Abstract:
Vibration dampening devices for arrows are installed in the arrow point end of the arrow shaft or in the nock end of the shaft or in both of those ends. These devices: (a) are fabricated from elastomeric materials; (b) have an elongated core surrounded by one or more annular, vibration dampening elements; and (c) employ decay time modification to attenuate shock and vibration. The devices are assembled in axially aligned relationship to an arrow point insert or arrow nock, and coupling features insure a positive connection between the dampening device and the arrow point insert or nock to which a device is assembled.

Description:
CROSS-REFERENCE TO A RELATED APPLICATION 
       [0001]    This application is related to and claims the benefit of the 3 May 2006 filing date of provisional patent application No. 60/797,257. 
     
     TECHNICAL FIELD OF THE INVENTION 
       [0002]    In one aspect, the present invention relates to the shock/vibration dampening and settling of an arrow as the arrow is shot (or launched) from a bow. 
         [0003]    In another aspect, the present invention relates to novel, improved, shock/vibration dampeners which are constructed and configured for installation in the hollow shaft of an arrow. 
         [0004]    And, in still another aspect, the present invention relates to arrows which have novel shock/vibration dampeners of the character described in the preceding paragraph and to assemblies of the dampener and an arrow component. 
       Definitions 
       [0005]    An arrow as that term is employed herein is an artifact with an elongated shaft configured and constructed to receive an arrow point at one end and a nock at the opposite end. Arrows as herein defined include those designed for cross bows and sometimes referred to as quarrels or bolts. 
         [0006]    A vibration dampener is a device which is fabricated from an elastomeric material and has a feature for attaching it in end-to-end relationship to a rigid arrow point insert or to a nock. The term “vibration dampener” is intended to identify devices which dampen shocks as well as vibrations. 
       BACKGROUND OF THE INVENTION 
       [0007]    The accuracy with which an arrow can be shot from a bow is of the utmost importance to all archers—bow hunters, target archers, those who use bows for fishing, and others. An arrow which is quiet in flight is also very important, perhaps most particularly to a bow hunter. A third feature, important in many types of archery, is an arrow which will minimize the damage which ensues if an arrow strikes one which was previously shot. 
         [0008]    Accuracy of a shot depends to a large part on how quickly an arrow can be made to settle and thereby assume a stable flight path when it is shot from a bow. An arrow which settles quickly is one which is also quiet in flight. 
         [0009]    Settling time can be shortened by decay time modification after the arrow has left the bow. The reduction in setting time is accompanied by an increase in accuracy. 
         [0010]    Minimization of shock and vibration by decay time modification can minimize the damage which occurs when an arrow strikes an arrow that has previously struck a target. Furthermore, the minimization of shock and vibration has the potential to decrease drag by minimizing flutter, thereby increasing the flight distance of an arrow. 
       SUMMARY OF THE INVENTION 
       [0011]    These important goals of settling time minimization and damage limitation are realized in accord with the principles of the present invention by installing a vibration dampener (vibration dampening device) in the shaft of an arrow. The dampener can be located at either the point end or the nock end of the arrow or at both the arrow point and nock ends. 
         [0012]    Dampeners which are useful for the stated purposes employ decay time modification to minimize shock and vibration. They are fabricated from an elastomer, preferably though not necessarily a NAVCOM® material. Acceptable performance typically dictates that the elastomer have a Shore A hardness in the range of ca. 12-20. 
         [0013]    The novel dampeners disclosed herein have an elongated body surrounded by one or more integral, annular vibration dampening elements. When shock and/or vibrations reach the dampener, its components, especially the annular dampening element(s), are so macroscopically and elastically displaced as to very rapidly reduce the time required for the shock and/or vibrations to decay to a harmless, very low level. This removes the factors which keep an arrow from settling, allowing this to occur very quickly and produce the wanted stable and quiet flight. 
