Energy storage device for a bow
An energy storage portion for a bow and a method of configuring the same. At least one first limb has both a distal portion and a proximal portion coupled to the first side of a center support. At least one second limb has both a distal portion and a proximal portion coupled to the second side of the center support. At least one first pulley is attached to the first limb at a location between the distal and the proximal portions of the first limb and at least one second pulley is attached to the second limb at a location between the distal and the proximal portions of the second limb.
1. An energy storage portion for a bow comprising:
a center support having a first side and a second side;
at least one first limb having a distal portion pivotally coupled to the first side of the center support at a distal limb mount and a proximal portion, pivotally coupled to the first side of the center support at a proximal limb mount;
at least one second limb having a distal portion pivotally coupled to the second side of the center support at a distal limb mount and a proximal portion pivotally coupled to the second side of the center support at a proximal limb mount;
at least one first pulley including a first string journal and a first power cable journal pulley pivotally attached to the first limb at a fixed position located between the distal portion and the proximal portions;
at least one second pulley including a second string journal and a second power cable journal pivotally attached to the second limb at a fixed position located between the distal portion and the proximal portions;
a draw string extending across the center support and engaged with the first and second string journals, the draw string including a first end secured to the first pulley and, a second end secured to the second pulley;
a first power cable engaged with the first power cable journal having a first end attached to the center support and a second end attached to the first pulley;
a second power cable engaged with the second power cable journal having a first end attached to the center support and a second end attached to the second pulley; and
couplings interposed between at least one of the distal portions or the proximal portions of the first and second limbs and the respective limb mounts that provides limb relief as the draw string is pulled to a drawn configuration.
2. The energy storage portion for a bow of claim 1 wherein the first and second limbs each comprise a pair of limbs arranged in a spaced apart configuration with the first and second pulleys located between the pair of limbs, respectively.
3. The energy storage portion for a bow of claim 1 wherein the first and second limbs are arranged in a concave or convex configuration with respect to the center support.
4. The energy storage portion for a bow of claim 1 wherein the first and second pulleys comprise cams.
5. The energy storage portion for a bow of claim 1 wherein the first and second pulleys are attached to the first and second limbs, respectively, generally at a midpoint between the distal and proximal portions.
6. The energy storage portion for a bow of claim 1 wherein the first and second power cables do not cross over the center support from the first side to the second side.
7. The energy storage portion of a bow of claim 1 wherein the couplings comprise rotating translation arms pivotally attached to one of the distal portions or the proximal portions of the first and second limbs and the respective limb mounts.
8. The energy storage portion for a bow of claim 7 wherein rotation of the rotating translation arms are synchronized by a synchronization assembly.
9. The energy storage portion for a bow of claim 1 wherein the couplings comprise pivoting couplings, linkage couplings, rotating couplings, sliding couplings, elastomeric couplings, or a combination thereof.
10. The energy storage portion for a bow of claim 1 wherein the center support provides limb relief between the proximal portion and the distal portion of the limbs.
11. The energy storage portion for a bow of claim 1 wherein the first and second pulleys, each rotate around first and second axes, wherein total displacement of the first axis toward the second axis as the draw string is pulled to a drawn configuration is less than about 3.5 inches.
12. The energy storage portion for a bow of claim 1 wherein the first and second pulleys each rotate around first and second axes, wherein total displacement of the first axis toward the second axis as the draw string is pulled to a drawn configuration is less than about 3.0 inches.
13. The energy storage portion for a bow of claim 1 wherein the first and second pulleys each rotate around first and second axes, wherein a separation between the first and second axes when the draw string is in a drawn configuration is less than about 10 inches.
14. The energy storage portion for a bow of claim 1 wherein the first and second pulleys each rotate around first and second axes, wherein a separation between the first and second axes when the draw string is in a released configuration is less than about 13 inches.
15. The energy storage portion for a bow of claim 1 comprising a finger guards on the center support with a shape corresponding to a space traversed by the draw string as it moves between the drawn configuration and the released configuration.
16. An energy storage portion for a bow comprising:
a center support having a first side and a second side;
at least one first limb having a distal portion pivotally coupled to the first side of the center support at a distal limb mount and aproximal portion pivotally coupled to the first side of the center support at a proximal limb mount;
at least one second limb having a distal portion pivotally coupled to the second side of the center support at a distal limb mount and a proximal portion pivotally coupled to the second side of the center support at a proximal limb mount;
at least one first pulley including a first string journal and a first power cable journal pulley pivotally attached to the first limb at a fixed position located at about a midpoint between the distal and proximal portions;
at least one second pulley including a second string journal and a second power cable journal pivotally attached to the second limb at a fixed position located at about a midpoint between the distal and proximal portions;
a draw string extending across the center support and engaged with the first and second string journals, the draw string including a first end secured to the first pulley and a second end secured to the second pulley;
a first power cable engaged with the first power cable journal having a first end attached to the center support and a second end attached to the first pulley; and
a second power cable engaged with the second power cable journal having a first end attached to the center support and a second end attached to the second pulley, wherein the first and second power cables do not cross over the center support from the first side to the second side.
17. The energy storage portion for a bow of claim 16 comprising couplings interposed between at least one of the distal portions or the proximal portions of the first and second limbs and the respective limb mounts that provides limb relief as the draw string is pulled to a drawn configuration.
18. The energy storage portion of a bow of claim 16 wherein the couplings comprise rotating translation arms pivotally attached to one of the distal portions or the proximal portions of the first and second limbs and the respective limb mounts.
19. The energy storage portion for a bow of claim 16 wherein the couplings comprise pivoting couplings, linkage couplings, rotating couplings, sliding couplings, elastomeric couplings, or a combination thereof.
20. The energy storage portion for a bow of claim 16 wherein the center support provides limb relief between the proximal portion and the distal portion of the limbs.