Compound bow

• US 4,201,182 A
• Filed: 04/15/1977
• Issued: 05/06/1980
• Est. Priority Date: 04/15/1977
• Status: Expired due to Term

• Current Assignee: Bass Research and Design Incorporated
• Original Assignee: Bass Research and Design Incorporated
• Inventors: Butler, Dennis L.
• Primary Examiner(s): Browne, William R.
• Application Number:
  US05/787,912
• Time in Patent Office: 1,117 Days
• Field of Search: 124/23 R, 124/24 R, 124/41 A, 124/88, 124/90, 124/86, 124/25 R
• US Class Current: 124/25.6
• CPC Class Codes: F41B 5/0094 Non-traditional bows, e.g. having hinged limbs or non-stave geometry
• CPC Class Codes: F41B 5/10 Compound bows compound crossbows F41B5/123

Abstract

A bow of the compound type for use in archery, having an upper and lower limb pivotally mounted at opposite ends of an elongated central frame member having a hand grasp portion formed thereon. First and second pivot members having continuously variable leverage characteristics are each connected to both the upper and lower limbs. When the drawstring is pulled back toward the cocked position, the limbs pivot and the variable leverage pivot members rotate from the position of least leverage to positions of progressively greater leverage. Thus, less force is required as the drawstring approaches the fully cocked position. When the drawstring is released, the variable leverage pivot members operate in reverse to progressively increase the velocity of the drawstring as it snaps from the cocked to the fully released position.

Claims

1. A compound bow, comprising limb means movable between a released position and a cocked position, bowstring means connected to said limb means to move said limb means from said released position to said cocked position when drawn, and variable leverage means connected to said limb means to apply variable leverage force on at least two points on said limb means as it is moved from said released to said cocked position, wherein said limb means includes a centrally disposed elongated frame member having a hand grasp section thereon, first and second limb members, said first limb member being mounted on said elongated frame member at one side of said hand grasp section thereof, said second limb member being mounted on said elongated frame member at the opposite side of said hand grasp section, wherein said variable leverage means includes first and second pivot members each having a pivotal axis, said pivot members each including a first anchor point spaced radially from said pivotal axis along a first radius, a second anchor point spaced radially from said pivotal axis along a second radius angularly displaced from said first radius, said first limb member being directly connected to said first anchor point of said first pivot member, first direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said first anchor point of said first pivot member, said second limb member being directly connected to said second anchor point of said first pivot member, second direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said second anchor point of said first pivot member, said second limb member being directly connected to said first anchor point of said second pivot member, third direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said first anchor point of said second pivot member, said first limb member being directly connected to said second anchor point of said second pivot member, and fourth direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said second anchor point of said second pivot member, wherein when viewed from one side said first anchor point of said first pivot member is at approximately the one o'"'"'clock position in relation to its pivotal axis when said bowstring means is in its released position and said first anchor point of said second pivot member is at approximately the five o'"'"'clock position in relation to its pivotal axis when said bowstring means is in its released position.

2. A compound bow, comprising limb means movable between a released position and a cocked position, bowstring means connected to said limb means to move said limb means from said released position to said cocked position when drawn, and variable leverage means connected to said limb means to apply variable leverage force on at least two points on said limb means as it is moved from said released to said cocked position, wherein said limb means includes a centrally disposed elongated frame member having a hand grasp section thereon, first and second limb members, said first limb member being mounted on said elongated frame member at one side of said hand grasp section thereof, said second limb member being mounted on said elongated frame member at the opposite side of said hand grasp section, wherein said variable leverage means includes first and second pivot members each having a pivotal axis, said pivot members each including a first anchor point spaced radially from said pivotal axis along a first radius, a second anchor point spaced radially from said pivotal axis along a second radius angularly displaced from said first radius, said first limb member being directly connected to said first anchor point of said first pivot member, first direct connecting means extending in a substantially straight line between the point of connection to aid first limb member and said first anchor point of said first pivot member, said second limb member being directly connected to said second anchor point of said first pivot member, second direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said second anchor point of said first pivot member, said second limb member being directly connected to said first anchor point of said second pivot member, third direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said first anchor point of said second pivot member, said first limb member being directly connected to said second anchor point of said second pivot member, and fourth direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said second anchor point of said second pivot member, wherein when viewed from one side said first anchor point of said first pivot member is at approximately the twelve o'"'"'clock position in relation to its pivotal axis when said bowstring means is in its drawn position and said first anchor point of said second pivot member is at approximately the six o'"'"'clock position in relation to its pivotal axis when said bowstring means is in its drawn position.

