# US 5,349,327 A · Monitor apparatus for a bed underlying water > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,349,327 A - Document ID: US5349327A - Status: Granted - Kind: A - Application number: 07/703,085 - Filed: 1991-05-20 - Granted: 1994-09-20 - Earliest claimed: 1990-05-30 - Assignees: Hydraulics Research Limited - Inventors: Colin B. Waters - Web page: https://patentgrep.com/patent/US5349327A ## CPC - G01P 5/04: using deflection of baffle-plates - E01D 19/02: Piers {(E01D19/005 takes precedence; towers for suspension bridges E01D19/14)}; Abutments (foundations E02D ){; Protecting same against drifting ice (against colliding vehicles E01F15/00)} - E02B 3/00: Engineering works in connection with control or use of streams, rivers, coasts, or other marine sites (barrages or weirs E02B7/00); Sealings or joints for engineering works in general - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) - E01D: CONSTRUCTION OF BRIDGES, {ELEVATED ROADWAYS} OR VIADUCTS; ASSEMBLY OF BRIDGES (bridges extending between terminal buildings and aircraft for embarking or disembarking passengers B64F1/305; {tracks for special kinds of railways E01B25/00; culverts E01F5/005}) - E02B: HYDRAULIC ENGINEERING (ship-lifting E02C; dredging E02F) ## Abstract A sensor is located in a bed underlying water. A downward array of sensors may be buried in the bed during normal flow conditions so as to be in a disabled mode. The sensor has an oscillatable arm (21) having a first end portion (22) for supporting the arm, and a second end portion (23) housing a sensor cell (25) e.g. an omni-directional mercury switch. The alarm signal may be indicative of risk of collapse of a hydraulic structure, e.g. the foundation of a bridge pier. ## Claims ### Claim 1 Monitor apparatus for a bed underlying water comprising one or more electrical sensors each assuming an enabled or a disabled mode of operation, depending upon the status of at least one physical condition of said bed, such that sufficient flow of water over said bed to induce scouring thereof will cause at least one of said one or more sensors to be in the enabled mode and to output an alarm signal in response to corresponding erosion of said bed, said one or more sensors being adapted to be in the disabled mode during normal flow conditions corresponding to insufficient flow of water over said bed to induce scouring thereof, circuitry means connected to said one or more sensors for receiving said alarm signal, and a support structure for said one or more sensors, and wherein said one or more sensors each comprise an arm oscillated by the flow of said water and having first and second end portions, each arm being supported at its first end portion by the support structure and the second end portion of each arm comprising at least one sensor cell. ### Claim 2 (depends on 1) Monitor apparatus claimed in claim 1, wherein said at least one sensor cell comprises at least one omni-directional tilt switch. ### Claim 3 (depends on 2) Monitor apparatus claimed in claim 2, wherein said at least one switch is an omni-directional mercury tilt switch. ### Claim 4 (depends on 1) The monitor apparatus as claimed in claim 1 wherein said first end portion of said arm extends in a generally horizontal direction, and said second end portion of said arm extends in a generally vertical direction and supports said at least one sensor cell. ### Claim 5 (depends on 1) Monitor apparatus as claimed in claim 1, wherein said circuitry means connected to said one or more sensors comprises at least one output terminal from each of said one or more sensors, said at least one output terminal from each of said one or more sensors and a portable alarm indicator being in signal communicating relationship with each other. ### Claim 6 A method of monitoring and determining when risk of collapse of a hydraulic structure exists with the aid of a sensor which comprises the steps of mounting the sensor in a body having an end pointing upwardly when the body is in water toward the surface of the water, arranging said sensor and body in a bed underlying water so that when the bed is scoured, the body becomes exposed to water and thereby oscillates whereby corresponding oscillations of said sensor occur and responding to the oscillations of said sensor so as to provide at least one alarm signal indicative of existence of said risk. ### Claim 7 A sensor arrangement for monitoring the condition of a bed underlying water comprising an arm oscillated by the flow of water and having first and second end portions, the arm being supported at its first end portion, and the second end portion comprising at least one sensor cell, said at least one sensor cell comprising at least one omni-directional switch. ### Claim 8 (depends on 7) A sensor arrangement as claimed in claim 7 wherein said at least one switch is an omni-directional mercury tilt switch.