CROSSBOW

Abstract

A crossbow includes a riser. The crossbow includes a first limb and a second limb. The first limb includes a first end and a second end. The second limb includes a first end and a second end. The first end of the first limb and the first end of the second limb are coupled to the riser. A first wheel is rotatably coupled to the first limb proximate the second end thereof. A second wheel is rotatably coupled to the second limb proximate the second end thereof. The crossbow includes a first power cord that includes a first end coupled to the riser and a second end coupled to the first wheel. The crossbow includes a second power cord a first end coupled to the riser and a second end coupled to the first wheel. The crossbow includes a bowstring. The crossbow includes an efficiency of at least 80%.

Description

FIELD

This disclosure relates generally to archery. More particularly, this disclosure relates to a compound bow such as a crossbow.

BACKGROUND

Bows are used for target shooting and as a weapon for hunting. Compound bows include cams configured for increasing the mechanical advantage for drawing of the bowstring. Some bow designs include cams configured for decreasing the draw force near the full draw position. In some bow designs, power cables are used for synchronizing the rotation of the cams.

SUMMARY

In some embodiments, a crossbow includes a riser. In some embodiments, the crossbow includes a first limb and a second limb. In some embodiments, the first limb includes a first end and a second end. In some embodiments, the second limb includes a first end and a second end. In some embodiments, the first end of the first limb and the first end of the second limb are coupled to the riser. In some embodiments, a first wheel is rotatably coupled to the first limb proximate the second end thereof. In some embodiments, a second wheel is rotatably coupled to the second limb proximate the second end thereof. In some embodiments, the crossbow includes a first power cord that includes a first end coupled to the riser and a second end coupled to the first wheel. In some embodiments, the crossbow includes a second power cord a first end coupled to the riser and a second end coupled to the first wheel. In some embodiments, the crossbow includes a bowstring. In some embodiments, the crossbow includes an efficiency of at least 80%.

In some embodiments, the crossbow is a reverse draw crossbow.

In some embodiments, the crossbow includes an energy storage system. In some embodiments, the energy storage system comprises the first limb, the second limb, the first wheel, the second wheel, the first power cord, the second power cord, and the bowstring.

In some embodiments, the crossbow has an efficiency of 80% to 100%. In some embodiments, the crossbow has an efficiency of 80% to 90%. In some embodiments, the crossbow has an efficiency of 80% to 85%. In some embodiments, the crossbow has an efficiency of 83%.

In some embodiments, the crossbow has a bowstring draw length of 15 inches.

In some embodiments, the crossbow has an intermediate position that is 9 inches from an un-cocked position.

In some embodiments, a distance between a cocked position and an un-cocked position is 15 inches.

In some embodiments, a draw-force of the crossbow is at least 240 lb_f at an intermediate position that is 9 inches from an un-cocked position.

In some embodiments, the crossbow is configured to provide a kinetic energy of at least 170 ft-lb_f for an arrow/bolt weighing 403 grains.

In some embodiments, a crossbow includes an energy storage system and a riser. In some embodiments, the crossbow has an efficiency of at least 80%.

In some embodiments, the energy storage system includes a first limb and a second limb. In some embodiments, the first limb includes a first end and a second end. In some embodiments, the second limb includes a first end and a second end. In some embodiments, the first end of the first limb and the first end of the second limb are coupled to the riser. In some embodiments, a first wheel is rotatably coupled to the first limb proximate the second end thereof. In some embodiments, a second wheel is rotatably coupled to the second limb proximate the second end thereof. In some embodiments, a first power cord includes a first end coupled to the riser and a second end coupled to the first wheel. In some embodiments, a second power cord includes a first end coupled to the riser and a second end coupled to the first wheel. In some embodiments, the energy storage system includes a bowstring.

In some embodiments, the crossbow has an efficiency of 80% to 100%. In some embodiments, the crossbow has an efficiency of 80% to 90%. In some embodiments, the crossbow has an efficiency of 80% to 85%. In some embodiments, the crossbow has an efficiency of 83%.

