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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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'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.
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.
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.
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.
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.
Referring now to the drawings,
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 56a-c of conventional construction are mounted to arrow shaft 46 toward its front end 54.
Referring now to
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.
Arrow point 48 and insert 64 have complementary external and internal threads collectively identified in
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.
The opposite end of vibration dampener 42 is an integral coupling segment 82, provided for assembling dampening device 42 to arrow insert 64.
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
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.
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.
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
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.
To a considerable extent, the slip fitting nock end vibration dampening device 44 shown in
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.
Nock 48 has a complementary, longitudinally extending, externally threaded lug or boss 106. The internal and external threads are collectively identified in
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.
A set of juxtaposed annular grooves 112 on the outer side 114 of dampening device coupling segment 100 (see
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
In those embodiments of the invention described below, elements common to those embodiments and the vibration dampeners shown in
The slip fitting vibration dampening device 116 illustrated in
Returning then to the drawings,
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.
As is best shown in
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.
Pulling on tail 156 in the direction indicated by arrow 158 in
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.
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.
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.
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
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.
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.
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
Referring now most particularly to
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.
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
With assembly 220 installed, the side wall 238 of arrow shaft 60 keeps knob 228 in arrow point insert 222.
The elongated, slip fitting, dampening device 224 illustrated in
The assembly 250 of arrow point insert 252 and vibration dampening device 224 shown in
Dampening device 270 differs from the previously described devices of that character primarily in that it has annular, integral, dampening devices 278a-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.
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.
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.
As shown in
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
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.
Shown in
Point end assembly 302 comprises a slip fitting vibration dampener 306 and an arrow point insert 130.
Vibration dampener 306 has a sinusoidal configuration like that of the vibration dampener shown in
The nock end assembly 304 is made up of a vibration dampener 308 and a nock 310.
Vibration dampener 308 has a body 224 with a sinusoidal profile and a dampening element 238 as shown in
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.
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.
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.
This application is related to and claims the benefit of the 3 May 2006 filing date of provisional patent application No. 60/797,257.
Number | Name | Date | Kind |
---|---|---|---|
3670712 | Izuta | Jun 1972 | A |
5351973 | Taniuchi et al. | Oct 1994 | A |
5562494 | Fujiwara | Oct 1996 | A |
5607364 | Hedrick et al. | Mar 1997 | A |
5718643 | Wright et al. | Feb 1998 | A |
5720487 | Kato | Feb 1998 | A |
5947326 | O'Hern et al. | Sep 1999 | A |
6036541 | Koumatsu | Mar 2000 | A |
6231456 | Rennie et al. | May 2001 | B1 |
6277041 | Fenn | Aug 2001 | B1 |
6595868 | Androlia | Jul 2003 | B1 |
6669585 | Sutherland et al. | Dec 2003 | B2 |
6802307 | Leven | Oct 2004 | B2 |
RE38983 | Antonious | Feb 2006 | E |
20050137026 | Stites et al. | Jun 2005 | A1 |
20060052190 | Palomaki et al. | Mar 2006 | A1 |
20080085793 | Palomaki et al. | Apr 2008 | A1 |
Number | Date | Country | |
---|---|---|---|
20070259743 A1 | Nov 2007 | US |
Number | Date | Country | |
---|---|---|---|
60797257 | May 2006 | US |