         [0014]    Annular dampening elements as described above are typically located toward one end of the dampener body with which they are integrated and dimensioned for a high tolerance slip fit in the shaft in which the dampener is installed (a typical slip fit is one in which the maximum diameter of a vibration dampener is smaller by less than 0.005 inch relative to the inside diameter of an arrow shaft in which the dampener is installed). This leaves an opposite, tip end portion of the dampener body free to wiggle and jiggle when shocks or vibrations are impressed on the dampener, a phenomenon which can significantly increase the effectiveness of the dampener. Also, the high tolerance slip fit provides for decay time modification by sliding friction between the dampening element and the inside wall of the hollow arrow shaft, by the dampener acting to resist motion of the arrow shaft, and by elastic deformation of the elastomeric dampener material. 
         [0015]    The preferred placement of the dampening elements is off-center with respect to an active segment of the device—for example, that segment between a coupling segment at one end of the device and a tip at the opposite end. The preferred off-center locational relationship of the dampening element(s) also enhances the functioning of the dampening device by keeping the device from resonating in phase with the shaft of the arrow in which the dampening device is installed. 
         [0016]    Yet another approach that can be employed to advantage is to employ a set of integral annular elements located along the entire length of the dampener&#39;s body component. This increases the number of vibration dampening elements, potentially adding to the decay time modifying ability of a dampener embodying the principles of the present invention. 
         [0017]    A dampener as disclosed herein is installed by slipping (or pressing) it into the hollow shaft of an arrow. This may increase the air pressure in the shaft to a level at which the dampener will pop back out of the shaft when the installation force is removed. This can be avoided by providing an end-to-end axial bore through the dampener. 
         [0018]    As stated above, dampeners embodying the principles of the present invention can be installed at either the point end or the nock end of an arrow. At the point end, the dampener can be pre-assembled before installation to the insert commonly provided to attach a point to the arrow shaft. At the nock end of an arrow, the dampener is attached directly to the nock in a pre-installation step in the preferred manner of installing the dampener. 
         [0019]    As indicated above, the novel dampeners disclosed herein are preferably dimensioned for high tolerance slip fit in with the arrow shafts in which they are installed, perhaps making it difficult to press the dampener into the shaft. The shaft-engaging surfaces of the dampener may in this case be lubricated before attempting to install the dampener. An epoxy adhesive capable of bonding the dampener to the arrow shaft or any other appropriate adhesive may be employed. 
         [0020]    Other objects, features, and advantages of the invention will be apparent to the reader from the foregoing and the appended claims and as the ensuing description and discussion proceeds in conjunction with the accompanying drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a side view of an arrow equipped with a point, a nock, and internal, slip fitting, point end and nock end vibration dampeners; the vibration dampeners embody the principles of the present invention and are constructed and installed in the arrow in accord with those principles; 
           [0022]      FIG. 2  is a longitudinal section through the  FIG. 1  arrow, arrow point, nock, both vibration dampeners, and an arrow point insert to which the point end vibration damper is assembled; 
           [0023]      FIG. 2A  is a first, enlarged scale fragment of  FIG. 2 ; 
           [0024]      FIG. 2B  is a second, enlarged scale fragment of  FIG. 2 ; 
           [0025]      FIG. 3  is an exploded view of: (a) the  FIG. 1  arrow; (b) the nock and nock end vibration dampener; (c) the point end vibration dampener; (d) the arrow point insert, and (e) the arrow point; 
           [0026]      FIG. 3A  is an enlarged scale view of the point end vibration dampener shown in  FIG. 3 ; except for scale, the two views are essentially alike; 
           [0027]      FIG. 3B  is a side view of a second, slip fitting, vibration dampening device embodying the principles of the present invention; this device has an alternate dampening element configuration that may also be employed in many, if not most, dampeners embodying those principles. 