In some embodiments, the crossbow is a reverse draw crossbow.

BRIEF DESCRIPTION OF THE DRAWINGS

References are made to the accompanying drawings that form a part of this disclosure and that illustrate embodiments in which the systems and methods described in this Specification can be practiced.

FIG. 1 is a perspective view of a crossbow, according to some embodiments.

FIG. 2 is a top view of the crossbow of FIG. 1, according to some embodiments.

FIG. 3 is a perspective view of an energy storage system for the crossbow of FIG. 1, according to some embodiments.

FIG. 4 is a top view of the energy storage system of FIG. 3, according to some embodiments.

FIG. 5 illustrates a power-curve or draw-curve (draw weight/force v. draw distance) for a crossbow, according to some embodiments.

Like reference numbers represent the same or similar parts throughout.

DETAILED DESCRIPTION

FIGS. 1 and 2, respectively, are a perspective view and a top view of a crossbow according to some embodiments. FIGS. 3 and 4, respectively, are a perspective view and a top view of an energy storage system 12 for the crossbow 10, according to some embodiments.

Referring to FIGS. 1-4 collectively, in some embodiments, the energy storage system 12 is defined at least in part by a riser 14, a first limb 16, and a second limb 18. In some embodiments, the first limb 16 extends between a first end 20 and a second end 22. In some embodiments, the second limb 18 extends between a first end 24 and a second end 26. In some embodiments, the first end 20 and the first end 24 of the first limb 16 and the and second limb 18, respectively, are coupled to or affixed to the riser 14.

In some embodiments, the energy storage system 12 includes a first wheel 28 and a second wheel 30. In some embodiments, the first wheel 28 is rotatably coupled to the first limb 16 proximate the second end 22 thereof. In some embodiments, the second wheel 30 is rotatably coupled to the second limb 18 proximate the second end 26 thereof. In some embodiments, the energy storage system 12 includes a first power cord 32 extending between, and coupled to or affixed to, the riser 14 and the first wheel 28. In some embodiments, the energy storage system 12 includes a second power cord 34 extending between, and coupled to or affixed to, the riser 14 and the second wheel 30. In some embodiments, the energy storage system 12 includes a bowstring 36 extending between, and coupled to or affixed to, the first wheel 28 and the and second wheel 30.

In some embodiments, the first wheel 28 and the second wheel 30 are drawn or displaced towards each other when the bowstring is pulled or drawn from the un-cocked position. In some embodiments of the crossbow 10, an axle-to-axle distance ATA between a central axis 94 of the first wheel 28 and a central axis 96 of the second wheel is 14.5 inches when the bowstring is un-cocked. In some embodiments, the axle-to-axle distance ATA between the central axis 94 of the first wheel 28 and the central axis 96 of the second wheel is 10 inches when the bowstring is un-cocked. It is to be appreciated that these values are examples, and the actual values can range beyond the stated 14.5 or 10 inches. For example, in some embodiments, the axle-to-axle distance ATA can be less than 10 inches. In some embodiments, the axle-to-axle distance ATA can be greater than 14.5 inches. In some embodiments, the axle-to-axle distance ATA can be from 10 inches to 14.5 inches.

A variety of parameters such as the design or configuration of one or more components of the crossbow 10 and the interaction between the one or more components can affect kinetic energy at discharge and an amount of energy stored at full draw. Some such parameters and/or components include the stiffness (or flexibility) of the limbs (e.g., the first limb 16 and the second limb 18), the cam design and operation, the cabling system, e.g., the configuration and interactions of the power cables, the bowstring, and the cams, reverse draw vs. forward draw, among others.

In some embodiments, it can be advantageous for a crossbow to have a higher efficiency as it can allow for easier cocking for a given output speed. In some embodiments, as a crossbow becomes more efficient, the crossbow is better suited to transfer more of its energy to the arrow rather than to be lost as noise and vibration, which can be detrimental in a hunting situation where stealth is important.

