Patent US3593270A successfully refreshed from Google Patents.
US3593270A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid level sensing and indicating system
Assignee: Individual
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Filing: 1967-07-10
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Granted: 1971-07-13
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Expires: 1987-07-10
Abstract
Abstract A system for preventing overheating of liquid cooled internal combustion engines comprising an improved radiator probe which cannot short out to produce a malfunction, an electronic warning circuit and an electronic test circuit so constructed that the test circuit can be relied upon to sense a failure in the alarm circuit without being masked by a compensating failure in the probe circuit.
Inventors
- 👤 Richard E Walker
- 👤 James D Heckelman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:33
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/24; G01F23/241
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
308 words
A system for sensing and indicating the liquid level of liquid cooled internal combustion engines having a radiator with a normal liquid level positioned remotely from the drivers compartment, a source of electrical energy at a potential different from ground, and an engine operating switch connecting to said source and having an ''''on'''' position for normal operation of the internal combustion engine, and a ''''test'''' position, said system comprising: a probe insulated from its surrounding and projecting below the liquid level of said radiator, first and second resistors connected in series circuit between said probe and said source of electrical energy, said first resistor being connected to the probe and the ratio of the resistance values of said first to said second resistors being no greater than approximately 1, a transistor between ground and said source and the base of which is connected to adjacent ends of said first and second resistors, said transistor being conductive when a biasing potential of the same type relative to ground as said source is supplied thereto, signal producing means in the emitter-collector circuit of said transistor effective to provide a warning signal when said transistor is conductive, a flexible plastic insulating tube one end of which surrounds said probe and the other end of which projects out of the radiator, said tube being nonwetted by the liquid in said radiator, a conductor extending through said tube from said probe establishing a circuit with said first resistor, means mounting said tube to said radiator and deforming said tube radially inwardly for effecting a seal relative to said conductor, and a third resistor connecting between said base of said transistor and said test position of said switch, said third resistor having a resistance value which makes the ratio of the resistance values of said first to said third resistors less than approximately 1.
Claim 2
Independent Claim
308 words
A system for sensing and indicating the liquid level of liquid cooled internal combustion engines having a radiator with a normal liquid level positioned remotely from the drivers compartment, a source of electrical energy at a potential different from ground, and an engine operating switch connecting to said source and having an ''''on'''' position for normal operation of the internal combustion engine, and a ''''test'''' position, said system comprising: a probe insulated from its surrounding and projecting below the liquid level of said radiator, first and second resistors connected in series circuit between said probe and said source of electrical energy, said first resistor being connected to the probe and the ratio of the resistance values of said first to said second resistors being no greater than approximately 1, a transistor between ground and said source and the base of which is connected to adjacent ends of said first and second resistors, said transistor being conductive when a biasing potential of the same type relative to ground as said source is supplied thereto, signal producing means in the emitter-collector circuit of said transistor effective to provide a warning signal when said transistor is conductive, a flexible plastic insulating tube one end of which surrounds said probe and the other end of which projects out of the radiator, said tube being nonwetted by the liquid in said radiator, a conductor extending through said tube from said probe establishing a circuit with said first resistor, means mounting said tube to said radiator and deforming said tube radially inwardly for effecting a seal relative to said conductor, and a third resistor connecting between said base of said transistor and said test position of said switch, said third resistor having a resistance value which makes the ratio of the resistance values of said first to said third resistors less than approximately 1.
Claim 3
Dependent Claim
28 words
The system of claim 1 in which the plastic tube extends from said probe to said drivers compartment and the sidewalls of which are impervious to the surroundings.
Claim 4
Dependent Claim
16 words
The system of claim 1 in which the first resistor is located within said plastic tube.
Claim 5
Dependent Claim
235 words
In a system for sensing and indicating the liquid level of liquid cooled internal combustion engines having a radiator with a liquid contacting probe therein positioned remotely from the drivers compartment, a source of electrical energy at a potential different from ground, and an engine operating switch connected to said source and having an ''''on'''' position for normal operation of the internal combustion engine, and a ''''start'''' position for the engine, said system comprising: first and second resistors connected in series circuit between the probe and the source of electrical energy, said first resistor being connected to the probe and the ratio of the resistance value of said first to said second resistors being no greater than approximately 1, a transistor the emitter and collector of which are connected between ground and said source, and the base of which is connected to adjacent ends of said first and second resistors, said transistor being conductive when a biasing potential of the same type relative to ground as said source is applied thereto, signal producing means in the emitter-collector circuit of said transistor effecting a warning signal when said transistor is conductive, and a third resistor connected between said base of said transistor and said ''''start'''' position of said switch, said third resistor having a resistance value which makes the ratio of the resistance values of said first to said third resistors no greater than approximately 1.
