Crossbow with pulleys that rotate around stationary axes
First Claim
1. A crossbow comprising:
- a frame comprising a center rail;
first and second flexible limbs attached to the frame;
a first cam assembly mounted to the frame and rotatable around a first axis, the first cam assembly comprising a first draw string journal having a first plane of rotation perpendicular to the first axis, and a first power cable take-up journal comprising a path that is not co-planar with the first plane of rotation;
a second cam assembly mounted to the frame and rotatable around a second axis, the second cam assembly comprising a second draw string journal having a second plane of rotation perpendicular to the second axis, and a second power cable take-up journal comprising a path that is not co-planar with the second plane of rotation;
a draw string received in the draw string journals in a reverse draw configuration with the draw string adjacent a down-range side when in a released configuration and secured to the first and second cam assemblies, wherein the draw string unwinds from the draw string journals as it translates from a released configuration to a drawn configuration, wherein a separation between the first axis and the second axis is about 3 inches to about 8 inches and the draw string in the drawn configuration comprises an included angle of less than about 25 degrees; and
first and second power cables having first ends operatively coupled to the first and second cam assemblies and received in the first and second power cable take-up journals, and second ends operatively coupled to the first and second flexible limbs, respectively,wherein the first and second power cable take-up journals displace the first and second power cables along the first and second axes relative to the first and second planes of rotation, respectively, and the first and second power cables wrap at least 270 degrees around the respective first and second power cable take-up journals as the drawstring is moved between the released configuration to the drawn configuration, and the first and second cables unwrap at least 270 degrees from the respective first and second power cable take-up journals as the drawstring is moved between the drawn configuration to the released configuration.
3 Assignments
0 Petitions
Accused Products
Abstract
A crossbow including a frame with a riser and a center rail. First and second flexible limbs are attached to the riser. A draw string is received in string guide journals in first and second cams rotatably attached to the frame. The draw string unwinds from the string guide journals as it translates between a released configuration and a drawn configuration. The first and second cams include at least first and second power cable take-up journals, respectively. At least first and second power cables are attached to the first and second limbs and received in the first and second power cable take-up journals, respectively. As the crossbow is drawn from the released configuration to the drawn configuration the first and second power cables wrap onto the respective first and second power cable take-up journals.
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Citations
25 Claims
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1. A crossbow comprising:
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a frame comprising a center rail; first and second flexible limbs attached to the frame; a first cam assembly mounted to the frame and rotatable around a first axis, the first cam assembly comprising a first draw string journal having a first plane of rotation perpendicular to the first axis, and a first power cable take-up journal comprising a path that is not co-planar with the first plane of rotation; a second cam assembly mounted to the frame and rotatable around a second axis, the second cam assembly comprising a second draw string journal having a second plane of rotation perpendicular to the second axis, and a second power cable take-up journal comprising a path that is not co-planar with the second plane of rotation; a draw string received in the draw string journals in a reverse draw configuration with the draw string adjacent a down-range side when in a released configuration and secured to the first and second cam assemblies, wherein the draw string unwinds from the draw string journals as it translates from a released configuration to a drawn configuration, wherein a separation between the first axis and the second axis is about 3 inches to about 8 inches and the draw string in the drawn configuration comprises an included angle of less than about 25 degrees; and first and second power cables having first ends operatively coupled to the first and second cam assemblies and received in the first and second power cable take-up journals, and second ends operatively coupled to the first and second flexible limbs, respectively, wherein the first and second power cable take-up journals displace the first and second power cables along the first and second axes relative to the first and second planes of rotation, respectively, and the first and second power cables wrap at least 270 degrees around the respective first and second power cable take-up journals as the drawstring is moved between the released configuration to the drawn configuration, and the first and second cables unwrap at least 270 degrees from the respective first and second power cable take-up journals as the drawstring is moved between the drawn configuration to the released configuration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A crossbow comprising:
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a frame comprising a center rail; first and second flexible limbs attached to the frame; a first cam assembly mounted to the frame and rotatable around a first axis, the first cam assembly comprising a first draw string journal having a first plane of rotation perpendicular to the first axis, and a first helical power cable take-up journal comprising a path that is not co-planar with the first plane of rotation; a second cam assembly mounted to the frame and rotatable around a second axis, the second cam assembly comprising a second draw string journal having a second plane of rotation perpendicular to the second axis, and a second helical power cable take-up journal comprising a path that is not co-planar with the second plane of rotation; a draw string received in the draw string journals in a reverse draw configuration with the draw string adjacent a down-range side when in a released configuration and secured to the first and second cam assemblies, wherein the draw string unwinds from the draw string journals as it translates from a released configuration to a drawn configuration, wherein a separation between the first axis and the second axis is about 3 inches to about 8 inches and the draw string in the drawn configuration comprises an included angle of less than about 25 degrees; and first and second power cables having first ends received in the first and second helical power cable take-up journals, and second ends operatively coupled to the first and second flexible limbs, respectively; wherein the first and second helical power cable take-up journals displace the first and second power cables along the first and second axes relative to the first and second planes of rotation, respectively, and the first and second power cables wrap at least 270 degrees around the respective first and second helical power cable take-up journals as the drawstring is moved between the released configuration to the drawn configuration, and the first and second power cables unwrap at least 270 degrees from the respective first and second helical power cable take-up journals as the drawstring is moved between the drawn configuration to the released configuration.
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20. A method of operating a crossbow comprising the steps of:
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locating a draw string in first and second draw string journals on first and second cam assemblies mounted to a frame, the first and second cam assemblies having first and second planes of rotation that are perpendicular to first and second axes of rotation, respectively, and first and second helical power cable take-up journal comprising paths that are not co-planar with the first and second planes of rotation; translating the draw string from a released configuration to a drawn configuration so the draw string unwinds from the draw string journals as the first and second cam assemblies rotate around the first and second axes, wherein a separation between the first axis and the second axis is about 3 inches to about 8 inches and the draw string in the drawn configuration comprises an included angle of less than about 15 degrees; wrapping the first and second power cables more than 270 degrees onto the first and second helical power cable take-up journals as the draw string translates from the released configuration to the drawn configuration, the first and second power cables having first ends operatively coupled to the first and second cam assemblies and second ends operatively coupled to the first and second flexible limbs, respectively; displacing the first and second power cables along the first and second axes relative the first and second planes of rotation of the first and second draw string journals as the bow string is translated from the released configuration to the drawn configuration; and unwrapping the first and second power cables more than 270 degrees from first and second helical power cable take-up journals as the draw string translates from the drawn configuration to the released configuration. - View Dependent Claims (21, 22, 23, 24, 25)
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Specification