           [0028]      FIG. 4  is an isometric view of a third, slip fitting, point end vibration dampener and arrow point insert assembly; the assembly, dampener, and insert all embody the principles of the present invention; 
           [0029]      FIG. 5  is a longitudinal section through the assembled point end vibration dampener and the arrow point insert; 
           [0030]      FIG. 6  is an exploded view of the point end vibration dampener and the arrow point insert; 
           [0031]      FIG. 7  is an isometric view of a fourth, slip fitting, point end vibration dampener and arrow point insert assembly; the assembly, dampener, and insert all embody the principles of the present invention; 
           [0032]      FIG. 8  is a longitudinal section through the assembly of  FIG. 7 ; 
           [0033]      FIG. 9  is an exploded view of the assembled  FIG. 7  vibration dampener and arrow point insert; 
           [0034]      FIG. 10  is an isometric view of a fifth, slip fitting, point end vibration dampener and arrow point insert assembly; the assembly, dampener, and insert all embody the principles of the present invention; 
           [0035]      FIG. 11  is a longitudinal section through the assembly of  FIG. 10 ; 
           [0036]      FIG. 12  is an exploded view of the  FIG. 10  vibration dampener and arrow point insert; 
           [0037]      FIG. 13  is a section through the point end of an arrow as shown in  FIG. 1  with the  FIG. 10  vibration dampener installed and an assembly-facilitating tail of the dampener removed; this figure also shows the installed arrow point insert and an arrow point threaded into the insert to mount the point to the arrow; 
           [0038]      FIG. 14  is an isometric view of a sixth, slip fitting, point end vibration dampener and arrow point insert assembly; the assembly, dampener, and insert all embody the principles of the present invention; 
           [0039]      FIG. 15  is a longitudinal section through the assembly of  FIG. 14 ; 
           [0040]      FIG. 16  is an exploded view of the  FIG. 14  vibration dampener and arrow point insert; 
           [0041]      FIG. 17  is an isometric view of a seventh, slip fitting, point end vibration dampener and arrow point insert assembly; the assembly, dampener, and insert all embody the principles of the present invention; 
           [0042]      FIG. 18  is a longitudinal section through the assembly of  FIG. 17 ; 
           [0043]      FIG. 19  is an exploded view of the  FIG. 17  vibration dampener and arrow point insert; 
           [0044]      FIG. 20  is a section through an arrow which has a hollow shaft and is equipped with an eighth point end vibration dampener and a second, also slip fitting, nock end vibration dampener, both constructed in accord with the principles of the present invention; also shown in this figure are a point end arrow insert, an arrow point, and a nock; 
           [0045]      FIG. 21  is an isometric view, to a larger scale, of an assembly composed of the  FIG. 20  vibration dampener and arrow point insert; 
           [0046]      FIG. 22  is a perspective view of the vibration dampener first shown in  FIG. 20 ; 
           [0047]      FIG. 23  is an exploded view of a nock end vibration dampener assembly; this assembly includes a nock and a vibration dampener as shown in  FIG. 20 ; and the assembly, dampener, and nock are all constructed in accord with the principles of the present invention; 
           [0048]      FIG. 24  is a section through an arrow with still other, slip fitting, point end and nock end vibration dampeners; a dampener/nock assembly; and a dampener/point insert assembly; the dampeners, nock, insert, and assemblies all embody the principles of the present invention; and 
           [0049]      FIG. 25  is an exploded view of the  FIG. 24  arrow. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0050]    Referring now to the drawings,  FIGS. 1 ,  2 ,  2 A,  2 B,  3 , and  3 A depict an arrow  40  equipped with: (1) a point end vibration dampener  42 , and (2) a nock end vibration dampener  44 . Both dampeners are constructed in accord with the principles of the present invention and installed in arrow  40  in accord with those principles. 
         [0051]    Arrow  40  has a hollow shaft  46 , an arrow point  48  at the rear end  50  of the shaft, and a nock  52  at the front end  54  of the shaft. Fletches  56   a - c  of conventional construction are mounted to arrow shaft  46  toward its front end  54 . 
         [0052]    Referring now to  FIGS. 2 ,  2 A, and  3 , point end vibration dampener  42  is dimensioned for a high tolerance slip fit in arrow shaft  46  and is installed in the hollow interior  60  of the shaft toward the rear end  50  of the shaft. Nock end vibration dampener  44  is similarly dimensioned for a high tolerance slip fit in arrow shaft  46  and is installed in the interior  60  of the shaft adjacent the forward, front end  54  of the shaft. 
