Liquid level sensor and alarm system

Apparatus for determining a liquid level condition of a liquid within a liquid holding tank, comprising:

• a float adapted to be positioned on a body of liquid within a liquid holding tank, including a first permanent magnet, one pole of which is directed upwardly;
• means defining a chamber partitioned in a fluid tight manner from the body of liquid;
• a second permanent magnet located within said chamber above and in line with said first permanent magnet;
• means forming a gas inlet port for said chamber and means forming a gas outlet port for said chamber;
• and
• a normally closed valve positioned above said second permanent magnet and within one of said ports and including a normally extended control member which is in line with said second permanent magnet, is depressible to open the valve, and projects into said chamber;
• wherein the float and the two magnets are so positioned that as the liquid level rises in the liquid holding tank the first permanent magnet is moved towards the second permanent magnet, and wherein the two permanent magnets have like poles facing towards each other, so that when the first permanent magnet is moved upwardly by the float a predetermined amount towards the second permanent magnet, by liquid being added to the liquid holding tank, the two magnets will tend to repel each other and in response the second magnet will be urged upwardly into contact with the valve control member, moving such valve control member into a valve opening position.

A liquid level sensor for use with a normally closed liquid holding tank having a top opening and a closure for such top opening which is connectable to the tank, said sensor comprising:

• a support tube which is connectable to the closure for the top opening in the liquid holding tank, to depend therefrom into the tank;
• a float adapted to float upon liquid in said liquid holding tank, said float carrying an upwardly directed first permanent magnet positioned within the lower portion of said support tube;
• transverse wall means within said support tube, completing a fluid tight closure above said first permanent magnet;
• a second permanent magnet positioned above said transverse wall means;
• a normally closed valve located within said support tube above said second permanent magnet, said valve including a normally extending control member which is depressible to open the valve, said control member being positioned above the second permanent magnet;
• and
• with said first and second permanent magnets being arranged to have like poles facing each other, and with the arrangement of the float and the two magnets being such that when the float is moved upwardly a predetermined amount by liquid being added to the liquid holding tank, the float will move the first permanent magnet towards the second permanent magnet, and a repelling force generated by the two magnets will cause the second permanent magnet to be lifted upwardly against the control member for the valve, depressing such control member to in that manner open the valve.

A liquid level sensor for use with a normally closed liquid holding tank having a top opening and a closure for such top opening which is connectable to the tank, comprising:

• a support tube having an upper section with an upper end which is connectable to the closure for the top opening in the liquid holding tank, to depend therefrom into the tank, and a lower end, and a lower section having an upper end connectable to the lower end of said upper section, and including a float cage at its lower end;
• a float within said float cage, adapted to float upon liquid within said liquid holding tank, said float including an upwardly projecting stem portion which is located within the lower section of said support tube;
• a first permanent magnet carried by the stem portion of said float;
• transverse wall means within said support tube completing a fluid tight closure above said first permanent magnet and also completing a chamber within said support tube above said transverse wall;
• a second permanent magnet located within said chamber;
• a normally closed valve located within said support tube above said second permanent magnet, said valve including a downwardly directed, normally extended control member which is depressible to open the valve, said control member being positioned above the second permanent magnet;
• and
• with said first and second permanent magnets being arranged to have like poles facing each other, and with the arrangement of the float and permanent magnets being such that when the float is moved upwardly a predetermined amount by liquid being added to the liquid holding tank the float will move the first permanent magnet towards the second permanent magnet, and the repelling force of the two permanent magnets will cause the second permanent magnet to be lifted upwardly against the control member for the valve, depressing such control member to in that manner open the valve.

Apparatus for signaling a full condition of a liquid holding tank, comprising:

• a supply of pressurized gas;
• a gas operated sound generator having an inlet for operating gas;
• first gas supplying conduit means extending from the supply of pressurized gas to said gas inlet, said first gas supplying conduit means including a normally closed valve means and gas pressure operated means for opening such valve means;
• second gas supplying conduit means extending from the supply of pressurized gas to said gas pressure operated means for opening said first valve means;
• second normally closed valve means in said second gas supplying conduit means including a downwardly directed, normally extended control member which when depressed will open said second valve means, to allow pressurized gas from the supply of pressurized gas to flow to the gas pressure operated means for opening the first valve means, to in turn allow pressurized gas to flow from the supply of pressurized gas to the sound generator, to operate the sound generator;
• and
• means for depressing said control member in response to the liquid holding tank becoming full, comprising:
• a float located within said liquid holding tank, said float carrying a first permanent magnet positioned below said second valve means;
• means defining a chamber between said first permanent magnet and said second normally closed valve means which includes a fluid tight lower wall;
• means defining an inlet port leading into said chamber and an outlet port leading out from said chamber, said second normally closed valve means being located within one of said ports, with its control member projecting into said chamber;
• and
• a second permanent magnet located within said chamber, said second permanent magnet being sized so that when it is on said lower wall the control member is extended, said first and second permanent magnets presenting like poles towards each other, so that each permanent magnet will tend to repel the other, said float and said two permanent magnets being arranged such that when the liquid level rises in the liquid holding tank to a predetermined level the first permanent magnet will be moved by the float towards the second permanent magnet and the repelling force of the two magnets will move the second magnet against the operating member, to depress such operating member to in that manner open the second valve means.