Efficiency of a crossbow (e.g. the crossbow 10) can be defined as a ratio of the kinetic energy of the arrow or bolt when discharged from the crossbow to the amount of energy stored when the bowstring is fully cocked, i.e., the amount of energy stored during the draw stroke, i.e., when the bowstring is pulled from the un-cocked position to the cocked position.

The kinetic energy is a function of the mass of the arrow or bolt and the discharge velocity (i.e., the initial velocity of the arrow or bolt when discharged):

$KE=\frac{1}{2}m{v}^2$

• • where, KE is the kinetic energy;
  • m is the mass of the arrow or bolt; and
  • v is the initial velocity of the arrow or bolt when discharged.

In some embodiments, the crossbow 10 is configured to provide a kinetic energy of approximately 170.93 ft-lb_f for an arrow/bolt weighing approximately 403.0 grains having an initial velocity of approximately 440.0 ft/sec when discharged.

In some embodiments, the stored energy is a function of the force required to draw the bowstring and the distance the bowstring is drawn or travels. Accordingly, the stored energy is the area under the power-curve representing the amount of force required to draw the bowstring vs. the distance the bowstring travels or is drawn.

In some embodiments, the stored energy in the crossbow 10 is the area under the draw force vs. draw distance curve shown in FIG. 5.

In the example curve shown in FIG. 5, crossbow 10 included a compression limb with a bowstring length of 38-⅝ inches and a cable of 13-¾ inches. The arrow weight was 403 grains.

In some embodiments, the crossbow 10 has a draw force that is substantially proportional to the draw distance between the un-cocked position and an intermediate position between the cocked and un-cocked positions. The un-cocked position is defined as the position of the bowstring at rest (or brace) after the crossbow has been fired or discharged. The cocked position is defined as the position of the bowstring when fully-drawn and held in place by a triggering mechanism.

In some embodiments, the intermediate position for the crossbow 10 of the instant disclosure is approximately 9.0 inches from the un-cocked position. In some embodiments, the bowstring draw-length is approximately 15.0 inches. That is, in some embodiments, the distance between the cocked and un-cocked positions is approximately inches.

In some embodiments, the draw-force is approximately 240.1 lb_f at the intermediate position of approximately 9.0 inches. Accordingly, the coefficient of proportionality is approximately 27.76 lb_f per inch of draw between the un-cocked position and the intermediate position at approximately 9.0 inches.

In some embodiments, when the bowstring is cocked and held at full-draw by the trigger mechanism, the energy stored in the energy storage system of the crossbow was measured to be approximately 205.84 ft-lb_f. In some embodiments, approximately 205.84 ft-lb_f of energy will be stored when the bowstring is drawn approximately 15.0 in from the un-cocked position in the crossbow 10.

In some embodiments, the resulting efficiency of the crossbow 10 is approximately

$\frac{170.93\mathrm{ft}-{\mathrm{lb}}_f}{25.84\mathrm{ft}-{\mathrm{lb}}_f}=0.83\mathrm{or}83.\%$

In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 81% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 82% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 83% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 84% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 85% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 86% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 87% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 88% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 89% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 90% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 91% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 92% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 93% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 94% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 95% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 96% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 97% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 98% and less than or equal to 100%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than 99% and less than or equal to 100%.

In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 99%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 98%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 97%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 96%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 95%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 94%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 93%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 92%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 91%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 90%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 89%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to88%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 87%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 86%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 85%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 84%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 83%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 82%. In some embodiments, the crossbow 10 is configured such that it has an efficiency of greater than or equal to approximately 80% and less than or equal to 81%.

In view thereof, modified and/or alternate structures or configurations providing structures and/or functionalities similar to the non-limiting exemplary embodiments disclosed herein may become apparent or obvious to a person of ordinary skills. Accordingly, any and all variants of the non-limiting exemplary embodiments disclosed herein are considered as being within the metes and bounds of the instant disclosure.

Aspects:

It is to be appreciated that any one of aspects 1-13 can be combined with any one of aspects 14-20.