         [0053]    Dampener  42  is preassembled in end-to-relationship to an arrow insert  64 . The dampener/insert assembly  65  is installed by sliding it into hollow shaft interior  60  with insert  64  between dampener  42  and the rear end  50  of the arrow shaft. 
         [0054]    Arrow point  48  and insert  64  have complementary external and internal threads collectively identified in  FIG. 2  by reference character  66 . After installation of assembly  65 , arrow point  48  is threaded into insert  64  until an annular ledge  68  on the arrow point engages and is tightened against the rear end  50  of arrow shaft  46 . An annular lip  70  at the rear end of arrow point insert  64  is at this juncture trapped between ledge  68  and shaft end  50  to retain the insert and the dampener  42  assembled to insert  64  in place in shaft  46 . 
         [0055]    Point end vibration dampener  42  has an elongated core  71  with a tip at one end. Tip  72  is free to wiggle and jiggle in the interior  60  of hollow arrow shaft  46  and thereby advantageously contribute to modification of the decay time of vibrations transmitted to the dampener. Tip  72  terminates in a freely movable, exposed end  73 . 
         [0056]    The opposite end of vibration dampener  42  is an integral coupling segment  82 , provided for assembling dampening device  42  to arrow insert  64 . 
         [0057]    An integral, off-center, quasi-toroidal dampening element  74 , which surrounds dampener core  72 , is located toward the coupling segment end  82  of the dampener (the right-hand end as seen in  FIG. 2A  in which the longitudinal center of the pertinent core segment  75  is identified by centerline  76 ). Without comprising the dampening function of element  74 , this leaves the tip  72  of the dampening device free to wiggle and jiggle without setting up unwanted, performance-degrading frequencies in arrow  40  as the dampening element  74  might do if it were centered along the core  71  of dampening device  42 . 
         [0058]    The coupling segment  82  of dampening device  42  has a frustoconical head  86  and a recess  87  located between head  82  and a tapered element  88  of the dampener. Element  88  is dimensioned to have a slip fit in the hollow interior  60  of arrow shaft  46 . 
         [0059]    The front end  88  of arrow point insert  64  has a complementary coupling segment  89  with a flange  90  and an adjoining, annular, frustoconical recess  92 . 
         [0060]    Dampening device  42  and arrow point insert  64  are preassembled by effecting relative movement between these two components in directions indicated by arrows  94  and  96  in  FIG. 2 . 
         [0061]    This relative movement is continued until the frustoconical head  88  of vibration dampener  42  snaps into the complementary annular, frustoconical recess  92  at the front end of arrow point insert  64 . That traps dampening device  42  between the side wall  98  of the insert and the flange  90  at the forward end of that component, thus positively locking or coupling vibration dampening device  42  and insert  64  together. 
         [0062]    To a considerable extent, the slip fitting nock end vibration dampening device  44  shown in  FIGS. 2 and 2A  resembles point end dampening device  42 ; and common elements of the two dampening devices have accordingly been identified by the same reference characters. 
         [0063]    Dampening device  44  differs from the device of that character at the point end of arrow  40  in that it has a coupling segment  100  with an internally threaded recess  102 . This recess opens onto the forward end  104  of the device. 
         [0064]    Nock  48  has a complementary, longitudinally extending, externally threaded lug or boss  106 . The internal and external threads are collectively identified in  FIG. 2B  by reference characters  108  and  109 . 
         [0065]    Nock  48  and vibration dampener  44  are preassembled by threading these components together. The resulting assembly  110  is then slid into hollow shaft  60  with dampening device segment  111  and dampening elements  74  . . .  80  having a slip fit relative to the interior wall side  85  of arrow shaft  60 . 
         [0066]    A set of juxtaposed annular grooves  112  on the outer side  114  of dampening device coupling segment  100  (see  FIG. 2A ) allows the damping device material to give as necessary to the extent that the dampening device/insert assembly  110  can be slid into the interior  60  of arrow shaft  46 . 
