Detection system for power equipment
AssigneeSd3, LLC
InventorsStephen F. Gass, J. David Fulmer
Life of this patent
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Abstract
A machine is disclosed having a detection subsystem adapted to detect contact between a person and a specified portion of the machine, and to distinguish that contact from contact with other materials. The detection subsystem imparts an electrical signal to a specified portion of the machine, and distinguishes that contact based on a predetermined frequency response of the electrical signal. A reaction subsystem then causes a predetermined action to take place. The machine may be a power saw designed to minimize injury in the event a person accidentally contacts the blade.
Claims20
For use with a woodworking machine having an operative portion configured to work by contacting items, a method of detecting contact between the operative portion and a portion of a human body, the method comprising:
- imparting an electrical signal including multiple frequency components onto the operative portion of the machine;
- monitoring the frequency response of the electrical signal by detecting changes in the electrical signal as a function of frequency when the operative portion contacts items;
- and
- if the operative portion of the machine contacts an item that causes the frequency response of the electrical signal to have predetermined characteristics at multiple frequency components indicative of contact between the operative portion and the portion of a human body, then designating the contact as contact with the portion of a human body.
A method of triggering an action to protect a user of a woodworking machine from accidental contact with a specified portion of the machine, the method comprising:
- imparting an electrical signal onto the specified portion of the machine, where the electrical signal includes multiple frequencies components;
- monitoring the frequency response of the electrical signal by detecting changes in one or more characteristics of the electrical signal as a function of frequency;
- and
- triggering the action when the frequency response indicates an unsafe condition between a human body and the specified portion of the machine.
For use with a woodworking machine having an operative portion configured to work by contacting items, a method of mitigating an unsafe condition between the operative portion and a portion of a human body, the method comprising:
- imparting an electrical signal including multiple frequency components onto the operative portion of the machine;
- monitoring the frequency response of the electrical signal by detecting changes in the electrical signal as a function of frequency when the operative portion is working;
- and
- if the frequency response of the electrical signal has predetermined characteristics at multiple frequency components indicative of an unsafe condition between the operative portion and the portion of a human body, then triggering an action to mitigate the unsafe condition.
Dependencies are inferred from the claim text.