably at least 65%, more preferably at least 75%, and most preferably at least 85%. Nocks for vertical bows and crossbows are often distinguished in their general shape, but both are collectively referred to herein as “nocks”. As used herein, the term “bows” refers generically to both vertical bows and crossbows. 
     The nock  21  illustrated in  FIGS.  1 - 5    is a clip-on nock. The prongs  23  flex outward  25  until the bowstring is seated in semi-circular opening  27 . In order to withstand the forces generated in high-powered bows, the polymeric material must have a high impact strength, but also requires sufficient flexibility to permit the nock prongs  23  to deflect when engaging with and disengaging from the bowstring  29 . The polymeric material preferably has a tensile strength of greater than about 10,000 pounds per square inch (psi) as determined by ASTM D638. The polymeric material preferably has a flexural strength of greater than about 20,000 psi as determined by ASTM D790. The polymeric material preferably has a flexural modulus of greater than 0.50×106 psi. The flexural modules is the ratio, within the elastic limit, of stress corresponding to strain. 
     The reinforcing material can be plastic, metal, ceramic, glass, wood, and/or natural and synthetic composite material, and so forth, as well as combinations thereof. For example, reinforcing material can be glass, carbon, titanium, aluminum, stainless steel, talc, mica, quartz, Wollastonite, as well as combinations thereof. The form of the reinforcing material can be fibers (including woven, nonwoven (e.g., felt), chopped, continuous, and/or random fibers), flakes, beads, particles, and combinations thereof. In one embodiment, the reinforcing material has an average aspect ratio (i.e., the ratio of a structure&#39;s size in different dimensions) of at least about 5:1, and more preferably at least about 7:1, and most preferably about 10:1. 
     In one embodiment, the nock  21  is molded from a high impact, transparent polycarbonate material filled with between about 10% to about 30% by weight reinforcing material. In one embodiment, the reinforcing material is about 20% by weight glass fibers or filamentous glass. The glass fibers preferably have diameters in the range of about 5 microns to about 100 microns and a length of less than about 2 millimeters. One polymeric material suitable for the present high impact nock is available from RTP Company of Winona, Wis. under the product designation RTP  303 . While the material is substantially transparent, it exhibits a slight yellow tint. Polyurethane, polyetherimide, nylon, polyetheretherketone, polyetherketone, and thermoplastic polyimide may also be used. Other polymeric materials suitable for the present nock  21  are disclosed in U.S. Pat. No. 9,434,334 (Marur et al.); U.S. Pat. No. 7,767,738 (Gagger et al.) and U.S. Pat. No. 5,859,119 (Hoefflin), which are hereby incorporated by reference. 
     Transparency is the physical property of allowing light to pass through a material without being scattered. Translucency, on the other hand, allows light to pass through, but the photons can be scattered either at interfaces where there is a change in index of refraction or internally. The nock  21  is preferably constructed from a polymeric material that is transparent (or transparent to certain wavelengths of light due to color tinting of the polymer), while the reinforcing material scatters some portion of the light from the light emitting device. Consequently, portions of the nock  21  both transparent and translucent. That is, a portion of the light emitted by the light emitting device is transmitted through the nock  21  and a portion of the light is scattered by the reinforcing material. 
     By altering the percentage of reinforcing material in the polymeric material it is possible to engineer the optimum balance of transmitted light (which creates more directional light source that is visible at a greater distance) and scattered light (which creates a hemispheric distribution of light that is visible from more angles). Applicants have identified a reinforcing material content of about 10% to about 30% by weight as providing optimal light distribution for lighted nock applications. 
     The nock  21  illustrated in  FIGS.  1 - 5    may be used with the crossbows illustrated in U.S. Pat. No. 9,494,379 (Yehle) entitled Crossbow, filed Apr. 14, 2016 and U.S. patent application Ser. No. 15/433,769 entitled Crossbow, filed Feb. 15, 2017, both of which are hereby incorporated by reference. In particular, the anti-dry fire mechanism disclosed in the patents noted above preferably engages with the nock  21  in the region  31  behind the bowstring  29 . The region  31  is preferably at least about 0.1 inches. Flat regions  33  illustrated in  FIG.  3    are preferably separate by a distance  35  of about 0.250 inches, which corresponds to a gap between fingers on a bowstring catch for the crossbow in the patents noted above. 
       FIGS.  6 A and  6 B  are cross-sectional views of the lighted nock assembly  20  in accordance with an embodiment of the present disclosure. In the illustrated embodiment, the light assembly  24  is a “bobber-light” that includes light emitting device  26 , such as a filament light, an LED, or other light producing device, electrically coupled to battery  28 . The nock  21  includes recess  22  configured to receive the light emitting device  26 . 
