Leakage sensor

Claim 2

An elongated capacitive sensing probe for sensing the presence of a liquid at any place along the length of the probe, comprising a flat cable having a length in excess of five feet made of first and second wires encased in an insulating material and supported substantially parallel to each other at a distance of greater than 1/2 inch by a plurality of spaced webs extending from the casing of one to the casing of the other such that over a substantial portion of the length of the cable there are open spaces between the encased wires, the wires extending out of the casings at one end of the cable to permit attachment to a capacitive sensing device and insulated at the other end, whereby when a liquid is present between the open spaces over a length as small as in the range of 2 % a change in the capacitance will occur of magnitude sufficient to operate a sensing alarm.

Claim 3

The invention according to claim 1, wherein said casing and said webs are integral with each other.

Claim 4

The invention according to claim 2 wherein said casing and webs are made of a plastic material.

Claim 5

The invention according to claim 3 wherein said plurality of webs is formed by first encasing said first and second wires with a continuous web connecting them and selectively cutting away portions of said web to form a plurality of connecting webs with spaces between them.

Claim 6

The invention according to claim 2 wherein said plurality of webs are equally spaced along the length of said cable.

Claim 7

The invention according to claim 2, wherein saId sensing probe cable is placed on a floor to sense leakage of a fluid onto the floor and further including: a. a protective channel placed over said sensing probe cable; and b. a plurality of attaching means at spaced intervals for holding said channel and said cable to the floor and to hold said channel off said floor so that leakage may reach said cable.

Claim 8

The invention according to claim 6, wherein each of said attaching means comprise: a. first and second spacers placed on opposite sides of said cable with said channel resting on said spacers; b. a bracket placed over said channel and resting on said first and second spacers; and c. first and second securing removable means inserted through said bracket on each side and said first and second spacers into the floor to hold said bracket, said spacers and said channel in place.

Claim 9

The invention according to claim 7 wherein said first and second securing means comprise threaded drive studs.

Claim 10

The invention according to claim 7 and further including a strip of thin plastic extending between said first spacer and the floor, over said cable and between said second spacer and the floor holding said cable in place.

Claim 11

A liquid sensing system to provide an indication of the presence of a liquid on a floor comprising: a. means for sensing changes in capacitance and providing an output alarm when a predetermined change occurs; b. an elongated capacitive sensing probe having a length of at least five feet comprising first and second wires encased in a plastic insulating material which further extends between the casing of one and the other at spaced intervals to maintain said wires substantially parallel to each other and separated by at least 1/2 inch thereby forming a flat cable with spaced open areas between the encased wires, said wires extending from the casings at one end and coupled to the said sensing means; and c. means to hold said flat cable substantially flat on the floor whereby liquid leakage will enter at least some of the open spaces in said cable to change its capacitance which will be sensed by said sensing means thereby resulting in an alarm indicating the leakage.

Claim 12

A liquid sensing system to provide an indication of the presence of a liquid on a floor comprising: a. means for sensing changes in capacitance and providing an output alarm when a predetermined change occurs; b. an elongated capacitive sensing probe having a length of at least five feet comprising first and second wires encased in a plastic insulating material which further extends between the casing of one and the other at spaced intervals to maintain said wires substantially parallel to each other and separated by at least 1/2 inch thereby forming a flat cable with spaced open areas between the encased wires, said wires extending from the casings at one end and coupled to the said sensing means; and c. means to hold said flat cable substantially flat on the floor whereby liquid leakage will enter at least some of the open spaces in said cable to change its capacitance which will be sensed by said sensing means thereby resulting in an alarm indicating the leakage.

Claim 13

The invention according to claim 10 wherein said system is placed on the sub floor under a raised floor on which electronic equipment is installed with the cables between portions of said equipment resting on the sub floor.

Claim 14

The invention according to claim 10 wherein said output alarm comprises: a. an aural output means; b. a visual output means; and c. means to reset said aural output means with said visual means remaining on until the sensing probe is dry.