Aspect 1. A crossbow, comprising: a riser; a first limb and a second limb, wherein the first limb comprises a first end and a second end; wherein the second limb comprises a first end and a second end; wherein the first end of the first limb and the first end of the second limb are coupled to the riser; a first wheel rotatably coupled to the first limb proximate the second end thereof; a second wheel rotatably coupled to the second limb proximate the second end thereof; and a first power cord, comprising: a first end coupled to the riser; a second end coupled to the first wheel; and a second power cord, comprising: a first end coupled to the riser; a second end coupled to the first wheel; and a bowstring; wherein the crossbow comprises an efficiency of at least 80%.

Aspect 2. The crossbow of aspect 1, wherein the crossbow is a reverse draw crossbow.

Aspect 3. The crossbow of one of aspects 1 or 2, wherein the crossbow comprises an energy storage system.

Aspect 4. The crossbow of aspect 3, wherein the energy storage system comprises the first limb, the second limb, the first wheel, the second wheel, the first power cord, the second power cord, and the bowstring.

Aspect 5. The crossbow of any one of aspects 1-4, wherein the crossbow comprises an efficiency of 80% to 100%.

Aspect 6. The crossbow of any one of aspects 1-5, wherein the crossbow comprises an efficiency of 80% to 90%.

Aspect 7. The crossbow of any one of aspects 1-6, wherein the crossbow comprises an efficiency of 80% to 85%.

Aspect 8. The crossbow of any one of aspects 1-7, wherein the crossbow comprises an efficiency of 83%.

Aspect 9. The crossbow of any one of aspects 1-8, wherein the crossbow has a bowstring draw length of 15 inches.

Aspect 10. The crossbow of any one of aspects 1-9, wherein the crossbow has an intermediate position that is 9 inches from an un-cocked position.

Aspect 11. The crossbow of any one of aspects 1-10, wherein a distance between a cocked position and an un-cocked position is 15 inches.

Aspect 12. The crossbow of any one of aspects 1-11, wherein a draw-force of the crossbow is at least 240 lb_f at an intermediate position that is 9 inches from an un-cocked position.

Aspect 13. The crossbow of any one of aspects 1-12, wherein the crossbow is configured to provide a kinetic energy of at least 170 ft-lb_f for an arrow/bolt weighing 403 grains.

Aspect 14. A crossbow, comprising: an energy storage system; and a riser, wherein the crossbow comprises an efficiency of at least 80%.

Aspect 15. The crossbow of aspect 14, wherein the energy storage system comprises: a first limb and a second limb, wherein the first limb comprises a first end and a second end; wherein the second limb comprises a first end and a second end; wherein the first end of the first limb and the first end of the second limb are coupled to the riser; a first wheel rotatably coupled to the first limb proximate the second end thereof; a second wheel rotatably coupled to the second limb proximate the second end thereof; and a first power cord, comprising: a first end coupled to the riser; a second end coupled to the first wheel; and a second power cord, comprising: a first end coupled to the riser; a second end coupled to the first wheel; and a bowstring.

Aspect 16. The crossbow of aspect 14 or aspect 15, wherein the crossbow comprises an efficiency of 80% to 100%.

Aspect 17. The crossbow of any one of aspects 14-16, wherein the crossbow comprises an efficiency of 80% to 90%.

Aspect 18. The crossbow of any one of aspects 14-17, wherein the crossbow comprises an efficiency of 80% to 85%.

Aspect 19. The crossbow of any one of aspects 14-18, wherein the crossbow comprises an efficiency of 83%.

Aspect 20. The crossbow of any one of aspects 14-19, wherein the crossbow is a reverse draw crossbow.

The terminology used herein is intended to describe embodiments and is not intended to be limiting. The terms “a,” “an,” and “the” include the plural forms as well, unless clearly indicated otherwise. The terms “comprises” and/or “comprising,” when used in this Specification, specify the presence of the stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and/or components.

