Vibration decay modifying accessories and methods of making the same

[0002] This is related to U.S. Provisional Patent application Serial No. 60/178,552, filed Jan. 26, 2000 now abandoned. The benefit of the filing date of that application is hereby claimed.

[0003] The present invention relates to novel accessories for archery bows and, more particularly, to such accessories which are capable of significantly reducing both bow jump and the noise made when an arrow is released.

[0004] U.S. Pat. Nos. 6,298,842 and 6,237,584 disclose archery bow accessories respectively identified in the commercial world by the names LIMB SAVER™ and STRING LEECH™.

[0005] A LIMB SAVER™ is an accessory that can be attached to the limbs of a bow and/or to the outer end of the stabilizer of a bow equipped with an accessory of that character to reduce the adverse effect of the vibrations set up in the bow when an arrow is released.

[0006] A STRING LEECH™ is designed to reduce the noise generated when an arrow is released. Devices with this objective are known in the trade as string silencers.

[0007] One type of STRING LEECH™ string silencer is knotted onto a bowstring, one at each end of the string. A second type of STRING LEECH™ is installed between two parts of a split bowstring and retained in place by complementary elements of the silencer.

[0008] There have now been invented and disclosed herein certain new and novel archery bow accessories which are also designed to reduce the noise made when an arrow is released and, in addition, to significantly reduce bow jump caused by release of the arrow. These shock absorbing accessories are attached to the riser of the bow. They can be used alone or in combination with LIMB SAVER™ and STRING LEECH™ accessories and/or in combination with other devices designated to attenuate the adverse effect on accuracy attributable to bow jump and noise when an arrow is released.

[0009] An accessory employing the principles of the present invention is attached to the riser of a bow, typically using the drilled and tapped hole provided for a conventional bow stabilizer.

[0010] The novel shock absorbing accessories disclosed herein are made up of a rigid transfer rod or transfer rod assembly, a viseo-elastic shock absorbing component, and a compression ring. When an arrow is released, vibrations set up in the bow are transferred to the riser with the transfer rod (or assembly) directing vibrations from the riser to the shock absorbing component of the accessory. The shock absorbing material reduces the time for which vibrations of a character that might effect accuracy are felt by the user. Also, the shock absorbing material causes maximum energy to be transferred to the arrow being released.

[0011] The shock absorbing component of the accessory is very effective, in part because it is preloaded as the accessory is assembled. The compression ring keeps the shock absorbing component in its compressed, preloaded state.

[0012] Shock absorber accessories as disclosed herein work well both with double cam bows—where the entire bow tends to jump forward when an arrow is released—and single cam bows—where the bottom of the bow tends to kick forward and upward on arrow release.

[0013] Accessories as disclosed herein are also relatively light, which is another significant advantage of these products.

[0014] The performance of a bow equipped with an accessory as disclosed herein can be enhanced by attaching a bow stabilizer or a vibration pattern modifier of the character disclosed in U.S. Pat. No. 6,298,842 to the accessory.

[0015] FIG. 1 is a pictorial illustration of a compound bow equipped with a shock absorbing accessory embodying the principles of the present invention and provided to reduce bow jump and noise when an arrow is released;

[0016] FIG. 2 is a perspective view of the shock absorbing accessory;

[0017] FIG. 3 is an exploded view of the shock absorbing accessory;

[0018] FIG. 4 is a view similar to FIG. 3 but with a shock absorbing component of the accessory shown in section taken substantially along line 4—4 of FIG. 2;

[0019] FIG. 5 is a graph showing the shock imparted to a representative compound bow when an arrow is released; and

[0020] FIG. 6 shows how the shock is reduced when the bow is fitted with a shock absorbing accessory as shown in FIGS. 1-4.

[0021] Referring now to the drawings, FIG. 1 depicts a compound bow 20 equipped with a vibration decay pattern modifying, shock absorber 22 embodying the principles of the present invention. Bow 20 has flexible limbs 24 and 26 mounted to the opposite ends of riser 28 and bow string 30. The bow string is strung around cams 32 and 34 at the ends of limbs 24 and 26 with the ends of the bow string being anchored to shafts 36 and 38 which rotatably support cams 32 and 34 from the limbs 24 and 26 of bow 20.

[0022] As is best shown in FIGS. 2-4, the vibration decay modifying accessory 22 has a unit 40 made up of elastomeric decay pattern modifying, elastomeric component 42 surrounded by a compression ring 44; a flanged tube 46 with integrated internal threads 90, and a flanged vibration transfer component 48 with integrated, externally threaded elements 50 and 52 at its opposite ends.