         [0067]    To the same end, assembly-facilitating grooves may be formed on the exterior of any of the other dampening devices disclosed hereinafter, including point end dampener  42  (see  FIGS. 2 ,  2 B, and  3 A). 
         [0068]    In those embodiments of the invention described below, elements common to those embodiments and the vibration dampeners shown in  FIGS. 2 ,  2 A,  2 B,  3 , and  3 A will again be identified by the same reference characters. 
         [0069]    The slip fitting vibration dampening device  116  illustrated in  FIG. 3B  is essentially like the just-described device  42 , but differs in that it has an integral dampening element  118  with the configuration of a thick washer rather than the toroidal configuration of the device  42  dampening element  74 . Like element  74 , the dampening element  118  of dampening device  116  has a longitudinally off-center relationship with the elongated core  71  of the device, allowing the tip  72  of device  116  to wiggle and jiggle. 
         [0070]    Returning then to the drawings,  FIGS. 4-6  depict an assembly  120  of an arrow point insert  122  and a slip fitting vibration dampening device  124 . Insert  120  has a coupling segment  126  which includes the reduced diameter end  128  of a stepped-down insert barrel  130 . 
         [0071]    The complementary coupling segment  132  of vibration dampening device  124  is akin to the coupling segment  82  of dampener  42  except that coupling segment  132  has an annular end segment  136  which surrounds point insert end  128  and butts against a ledge  138  at the junction of that end and the body  142  of point insert barrel  130 . 
         [0072]    As is best shown in  FIG. 5 , dampening device  134  also has an integral, annular, off-center dampening element  144  with a configuration different from the corresponding element  74  of device  42 . Specifically, dampening element  144  has an annular disk  145  and integral stubs  146  and  147 , which are centered on the axial centerline  148  of dampening element  144  and extend in opposite directions from disk  145 . 
         [0073]      FIGS. 7-9  depict an assembly  150  of a slip fitting vibration dampening device  152  and an arrow point insert  154 . 
         [0074]    Dampening device  152  differs from those discussed above in that an integral, elongated tail  156  extends longitudinally from the head  86  of the dampening device to and through insert  154 . 
         [0075]    Pulling on tail  156  in the direction indicated by arrow  158  in  FIG. 9  draws the dampening device into the bore  160  of the insert  154  and snaps head  86  into insert recess  92 . 
         [0076]    Tail  156  has a weakened end segment  162  at the location where the tail is integrated with the head  86  of dampening device  152 . Once dampening device head  186  is seated in insert recess  92 , a firm pull or yank on tail  156  will easily detach the tail from dampening device  152 . 
         [0077]    Dampening device assembly  150  also differs from the dampening device assemblies previously disclosed in that its vibration dampener  152  has multiple, off-center dampening elements rather than a single dampening element as the latter do. These dampening elements, identified by reference characters  162  and  164 , are integral with and located along the core  71  of vibration dampener  152  with a short gap  166  between the two dampening elements. 
         [0078]    That dampening elements  162  and  164  are off-center with respect to the relevant section  167  of dampening device core  71  is made clear by the locational relationship of the dampening elements  162  and  164  to the center of section  167 , which is identified by centerline  169 . 
         [0079]      FIGS. 10-12  depict an assembly  170  of an arrow point insert  172  and a slip fitting, point end vibration dampener  174 .  FIG. 13  shows the assembly  170  installed in the hollow shaft  60  of arrow  40  and also shows the arrow point  48  mounted to the arrow point insert  172  of assembly  170 . 
         [0080]    Vibration dampening device  174  has a conical, tapered tip  177  and a coupling segment  176  with a snap-in head  178  resembling the dampener head  86  shown in  FIGS. 2 and 2B . A coupling segment  180  of insert  172  has a recess  182  with a complementary head-receiving configuration. 
         [0081]    There is a bore  184  extending from end-to-end through dampening device  174 . This passage communicates with the ambient surroundings through arrow point insert central bore segments  186  and  188  when dampening device/arrow point insert assembly  170  is pressed into arrow shaft  60  and tail  156  then removed. This relieves any air pressure which might have built up in the interior of shaft  60  as assembly  170  is pressed in place. The build-up of significant pressure in arrow shaft  60  is to be avoided as this pressure might possibly reach a level sufficiently high to pop assembly  170  out of the arrow shaft when the installation pressure on assembly  170  is released. 
