ARCHERY BOWSTRING

Abstract

An archery bowstring includes a plurality of strands, each strand made from a plurality of fibers. The fibers forming the strands are grouped together in a minimally twisted configuration to form the strands. The strands may be twisted together to form the bowstring.

Description

BACKGROUND OF THE INVENTION

Various types of bowstrings are known in the art. In particular, bowstrings are known to utilize multiple strands that can be twisted together to from the bowstring.

Known bowstrings and archery bow cables utilize strands of material, wherein a strand is formed from one or more raw fibers. The raw fibers can be mono-filament, multi-filament or combinations thereof. The raw fibers are twisted together to form a strand. The fibers in a strand generally have a twist rate of 2 to 3 turns per inch of strand.

A bowstring generally comprises a plurality of strands. The strands are generally twisted together at a twist rate of 0.5 to 0.75 twists per inch of bowstring.

When installed in a bow, a bowstring/cable is under constant tension, and most bowstrings are susceptible to stretching over time. For example, lubricants used in the manufacturing process can be squeezed out from between the fibers, and the components making up the bowstring are allowed to reach their natural lengths.

String stretch can impact the draw length of the bow, as well as the positioning of the knock point, peep sight, and cam alignment.

Advancements in bowstring materials, design, and preparation have led to reduced string stretch in general. Despite these advancements, however, there remains a need for bowstrings having reduced stretch and elongation as the bow is used. There further remains a need for bowstrings that are quieter and faster shooting, for example producing less noise and vibration at launch.

U.S. Pat. No. 5,676,123, U.S. Pat. No. 5,676,123, U.S. Pat. No. 5,752,469, U.S. Pat. No. 6,651,643, U.S. Pat. No. 7,182,079, U.S. Pat. No. 7,231,915 and US 2012/0152219 teach examples of bowstrings.

The art referred to and/or described above is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. §1.56(a) exists.

All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.

Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.

A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims.

BRIEF SUMMARY OF THE INVENTION

In some embodiments, a bowstring comprises a first plurality of strands and a second plurality of strands. The first plurality of strands are twisted into a first bundle and the second plurality of strands are twisted into a second bundle, and the two bundles are twisted together to form the bowstring. The strands used, prior to being bundled, can originally comprise traditionally twisted fibers, minimally twisted fibers, or a combination thereof. In some embodiments, the first bundle is twisted in a first direction and the second bundle is twisted in a second direction opposite the first direction.

In some embodiments, a bowstring comprises a plurality of strands, each strand having a plurality of fibers. In some embodiments, the fibers of a strand are minimally twisted along their length. In some embodiments, a strand has 1.5 twists per inch or less.

In some embodiments, a bowstring comprises a plurality of strands, the bowstring having been formed using strands that comprise, or consist of, minimally twisted fibers.

In some embodiments, a bowstring comprises a plurality of strands, the bowstring having been formed using at least one strand that comprises, or consists of, a plurality of fibers having minimal twist along their length.

In some embodiments, a strand has a flat profile.

In some embodiments, the bowstring further comprises a serving wrapped around at least a portion thereof.

In some embodiments, the fibers are made from ultra-high molecular weight polyethylene, aromatic polyester, or combinations thereof.

In some embodiments, the bowstring has between 10 and 30 strands.

These and other embodiments which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages and objectives obtained by its use, reference can be made to the drawings which form a further part hereof and the accompanying descriptive matter, in which there are illustrated and described various embodiments of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows a side view of an archery bow.

FIG. 2 shows an embodiment of a portion of a bowstring.

FIG. 3A shows of an embodiment a strand having minimally twisted fibers.

FIG. 3B shows of an embodiment a strand having fibers that are twisted.

FIG. 4 shows a close-up view of an embodiment of a bowstring.

DETAILED DESCRIPTION OF THE INVENTION

While this invention may be embodied in many different forms, there are described in detail herein specific embodiments of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated.

For the purposes of this disclosure, like reference numerals in the figures shall refer to like features unless otherwise indicated.

