Asymmetric Torsion Spring Snowshoe Binding
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Solution Overview
Problem
Snowshoes with spring-loaded suspension systems often experience the 'snow-flip' phenomenon, where the snowshoe deck lifts and flips snow onto the user's legs, particularly for users with specific gaits, due to the pre-loading bias towards a neutral position, which previous adjustments to bias angle or spring tension only partially mitigate.
Innovation Solution
A suspension system that pre-loads the snowshoe tail towards a prescribed angle but allows free rotation of the binding when pitched forward beyond the neutral position, eliminating torsional biasing forces during extreme pitch, thereby preventing the snowshoe tail from flipping upward at toe-off, using a support frame with a horizontal pivot connection and optional rotation limiting features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the spring-loaded suspension system pre-loads the snowshoe tail towards a neutral position, then the snowshoe maintains stability and prevents catching on snow, but it causes the snow-flip phenomenon where the deck lifts and flips snow onto the user's legs
Solution Approach 1:
The patent changes the parameter of torsional biasing force by providing an asymmetric torsion spring that applies different amounts of biasing force in different directions. The spring is configured to apply less biasing force when the deck rotates in the upward direction (preventing snow-flip) while maintaining sufficient biasing force when the deck rotates downward (maintaining stability). This selective parameter change resolves the contradiction between stability and snow-flip prevention.
Solution Approach 2:
The patent makes the torsional biasing force dynamic rather than static by using an asymmetric torsion spring that automatically adjusts the amount of biasing force based on the direction and magnitude of deck rotation. The spring's asymmetric winding allows it to be softer in one direction and stiffer in the other, creating a dynamic response that adapts to the user's gait and terrain conditions, thereby eliminating snow-flip while maintaining stability.
2Object-generated harmful factors
If the bias angle is adjusted to a very high pitch angle to reduce snow-flip, then the snow-flip effect is reduced, but the spring tension loading increases and the snowshoe hangs vertically from the binding
Solution Approach 1:
Instead of changing the bias angle parameter to reduce snow-flip, the patent changes the parameter of torsional stiffness distribution by using an asymmetric torsion spring. This allows the neutral position to remain at an optimal angle while the spring provides differentiated resistance: lighter resistance for upward rotation (preventing snow-flip without excessive tension) and heavier resistance for downward rotation (maintaining stability). This resolves the contradiction by addressing snow-flip through asymmetric force distribution rather than angle adjustment.
3Object-generated harmful factors
If the spring tension is reduced to eliminate snow-flip, then the snow-flip effect is reduced, but the snowshoe loses its ability to return to neutral position and maintain stability
Solution Approach 1:
The patent changes the parameter of torsional biasing force from a uniform value to a direction-dependent value using an asymmetric torsion spring. The spring is wound asymmetrically so that it provides lighter biasing force (reducing snow-flip) in the upward rotation direction while maintaining stronger biasing force (ensuring stability) in the downward rotation direction. This selective parameter modification resolves the contradiction by allowing reduced tension only where needed to prevent snow-flip, while maintaining sufficient tension for overall stability.
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
This design effectively eliminates the snow-flip effect by allowing the snowshoe tail to rest against the terrain during extreme pitch positions, maintaining the benefits of spring-loaded biasing while preventing unwanted snow lift, and providing flexibility in pitch range.
Implementation Method 1
a first asymmetric torsion spring connected between the binding and the snowshoe frame and configured to apply a first amount of torsional biasing force to the snowshoe deck when the snowshoe deck rotates in a first direction about a longitudinal axis of the snowshoe and a second amount of torsional biasing force to the snowshoe deck when the snowshoe deck rotates in a second direction about the longitudinal axis
Data Source
AI summary
A snowshoe has an improved spring-loaded suspension system that reduces or eliminates snow flip as the user lifts the boot and advances it forward. In a principal embodiment the footbed and front claw of the binding are positioned on a spring-suspended frame in such a way that the footbed/claw can freely rotate relative to the snowshoe deck beyond a certain degree of pitch angle.