3. A compound bow, comprising limb means movable between a released position and a cocked position, bowstring means connected to said limb means to move said limb means from said released position to said cocked position when drawn, and variable leverage means connected to said limb means to apply variable leverage force on at least two points on said limb means as it is moved from said released to said cocked position, wherein said limb means includes a centrally disposed elongated frame member having a hand grasp section thereon, first and second limb members, said first limb member being mounted on said elongated frame member at one side of said hand grasp section thereof, said second limb member being mounted on said elongated frame member at the opposite side of said hand grasp section, wherein said variable leverage means includes first and second pivot members each having a pivotal axis, said pivot members each including a first anchor point spaced radially from said pivotal axis along a first radius, a second anchor point spaced radially from said pivotal axis along a second radius angularly displaced from said first radius, said first limb member being directly connected to said first anchor point of said first pivot member, first direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said first anchor point of said first pivot member, said second limb member being directly connected to said second anchor point of said first pivot member, second direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said second anchor point of said first pivot member, said second limb member being directly connected to said first anchor point of said second pivot member, third direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said first anchor point of said second pivot member, said first limb member being directly connected to said second anchor point of said second pivot member, and fourth direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said second anchor point of said second pivot member, wherein when viewed from one side said second anchor point of said first pivot member is at approximately the four o'"'"'clock position in relation to its pivotal axis when said bowstring means is in its released position and said second anchor point of said second pivot member is at approximately the two o'"'"'clock position in relation to its pivotal axis when said bowstring means is in its released position.

4. A compound bow, comprising limb means movable between a released position and a cocked position, bowstring means connected to said limb means to move said limb means from said released position to said cocked position when drawn, and variable leverage means connected to said limb means to apply variable leverage force on at least two points on said limb means as it is moved from said released to said cocked position, wherein said limb means includes a centrally disposed elongated frame member having a hand grasp section thereon, first and second limb members, said first limb member being mounted on said elongated frame member at one side of said hand grasp section thereof, said second limb member being mounted on said elongated frame member at the opposite side of said hand grasp section, wherein said variable leverage means includes first and second pivot members each having a pivotal axis, said pivot members each including a first anchor point spaced radially from said pivotal axis along a first radius, a second anchor point spaced radially from said pivotal axis along a second radius angularly displaced from said first radius, said first limb member being directly connected to said first anchor point of said first pivot member, first direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said first anchor point of said first pivot member, said second limb member being directly connected to said second anchor point of said first pivot member, second direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said second anchor point of said first pivot member, said second limb member being directly connected to said first anchor point of said second pivot member, third direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said first anchor point of said second pivot member, said first limb member being directly connected to said second anchor point of said second pivot member, and fourth direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said second anchor point of said second pivot member, wherein when viewed from one side said second anchor point of said first pivot member is at approximately the three o'"'"'clock position in relation to its pivotal axis when said bowstring means is in its drawn position and said second anchor point of said second pivot member is at approximately the three o'"'"'clock position in relation to its pivotal axis when said bowstring means is in its drawn position.

5. A compound bow as set forth in claim 4, wherein said first and second limb members are arcuate in configuration.

6. A compound bow as set forth in claim 4, wherein said first and second limb members are resilient and flex when moved to said cocked position by said bowstring means.

