Quick Change Mower Blade Assembly with Spring-Loaded Retainer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing rotary mower blades on grass mowing machines are difficult to remove and install due to the need for high torque on center attachment bolts, which are hard to reach and require additional tools, making the process time-consuming and cumbersome.
Innovation Solution
A quick change rotary mower blade assembly featuring a spindle with a compression spring and a blade retainer with arms that locks the blade in place without requiring a wrench or socket, allowing for easy removal and installation from above the mower deck without applying high torque to the center bolt.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a center attachment bolt and washer assembly is used to secure the blade to the spindle assembly, then the blade can be securely attached, but the blade becomes difficult to remove and install due to limited accessibility and the need for high torque applications under the mower deck
Solution Approach 1:
The patent inverts the traditional bolt-securing mechanism by using a spring-loaded retainer system that locks the blade from above rather than requiring torque application to a bolt from below. The retainer engages with the blade shaft and uses spring force to maintain secure attachment, eliminating the need for high torque wrench operations under the deck.
Solution Approach 2:
The patent introduces a spring-loaded retainer as an intermediary mechanism between the blade and the spindle assembly. This retainer system mediates the connection by providing secure attachment through spring force and geometric locking, replacing the direct bolt-to-spindle connection that requires difficult torque application.
2Strength
If a wrench or socket is used to tighten the center attachment bolt, then the blade can be securely fastened, but additional tools and space are required that are not available in the limited ground clearance area
Solution Approach 1:
The patent extracts the need for external wrenching tools by integrating the securing mechanism directly into the blade assembly itself. The spring-loaded retainer is part of the blade unit, eliminating the separate wrench or socket tool that would be required with a traditional bolt system.
Solution Approach 2:
The blade assembly becomes self-sufficient with the integrated spring-loaded retainer that automatically engages and secures the blade to the spindle. The system serves itself by using spring force to maintain attachment without requiring external tools or additional space for tool manipulation.
3Productivity
If high torque is applied to break the bolt loose, then the blade can be removed, but additional leverage tools like levers or wood blocks are required to lock the blade in position
Solution Approach 1:
Instead of requiring external levers or blocks to provide counter-leverage for bolt removal, the patent inverts the approach by using the spring force itself to provide the necessary leverage for blade removal. The compressed spring automatically pushes the retainer off the blade shaft when upward force is applied, eliminating the need for additional leverage tools.
4Manufacturing precision
If the blade is locked tightly to prevent movement during torqueing, then proper torque can be applied, but the process becomes more complex requiring additional locking mechanisms
Solution Approach 1:
The spring-loaded retainer system is self-locking through its geometric design and spring force. The retainer arms engage with the blade shaft and the spring maintains constant pressure to prevent movement during operation, providing inherent stability without requiring separate locking mechanisms or complex procedures.
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
Enables quick and easy blade changes without the need for tools, reducing the effort and time required for maintenance, improving accessibility and safety by eliminating the need for high torque applications under the mower deck.
Implementation Method 1
a compression spring positioned in the internal bore... the spring exerting a force urging the shaft out so that the mower blade engages the pair of arms to lock the mower blade in the blade retainer
Data Source
AI summary
A quick change rotary mower blade assembly includes a mower blade attached to a blade assembly pin that is inserted into an internal bore in a spindle extending through a housing under the mower deck. A blade retainer on the lower end of the spindle has a pair of notches holding and locking the mower blade in place.