Shooting Bow Pulley Cable Routing for Timing and Interference
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Solution Overview
Problem
Existing archery bows face issues with cable interference, twisting, and torque due to off-angle cable placement, which affects performance and assembly, particularly in binary cam systems where cables are not efficiently routed around cams, leading to timing and efficiency problems.
Innovation Solution
A shooting bow design with pulleys that couples the power end of first and second cables to first and second cams and the control end back to first and second limbs, utilizing a string latch housing, bow riser, barrel, and cams with pulleys or semi-circular tracks to manage cable routing and tensioning, allowing for proper timing and reduced interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If cables are routed off-angle to avoid interference with arrow flight, then cable interference is reduced, but cable twisting and torque increase
Solution Approach 1:
The patent introduces pulleys as intermediary components that the cables pass through. These pulleys are positioned on the limb at the arrow rest location, serving as mediators that guide the cables in a straight line parallel to the limb. This intermediary mechanism allows the cables to maintain proper alignment and timing while avoiding interference with arrow flight, eliminating both cable interference and twisting issues simultaneously
2Stability of the object's composition
If cables are routed straight parallel to the limb, then cable timing and alignment improve, but cable interference with arrow flight increases
Solution Approach 1:
The patent relocates the cable routing from the traditional cam-based system to a new spatial dimension at the arrow rest location. By positioning pulleys at this specific location on the limb, the cables are redirected into a third spatial arrangement that is parallel to the limb and clear of the arrow flight path. This dimensional change allows straight cable routing without interference
3Stability of the object's composition
If four cables are used in a binary cam system, then cam timing control improves, but device complexity and assembly difficulty increase
Solution Approach 1:
The patent segments the cable system into two independent single-cable-per-limb configurations rather than using a four-cable binary cam system. Each limb has its own cable running independently from the cam to the pulley at the arrow rest. This segmentation simplifies the overall system complexity while maintaining proper cam timing control through the pulley mechanism
Solution Approach 2:
The patent extracts the cable routing function from the traditional cam-based system and relocates it to the arrow rest location with pulleys. This extraction removes the complexity of routing four cables through opposing cams and instead uses a simpler configuration where each cable runs independently through its own pulley, reducing assembly difficulty while maintaining timing control
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively addresses cable interference and twisting issues, enhancing the performance and assembly efficiency of archery bows by ensuring proper cable timing and routing, thereby improving the overall shooting experience.
Implementation Method 1
A first pulley is pivotally retained on a first side of the barrel. A second pulley is pivotally retained on a second side of the barrel.
Data Source
AI summary
A shooting bow includes pulleys, a string latch housing, bow riser, barrel, first limb, second limb, a first cam, and a second cam. The bow riser is enjoined with the barrel. The first and second limbs extend from the bow riser. The first and second cams are pivotally retained on the first and second limbs. A bowstring is retained by the first and second cams. A first pulley and a second pulley are retained on the barrel. Both cams have a string track and a cable track. One end of the string is coupled to the first cam and the other end is coupled to the second cam. As for both cables, one end is coupled to the first cam, the middle of the cable travels around a pulley or track, and the other end is coupled to the first limb, first cam axle or back to the cam.