Apparatus for determining a low liquid level condition of a liquid holding tank, comprising:

• a float adapted to be positioned on a body of liquid within a liquid holding tank, including a first permanent magnet, one pole of which is directed downwardly;
• means defining a chamber partitioned in a fluid tight manner from the body of liquid;
• a second permanent magnet located within said chamber below and in line with said first permanent magnet;
• means forming a gas inlet port for said chamber and means forming a gas outlet port for said chamber;
• a normally closed valve positioned below said second permanent magnet and within one of said ports and including a normally extended control member which is in line with said second permanent magnet, is depressible to open the valve, and projects into said chamber;
• and
• means normally biasing said second magnet away from contact with said control member;
• wherein the float and the two magnets are so positioned that as the liquid level drops in the liquid holding tank the first permanent magnet is moved towards the second permanent magnet, and wherein the two permanent magnets have like poles facing towards each other, so that when the first permanent magnet moves downwardly with the float a predetermined amount towards the second permanent magnet, by liquid being removed from the liquid holding tank, the two magnets will tend to repel each other and in response the second magnet will be urged downwardly into contact with the valve control member in opposition to said biasing force, moving such valve control member into a valve opening position.

A liquid level sensor for use with a normally closed liquid holding tank having a bottom opening and a closure for such bottom opening which is connectable to the tank, said sensor comprising:

• a support tube which is connectable to the closure for the bottom opening in the liquid holding tank, to extend upwardly therefrom into the tank;
• a float adapted to float upon liquid in said liquid holding tank, said float carrying a downwardly directed first permanent magnet positioned within the upper portion of said support tube;
• transverse wall means within said support tube, completing a fluid tight closure below said first permanent magnet;
• a second permanent magnet positioned below said transverse wall means;
• a normally closed valve located within said support tube below said second permanent magnet and above the closure for said bottom opening, said valve including a normally extending control member which is depressible to open the valve, said control member being positioned below the second permanent magnet;
• and
• means normally biasing the second permanent magnet away from contact with said control member;
• with said fluid tight closure completed by said transverse wall means isolating the second permanent magnet and the normally closed valve in a fluid tight manner from the interior of the holding tank;
• and
• with said first and second permanent magnets being arranged to have like poles facing each other, and with the arrangement of the float and the two magnets being such that when the float moves downwardly a predetermined amount by liquid being removed from the liquid holding tank, the float will move the first permanent magnet towards the second permanent magnet, and a repelling force generated by the two magnets will cause the second permanent magnet to be forced downwardly against the control member for the valve, in opposition to the biasing force, depressing such control member to in that manner open the valve.

A liquid level sensor for use with a liquid holding tank, said sensor comprising:

• a support tube which is connectable to a bottom portion of the tank, to extend upwardly therefrom into the tank;
• a float adapted to float upon liquid in said liquid holding tank, said float carrying a downwardly directly first permanent magnet positioned within the upper portion of said support tube, and said float being located within a cage for said float, said cage being connected to the upper end of said support tube;
• transverse wall means within said support tube, completing a fluid tight closure below said first permanent magnet;
• a second permanent magnet positioned below said transverse wall means;
• a normally closed valve located within said support tube below said second permanent magnet, said valve including a normally extending control member which is depressible to open the valve, said control member being positioned below the second permanent magnet;
• wherein a chamber is formed within said support tube, below said transverse wall means and above said normally closed valve;
• means defining an inlet port leading into said chamber and an outlet port leading out from said chamber;
• and
• means normally biasing the second permanent magnet away from contact with said control member;
• with said first and second permanent magnets being arranged to have like poles facing each other, and with the arrangement of the float and the two magnets being such that when the float moves downwardly a predetermined amount by liquid being removed from the liquid holding tank, the float will move the first permanent magnet towards the second permanent magnet, and a repelling force generated by the two magnets will cause the second permanent magnet to be forced downwardly against the control member for the valve, in opposition to the biasing force, depressing such control member to in that manner open the valve;
• and
• wherein said valve is located within one of said ports, with its control member projecting into said chamber, and said second permanent magnet is located within said chamber.

A liquid level sensor for use with a liquid holding tank, comprising:

• a support tube having a lower section with a lower end which is connectable to a bottom portion of the liquid holding tank, to extend therefrom into the tank, and an upper end, and an upper section having a lower end connectable to the upper end of said lower section, and including a float cage at its upper end;
• a float within said float cage, adapted to float upon liquid within said liquid holding tank, said float including a downwardly projecting stem portion which is received within the upper section of said support tube;
• a first permanent magnet carried by the stem portion of said float;
• transverse wall means within said support tube completing a fluid tight closure below said first permanent magnet and also completing a chamber within said support tube below said transverse wall;
• a second permanent magnet located within said chamber;
• a normally closed valve located within said support tube below said second permanent magnet, said valve including an upwardly directed, normally extended control member which is depressible to open the valve, said control member being positioned below the second permanent magnet;
• means normally biasing the second permanent magnet away from contact with said control member;
• and
• with said first and second permanent magnets being arranged to have like poles facing each other, and with the arrangement of the float and permanent magnets being such that when the float moves downwardly a predetermined amount by liquid being removed from the liquid holding tank the float will move the first permanent magnet towards the second permanent magnet, and the repelling force of the two permanent magnets will cause the second permanent magnet to be forced downwardly against the control member for the valve, depressing such control member to in that manner open the valve.