     In the illustrated embodiment, elastomeric member  30  maintains gap  32  between light emitting device  26  and the battery  28  corresponding to the battery  28  being disconnected from the light emitting device  26  (see  FIG.  7 A ). The light assembly  24  is biased to the deactivated configuration by the elastomeric member  30 . 
     As best illustrated in  FIG.  6 B , on launch the bowstring (not shown) applies force  34  to displace the nock  21  into the arrow shaft  36 , reducing or closing the gap  38 . Bottom surface  40  of the recess  22  simultaneously displaces the light emitting device  26  toward the battery  28  to complete the circuit and altering the light emitting device to an activated state (see e.g.,  FIG.  7 B ). Elastomeric insert  46  secures the battery  28  to the inside surface  44  of the arrow shaft  36  so as to create force  48  that opposes the force  34  applied to the light emitting device  26  by displacement of the nock  21 . The opposing forces  34  and  48  compress the elastomeric material  30  and substantially closes the gap  32 , resulting in the battery  28  being electrically coupled to the light emitting device  26  (see  FIG.  7 B ). The light emitting device  26  is now in the activated state. 
     The light assembly  24  is moved to the deactivated configuration by pulling the nock  21  slightly out of the arrow shaft  36  as illustrated in  FIG.  6 A  and reestablishing the gap  38 . The elastomeric material  30  simultaneously displaces the light emitting device  26  away from the battery  28  and opens the circuit to deactivate the light emitting device  26  (see e.g.,  FIG.  7 A ). The light assembly  24  is normally biased to the deactivated configuration absent an external force. 
       FIGS.  7 A and  7 B  illustrate the light assembly  24  in accordance with an embodiment of the present disclosure.  FIG.  7 A  illustrates the light assembly  24  in the deactivated configuration and  FIG.  7 B  illustrates the activated configuration. The light emitting device  26  includes a pair of electrical contacts  50  and  52  that extend rearward within housing  54  toward the battery  28 . In the illustrated embodiment the contact  50  is engaged with one pole of the battery  28  at all times. In the deactivated configuration the contact  52  is separated from the other pole  56  of the battery  28 . The elastomeric member  30  maintains that separation. In another embodiment, a metal spring may be located generally concentrically around the pole  56  to serve as both the contact  50  and to provide the biasing force of the elastomeric member  30 . In both embodiments the light assembly  24  is biased to the inactive configuration. 
     As illustrated in  FIG.  7 B , when the light assembly  24  is subject to a longitudinal compressive force  58  the elastomeric member  30  is elastically deformed and compressed a sufficient amount so the contact  52  engages with the other pole  56  of the battery  28 , completing the circuit so the light emitting device  26  is in the activated state. When the longitudinal compressive force  58  is removed the elastomeric member  30  automatically returns to its original size and shape (see  FIG.  7 A ), which displaces the contact  52  way from the pole  56  of the battery  28  to move the light emitting device  26  to the deactivated state. 
     In another embodiment, the light emitting device  26  is secured in the recess  22  in the nock  21 . When the nock  21  is pulled away from the arrow shaft  36  and the gap  38  is reset, the light emitting device  26  and the contact  52  are also displaced away from the pole  56  of the battery  28  and the light emitting device  26  is in the deactivated state. The elastomeric member  30  is not required in this embodiment. 
     In an alternate embodiment illustrated in  FIG.  7 C , one or more accelerometer switches or an integrated circuit accelerometer  100 A,  100 B (“ 100 ”) control activation of the light emitting device  26 , such as disclosed in U.S. Pat. No. 7,993,224 (Brywig), which is hereby incorporated by reference. The switches  100  respond to the forces resulting from the acceleration of the arrow upon release or deceleration of the arrow upon impact with a target. In one embodiment, multiple accelerometer switches  100  are provided to sense acceleration and/or deceleration along multiple axes  102 ,  104 . For example, axis  102  may be located along a longitudinal axis of the arrow and the axis  104  is perpendicular to the axis  102 . Triggering of the light emitting device  26  preferably requires a combination of acceleration and/or deceleration signals along the two different axes  102 ,  104 . 
       FIGS.  8 A and  8 B  illustrate an alternate lighted nock assembly  20  used in combination with bushing  60  in accordance with an embodiment of the present disclosure. The bushing  60  is a hollow cylinder that is interposed between the nock  21  and the arrow shaft  36  to reinforce the shaft  36 . The light assembly  24  extends through center opening  62  in the bushing  60 . The bushing  60  is preferably aluminum or other light-weight metal. 