Claim 6
Dependent Claim
235 words
In a system for sensing and indicating the liquid level of liquid cooled internal combustion engines having a radiator with a liquid contacting probe therein positioned remotely from the drivers compartment, a source of electrical energy at a potential different from ground, and an engine operating switch connected to said source and having an ''''on'''' position for normal operation of the internal combustion engine, and a ''''start'''' position for the engine, said system comprising: first and second resistors connected in series circuit between the probe and the source of electrical energy, said first resistor being connected to the probe and the ratio of the resistance value of said first to said second resistors being no greater than approximately 1, a transistor the emitter and collector of which are connected between ground and said source, and the base of which is connected to adjacent ends of said first and second resistors, said transistor being conductive when a biasing potential of the same type relative to ground as said source is applied thereto, signal producing means in the emitter-collector circuit of said transistor effecting a warning signal when said transistor is conductive, and a third resistor connected between said base of said transistor and said ''''start'''' position of said switch, said third resistor having a resistance value which makes the ratio of the resistance values of said first to said third resistors no greater than approximately 1.
Claim 7
Independent Claim
161 words
A system for sensing and indicating the liquid level of engines having a liquid coolant system, said system comprising: an ignition switch having a test position and a run position, a sensor element in said coolant system establishing a short circuit to ground to the engine when contacted by liquid in said coolant system, first and second resistors in series between said sensor element and said run position of said ignition switch, a transistor having its base electrode connected to the junction of said first and second resistors, a solenoid in the emitter-collector circuit of said transistor, said solenoid having normally open contacts which are closed when said solenoid is energized, an indicator light connected to said contacts to indicate whether or not liquid is in contact with said sensor element, and means connecting said test position of said switch to the base of said transistor to actuate said system whether or not liquid is in contact with said sensor element.
Claim 8
Independent Claim
161 words
A system for sensing and indicating the liquid level of engines having a liquid coolant system, said system comprising: an ignition switch having a test position and a run position, a sensor element in said coolant system establishing a short circuit to ground to the engine when contacted by liquid in said coolant system, first and second resistors in series between said sensor element and said run position of said ignition switch, a transistor having its base electrode connected to the junction of said first and second resistors, a solenoid in the emitter-collector circuit of said transistor, said solenoid having normally open contacts which are closed when said solenoid is energized, an indicator light connected to said contacts to indicate whether or not liquid is in contact with said sensor element, and means connecting said test position of said switch to the base of said transistor to actuate said system whether or not liquid is in contact with said sensor element.
Claim 9
Dependent Claim
120 words
A fluid level indicator comprising: a ground; a reservoir containing a conductive fluid and electrically connected to said ground; a probe submerged in said fluid, said probe and said fluid forming a connection to ground; an ignition switch with a power terminal and with test and run terminals; a transistor having a base connected to said probe and an emitter-collector circuit; a warning device, said emitter-collector circuit operating said warning device to energize said device when liquid is not in contact with said probe, and means connecting said test position of said ignition switch to said base of said transistor to actuate said transistor and operate said warning device whether or not said liquid is in contact with said probe.
Claim 10
Dependent Claim
120 words
A fluid level indicator comprising: a ground; a reservoir containing a conductive fluid and electrically connected to said ground; a probe submerged in said fluid, said probe and said fluid forming a connection to ground; an ignition switch with a power terminal and with test and run terminals; a transistor having a base connected to said probe and an emitter-collector circuit; a warning device, said emitter-collector circuit operating said warning device to energize said device when liquid is not in contact with said probe, and means connecting said test position of said ignition switch to said base of said transistor to actuate said transistor and operate said warning device whether or not said liquid is in contact with said probe.