7. A compound bow, comprising limb means movable between a released position and cocked position, bowstring means connected to said limb means to move said limb means from said released position to said cocked position when drawn, and varible leverage means connected to said limb means to apply variable leverage force on at least two points on said limb means as it is moved from said released to said cocked position, wherein said limb means includes a centrally disposed elongated frame member having a hand grasp section thereon, first and second limb members, said first limb member being mounted on said elongated frame member at one side of said hand grasp section thereof, said second limb member being mounted on said elongated frame member at the opposite side of said hand grasp section, wherein said variable leverage means includes first and second pivot members each having a pivotal axis, said pivot members each including a first anchor point spaced radially from said pivotal axis along a first radius, a second anchor point spaced radially from said pivotal axis along a second radius angularly displaced from said first radius, said first limb member being directly connected to said first anchor point of said first pivot member, first direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said first anchor point of said first pivot member, said second limb member being directly connected to said second anchor point of said first pivot member, second direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said second anchor point of said first pivot member, said second limb member being directly connected to said first anchor point of said second pivot member, third direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said first anchor point of said second pivot member, said first limb member being directly connected to said second anchor point of said second pivot member, and fourth direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said second anchor point of said second pivot member, first link means to connect said first limb member directly to said first anchor point of said first pivot member, second link means to connect said second limb member directly to said first anchor point of said second pivot member, third link means to connect said second limb member directly to said second anchor point of said first pivot member, and fourth link means to connect said first limb member directly to said second anchor point of said second pivot member, wherein said first and second link means each includes a first link member one end of which is anchored at said first anchor point of respective ones of said pivot members, the opposite end of said first link member being connected to the inner end region of respective ones of said limb members, said third and fourth link means each include a second link member extending between said second anchor point of respective ones of said pivot members and an intermediate point of respective ones of said limb members, including a first plane of reference extending through the pivotal axes of both of said first and second pivot members, a second plane of reference extending through the pivotal axis of said first pivot member at right angles to said first plane of reference, a third plane of reference extending through the pivotal axis of said second pivot member at right angles to said first plane of reference, said first and second link means being respectively on the outboard side of said second and third planes of reference and spaced respectively therefrom, said first and second link means being relatively closer to said second and third planes respectively when said bowstring means is in its released position and relatively farther therefrom when said bowstring means is in its drawn position.

8. A compound bow as set forth in claim 7, wherein said third and fourth link means are on the bowstring side of said first plane of reference and relatively closer to said first plane of reference when said bowstring is in its released position and relatively farther therefrom when said bowstring is in its drawn position.

9. A compound bow as set forth in claim 7, wherein said first link member is a link rod, one end of which is pivotally anchored at said first anchor point of respective ones of said first and second pivot members, and said second link member is a cord extending under tension between said second anchor point of respective ones of said pivot members and said intermediate point of respective ones of said limb members.

10. A compound bow, comprising limb means movable between a released position and a cocked position, bowstring means connected to said limb means to move said limb means from said released position to said cocked position when drawn, and variable leverage means connected to said limb means to apply variable leverage force on at least two points on said limb means as it is moved from said released to said cocked position, wherein said limb means includes a centrally disposed elongated frame member having a hand grasp section thereon, first and second limb members, said first limb member being mounted on said elongated frame member at one side of said hand grasp section thereof, said second limb member being mounted on said elongated frame member at the opposite side of said hand grasp section, wherein said variable leverage means includes first and second pivot members each having a pivotal axis, said pivot members each including a first anchor point spaced radially from said pivotal axis along a first radius, a second anchor point spaced radially from said pivotal axis along a second radius angularly displaced from said first radius, said first limb member being directly connected to said first anchor point of said first pivot member, first direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said first anchor point of said first pivot member, said second limb member being directly connected to said second anchor point of said first pivot member, second direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said second anchor point of said first pivot member, said second limb member being directly connected to said first anchor point of said second pivot member, third direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said first anchor point of said second pivot member, said first limb member being directly connected to said second anchor point of said second pivot member, and fourth direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said second anchor point of said second pivot member, first link means to connect said first limb member directly to said first anchor point of said first pivot member, second link means to connect said second limb member directly to said first anchor point of said second pivot member, third link means to connect said second limb member directly to said second anchor point of said first pivot member, and fourth link means to connect said first limb member directly to said second anchor point of said second pivot member, wherein said first and second link means each include a first link member one end of which is anchored at said first anchor point of respective ones of said pivot members, the opposite end of said first link member being connected to the inner end region of respective ones of said limb members, said third and fourth link means each include a second link member extending between said second anchor point of respective ones of said pivot members and an intermediate point of respective ones of said limb members, wherein said first link members of said first and second link means extend at acute angles to the first radii of said first and second pivot members to which they are respectively anchored when said bowstring means is in its released position and said first link members extend at other than an acute angle to said radii when said bowstring means is in its drawn position.

