Lawn Mower Deck Lifting Assembly with Spring Biasing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lawn mower deck lifting mechanisms require high forces at the extremes of motion and lack consistency throughout the range, making them inefficient and difficult to operate.
Innovation Solution
A deck lifting assembly with pivotable lifting brackets and biasing members, such as linear springs, that apply torque to assist in raising and lowering the deck, along with a preload adjustment mechanism to optimize force distribution, ensuring a substantially constant pedal force is required throughout the motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional deck lifting mechanisms are used, then the deck can be raised and lowered, but high forces are required at the extremes of motion and force consistency is poor throughout the range
Solution Approach 1:
The patent applies dynamics by making the lifting mechanism adaptable through adjustable biasing forces. The biasing members (springs) can be adjusted to change the force characteristics throughout the range of motion, allowing the system to optimize pedal force consistency dynamically rather than being fixed. This enables the mechanism to maintain more uniform force requirements from fully raised to fully lowered positions.
Solution Approach 2:
The patent changes physical parameters by adjusting the biasing force of the springs and the geometry of the lifting brackets. By modifying spring preload and bracket pivot points, the force distribution throughout the range of motion can be optimized. This parameter adjustment allows the system to achieve substantially constant pedal force across different deck positions, resolving the force consistency issue.
2Ease of operation
If biasing members are added to apply torque to lifting brackets, then operator effort is reduced, but device complexity increases
Solution Approach 1:
The biasing members (springs) are configured to automatically provide assistive torque throughout the deck's range of motion without requiring external power sources or complex control systems. The springs self-generate the necessary force based on their preloading and the mechanical geometry, reducing operator effort while maintaining a relatively simple mechanical structure. The inclusion of a preload adjustment mechanism allows operators to customize the assistive force without adding complexity.
3Productivity
If multiple lifting brackets are used to improve force distribution, then lifting performance is enhanced, but structural complexity increases
Solution Approach 1:
The lifting system is segmented into multiple independent lifting brackets (typically three), each equipped with its own biasing member. This segmentation allows the total lifting task to be distributed across multiple points, improving force distribution and lifting performance. Each bracket operates semi-independently, providing redundant support and better mechanical advantage while keeping individual component complexity low. The modular nature of segmented brackets makes the system more manageable despite having multiple components.
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 solution provides a consistent and efficient deck lifting mechanism with minimal variation in pedal force, ensuring easy operation and reduced operator effort across the entire range of motion, with the minimum force being greater than 75% of the maximum force.
Implementation Method 1
the biasing member includes a linear spring; and wherein a first end of the linear spring is interconnected to the first lifting bracket and a second end of the linear spring is interconnected to the second lifting bracket
Implementation Method 2
rotation of the first lifting bracket in its raising direction and rotation of the second lifting bracket in its raising direction causes extension of the linear spring and an increase in the biasing force
Data Source
AI summary
A deck lifting assembly for a lawn mower includes first and second lifting brackets and a biasing member interconnecting the first and second lifting brackets or to biasing brackets separate from the lifting brackets. The biasing member imparts a biasing force on each of the lifting brackets or biasing brackets to cause each lifting bracket to rotate in a direction that raises the mower deck.