Propulsion Lockout Mechanism for Walk-Behind Mower Control
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Solution Overview
Problem
Existing walk-behind mowers lack a simple and effective mechanism to restrict propulsion, leading to unnecessary energy consumption and difficulty in manual operation when navigating obstacles or steep slopes.
Innovation Solution
A control system incorporating a handle assembly with a speed control apparatus and a lockout apparatus that allows the operator to selectively restrict the movement of the control grip, enabling the mower to be manually pushed without propulsion assistance and conserving energy by disengaging the prime mover.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the propulsion system is engaged to assist manual operation, then the mower can navigate challenging terrain more easily, but energy is consumed unnecessarily and rolling resistance increases
Solution Approach 1:
The lockout apparatus is activated before manual operation begins, preventing the propulsion system from engaging accidentally. This preliminary action ensures the mower remains in manual-only mode, eliminating unnecessary energy consumption while maintaining ease of operation during tasks like navigating obstacles or steep slopes
2Productivity
If the control grip is always free to move, then the propulsion system can be activated quickly when needed, but accidental activation occurs making manual operation difficult
Solution Approach 1:
The control grip transitions from a locked state during manual operation to an unlocked state when the lockout apparatus is deactivated. This dynamic state change allows the system to adapt between manual-only mode (preventing accidental propulsion) and propulsion-ready mode (allowing quick activation), resolving the contradiction between quick activation and ease of manual pushing
3Loss of energy
If the lockout apparatus restricts control grip movement, then accidental propulsion is prevented and energy is conserved, but the ability to quickly activate propulsion is reduced
Solution Approach 1:
The lockout apparatus acts as an intermediary mechanism between the operator's intent and the propulsion system activation. When activated, it physically blocks the control grip from moving, preventing accidental propulsion and conserving energy. When deactivated, it allows full control grip movement, enabling quick propulsion activation. This intermediary device resolves the contradiction by providing conditional control based on operational needs
Data Source
AI summary
A control system for a ground working vehicle. The control system may include a handle assembly including a handle member extending upwardly and rearwardly from a chassis of the vehicle. The control system may also include a speed control apparatus including a control grip operably connected to, and translatable along, the handle member. Translation of the control grip may activate a transmission to move the chassis in the forward direction when the control grip is translated downwardly along the handle member towards the chassis. Further, the control system may include a lockout apparatus movably attached to a handle member. The lockout apparatus may be adapted to selectively and physically restrict movement of the control grip relative to the handle member.