Pruning Shears Flat Spring Rounded Surface Friction
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Solution Overview
Problem
Existing pruning shears or secateurs experience noise and abrasion due to sliding friction between metal components, particularly the flat spring element and the second shear part, during cutting and opening operations.
Innovation Solution
The design incorporates a laminated or flat spring element with a rounded surface or curve on the second shear part to facilitate a rolling motion instead of sliding, minimizing friction, and includes a lubricant reservoir to reduce abrasion and noise further.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a flat spring element and second shear part are made of metal with sliding movement, then the shears can perform cutting operations, but noise and abrasion occur due to friction
Solution Approach 1:
The contacting surface of the second shear part is designed with a rounded surface or curve instead of a flat surface. This curvature enables the laminated spring element to roll rather than slide during shears operation, transforming sliding friction into rolling friction, which significantly reduces noise and abrasion while maintaining cutting functionality
Solution Approach 2:
The patent changes the physical state of the contacting surface by introducing a lubricant reservoir that supplies lubricant to the contact zone. This parameter change from dry to lubricated contact further reduces friction, preventing metal-to-metal direct contact and eliminating the harmful noise and abrasion effects
2Object-generated harmful factors
If a rounded surface is introduced to reduce friction, then noise and abrasion are minimized, but the device complexity increases
Solution Approach 1:
The lubricant reservoir is integrated directly into the second shear part structure, merging the lubrication system with the existing component. This combination approach adds the necessary lubrication function without requiring separate, complex lubrication mechanisms, thus minimizing the increase in device complexity while still achieving reduced friction
Solution Approach 2:
The lubricant reservoir is designed to automatically supply lubricant to the contact surface during shears operation. The system serves itself by utilizing the natural movement of the shears to distribute lubricant, eliminating the need for external lubrication mechanisms or manual intervention, thereby keeping the device complexity low
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 arrangement significantly reduces abrasion and noise by minimizing friction and ensuring consistent lubrication, enhancing the operational efficiency and longevity of the shears.
Implementation Method 1
the second shear part comprises a rounded surface or curve at a contacting area which constitutes the touching zone between the second shear part and the laminated or flat spring element... during the opening and closing movement of the shears at least partially a rolling motion of the rounded surface or curve of the second shear part on the laminated or flat spring element is executed
Implementation Method 2
the second shear part comprises a rounded surface or curve at a contacting area which constitutes the touching zone between the second shear part and the laminated or flat spring element
Data Source
Figure 1~3
Figure 4~5
Figure 6
AI summary
The invention relates to shears, in particular pruning shears or secateurs (1), comprising a first shear part (3) and a second shear part (3'). Each of the first and second shear parts (3,3') have a cutting blade (11, 11') and a shaft or lever arm (5, 5') which are arranged at opposite sides of a pivot (7) which rotatably connects the first and second shear parts (3, 3') with each other. The shears further comprise a laminated or flat spring element (27) acting upon the first and second shear parts (3, 3') to move the shears on to an open position. The laminated or flat spring element (27) comprises a first portion (27') fixedly arranged at or allocated to the first shear part (3) and a flexibly arranged second portion (27'') acting on the second shear part (3'). In order to provide a movement of the laminated or flat spring element (27) on a contacting surface at the second shear part (3') without or with only very low friction, thus avoiding occurrence of noise or abrasion, the second shear part (5') comprises a rounded surface or curve at a contraction area which constitutes the touching zone between the second shear part (5') and the laminated or flat spring element (27).