11. A compound bow as set forth in claim 10, wherein said angle which is other than an acute angle is an obtuse angle.

12. A compound bow as set forth in claim 10, wherein said angle which is other than an acute angle is a right angle.

13. A compound bow, comprising limb means movable between a released position and a cocked position, bowstring means connected to said limb means to move said limb means from said released position to said cocked position when drawn, variable leverage means connected to said limb means to apply variable leverage force on at least two points on said limb means as it is moved from said released to said cocked position, wherein said limb means includes a centrally disposed elongated frame member having a hand grasp section thereon, first and second limb members, said first limb member being mounted on said elongated frame member at one side of said hand grasp section thereof, said second limb member being pivotally mounted on said elongated frame member at the opposite side of said hand grasp section, wherein said variable leverage means includes first and second pivot members each having a pivotal axis, said pivot members each including a first anchor point spaced radially from said pivotal axis along a first radius, a second anchor point spaced radially from said pivotal axis along a second radius angularly displaced from said first radius, said first limb member being directly connected to said first anchor point of said first pivot member, first direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said first anchor point of said first pivot member, said second limb member being directly connected to said second anchor point of said first pivot member, second direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said second anchor point of said first pivot member, said second limb member being directly connected to said first anchor point of said second pivot member, third direct connecting means extending in a substantially straight line between the point of connection to said second limb member and said first anchor point of said second pivot member, said first limb member being directly connected to said second anchor point of said second pivot member, and fourth direct connecting means extending in a substantially straight line between the point of connection to said first limb member and said second anchor point of said second pivot member, first link means to connect said first limb member to said first anchor point of said first pivot member, second link means to connect said second limb member to said first anchor point of said second pivot member, third link means to connect said second limb member to said second anchor point of said first pivot member, and fourth link means to connect said first limb member to said second anchor point of said second pivot member, wherein said first and second link means each include a first link member one end of which is anchored at said first anchor point of respective ones of said pivot members, the opposite end of said first link member being connected to the inner end region of respective ones of said limb members, said third and fourth link means each include a second link member extending between said second anchor point of respective ones of said pivot members and an intermediate point of respective ones of said limb members, wherein said second link members of said third and fourth link means extend at obtuse angles to the second radii of said first and second pivot members to which said second link members are respectively connected when said bowstring means is in its released position and said second link members extend at other than an obtuse angle to said radii when said bowstring means is in its drawn position.

14. A compound bow as set forth in claim 13, wherein said angle which is other than an obtuse angle is an acute angle.

15. A compound bow as set forth in claim 13, wherein said angle which is other than an obtuse angle is a right angle.

16. A compound bow, comprising limb means movable between a released position and a cocked position, bowstring means connected to said limb means to move said limb means from said released position to said cocked position when drawn, and variable leverage means connected to said limb means to apply variable leverage force on said limb means as it is moved from said released to said cocked position, wherein said variable leverage means includes first and second pivot members mounted in spaced apart relationship on said bow, said pivot members each including a pivotal axis, a first anchor point spaced radially from said pivotal axis along a first radius and a second anchor point spaced radially from said pivotal axis along a second radius angularly disposed from said first radius, said limb means including first and second limb members, said first limb member being directly connected to said first anchor point of said first pivot member, first direct connecting means including a first link means extending in a substantially straight line between the point of connection to said first limb member and said first anchor point of said first pivot member, said second limb member being directly connected to said second anchor point of said first pivot member, second direct connecting means including a second link means extending in a substantially straight line between the point of connection to said second limb member and said second anchor point of said first pivot member, said second limb member being directly connected to said first anchor point of said second pivot member, third direct connecting means including a third link means extending in a substantially straight line between the point of connection to said second limb member and said first anchor point of said second pivot member, said first limb member being directly connected to said second anchor point of said second pivot member, and fourth direct connecting means including a fourth link means extending in a substantially straight line between the point of connection to said first limb member and said second anchor point of said second pivot member.

