Fiber optic load sensing device
First Claim
1. A treadle sensing device for vehicular traffic adapted to be mounted transversely on a roadway and to receive and sense a downward load of the type imparted by a vehicle wheel comprisinga longitudinal elastomeric envelope having spaced apart longitudinal walls in a lengthwise region of said envelope adapted to receive said load;
- a portion of foam rubber embedded within said envelope;
a fiber optic cable supported by said foam rubber within said region of said elastomeric envelope and running generally perpendicular to the direction of the load to be applied substantially the length of said region, said fiber optic cable having a first end adapted to be connected to a signal source of light and a second end adapted to be connected to a receiver;
means permitting deformation of said fiber optic cable within said envelope when a transverse load of the type applied by a vehicle wheel is applied to said envelope sufficient to significantly alter the amount of light transmitted through said fiber optic cable; and
means for preventing complete compression of said foam rubber where said fiber optic cable rests against said foam rubber during application of said load when said device is mounted on a roadway.
2 Assignments
0 Petitions
Accused Products
Abstract
A transverse load sensitive optical treadle switch. The switch includes a deformable longitudinal housing and a fiber optic assembly positioned within the housing. The fiber optic assembly includes an optical fiber having a first end and a second end, the optical fiber being subject to bending upon application of a transverse load to said housing. Means for mounting the optical fiber in the housing so as to permit bending of the fiber in response to application of a transverse load to said housing are provided, the degree of bending being sufficient to cause a significant decrease in passage of light through said fiber when said fiber is bent. Means permitting introduction of light into said optical fiber at the first end of the optical fiber and means for permitting the exit of light from the second end are also provided.
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Citations
21 Claims
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1. A treadle sensing device for vehicular traffic adapted to be mounted transversely on a roadway and to receive and sense a downward load of the type imparted by a vehicle wheel comprising
a longitudinal elastomeric envelope having spaced apart longitudinal walls in a lengthwise region of said envelope adapted to receive said load; -
a portion of foam rubber embedded within said envelope; a fiber optic cable supported by said foam rubber within said region of said elastomeric envelope and running generally perpendicular to the direction of the load to be applied substantially the length of said region, said fiber optic cable having a first end adapted to be connected to a signal source of light and a second end adapted to be connected to a receiver; means permitting deformation of said fiber optic cable within said envelope when a transverse load of the type applied by a vehicle wheel is applied to said envelope sufficient to significantly alter the amount of light transmitted through said fiber optic cable; and means for preventing complete compression of said foam rubber where said fiber optic cable rests against said foam rubber during application of said load when said device is mounted on a roadway.
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2. A load sensing device adapted to be mounted transversely on a roadway and to receive downwardly applied loads of the type imparted by an automotive vehicle wheel comprising
a longitudinal envelope having spaced apart peripheral walls defining an interior space therebetween in a region of said envelope adapted to receive said load, said walls remaining substantially longitudinally parallel to one another substantially throughout the region of said envelope adapted to receive said load, at least one of said walls in said region having an elastically deformable portion having a first interior surface deflectable into said interior space towards an opposing second interior surface of one of said peripheral walls upon the application of said load to said envelope; -
a relatively soft compressible elastomeric insert embedded in said interior space of said envelope; a fiber optic cable longitudinally positioned within said interior space of said envelope and resting against said insert, said fiber optic cable comprising an optical fiber having a first end adapted to receive light and a second end adapted to permit the exit of said light, said fiber optic cable being subject to sufficent deformation into said insert upon deflection of said first interior surface caused by application of said load so as to permit localized bending of said optical fiber sufficient to substantially alter the light transmitted through the optical fiber; and means for preventing complete compression of said elastomeric insert where said fiber optic cable rests against said elastomeric insert during application of said load when said device is mounted on the surface of the roadway. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification