Handle-Mounted Compliant Controls for Walk-Behind Mowers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing walk power mowers have complex and costly mechanical components such as pivots, bushings, and springs to mount operational controls on the handle, increasing complexity and cost.
Innovation Solution
The use of compliant mechanisms to mount traction drive and implement controls on the handle assembly, allowing for force and motion transmission through elastic body deformation, reducing the need for rigid pivots and mechanical springs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional mechanical components (pivots, bushings, springs) are used to mount operational controls on the handle, then reliable control pivoting is achieved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent replaces traditional mechanical pivot components (pivots, bushings, springs, fasteners) with a compliant mechanism that uses elastic deformation of a flexible printed circuit board to achieve the same pivoting motion. This substitution eliminates multiple discrete mechanical parts while maintaining the functional reliability of control movement, directly resolving the contradiction between reliability and complexity.
Solution Approach 2:
The invention changes the physical state and properties of the control mounting system by using a flexible printed circuit board with controlled elastic properties. The compliant mechanism utilizes the material's elasticity and flexibility parameters to enable pivoting motion, transforming the approach from rigid mechanical joints to elastic deformation-based motion, thereby reducing component count while maintaining functionality.
2Ease of operation
If traditional mechanical components are used to mount operational controls, then control functionality is achieved, but manufacturing cost increases
Solution Approach 1:
The patent merges multiple discrete mechanical components (pivots, bushings, springs, fasteners) into a single integrated flexible printed circuit board structure. This consolidation eliminates the need for assembly of multiple parts and reduces inventory requirements, directly lowering manufacturing costs while preserving full control functionality through the compliant mechanism's elastic deformation.
Solution Approach 2:
By replacing the traditional mechanical component assembly with a flexible printed circuit board-based compliant mechanism, the invention eliminates the costs associated with manufacturing, inventory, and assembly of multiple discrete mechanical parts. The flexible circuit board can be manufactured using standard PCB fabrication processes, significantly reducing overall manufacturing cost while maintaining ease of operation.
3Stability of the object's composition
If rigid pivots and mechanical springs are used, then control mounting is achieved, but the arc of movement is limited
Solution Approach 1:
The invention changes the mechanical properties of the mounting system by using a flexible printed circuit board with specific elastic moduli and thickness parameters. These parameter changes allow the compliant mechanism to achieve larger deformation ranges and consequently larger arcs of movement compared to rigid pivot systems, while maintaining mounting stability through the board's elastic recovery properties.
Solution Approach 2:
The patent employs a flexible printed circuit board as a thin, flexible structure that can elastically deform to accommodate control movement. This flexible film approach allows for greater movement arcs compared to rigid pivots, as the thin circuit board can bend and deform elastically through a wider range of motion while maintaining structural integrity and stable mounting of the control elements.
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
Simplifies the control mechanism, reducing costs and complexity while maintaining control functionality, and allowing for a larger throw or arc of movement for the controls.
Implementation Method 1
The at least one control acts through a compliant mechanism to effect control of the at least one of the traction drive or implement. The compliant mechanism allows for force and motion transmission through elastic body deformation.
Data Source
AI summary
An outdoor power equipment unit, such as a lawn mower, includes a frame movable over the ground. A handle assembly is provided on the frame to allow an operator to walk on the ground behind the handle assembly while operating the unit. A traction drive and a ground grooming or working implement are carried on the frame. A traction control hand grip and an implement control bail are carried on the handle assembly. Both the hand grip and the bail are movable relative to the handle assembly by flexure provided by first and send compliant mechanisms.