In some embodiments, the bowstring comprises a first plurality of strands that are twisted together to form a first bundle and a second plurality of strands that are twisted together to form a second bundle. In turn, the first and second bundles are twisted together to form the bowstring. In some embodiments, a direction of twist of the first bundle (e.g. clockwise) is different from a direction of twist in the second bundle (e.g. counter-clockwise). In some embodiments, the individual strands comprise fibers that twist with one another along their length. In some embodiments, the individual strands comprise fibers that have a minimal amount of twist with one another along their length.

For the purposes of this application, “minimal twist” in a strand is defined as having 1.5 twists per inch of strand or less.

In some embodiments, a strand has less than 1 twist per inch. In some embodiments, a strand has ¾ twist per inch or less.

In some embodiments, a bowstring comprises a plurality of strands, each strand comprising a plurality of fibers. The strands may twist with one another along the length of the bowstring. In some embodiments, the fibers of one or more strands used to form the bowstring are arranged in a substantially parallel fashion and are minimally twisted along their length.

In some embodiments, a first strand of a bowstring comprises a plurality of fibers that twist with one another along the length of the first strand, and a second strand of the bowstring comprises a plurality of fibers that exhibit minimal twist along the length of the second strand.

Turning to FIG. 1, an archery bow 100 is shown comprising a riser 102, limbs 104 attached to the riser 102, a plurality of rotatable members 106, and a bowstring 10. Although the archery bow 100 is shown as a compound bow, a recurve bow, cross-bow, or any other suitable type of non-compounding or compounding archery bow is contemplated.

Turning to FIG. 2, in some embodiments, the bowstring 10 comprises a plurality of strands 12, and each strand comprises a plurality of fibers 14.

The bowstrings 10 disclosed herein can be made from any suitable material. In some embodiments, a bowstring 10 can comprise polyethylene, for example SPECTRA® synthetic fiber available from Honeywell International Inc., DYNEEMA® fibers available from DSM High Performance Fibers, and the like. In some embodiments, a bowstring 10 can comprise polyester, for example Vectran® available from Kuraray Co. (Japan), and DACRON® available from Invista North America, and the like. In some embodiments, a bowstring 10 can comprise poly-paraphenylene terephthalamide, such as KEVLAR® available from E.I. DuPont, and the like. In some embodiments, a bowstring 10 can comprise any suitable combination of these materials. In some embodiments, a bowstring 10 can comprise fibers of the materials described herein. In some embodiments, a bowstring 10 comprises various fibers of different materials.

Further, spools of bowstring materials (e.g. king spools) comprising one or more suitable materials are available commercially, such as from BCY Bowstring of Middletown, Conn. For example, 452X Bowstring from BCY Bowstring comprises 67% SK75 Dyneema® and 33% Vectran®.

A spool of commercially available bowstring material often comprises a spool of strand 12 material, which typically contains up to 10,000 feet of strand 12.

A bowstring 10 often comprises between twelve and twenty-eight individual strands 12, and the strands 12 within the bowstring 10 twist around one another along the length of the bowstring.

Desirably, the individual fibers 14 are grouped into the strands 12. A strand 12 comprises any suitable number of fibers 14, and the specific number of fibers 14 in a strand 12 can change depending upon the material. For example, a 400d (denier) fiber of Dyneema® includes approximately 166 filaments of material, and a 400d fiber of Vectran® includes approximately 40 filaments of material.

In some embodiments, a strand 12 comprises a plurality of fibers 14 arranged to have a similar orientation. In some embodiments, a strand 12 further comprises wax, which can help lubricate, prevent abrasion and help bind the fibers 14 together. In some embodiments, a strand 12 comprises at least 5% wax as measured by weight.

In some embodiments, the fibers 14 of a strand twist with one another along the length of the strand.

In some other embodiments, a strand 12 comprises minimally twisted fibers 14, wherein the fibers 14 of that strand 12 have 1.5 twists per inch or less. In some embodiments, the fibers 14 of a strand 12 have ¾ twists per inch or less. In some embodiments, the fibers 14 within a strand 12 are substantially parallel to one another. In some embodiments, a bowstring 10 is formed with a plurality of strands 12 that were each formed with minimally twisted fibers 14.

Commercially available spools of strand 12 material typically comprise twisted fibers 14, generally having 2 to 3 twists per inch. Some suppliers are capable of providing spools of strand 12 material comprising minimally twisted fibers 14—for example, BCY Bowstring can provide spools of “452X No Twist.”

