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US 5,856,644 AGranted
Drape sensor
OwnerLester E. Burgessinventor
Life of this patent
Estimating the term…
Abstract
A freely hanging drape sensor distinguishing between weak and strong activation of the sensor includes a piezoresistive cellular material and standoff layer for providing an analog signal correlated with the strength of an activating force, as well as an on-off function. The drape sensor can be used in conjunction with moving objects, such as electrically operated doors to provide safety door edges. Alternatively, the drape sensor can be used as freely hanging curtains to detect objects moving into contact therewith.
Claims23
In combination:
- a) a door having an edge;
- and
- b) attached to the door edge and depending therefrom, a freely and flaccidly hanging pressure actuated switching device which includes
- first and second conductive layers,
- a layer of compressible and conductive piezoresistive material for making electrical contact between first and second conductive layers, and
- at least one insulative spacer means for spacing apart said piezoresistive material and said second conductive layer, said spacer means having open spaces to permit passage therethrough of at least a portion of the piezoresistive material,
- wherein in response to a predetermined amount of force applied thereto at least some of said piezoresistive material disposes itself through at least some of said open spaces to make electrical contact with said second conductive layer.
4 more elements
A method for sensing the movement of bodies through a passageway, comprising:
- a) providing at least one sensor, said sensor including,
- first and second conductive layers,
- a layer of compressible piezoresistive material for making electrical contact between the first and second conductive layers, and
- at least one insulative spacer means for spacing apart said piezoresistive material and said second conductive layer, said spacer means having open spaces to permit passage therethrough of at least a portion of the piezoresistive material,
- wherein in response to a predetermined amount of actuation force applied thereto said piezoresistive material disposes itself through at least some of said open spaces to make electrical contact with said second conductive layer, and
- wherein each sensor is connected to an electric power source such that a signal is generated when said piezoresistive material makes contact with said second conductive layer, said signal indicating the magnitude of the actuation force;
- b) positioning said at least one sensor within said passageway such that said sensor freely and flaccidly hangs from a support;
- c) conducting said signal to analyzer means.
5 more elements
Dependencies are inferred from the claim text.