Bridge failure alarm

• US 5,479,150 A
• Filed: 05/02/1994
• Issued: 12/26/1995
• Est. Priority Date: 05/02/1994
• Status: Expired due to Fees

• Current Assignee: Douglas L. Schmidt, Robert A. Schmidt
• Original Assignee: Douglas L. Schmidt, Robert A. Schmidt
• Inventors: Schmidt, Robert A., Schmidt, Douglas L.
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): Lee, Benjamin C.
• Application Number:
  US08/235,892
• Time in Patent Office: 603 Days
• Field of Search: 340/540, 340/686, 340/652, 340/533, 340/568, 250/13, 250/227.14, 250/227.15, 250/227.17, 370/540, 385/13, 200/61.49, 116/215, 367/105, 367/112, 367/113
• US Class Current: 340/540
• CPC Class Codes: G08B 21/10 responsive to calamitous events, e.g. tornados or earthquakes

Abstract

A bridge failure alarm system designed to be used with bridges has a plurality of spans across the length of the bridge, activates an alarm whenever the distance between any two adjacent spans is greater than a predetermined safe distance. This is accomplished by providing a conduction path extending from one end of the bridge along a first side of the bridge to the other end of the bridge and then back to the first end of the bridge by a conduction path located on the other side of the bridge. Between every expansion joint located between each adjacent span of the bridge are two jumpers to provide electrical connection across the expansion joints, one jumper located on each side of the bridge proximate to each expansion joint. In this manner, should any one of the expansion joints exceed a predetermined width placing two adjacent spans at a distance greater than the predetermined safe distance, at least one of the jumpers located therebetween will break the conduction path causing the alarm to be activated.

Claims

1. A bridge failure alarm system for producing an alarm signal to alert a user about to cross a bridge having a plurality of spans thereacross, that it is unsafe to cross in the event that an expansion joint space between any two adjacent spans of said bridge is greater than a predetermined safe distance, comprising:

a conduction loop including a pair of conducting wires separately running along opposite sides of each span of the bridge;

means for determining if an expansion joint space between two adjacent spans of said bridge is greater than said predetermined safe distance by breakage of at least one of the conducting wires; and

means for generating said alarm signal in the event that said expansion joint space between any two adjacent spans of the bridge is greater than said predetermined safe distance as determined by said means for determining.

2. A bridge failure alarm system as claimed in claim 1, wherein each one of said plurality of spans include two corners at a front end thereof and two corners at a back end thereof with two sides, each span extending from one of the front corners to one of the back corners;

and further, wherein one of said pair of conducting wires extends from one of said front corners to one of said back corners and the other one of said pair of conducting wires extends from an opposite one of said front corners to an opposite one of said back corners.

3. A bridge failure alarm system for producing an alarm signal to alert a user about to cross a bridge having a plurality of spans thereacross, that it is unsafe to cross in the event that an expansion joint space between any two adjacent spans of said bridge is greater than a predetermined safe distance, comprising:

means for determining if an expansion joint space between two adjacent spans of said bridge is greater than said predetermined safe distance;

each one of said plurality of spans includes a pair of conducting wires which separately run along opposite sides of each span;

each one of said plurality of spans includes two corners at a front end thereof and two corners at a back end thereof with two sides, each span extending from one of the front corners to one of the back corners; and

further, wherein one of said pair of conducting wires extends from one of said front corners to one of said back corners and the other one of said pair of conducting wires extends from an opposite one of said front corners to an opposite one of said back corners;

a plurality of conduits having a first end and a second end, said plurality of conduits attached to both a first side of the bridge and a second side of the bridge, each span having one conduit attached thereto located on the first side of the bridge and one conduit attached thereto located on the second side of the bridge;

a conducting wire including said pairs of conducting wires extending through each conduit from the front end of the bridge along the first side thereof to the back end of the bridge along the first side thereof, and along the back end thereof from the first side thereof to the second side thereof, and from the back end of the bridge along the second side thereof back to the front end of the bridge along the second side thereof;

jumper arrangements located along both the first and second sides of the bridge proximate each expansion joint thereof for maintaining a conduction path across each expansion joint; and

means for generating said alarm signal in that said expansion joint space between any two adjacent spans of the bridge is greater than said predetermined safe distance as determined by said means for determining.

4. The bridge failure alarm system for producing an alarm signal to alert a user about to cross a bridge having a plurality of spans thereacross, that it is unsafe to cross in the event that an expansion joint space between any two adjacent spans of said bridge is greater than a predetermined safe distance, comprising:

means for determining if an expansion joint space between two adjacent spans of said bridge is greater than said predetermined safe distance;

each one of said plurality of spans includes a pair of conducting wires which separately run along opposite sides of each span;

each one of said plurality of spans includes two corners at a front end thereof and two corners at a back end thereof with two sides, each span extending from one of the front corners to one of the back corners; and

further, wherein one of said pair of conducting wires extends from one of said front corners to one of said back corners and the other one of said pair of conducting wires extends from an opposite one of said front corners to an opposite one of said back corners;

a plurality of conduits having a first end and a second end, said plurality of conduits attached to both a first side of the bridge and a second side of the bridge, each span having one conduit attached thereto located on the first side of the bridge and one conduit attached thereto located on the second side of the bridge;

a conducting wire including said pairs of conducting wires extending through each conduit from the front end of the bridge along the first side thereof to the back end of the bridge along the first side thereof, and along the back end thereof from the first side thereof to the second side thereof, and from the back end of the bridge along the second side thereof back to the front end of the bridge along the second side thereof;

jumper arrangements located along both the first and second sides of the bridge proximate each expansion joint thereof for maintaining a conduction path across each expansion joint;

a pair of pins extending out from said each one of said adjacent spans proximate said expansion joint in closest proximity to one jumper arrangement;

means for clamping said conducting wire to each of said pair of pins;

a slip connector arrangement located on said conducting wire between said pair of pins; and

means for generating said alarm signal in the event that said expansion joint space between any two adjacent spans of the bridge is greater than said predetermined safe distance as determined by said means for determining.