     The present disclosure is not limited to the light assemblies  24  illustrated herein. The present lighted nock assembly  20  can be modified to operate with a variety of light assemblies, including without limitation the light assemblies disclosed in U.S. Pat. No. 4,340,930 (Carissimi), U.S. Pat. No. 4,547,837 (Bennett); U.S. Pat. No. 5,134,552 (Call et al.); U.S. Pat. No. 6,123,631 (Ginder); U.S. Pat. No. 6,736,742 (Price et al.); U.S. Pat. No. 7,021,784 (DiCarlo); U.S. Pat. No. 7,211,011 (Sutherland); U.S. Pat. No. 7,837,580 (Huang); U.S. Pat. No. 7,931,550 (Lynch); U.S. Pat. No. 7,927,240 (Lynch); U.S. Pat. No. 7,993,224 (Brywig); U.S. Pat. No. 8,342,990 (Price); U.S. Pat. No. 8,540,594 (Chu); U.S. Pat. No. 8,758,177 (Minica); U.S. Pat. No. 8,777,786 (Bay); U.S. Pat. No. 8,944,944 (Pedersen et al.); U.S. Pat. No. 9,140,527 (Pedersen et al.); U.S. Pat. No. 9,151,580 (Pedersen); U.S. Pat. No. 9,243,875 (Minica); U.S. Pat. No. 9,279,647 (Marshall); U.S. Pat. No. 9,279,648 (Marshall); U.S. Pat. No. 9,279,649 (Bay); U.S. Pat. No. 9,404,720 (Pedersen); U.S. Pat. No. 9,423,219 (Pedersen et al.); U.S. Pat. No. 9,518,806 (Pedersen); U.S. Pat. No. 9,546,851 (Kim); 2015/0192395 (Beck), which are hereby incorporated by reference. 
     The present disclosure is applicable to any nock configuration, including without limitation, flat, half-moon, slotted, and universal nocks, such as disclosed in U.S. Pat. No. 9,441,925 (Palomaki et al.); U.S. Pat. No. 9,285,195 (Palomaki et al.); U.S. Pat. No. 9,212,874 (Harding); U.S. Pat. No. 8,622,855 (Bednar et al.); U.S. Pat. No. 7,189,170 (Korsa et al.); U.S. Pat. No. 5,803,843 (Anderson et al.); D717,389 (Huang); D664,625 (Minica); D641,827 (Errett); and D595,803 (Giles), which are hereby incorporated by reference. 
       FIG.  9    illustrates a lighted nock assembly  70  including a light assembly  24  and a half-moon nock  72  in accordance with an embodiment of the present disclosure.  FIG.  10    illustrates a lighted nock assembly  80  including a light assembly  24  and a V-nock  82  in accordance with an embodiment of the present disclosure.  FIG.  11    illustrates a lighted nock assembly  90  including a light assembly  24  and a flat nock  92  in accordance with an embodiment of the present disclosure. 
       FIGS.  12 A through  12 C  illustrate an alternate lighted nock assembly  120  used in combination with bushing  122  in accordance with an embodiment of the present disclosure. The bushing  122  is preferably constructed from a light weight metal and is sized to be receive within arrow shaft  142 . In the illustrated embodiment, the bushing  122  includes shoulder  123  that engages with rear end  125  of the arrow shaft  142 . 
     In the illustrated embodiment, the light assembly  124  is a “bobber-light” that includes light emitting device  126 , such as a filament light, an LED, or other light producing device, electrically coupled to battery  128 . See also,  FIG.  15   . The light emitting device  126  is mechanically coupled to a battery  128 . Displacing the light emitting device  126  toward the battery  128  activates the light emitting device  126  and displacing the light emitting device  126  away from the battery  128  deactivates the light emitting device.  FIG.  12 B  illustrates the lighted nock assembly  120  in a deactivated configuration  110  and  FIG.  12 C  illustrates the lighted nock assembly  120  in an activated configuration  112 , as will be discussed further herein. 
     As best illustrated in  FIG.  12 B , the nock  130  includes recess  132  configured to receive the light assembly  124  (see also  FIG.  14 A ). The light emitting device  126  is secured in the recess  132  using a variety of means, such as fasteners, adhesives, inter-locking structures, and the like. Only the light emitting device  126  is attached to the nock  130  so the remainder of the light assembly  124  can move relative to the nock, as illustrated in  FIG.  12 C . The nock  130  is preferably molded from a transparent, high impact strength polymeric material, as discussed herein. 
     Battery  128  is secured to inside surface  138  of the bushing  122  by battery stop  136 . The battery stop  136  is attached to the battery  128  at a location offset from the nock  130 , even in the activated configuration  112 . The battery stop  136  is a discrete component from the nock  130  and the bushing  122 . Consequently, the nock  130  is coupled to the battery stop  136  by the battery  128 , such that movement of the nock  130  relative to the bushing  122  is independent from the engagement of the battery stop  136  with the bushing  122 . 
     Distal end  127  of the bushing  122  preferably includes a structure  129 , such as a ridge or a shoulder that limits displacement of the battery stop  136  in direction  131 . The tolerances on the battery stop  136  are such that it can slide within the bushing  122 , but substantially limits radial displacement of the battery  128  within the arrow shaft  142 . This configuration also serves to reinforce the nock  130  from torque applied by a bowstring. These forces are substantially contained within the bushing  122 , rather than the arrow shaft  142 . 
     In the illustrated embodiment, the battery  128  is glued to center opening  148  that extends through the battery stop  136 . The center opening  148  permits the battery stop  136  to be slid along the battery  128  to the optimum location before being glued in place. It is also possible to use a longer battery  128  that extends past distal end of the battery stop  136 . 
     Friction member  134 , such as an elastomeric O-ring, is located in recess  135  in the battery stop  136 . See also,  FIGS.  16 A and  16 B . The friction member  134  engages with inside surface  138  of the bushing  122  rather than inside surface  140  of the arrow shaft  142 . In the illustrated embodiment, inside surface  138  of the bushing  122  includes recess  144  that receives a portion of the friction member  134 . Locating the O-ring  134  in the opposing recesses  135 ,  144  resists longitudinal displacement of the battery  128  in the bushing  122  a sufficient amount to permit the nock  130  to be pulled to reset the gap  152  to the deactivated configuration  110 , without removing the lighted nock assembly  120  from the bushing  122  (see  FIG.  12 C ). By applying additional pulling force to the nock  130 , the entire lighted nock assembly  120  (light assembly  124 , battery stop  136 , and nock  130 ) can be removed from the bushing  122  and replaced. 
     Because the lighted nock assembly  120  is contained within the bushing  122 , forces applied to the nock  130  during launch are transmitted to the shaft  142  through the bushing  122 . For example, radial outward forces  146  transmitted to the battery stop  136  and friction member  134  are contained by the bushing  122 , rather than the arrow shaft  142 . Many existing lighted nock systems have components that transfer forces to the inside surface of the arrow shaft, causing arrow shaft fractures. The present system isolates the forces generated by the nock  130  within the bushing  122 , so any forces experience by the nock  130  are transmitted to the arrow shalt  142  by the bushing  122 , greatly extending arrow life. When combined with a nock molded from a transparent, high impact strength polymeric material, the present lighted nock assembly  120  is suitable for use with high-powered bows and crossbows. 
     On launch the bowstring (not shown) applies force  150  that displaces the nock  130  into the arrow shaft  142  to the activated configuration  112  shown in  FIG.  12 C , reducing or closing the gap  152 . Bottom surface  154  of the recess  132  simultaneously displaces the light emitting device  126  toward the battery  128 , completing the circuit and placing the light emitting device  126  to an activated state. The friction member  134  secures the battery  128  to the inside surface  138  of the bushing  122  so as to create force  156  that opposes the force  150  applied to the light emitting device  126  by displacement of the nock  130 . The opposing forces  150  and  156  displace the light emitting device  126  toward the battery  128  to substantially reduce or close the gap  158  and to activate the light emitting device  126 . 
     The light assembly  124  is moved to the deactivated configuration  110  by pulling the nock  130  slightly out of the arrow shaft  142  to reestablish the gap  152 , as illustrated in  FIG.  12 B . The friction member  134  secures the battery stop  136  that is attached to the battery  128  within the bushing  122  in opposition to the nock  130  being pulled away from the bushing  122 . Consequently, the light emitting device  126  can be deactivated without removing the light assembly  124  from the bushing  122 . 
       FIGS.  13 A and  13 B  show the lighted nock assembly  120  separated from the bushing  122 . Since the battery stop  136  is glued to the battery  128  and the LED  126  is glued to the nock  130 , the entire lighted nock assembly  120  can be removed from the bushing  122 . In the event the light assembly  124  is not working or the nock  130  damaged, the user can pull the entire lighted nock assembly  120  from the bushing  122  by overcoming the frictional coupling generated by the friction member  134  engaged with the recess  144  (see  FIG.  12 B ) in the bushing  122 . A replacement lighted nock assembly  120  is then re-inserted into the bushing  122 . This configuration permits the bushing  122  to be permanently attached, such as with an adhesive, to the arrow shaft  142  (see  FIG.  12 B ). 
     The nock  130  preferably includes one or more ridges  160  that mate with corresponding grooves  162  located on inside surface  138  in center opening  164  of the bushing  122 . The ridges  160  and grooves  162  prevent the nock  130  from rotating axially relative to the bushing  122  so the nock opening  166  is retained in the correct orientation relative to the arrow shaft  142 . See also,  FIGS.  14 A and  14 B . 
       FIGS.  17 A and  17 B  illustrate the lighted nock assembly  120  and the bushing  122  with stop tab  170  located in the gap  152  (see  FIG.  12 A ) to prevent inadvertent activation of the light assembly  124 . The tab stop  170  is useful for shipping purposes and for carrying arrows containing the present lighted nock assembly  120  in the field. The stop tab  170  includes one or more arms  172  that wrap around the stem of the nock  130  and block the gap  152  from closing. The arms  172  are designed to flex outward during insertion into, and removal from, the gap  152 . 
     In the illustrated embodiment, the tab stop  170  includes a handle portion  174  that is large enough to prevent the nock  130  from being engaged with a crossbow trigger housing, forcing the user to remove the tab stop  170  before nocking the arrow. The handle portion  174  preferably has at least one major dimension  176  that is at least about two times an outside diameter  180  of the arrow shaft  142  (see  FIG.  12 B ) coupled to the nock  130 , and more preferably at least about three times the outside diameter of the arrow shaft. 
       FIG.  18    illustrates a matched weight arrow  190  that can be both lighted and non-lighted, in accordance with an embodiment of the present disclosure. As used herein, “matched weight arrows” refers to a plurality of arrows with the same functional characteristics, such as for example, length, stiffness, weight, and diameter, that exhibit substantially similar flight characteristics when launched from the same bow. The present matched weight arrows  190  have a weight difference of less than about 10%, more preferably less than about 5%, and most preferably less than about 2%. In operation, matched weight arrows can be used interchangeable without adjusting the sight or scope on the bow. 
     The arrow  190  includes a threaded front insert  192  that receives an arrow head (not shown), a shaft  194 , fletching  196 , and a rear opening  198  configured to receive any of the bushings and/or nocks disclosed herein. The present matched weight arrow  190  is configured to have substantially the same weight, whether used with our without the present lighted nock assembly  120 , so their flight characteristics are the substantially the same. Consequently, a user can select either a lighted arrow or a non-lighted arrow without having to compensate for different weight arrows. 
     For a non-lighted arrow  190 , for example, the bushing  60  (see  FIG.  8 B ) and the nock  21  ( FIG.  1   ) are inserted into the rear opening  198 , without the lighted nock assembly  120 . 
     For a lighted arrow  190 , for example, the present lighted nock assembly  120  and bushing  122  is inserted into the rear opening  198 . Since the lighted nock assembly  120  and bushing  122  are heavier than just the nock  21  and bushing  60 , weight is preferably removed elsewhere from the lighted arrow, such as from the shaft  194 , the threaded front insert  192 , or the fletching  196 , so the lighted arrow weighs substantially the same as a non-lighted arrow. In one embodiment, weight is removed from the front insert  192  of the lighted arrow to offset the weight added by the lighted nock assembly  120 . In one embodiment, the rear bushing  122  used with the lighted arrow assembly  120  is lighter than the bushing  60 , to offset some or all of the weight difference. In another embodiment, weight is added to the non-lighted arrows, such for example, in the threaded front insert  192  or the rear bushing  60 , equal to the amount of weight added by the lighted nock assembly  120  and bushing  122 . Consequently, the user can carry both lighted arrows and non-lighted arrows having substantially the same weight and flight characteristics. These matched weight arrows  190  can be used interchangeable without effecting accuracy. 
     Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within this disclosure. The upper and lower limits of these smaller ranges which may independently be included in the smaller ranges is also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either both of those included limits are also included in the disclosure. 
     Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the various methods and materials are now described. All patents and publications mentioned herein, including those cited in the Background of the application, are hereby incorporated by reference to disclose and described the methods and/or materials in connection with which the publications are cited. 
     The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present disclosure is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed. 
     Other embodiments are possible. Although the description above contains much specificity, these should not be construed as limiting the scope of the disclosure, but as merely providing illustrations of some of the presently preferred embodiments. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of this disclosure. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes disclosed. Thus, it is intended that the scope of at least some of the present disclosure should not be limited by the particular disclosed embodiments described above. 
     Thus the scope of this disclosure should be determined by the appended claims and their legal equivalents. Therefore, it will be appreciated that the scope of the present disclosure fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present disclosure, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims.