Crossbow Crank One-Way Mechanism and Release Lever
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Solution Overview
Problem
Crossbows often require high draw weights, making them difficult to cock manually, and existing cocking devices may not provide safe and reliable assistance.
Innovation Solution
A crossbow crank with a housing and a shaft that includes a one-way mechanism to allow rotation in one direction while preventing it in the other, along with a release mechanism and a biasing member to facilitate easy engagement and disengagement, providing a mechanical advantage for cocking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a one-way mechanism is used to prevent rotation in one direction, then the reliability of the cocking mechanism is improved, but the device complexity increases
Solution Approach 1:
A release mechanism acts as an intermediary component between the one-way mechanism and the shaft. This release mechanism includes a release lever that can pivot between positions to engage or disengage the one-way mechanism, allowing controlled rotation while maintaining reliability through the intermediary engagement/disengagement action.
Solution Approach 2:
The release mechanism introduces dynamic behavior to the system by allowing the one-way mechanism to be selectively engaged or disengaged through the pivoting release lever. This dynamic control enables the mechanism to transition between locked and unlocked states, improving reliability while managing complexity through controlled movement.
2Ease of operation
If a release mechanism is added to disengage the one-way mechanism, then the ease of operation is improved, but the device complexity increases
Solution Approach 1:
The release lever pivots dynamically between engaged and disengaged positions, allowing the user to easily control the engagement state of the one-way mechanism. This dynamic pivoting action simplifies operation while the added component increases complexity, which is acceptable given the improved ease of operation.
Solution Approach 2:
The release mechanism serves as an intermediary between the user's input and the one-way mechanism, providing a user-friendly interface for engaging and disengaging the cocking function. This intermediary layer improves ease of operation by translating simple user actions into controlled mechanism engagement.
3Ease of operation
If a biasing member is used to bias the release mechanism, then the ease of operation is improved, but the device complexity increases
Solution Approach 1:
The biasing member provides self-service functionality by automatically returning the release lever to its engaged position after disengagement. This automatic return action eliminates the need for manual resetting, improving ease of operation while the added spring component increases device complexity, which is acceptable given the automated functionality.
4Ease of operation
If a crank arm with quick release mechanism is used, then the ease of operation is improved, but the device complexity increases
Solution Approach 1:
The quick release mechanism on the crank arm introduces dynamic engagement and disengagement capability, allowing the crank arm to be quickly attached and detached from the shaft. This dynamic feature improves ease of operation for setup and adjustment while the additional mechanism increases device complexity, which is acceptable given the improved operational flexibility.
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 crossbow crank reduces the effort required to cock a crossbow by allowing rotation in one direction while preventing it in the other, enhancing safety and reliability through a secure engagement mechanism.
Implementation Method 1
A one-way mechanism is arranged to prevent rotation of the shaft in a first rotational direction, but allow rotation in a second direction
Implementation Method 2
a biasing member is arranged to bias the release mechanism to its first position
Data Source
AI summary
In some embodiments, a crossbow crank comprises a housing and a shaft rotatable with respect to the housing. A one-way mechanism is arranged to prevent rotation of the shaft in a first rotational direction, but allow rotation in a second direction. A release mechanism is arranged to disengage the one-way mechanism from the shaft. The release mechanism has a first position and a second position, wherein the release mechanism moves along a length of the shaft between the first position and the second position.