17. A compound bow as set forth in claim 16, wherein said first and third link means includes a link rod one end of which is pivotally anchored at said first anchor point of respective ones of said pivot members, the opposite end of said link rod being connected to the inner end region of respective ones of said limb members, said second and fourth link means includes a cord extending under tension between said second anchor point of respective ones of said pivot members and an intermediate point of respective ones of said limb members.

18. A compound bow as set forth in claim 17, wherein said limb means includes a centrally disposed elongated frame member having a hand grasp section thereof, said first limb member being pivotally mounted on said elongated frame member at one side of said hand grasp section thereof, said second limb member being pivotally mounted on said elongated frame member at the opposite side of the said hand grasp section, wherein said inner end region of said limb members is inwardly of the pivot point at which they are pivotally mounted respectively on said elongated frame member and said intermediate point of said limb members is outwardly of said pivot point.

19. A compound bow as set forth in claim 17, wherein said first and second link means are adjustable to vary the distance between their respective anchor points to respective pivot members and their respective connections to respective ones of said limb members.

20. A compound bow as set forth in claim 17, wherein said third and fourth link means include adjustable members connected to respective ones of said cords to vary the tension of said cords.

21. A compound bow, comprising limb means movable between a released position and a cocked position, bowstring means connected to said limb means to move said limb means from said released position to said cocked position when drawn, and leverage means connected to said limb means to apply resistive force to said limb means to resist movement thereof from said released position to said cocked position, including a limb mounting member, said limb means including a first limb member and a second limb member, said first and second limb members being pivotally mounted at single points respectively on said limb mounting member for pivotal movement of said limb members between said released position on said cocked position, said leverage means applying said resistive force to said pivotally mounted limb members to resist movement thereof from said released position to said cocked position, and said leverage means being connected to said mounting member and pivotable through an arc to aid in applying a variable force to the limb means when the limb means is drawn toward a cocked position.

22. A compound bow, comprising limb means movable between a released position and a cocked position, bowstring means connected to said limb means to move said limb means from said released position to said cocked position when drawn, lever means connected to said limb means to apply resistive force to said limb means to resist movement thereof from said released position to said cocked position, including a limb mounting member, said limb means including a first limb member and a second limb member, said first and second limb members being pivotally mounted at single points respectively on said limb mounting member for pivotal movement of said limb member between said released position and said cocked position, said lever means applying said resistive force to said pivotally mounted limb members to resist movement thereof from said released position to said cocked position, wherein said first and second limb members are resilient, and said lever means being connected to said mounting member and pivotable through an arc in applying a variable force to the limb means when the limb means is drawn toward a cocked position.

23. A compound bow, comprising limb means movable between a released position and a cocked position, bowstring means connected to said limb means to move said limb means from said released position to said cocked position when drawn, lever means connected to said limb means to apply resistive force to said limb means to resist movement thereof from said released position to said cocked position, including a limb mounting member, said limb means including a first limb member and a second limb member, said first and second limb members being pivotally mounted at single points respectively on said limb mounting member for pivotal movement of said limb member between said released position and said cocked position, said lever means applying said resistive force to said pivotally mounted limb members to resist movement thereof from said released position to said cocked position, wherein said limb mounting member includes a hand grasp portion, said first limb member being pivotally mounted on one side of said hand grasp portion, said second limb member being pivotally mounted on the opposite side of said hand grasp portion and said lever means being connected to said mounting member and pivotable through an arc in applying a variable force to the limb means when the limb means is drawn toward a cocked position.