Sewer drain alarm unit

Claim 2

An alarm unit for use in a sewer drain of a dwelling or the like comprising a solid walled plug having integral male pipe threads thereon adapted for fitting the female threads on an access opening to a low level pipe in said drain, a pivotal arm attached beneath said solid wall on the side toward said access opening, a float for sensing a rise in fluid level at said access opening, means for hanging said float from said arm at a predetermined level relative to said drain pipe with the arm in one pivotal position, means for biasing said arm toward another pivotal position in the absence of the weight of said float, and means for actuating an alarm when said arm goes to said other pivotal position comprising magnetic means attached to said arm, and proximity switch means actuated by said magnetic means.

Claim 3

An alarm unit according to claim 1, wherein at least part of said solid wall adjacent to said proximity switch being nonmagnetic material in order to pass the magnetic field from said magnetic means therethrough.

Claim 4

An alarm unit according to claim 2, wherein said float hanging means comprises a flexible stretch-free line.

Claim 5

An alarm unit according to claim 3, wherein said arm-biasing means comprises a counterweight.

Claim 6

An alarm unit according to claim 5, further comprising pipe extension means for providing a vertical chamber to contain said hanging float.

Claim 7

An alarm unit according to claim 4, further comprising a pair of integral lugs on said solid wall and a pivot pin for supporting said pivotal arm.

Claim 8

An alarm unit according to claim 4 wherein said flexible line comprises a corrosion proof chain.

Claim 9

An alarm unit according to claim 4, wherein said magnetic means comprises a permanent magnet, and said proximity switch means comprises a magnetic type reed switch.

Claim 10

An alarm unit for use in a sewer drain of a dwelling or the like, comprising a solid walled plug having integral male pipe threads thereon adapted for fitting the female threads on an access opening to a low level pipe in said drain, said solid wall being nonmagnetic to permit passage of a magnetic field therethrough, a pair of lugs integral with said solid wall and protruding therefrom on the side toward said access opening when the plug is mounted therein, a corrosion proof pivot pin extending between said lugs, an angled arm mounted on said pivot pin for free pivotal movement between two extreme positions one for each end of said arm being in contact with said solid wall, a spherical float for sensing a rise in fluid level in said sewer drain adjacent to said low level drain pipe, a corrosion proof chain for hanging said float from one end of said angled arm, a permanent magnet attached to said one end of said angled arm on the side toward said solid wall, a counterweight attached to the other end of said angled arm for biasing said arm into the extreme position with said permanent magnet in contact with said solid wall, said spherical float being heavy enough to hold said angled arm in the other extreme position when hanging free, a recess in the outside surface of said solid wall adjacent to the location where said permanent magnet contacts the other side thereof, a magnetic type reed switch mounted in said recess for being actuated when said permanent magnet contacts said solid wall, and electrical circuit connections for connecting said switch into an alarm circuit.

Claim 11

An alarm unit for use in a sewer drain of a dwelling or the like, comprising a solid walled plug having integral male pipe threads thereon adapted for fitting the female threads on an access opening to a low level pipe in said drain, said solid wall being nonmagnetic to permit passage of a magnetic field therethrough, a pair of lugs integral with said solid wall and protruding therefrom on the side toward said access opening when the plug is mounted therein, a corrosion proof pivot pin extending between said lugs, an angled arm mounted on said pivot pin for free pivotal movement between two extreme positions one for each end of said arm being in contact with said solid wall, a spherical float for sensing a rise in fluid level in said sewer drain adjacent to said low level drain pipe, a corrosion proof chain for hanging said float from one end of said angled arm, a permanent magnet attached to said one end of said angled arm on the side toward said solid wall, a counterweight attached to the other end of said angled arm for biasing said arm into the extreme position with said permanent magnet in contact with said solid wall, said spherical float being heavy enough to hold said angled arm in the other extreme position when hanging free, a recess in the outside surface of said solid wall adjacent to the location where said permanent magnet contacts the other side thereof, a magnetic type reed switch mounted in said recess for being actuated when said permanent magnet contacts said solid wall, and electrical circuit connections for connecting said switch into an alarm circuit.

Claim 12

A sewer drain back-up warning unit, comprising in combination a pipe threaded cap for replacing the plug of an access opening into said sewer drain, said cap having a solid wall for maintaining said access opening plugged, an angled arm pivotally mounted on the inside of said solid wall for free pivotal movement between two positions limited by said wall, a float hung from one end of said arm by a flexible chain having a predetermined length, a magnet carried by said float end of said arm, said solid wall being nonmagnetic at least in the vicinity of said magnet, a counterweight on the other end of said arm for biasing the arm into said position with the magnet adjacent to said wall when the weight of said float is removed, and magnetic switch means adapted for actuation by said magnet when said arm is in said biased position.

Claim 13

A sewer drain back-up warning unit, comprising in combination a pipe threaded cap for replacing the plug of an access opening into said sewer drain, said cap having a solid wall for maintaining said access opening plugged, an angled arm pivotally mounted on the inside of said solid wall for free pivotal movement between two positions limited by said wall, a float hung from one end of said arm by a flexible chain having a predetermined length, a magnet carried by said float end of said arm, said solid wall being nonmagnetic at least in the vicinity of said magnet, a counterweight on the other end of said arm for biasing the arm into said position with the magnet adjacent to said wall when the weight of said float is removed, and magnetic switch means adapted for actuation by said magnet when said arm is in said biased position.