Pivoting Handlebar Ground Speed Control for Walk-Behind Equipment
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Solution Overview
Problem
Existing walk-behind power equipment units, such as power mowers, lack efficient systems for varying ground speed based on operator input, leading to inconsistent performance across different terrains and walking speeds.
Innovation Solution
A power equipment unit with a handlebar that pivots in response to operator force, connected to a force sensor generating electrical signals to control an electric motor for variable ground speed, allowing precise adjustment of propulsion based on operator input.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual propulsion is used to vary ground speed, then operator control over speed is improved, but operator effort and inconsistency across terrains worsen
Solution Approach 1:
The patent replaces the mechanical manual propulsion system with an electric motor system. The electric motor automatically adjusts ground speed based on terrain conditions and operator inputs through electronic control, eliminating the need for manual physical effort while maintaining consistent and reliable speed control across varying terrains.
2Device complexity
If fixed ground speed is used, then mechanical simplicity is improved, but adaptability to different terrains and operator walking speeds worsens
Solution Approach 1:
The patent implements a dynamic ground speed control system where the electric motor's speed is continuously adjustable based on real-time conditions. The system responds to terrain variations and operator inputs by dynamically modifying propulsion speed, allowing the equipment to adapt to different terrains and operator walking speeds while maintaining reasonable system complexity through electronic control.
3Reliability
If automated ground speed control is implemented, then consistency and adaptability are improved, but system complexity worsens
Solution Approach 1:
The patent employs a feedback control system where sensors detect terrain conditions and operator inputs, and the controller adjusts the electric motor's ground speed accordingly. This feedback mechanism ensures consistent and reliable speed control while adapting to varying conditions, managing system complexity through intelligent electronic control rather than mechanical complexity.
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 seamless adaptation of ground speed to operator effort, enhancing maneuverability and efficiency across varying terrains without manual propulsion, improving user experience and operational control.
Implementation Method 1
a force sensor operatively connected to the handle tube and configured to contact the actuator such that the actuator, in response to pivotal motion of the handlebar about the handlebar pivot, imparts a force Fs to the force sensor, the force sensor configured to produce an electrical sensor signal corresponding to the force F
Data Source
AI summary
A walk-behind powered equipment unit (e.g., grounds care vehicle such as a power mower) having a ground speed control system. The system may include a handle formed by a handle tube having a proximal end attached to the housing, and a handlebar mounted to the handle tube at a handlebar pivot such that the handlebar may pivot about the handlebar pivot relative to the handle tube in response to a force F applied by the operator to the handlebar, e.g., when the operator walks in a forward direction. An actuator of the handlebar, in response to pivotal motion of the handlebar about the handlebar pivot, imparts a force Fs to a force sensor. The force sensor is configured to produce an electrical sensor signal corresponding to the force F and provide that signal to a propulsion motor.