         [0082]    Bore  184  also reduces the area of tail  156  at the end  160  of the tail. This provides for easy removal of the tail after assembly  170  is installed. 
         [0083]    Vibration dampening device  152  has two integral, off-center dampening elements  189  and  190 . These elements are spaced along the core  71  of device  152 . Inboard dampening element  189  has the quasi-toroidal configuration described above, and outboard dampening element  190  has the shouldered disk configuration best shown in  FIGS. 4-6 . 
         [0084]    Referring now most particularly to  FIG. 13 , arrow point  48  is mounted to arrow point insert  172  after dampening device tail  156  is removed. The arrow point shaft  191  is slid into the insert as indicated by arrow  192  in  FIG. 13 . Then, externally threaded segment  194  of arrow point shaft  191  is threaded into the internally threaded section  186  of insert  172  until the annular ledge  68  on arrow point  48  is seated against the lip  70  of arrow point insert  172 . At this point, the end  196  of threaded arrow point shaft  191  is pressed against the apposed end  198  of vibration dampening device  174 , compressing the elastomeric material from which the dampening device is fabricated. This provides a frictional lock between arrow point  48  and insert  172 , keeping the arrow point  48  from unscrewing during use of arrow  40 . 
         [0085]      FIGS. 14-16  depict an assembly  220  of an arrow point insert  222  and a slip fitting vibration dampening device  224 . Vibration dampening device  224  differs from those discussed previously in that the coupling segment  226  of the device is a transversely-oriented knob (or head)  228  connected to a body  230  of the device by an integral transition segment  231 . 
         [0086]    Arrow point insert  222  has a transverse cut-out  232  configured and dimensioned to accept the knob  228  of dampening device  224  in a slip fitting relationship and a communicating slot  234  for the transition segment  231  of dampening device  224 . Slot  234  opens onto end  235  of the insert. 
         [0087]    The components of assembly  220  are joined together by pressing dampening device knob  228  sideways through arrow point insert cut-out  232  as indicated by arrow  236  in  FIG. 14 . Transition segment  231  of dampening device slides through the slot  234  in insert  222  as knob  228  moves in the arrow  236  direction. 
         [0088]    With assembly  220  installed, the side wall  238  of arrow shaft  60  keeps knob  228  in arrow point insert  222 . 
         [0089]      FIGS. 14-16  also introduce yet another way of providing vibration dampening devices embodying the principles of the present invention with off-center dampening elements and further show that the devices need not have straight-sided configurations of those previously discussed dampening devices do. 
         [0090]    The elongated, slip fitting, dampening device  224  illustrated in  FIGS. 14-16  has a sinusoidal profile rather than a straight one; and an integral dampening element is provided by a node  238  in the dampener. Centerline  240  shows that this node is offset, being closer to the proximate end  242  of the pertinent dampener segment  244  than it is to the tip end  72  of the dampener. This leaves tip  248  free to wiggle and jiggle and effectively modify the decay time of vibrations set up in the dampening device. 
         [0091]    The assembly  250  of arrow point insert  252  and vibration dampening device  224  shown in  FIGS. 17-19  differs from the assembly  220  just described primarily in that the slot  234  in which dampening device transition segment  231  is seated cuts through two opposite sides of the insert. Slot  234  and cut-out  232  divide the coupling segment  256  of insert  252  into two facing, resiliently displaceable elements (or jaws)  258  and  260 . When the transverse head  228  of dampening device  230  is pressed through the communicating cut-out  262  (see arrow  263 ), the transition segment  231  of dampening device  230  forces jaws  258  and  260  apart as indicated by arrows  264  and  266  in  FIG. 19 . Thereafter, because of their resiliency, jaws  258  and  260  restore toward each other; i.e., in directions opposite those indicated by arrows  264  and  266 . The result is that the dampening device transition section  231  and head  228  are clamped between jaws  258  and  260 , firmly securing the transverse head  228  of the dampening device  230  in arrow point insert  252 . 