It is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the shape, size, and arrangement of parts without departing from the scope of the present disclosure. This Specification and the embodiments described are examples, with the true scope and spirit of the disclosure being indicated by the claims that follow.

While multiple non-limiting exemplary embodiments are disclosed herein, it should be clearly understood that there is no intent, implied or otherwise, to limit the disclosure to the illustrated and/or described exemplary embodiments. Variations or alternatives of the disclosed exemplary embodiments will become apparent or obvious to a person of ordinary skills. For instance, while reference may be made to particular feature(s), configuration(s), function(s), etc., the spirit, scope, and intent of the disclosure is considered to also encompass embodiments structured or configured to function and/or providing functionalities similar to the disclosed embodiments. Accordingly, any and all variants of the non-limiting exemplary embodiments disclosed herein are considered as being within the metes and bounds of the instant disclosure.

Claims

1. A crossbow, comprising: a riser;a first limb and a second limb, wherein the first limb comprises a first end and a second end;wherein the second limb comprises a first end and a second end;wherein the first end of the first limb and the first end of the second limb are coupled to the riser;a first wheel rotatably coupled to the first limb proximate the second end thereof;a second wheel rotatably coupled to the second limb proximate the second end thereof; anda first power cord, comprising: a first end coupled to the riser;a second end coupled to the first wheel; anda second power cord, comprising: a first end coupled to the riser;a second end coupled to the first wheel; anda bowstring;wherein the crossbow comprises an efficiency of at least 80%.

2. The crossbow of claim 1, wherein the crossbow is a reverse draw crossbow.

3. The crossbow of claim 1, wherein the crossbow comprises an energy storage system.

4. The crossbow of claim 3, wherein the energy storage system comprises the first limb, the second limb, the first wheel, the second wheel, the first power cord, the second power cord, and the bowstring.

5. The crossbow of claim 1, wherein the crossbow comprises an efficiency of 80% to 100%.

6. The crossbow of claim 1, wherein the crossbow comprises an efficiency of 80% to 90%.

7. The crossbow of claim 1, wherein the crossbow comprises an efficiency of 80% to 85%.

8. The crossbow of claim 1, wherein the crossbow comprises an efficiency of 83%.

9. The crossbow of claim 1, wherein the crossbow has a bowstring draw length of 15 inches.

10. The crossbow of claim 1, wherein the crossbow has an intermediate position that is 9 inches from an un-cocked position.

11. The crossbow of claim 1, wherein a distance between a cocked position and an un-cocked position is 15 inches.

12. The crossbow of claim 1, wherein a draw-force of the crossbow is at least 240 lbf at an intermediate position that is 9 inches from an un-cocked position.

13. The crossbow of claim 1, wherein the crossbow is configured to provide a kinetic energy of at least 170 ft-lbf for an arrow/bolt weighing 403 grains.

14. A crossbow, comprising: an energy storage system; anda riser,wherein the crossbow comprises an efficiency of at least 80%.

15. The crossbow of claim 14, wherein the energy storage system comprises: a first limb and a second limb, wherein the first limb comprises a first end and a second end;wherein the second limb comprises a first end and a second end;wherein the first end of the first limb and the first end of the second limb are coupled to the riser;a first wheel rotatably coupled to the first limb proximate the second end thereof;a second wheel rotatably coupled to the second limb proximate the second end thereof; anda first power cord, comprising: a first end coupled to the riser;a second end coupled to the first wheel; anda second power cord, comprising: a first end coupled to the riser;a second end coupled to the first wheel; anda bowstring.

16. The crossbow of claim 14, wherein the crossbow comprises an efficiency of 80% to 100%.

17. The crossbow of claim 14, wherein the crossbow comprises an efficiency of 80% to 90%.

18. The crossbow of claim 14, wherein the crossbow comprises an efficiency of 80% to 85%.

19. The crossbow of claim 14, wherein the crossbow comprises an efficiency of 83%.

20. The crossbow of claim 14, wherein the crossbow is a reverse draw crossbow.