It should be noted that strand 12 material comprising minimally twisted fibers 14 generally requires special processing, as it will have less twist than traditional twisted strands.

FIG. 3A shows an embodiment of a strand 12 comprising minimally twisted fibers 14. The fibers 14 can be bundled such that the strand 12 has any suitable cross-sectional shape (e.g. prior to being formed into a bowstring). In some embodiments, the fibers 14 are arranged to produce a strand 12 having a flat profile. Further, in some embodiments, one or more of the strands 12 of the bowstring 10 are fewer than ten fibers 14 thick.

In some embodiments, the fibers 14 extend parallel to one another in a minimally twisted configuration. In some embodiments, the fibers 14 extend substantially linearly along the length of the strand 12 without being wrapped around one another. In some embodiments, a bowstring 10 is formed from strands 12 of material, wherein the strands 12 were made from minimally twisted fibers 14.

FIG. 3B shows an embodiment of a strand 12 comprising twisted fibers 14. In some embodiments, the fibers 14 are twisted around one another to form the strands 12, for example having greater than 1.5 twists per inch.

As used herein, the term “twists per inch” describes the number of times a strand or fiber (or other like member) is revolved per inch of strand.

A bowstring 10 made from strands 12 comprising minimally twisted fibers 14 is less elastically deformable than bowstrings having fibers 14 that are twisted together at higher rates of twist. Consequently, a bowstring 10 formed from strands 12 comprising minimally twisted fibers 14 yields superior performance via reduced stretch. In particular, the bowstring 10 formed from minimally twisted strands 12 has less stretch upon drawing the bow and is also believed to exhibit less stretch over time.

Turning to FIG. 4, in some embodiments, the bowstring 10 comprises a plurality of strands 12 grouped into a bundle 16. In some embodiments, a plurality of bundles 16 are twisted together to form the bowstring 10. It has been discovered that in twisting the strands 12 into bundles 16, the bowstring 10 is unexpectedly quieter than, for example, a bowstring 10 having strands 12 that are not first twisted into bundles 16.

In some embodiments, a bundle 16 is formed from strands 12 comprising minimally twisted fibers 14, for example as described above. In some embodiments, a bundle 16 is formed from strands 12 comprising fibers 14 that twist along the length of the strand. In some embodiments, a bundle 16 is formed from first strands and second strands, wherein the first strands comprise twisted fibers 14 and the second strands comprise minimally twisted fibers 14.

In some embodiments, the bundles 16 comprise a first bundle 16a and a second bundle 16b. In some embodiments, the strands 12 of the first bundle 16a are twisted in a first direction, for example clockwise, and the strands 12 of the second bundle 16b are twisted in a second direction, for example counterclockwise. In this way, rotation imputed into the bowstring 10 from the clockwise twisted strands is counteracted by the counterclockwise twisted strands, for example as shown in U.S. Pat. No. 5,752,496, which is herein incorporated by reference.

In some embodiments, each bundle 16 is made of eleven strands 12. In this way, in some embodiments, the bowstring 10 is made of twenty-two total strands 12 and two bundles 16.

Although FIG. 4 illustrates two bundles 16a and 16b, in some embodiments, the bowstring 10 comprises more than two bundles 16, for example, 3, 4, 5, 6, or more bundles 16, each comprising a plurality of strands 12.

In some embodiments, a bowstring 10 comprises at least one bundle 16 comprising strands 12 made from minimally twisted fibers 14 and at least one bundle 16 comprising strands 12 made from traditionally twisted fibers 14. In some embodiments, a bowstring 10 comprises two bundles 16 each comprising strands 12 made from minimally twisted fibers 14 and two bundles 16 each comprising strands 12 made from traditionally twisted fibers 14.

In some embodiments, a bundle 16 comprises strands 12 that are twisted about one another in a first direction (e.g. clockwise), and the strands 12 comprise fibers 14 that are twisted in a second direction (e.g. counterclockwise). Thus, the twisting of the fibers 14 within a strand 12 can be opposite the twisting of the strands 12 within the bowstring 10.