         [0092]      FIGS. 20-23  depict: (a) yet another elastomeric, vibration dampening device  270  embodying the principles of the present invention; (b) a point end assembly  272  in which dampening device  270  is joined to an arrow point insert  274 ; and (c) a second, nock end assembly  276  in which dampening device  270  is mounted to arrow nock  277 . Both dampening devices are dimensioned for a high tolerance slip fit in arrow shaft  46 . 
         [0093]    Dampening device  270  differs from the previously described devices of that character primarily in that it has annular, integral, dampening devices  278   a - e —in this embodiment, quasi-toroidal—spaced the length of dampening device core  280 . As in the vibration dampening devices discussed above, dampening element  278  accommodates performance-enhancing jijggling and flopping of the tip  288  of the device. 
         [0094]    Dampening device  270  is assembled to arrow point insert  274  by sliding an end segment  282  of the device into a complementary socket  284  opening onto the front end  286  of the insert. 
         [0095]    The dampening device  270  is assembled to nock  277  in essentially the same manner as it is to arrow point insert  274 ; in this case, by sliding end segment  282  of the device into a complementary socket  288  in the stem  290  of nock  277 . 
         [0096]    As shown in  FIG. 20 , the assembly  272  of dampening device  270  and insert  274  is installed in the rear end  292  of arrow shaft  60  in essentially the same manner that the dampening device/insert assemblies described above are. 
         [0097]    Similarly, the assembly  276  of dampening device  270  and nock  277  is installed in the front or forward part  294  of arrow shaft  60  in the same manner that the nock/dampening device  110  depicted in  FIG. 2A  is. Internal threads  275  are provided for attaching an arrow point (not shown) to the insert. 
         [0098]    An appropriate adhesive may be employed to promote the bond between the dampening device end segment  282  and the insert or nock. However, the use of super glue, other cyanoacrylates, and related compounds is preferably avoided as such compounds may degrade the elastomeric dampening device material and lead to its failure or inability to be retained in assembled relationship to an associated arrow point insert or nock. 
         [0099]    Shown in  FIGS. 24 and 25  is an arrow  300  equipped with: (a) a vibration dampener/point insert assembly  302  as described above and illustrated in  FIGS. 7-9 , and (b) a nock end assembly  304 . 
         [0100]    Point end assembly  302  comprises a slip fitting vibration dampener  306  and an arrow point insert  130 . 
         [0101]    Vibration dampener  306  has a sinusoidal configuration like that of the vibration dampener shown in  FIGS. 14-16  and a coupling segment  92  with a frustoconical head  86  as first shown in  FIGS. 5 and 6 . 
         [0102]    The nock end assembly  304  is made up of a vibration dampener  308  and a nock  310 . 
         [0103]    Vibration dampener  308  has a body  224  with a sinusoidal profile and a dampening element  238  as shown in  FIGS. 14-16 . Axially aligned, and integral, with body  224  is a coupling segment  240 , also configured as shown in  FIGS. 5 and 6 . 
         [0104]    Nock  310  has a head  312  with a conventional arrow string-receiving notch  314  and an axially aligned stem  316  with a stepped-down free end segment  317 . Formed in stem  316  and opening onto the exposed end  318  of the stem is a first cylindrical and then frustoconical recess  320 . The frustoconical segment  322  of recess has a configuration complementing that of vibration dampener head  86 . Head  86  is trapped in the frustoconical segment  322  of recess  320 , securely locking vibration dampener  306  and arrow point insert  130  together. 
         [0105]    In those several representative embodiments of the invention described above, an appropriate lubricating adhesive may be employed to facilitate the installation of the point end or nock end assembly in the arrow shaft. The subsequent curing of the adhesive further serves to keep the assembly in place. 
         [0106]    The principles of the present invention may be embodied in forms other than those specifically disclosed herein. Therefore, the present embodiments are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced herein.