Apparatus for signaling a low level condition of a liquid holding tank, comprising:

• a supply of pressurized gas;
• a gas operated sound generator having an inlet for operating gas;
• first gas supplying conduit means extending from the supply of pressurized gas to said gas inlet, said first gas supplying conduit means including a normally closed valve means and gas pressure operated means for opening such valve means;
• second gas supplying conduit means extending from the supply of pressurized gas to said gas pressure operated means for opening said first valve means;
• second normally closed valve means in said second gas supplying conduit means including an upwardly directed normally extended control member which when depressed will open said second valve means, to allow pressurized gas from the supply of pressurized gas to flow to the gas pressure operated means for opening the first valve means, to in turn allow pressurized gas to flow from the supply of pressurized gas to the sound generator, to operate the sound generator;
• and
• means for depressing said control member in response to a predetermined drop in the level of a liquid in the liquid holding tank, comprising:
• a float located within said liquid holding tank, said float carrying a first permanent magnet positioned above said second valve means;
• means defining a chamber between said first permanent magnet and said second normally closed valve means which includes a fluid tight upper wall;
• means defining an inlet port leading into said chamber and an outlet port leading out from said chamber, said second normally closed valve means being located within one of said ports, with its control member projecting into said chamber;
• a second permanent magnet located within said chamber;
• and
• means normally biasing said second permanent magnet away from contact with said control member;
• said first and second permanent magnets presenting like poles towards each other, so that each permanent magnet will tend to repel the other, said float and said two permanent magnets being arranged such that when the liquid level drops in the liquid holding tank the first permanent magnet will be moved by the float towards the second magnet and the repelling force of the two magnets will move the second magnet against the operating member, in opposition to the biasing force, to depress such operating member to in that manner open the second valve means.

A liquid level sensor for use with a normally closed liquid holding tank having a top wall, a bottom wall, an opening through one of said walls, and a closure for such opening which is connectable to the tank, said sensor comprising:

• a support tube which is connectable to the closure for the opening in the liquid holding tank, to extend inwardly therefrom into the tank;
• a float adapted to float upon liquid in said liquid holding tank, said float carrying an outwardly directed first permanent magnet positioned within the inner portion of said support tube;
• transverse wall means within said support tube, completing a fluid tight closure outward of said first permanent magnet;
• a second permanent magnet positioned outwardly of said transverse wall means;
• and
• a normally closed valve located within said support tube outward of said second permanent magnet and inward of the closure for said opening, said valve including a normally extending control member which is depressible to open the valve, said control member being positioned outwardly of the second permanent magnet;
• with said fluid tight closure completed by said transverse wall means isolating the second permanent magnet and the normally closed valve in a fluid tight manner from the interior of the holding tank;
• and
• with said first and second permanent magnets being arranged to have like poles facing each other, and with the arrangement of the float and the two magnets being such that when the liquid level in the liquid holding tank moves toward said transverse wall a predetermined amount, the float will move the first permanent magnet towards the second permanent magnet, and a repelling force generated by the two magnets will cause the second permanent magnet to be urged against the control member for the valve, depressing such control member to in that manner open the valve.

A liquid level sensor for use with a normally closed liquid holding tank having a top wall, a bottom wall, an opening through one of said walls, and a closure for such opening which is connectable to the tank, said sensor comprising:

• a support tube which is connectable to the closure for the opening in the liquid holding tank, to extend inwardly therefrom into the tank;
• a float adapted to float upon liquid in said liquid holding tank, said float carrying an outwardly directed first permanent magnet positioned within the inner portion of said support tube, and said float being located within a cage for said float, said cage being connected to the inner end of said support tube;
• transverse wall means within said support tube, completing a fluid tight closure outward of said first permanent magnet;
• a second permanent magnet positioned outwardly of said transverse wall means;
• a normally closed valve located within said support tube outward of said second permanent magnet, said valve including a normally extending control member which is depressible to open the valve, said control member being positioned outwardly of the second permanent magnet;
• wherein a chamber is formed within said support tube, outward of said transverse wall means and inward of said normally closed valve;
• and
• means defining an inlet port leading into said chamber and an outlet port leading out from said chamber;
• wherein said valve is located within one of said ports, with its control member projecting into said chamber, and said second permanent magnet is located within said chamber;
• with said first and second permanent magnets being arranged to have like poles facing each other, and with the arrangement of the float and the two magnets being such that when the liquid level in the liquid holding tank moves toward said transverse wall, the float will move the first permanent magnet towards the second permanent magnet, and a repelling force generated by the two magnets will cause the second permanent magnet to be urged against the control member for the valve, depressing such control member to in that manner open the valve.