In some embodiments, a bowstring 10 comprises a first bundle 16a and a second bundle 16b, which twist about one another along the length of the bowstring 10. The first bundle 16a comprises first strands 12 that are twisted about one another in a first direction (e.g. clockwise), and the first strands 12 comprise fibers 14 that are twisted about one another in a second direction (e.g. counterclockwise). The second bundle 16b comprises second strands 12 that are twisted about one another in the second direction (e.g. counter-clockwise), and the second strands 12 comprise fibers 14 that are twisted about one another in the first direction (e.g. clockwise).

The bowstring 10 is formed in a number of steps. In some embodiments, the fibers 14 are first formed. In some embodiments, the fibers 14 are drawn or spun from one or more polymeric materials. The fibers 14 are then bundled together into strands 12. The fibers 14 can be bundled together in a minimally twisted configuration or, in some embodiments, they can be twisted together with a particular number of twists per inch. In some embodiments, spools of strands 12 of material are provided.

In some embodiments, the strands 12 are bundled together. In some embodiments, this is achieved using a spool of strand 12 and a bowstring jig comprising longitudinally opposed pins. The strand 12 is wrapped around the pins until a bundle is formed having the desired number of strands 12. The bundle can then be placed on a string winding machine, which will twist the strands 12 about one another to form the bowstring 10, or a bundle 16 for use in a bowstring 10. Thereafter, a serving can be added to certain sections of the bowstring, as desired.

The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this field of art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to.” Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.

In addition to the foregoing, various features discussed or shown with respect to certain embodiments can be incorporated into other embodiments described herein or incorporated by reference. For example, the features described with respect to FIG. 1 are not limited to the embodiment of FIG. 1, and can be incorporated into embodiments shown, for example, in FIGS. 2 and 3.

The teachings disclosed herein with respect to a bowstring 10 can also be applied to various other cables of a compound bow, such as a power cable, a secondary feed-out cable, etc.

Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below.

This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.

Claims

1. A bowstring comprising:

a plurality of strands, each strand comprising a plurality of fibers, wherein at least one strand comprises fibers having 1.5 turns per inch or less.

2. The bowstring of claim 1, wherein at least one strand comprises fibers having ¾ turns per inch or less.

3. The bowstring of claim 1, wherein each strand comprises fibers having 1.5 turns per inch or less.

4. The bowstring of claim 1, comprising a first bundle of strands and a second bundle of strands, the two bundles twisted about one another.

5. The bowstring of claim 4, wherein the first bundle comprises strands twisted about one another in a first direction and the second bundle comprises strands twisted about one another in a second direction opposite the first direction.

6. The bowstring of claim 1, wherein the strands each have a flat profile.

7. The bowstring of claim 1 further comprising a serving wrapped around at least a portion thereof.

8. The bowstring of claim 1, wherein the fibers are made from ultra-high molecular weight polyethylene, aromatic polyester, or combinations thereof.

9. The bowstring of claim 1, wherein the bowstring has between 10 and 30 strands.

10. The bowstring of claim 1, wherein each strand comprises fibers that are minimally twisted.

11. The bowstring of claim 1, wherein said strands are twisted about one another along the length of the bowstring.

12. A bow comprising the bowstring of claim 1.

13. A bowstring comprising:

a plurality of first strands twisted about one another to form a first bundle; and

a plurality of second strands twisted about one another to form a second bundle;

the first bundle and the second bundle twisted about one another along a length of the bowstring.

14. The bowstring of claim 13, wherein at least one of said first strands comprises a plurality of fibers having a minimal twist along their length.

15. The bowstring of claim 14, wherein at least one of said second strands comprises a plurality of fibers having a minimal twist along their length.

16. The bowstring of claim 13, wherein said first strands and said second strands each comprise a plurality of fibers having a minimal twist along their length.

17. The bowstring of claim 13, said first strands are twisted about one another in a first rotational direction and said second strands are twisted about one another in a second rotational direction.

18. The bowstring of claim 17, wherein said first strands each comprise a plurality of fibers that are twisted about one another in the second rotational direction.

19. The bowstring of claim 18, wherein said second strands each comprise a plurality of fibers that are twisted about one another in the first rotational direction.