Pruning Shears Locking Mechanism for Ergonomic Blade Positioning
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Solution Overview
Problem
Existing pruning shears face issues with exposed return springs prone to damage and ergonomic discomfort, particularly for users with small hands, due to fixed maximum opening and constant pressure requirements for cutting slender elements of varying sizes.
Innovation Solution
The design incorporates temporary locking means between the blades and handles in intermediate positions, protecting the return mechanism from dust and water and enhancing ergonomics by allowing adjustable positions for comfortable use, including a flexible finger cooperating with stop elements and a slider for translational movement, ensuring the return mechanism is not exposed and allowing for comfortable grip and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the return spring is exposed to facilitate blade movement, then the blade operation is smooth, but the spring is vulnerable to damage, dust, and water
Solution Approach 1:
The return spring is nested inside the handle structure, specifically within a cavity formed by the first and second handle parts. This nesting protects the spring from external damage, dust, and water while still allowing it to function for returning the blades to the open position.
2Adaptability or versatility
If the maximum opening between blades is increased to cut larger elements, then the cutting capacity is improved, but users with small hands experience ergonomic discomfort due to constant pressure requirement
Solution Approach 1:
The locking mechanism introduces dynamic adjustability to the handle position. Users can lock the handles at different opening positions (fully open, intermediate, or closed) depending on the size of the element being cut. This eliminates the need for users with small hands to constantly exert pressure to maintain an intermediate position, improving ergonomic comfort while preserving cutting capacity for various element sizes.
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 solution protects the return mechanism from damage and provides improved ergonomics for users, allowing secure cutting of slender elements of various diameters without constant pressure, enhancing usability and reducing strain for users with small hands.
Implementation Method 1
a return member, generally in the form of a spring, which tends to spread the blades towards the maximum open position
Implementation Method 2
a flexible finger capable of cooperating with first stop elements provided on the first blade or handle
Data Source
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AI summary
A cutting tool, of the pruning shears type, equipped with two sharp-edged blades pivoted for rotation about a common axis, each blade extended by a handle so that the tool can be gripped with one hand, comprising means for temporarily locking the blades and corresponding handles in an intermediate position between the fully open position and the closed position where the cutting edges of the blades are in contact or partially overlapping. These temporary locking means comprise a locking element mounted on one of the two blades (or a first handle), movable according to the rotation of the second blade, and one end of which is provided with a flexible finger adapted to cooperate with first stop elements on the first blade or handle, each first stop element corresponding to one of the opening positions: respectively, maximum, intermediate, and closed.