[0023] Referring now primarily to FIGS. 3 and 4, the elastomeric component 42 of unit 40 has a circular profile (see FIG. 2). The major elements of component 42 are a head 54 and an integral, depending stem 56 with straight and beveled conical profile elements 58 and 60. The head 54 of component 42 has a vertical edge 63 between two, integral, tapered edges 62 and 64. The lower part of head 54 constitutes a skirt 66 with an inner edge 68 which is concentrically spaced about the lower part of head 54 and its inner edge 70. This leaves a gap 72 between the head 54 and stem 56 of component 54, which allows decay pattern modifying movement of head 54 relative to stem 56.

[0024] Decay pattern modifying movement of head 54 is further promoted by concentric, inverted pyramid grooves 74 and 76 in the upper part 62 of head 54 and by pockets or recesses which are equiangularly spaced around the periphery of integral stem element 56. These pockets, all identified by reference character 77 (see FIG. 3) for the sake of convenience, have closed inner ends and open onto the groove 72 between head and stem components 54 and 56.

[0025] The stem 56 of decay pattern modifying, elastomeric component 42 can vibrate or oscillate in directions generally normal to the longitudinal axis 78 of accessory 22 in any and all directions around the circumference of the transfer component 48. At the same time, head 54 of the component 42 can oscillate laterally and vertically (with that component oriented as shown in FIG. 4), and the edge portion 63 can also oscillate around the circumference of the head in directions generally paralleling axis 78.

[0026] The effectiveness of accessory 22 is promoted by preloading the elastomeric component 42 of the accessory. Preloading is accomplished by first installing the elastomeric component 42 in ring 44, which generally spans the edge element 63 of head 54. Next, flanged component 46 is installed in a central bore 80 extending from top to bottom through elastomeric component 42 with a tubular element 82 of component 46 located in, and extending from the top to the bottom of component 42 and with a flange 84 of component 46 butting the top edge 86 of the elastomeric component 42. Next, the externally threaded element 50 of vibration transfer component 48 is threaded into the tubular element 82 of component 46, the external threads 88 on element 50 engaging the complimentary internal threads 90 in tubular element 82 and drawing components 46 and 48 together until the flange 92 on component 48 engages, and presses against, the bottom edge 94 of elastomeric component stem 56, squeezing elastomeric component 42 in a vertical direction. This action generates a laterally extending force which is maintained in element 42 by the tubular element 82 of component 46 and compression ring 44, which keep component 42 from expanding inwardly or outwardly by effective “squeezing.”

[0027] The rotation of component 48 in sleeve 82 is continued until the flange 92 of component 48 engages the lower end 96 of tubular element 82. As best shown in FIG. 4, this end 96 is spaced from the bottom 94 of elastomeric component stem 56. The load applied to elastomeric component 42 can be provided at a selected level by adjusting this spacing.

[0028] Accessory 22 is, in the illustrated, exemplary application of the invention, mounted to the riser 28 of bow 20 by threading element 52 of accessory component 48 into a drilled and tapped, blind aperture 97 in the riser until the bottom or lower edge 98 of the accessory component element 48 is seated on, and frictionally engaged with, the front edge 100 of riser 28.

[0029] FIGS. 5 and 6 compare the decay pattern of a bow such as the one illustrated in FIG. 1 without an accessory as disclosed herein (FIG. 5) with the decay pattern for the same bow equipped with an accessory of the character identified by reference character 22. It will be apparent to the reader that accessory 22 significantly shortens the decay time of the vibrations set up in the bow when an arrow is released, especially those larger and consequently more deleterious vibrations. The result is a significant advantage. The practical result, as discussed above, is a marked reduction both in bow jump when an arrow is released and the noise generated when that action occurs.

[0030] The shock absorbing elastomeric component 42 (see FIG. 4) of the present invention is preferably fabricated from a soft, viseo-elastic material with a Shore A hardness in the range of 3 to 20.

[0031] One suitable viseo-elastic material is NAVCOM™. NAVCOM™ is a soft, amorphous, rubber-like material which contains a mixture of chloroprene and butyl polymers and has the following physical properties (representative).

[0032] While the invention is described and illustrated here in the context of a preferred embodiment, the invention may be embodied in many forms without departing from the spirit or the essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive. The scope of the invention is 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 intended to be embraced therein.