Compound bow with counteracting weight

• US 5,809,982 A
• Filed: 12/23/1996
• Issued: 09/22/1998
• Est. Priority Date: 12/23/1996
• Status: Expired due to Term

• Current Assignee: MCP IP, LLC
• Original Assignee: Mathew A. McPherson
• Inventors: McPherson, Mathew A.
• Primary Examiner(s): Graysay, Tamara L.
• Assistant Examiner(s): Beach, Thomas A.
• Application Number:
  US08/772,360
• Time in Patent Office: 638 Days
• Field of Search: 124/256, 124/23.1, 124/25, 124/44.8, 124/27, 124/900, 124/1
• US Class Current: 124/25.6
• CPC Class Codes: F41B 5/10 Compound bows compound crossbows F41B5/123
• CPC Class Codes: F41B 5/105 Cams or pulleys for compound bows
• CPC Class Codes: Y10S 124/90 Limb tip rotatable element structure

Abstract

An inventive cam body which includes a counteracting weight which generates a net counteracting centrifugal force to act against the forward force of the bow.

Claims

1. A rotating member for use with a compound bow, comprising:

a body having a rotation point for journaling the body to a bow limb, the body having a rest position and a drawn position in use with respect to the bow limb, the body including a counteracting weight constructed and arranged such that when the body returns to the rest position from the drawn position a net counteracting centrifugal force is generated acting against a forward force of the bow, wherein the body is a pulley.

2. A rotating member for use with a compound bow, comprising:

a body having a rotation point for journaling the body to a bow limb, the body having a rest position and a drawn position in use with respect to the bow limb, the body including a counteracting weight constructed and arranged such that when the body returns to the rest position from the drawn position a net counteracting centrifugal force is generated acting against a forward force of the bow, wherein the body is a cam.

3. The rotating member of claim 2 wherein the counteracting weight is made of a material which is denser than the material of the cam.

4. The rotating member of claim 3 wherein the cam is made of aluminum and the counteracting weight is made of tungsten.

7. The rotating member of claim 2 wherein the cam includes an extension arm, the cam being constructed and arranged such that a bowstring contact point lies on the extension arm, whereby the effective length of the bowstring is shortened.

5. A rotating member for use with a compound bow, comprising:

a body having a rotation point for journaling the body to a bow limb, the body having a rest position and a drawn position in use with respect to the bow limb, the body including a counteracting weight constructed and arranged such that when the body returns to the rest position from the drawn position a net counteracting centrifugal force is generated acting against a forward force of the bow, wherein a sum of two sides of a right triangle defined by a bowstring contact point and the rotation point is greater than three inches.

6. The rotating member of claim 5 wherein a lever ratio of the cam is between 1 and 3.

8. The rotating member of claim 6 wherein a portion of the cam, when mounted on a bow limb, extends inwardly from an inside surface of the bow limb, and where the cam includes an extension arm attached to the portion of the cam extending inwardly, the cam and extension arm including a peripheral groove, the cam constructed and arranged such that a bowstring contact point lies on the extension arm, resulting in a shorter effective string length.

9. A rotating member for use with a compound bow, comprising:

a body having a rotation point for journaling the body to a bow limb, the body having a rest position and a drawn position in use with respect to the bow limb, the body including a counteracting weight constructed and arranged such that when the body returns to the rest position from the drawn position a net counteracting centrifugal force is generated acting against a forward force of the bow, wherein the counteracting weight is movably mounted to the body the counteracting weight moves between a drawn position on the body and a rest position on the body to generate the net counteracting centrifugal force and wherein the body includes a counteracting weight chamber containing the counteracting weight which is held in a rest position in the chamber by gravity when the body is in the rest position and which is moved by gravity to a drawn position when the body is rotated to the drawn position, the chamber constructed and arranged such that a counteracting centrifugal force is generated acting against the forward force of the bow when the body rotates to the rest position from the drawn position, causing the counteracting weight to move from the drawn to the rest position in the chamber.

10. The rotating member of claim 9 wherein the weight is comprised of at least one tungsten ball bearing in an oil bath.

11. The rotating member of claim 9 wherein the weight is spring mounted in the counteracting weight chamber.

12. A rotating member for use with a compound bow, comprising:

a body having a rotation point for journaling the body to a bow limb, the body having a rest position and a drawn position in use with respect to the bow limb, the body including a counteracting weight constructed and arranged such that when the body returns to the rest position from the drawn position a net counteracting centrifugal force is generated acting against a forward force of the bow, wherein the counteracting weight is movably mounted to the body the counteracting weight moves between a drawn position on the body and a rest position on the body to generate the net counteracting centrifugal force and wherein the counteracting weight is a movable arm mounted for rotation to the body.

13. The rotating member of claim 12 including a spring connecting the movable arm to the body and wherein the centrifugal force generated by the body rotating back to the rest position causes the movable arm to move from a compressed to an uncompressed state to generate a net counteracting centrifugal force.

14. A compound bow comprising:

a pair of flexible resilient first and second bow limbs, each bow limb having an inner and outer end;

a handle connecting the inner ends of the bow limbs;

a rotating member attached to the outer end of each bow limb;

a bowstring arranged relative to the rotating members such that in use the bow has a rest position and a drawn position, wherein as the bow is moved to the drawn position by pulling the bowstring each rotating member rotates about a rotation point and the bow limbs are flexed to store energy, and wherein when the bowstring is released the rotating members rotate in the opposite direction and the bow limbs unflex, the movement of the bowstring and bow limbs creating a forward force on the bow when the bow returns to the rest position;

at least one of the rotating members having a counterbalancing weight portion spaced from the rotation point of the rotating member, the rotating member being constructed and arranged to generate a counteracting centrifugal force acting against the forward force of the bow as the bow returns to the rest position.

15. The compound bow of claim 14 wherein the bow limbs have inside and outside surfaces and where the rotating member is mounted to the bow limb such that at rest part of the rotating member extends inwardly from the inside surface of the bow limb, and wherein the counterbalancing weight portion of the rotating member is positioned on the part of the rotating member which extends inwardly from the inside surface of the bow limb.

16. The compound bow of claim 15 wherein at least one of the rotating members is a pulley.

17. The compound bow of claim 15 wherein at least one of the rotating members is a cam.

18. The compound bow of claim 14 wherein both rotating members include a counterbalancing weight portion.

19. The compound bow of claim 18 wherein at least one rotating member is a pulley.

20. The compound bow of claim 18 wherein at least one rotating member is a cam.

21. The compound bow of claim 18 wherein both rotating members are cams.

22. The compound bow of claim 14 wherein the counterbalancing weight portion is made of a denser material than the rotating member material.

23. The compound bow of claim 22 wherein the rotating member is made of aluminum and the counterbalancing weight portion is made of tungsten.