Claim 11
Dependent Claim
134 words
A fluid level indicator adapted for use on vehicles, said fluid level indicator comprising: an ignition switch with a power terminal in conductive relationship with the battery and with test and run terminals; first control means including a transistor in conductive relationship between the ignition switch and ground and made conductive in the test condition of the ignition switch, said first control means including a probe disposed to a depth corresponding to the minimum acceptable level of the fluid level; second control means including a transistor normally nonconductive and conductively disposed between said run terminal and a lamp, said transistor in the second control means being driven conductive by an interruption of current flow in the first control means due to the fluid level dropping below a minimum acceptable level thereby lighting the lamp.
Claim 12
Dependent Claim
134 words
A fluid level indicator adapted for use on vehicles, said fluid level indicator comprising: an ignition switch with a power terminal in conductive relationship with the battery and with test and run terminals; first control means including a transistor in conductive relationship between the ignition switch and ground and made conductive in the test condition of the ignition switch, said first control means including a probe disposed to a depth corresponding to the minimum acceptable level of the fluid level; second control means including a transistor normally nonconductive and conductively disposed between said run terminal and a lamp, said transistor in the second control means being driven conductive by an interruption of current flow in the first control means due to the fluid level dropping below a minimum acceptable level thereby lighting the lamp.
Claim 13
Dependent Claim
126 words
A fluid level indicator adapted for use with vehicles, said fluid level indicator comprising: an ignition switch with a power terminal in conductive relationship with the battery and with test and run terminals; a first transistor having its emitter and collector terminals cOnnected between said ignition switch and ground, a first resistor in series between said first transistor and ground, a fluid level probe connected to the base of said first transistor, a second resistor connected between said ignition switch and said base of said first transistor, a second transistor connected between said ignition switch and ground with its base connected to the junction of said first transistor and said first resistor, and a lamp and diode positioned in the emitter-collector circuit of said second transistor.
Claim 14
Dependent Claim
126 words
A fluid level indicator adapted for use with vehicles, said fluid level indicator comprising: an ignition switch with a power terminal in conductive relationship with the battery and with test and run terminals; a first transistor having its emitter and collector terminals cOnnected between said ignition switch and ground, a first resistor in series between said first transistor and ground, a fluid level probe connected to the base of said first transistor, a second resistor connected between said ignition switch and said base of said first transistor, a second transistor connected between said ignition switch and ground with its base connected to the junction of said first transistor and said first resistor, and a lamp and diode positioned in the emitter-collector circuit of said second transistor.
Claim 15
Dependent Claim
149 words
An electrode assembly comprising: a carbon probe insulated from its surroundings for projecting below a liquid level, a flexible plastic insulating tube one end of which surrounds said carbon probe and the other end of which projects outwardly, an electrical conductor inside said tube extending from said carbon probe through said tube, support means surrounding said tube and deforming said tube radially inwardly for effecting a seal relative to said conductor, said tube being nonwetted by the liquid in said radiator, and having a clearance space between said conductor and the internal sidewalls of said tube adjacent said carbon probe, said conductor comprising a looped section of stranded metal wire located in said clearance space between said carbon probe and the portion of said tube deformed against said conductor, and whereby substantially all stress is relieved from the connection of said conductor to said carbon probe due to vibration.
Claim 16
Dependent Claim
149 words
An electrode assembly comprising: a carbon probe insulated from its surroundings for projecting below a liquid level, a flexible plastic insulating tube one end of which surrounds said carbon probe and the other end of which projects outwardly, an electrical conductor inside said tube extending from said carbon probe through said tube, support means surrounding said tube and deforming said tube radially inwardly for effecting a seal relative to said conductor, said tube being nonwetted by the liquid in said radiator, and having a clearance space between said conductor and the internal sidewalls of said tube adjacent said carbon probe, said conductor comprising a looped section of stranded metal wire located in said clearance space between said carbon probe and the portion of said tube deformed against said conductor, and whereby substantially all stress is relieved from the connection of said conductor to said carbon probe due to vibration.
Claim 17
Dependent Claim
33 words
The system of claim 9 in which said conductor has a metal sleeve soldered thereto, and said means for mounting said tube comprises a compression fitting which squeezes said tube and said sleeve.
Claim 18
Dependent Claim
24 words
The system of claim 10 having a flexible plastic in said tube encasing said looped wire and extending between said probe and said sleeve.
Claim 19
Dependent Claim
25 words
The system of claim 9 in which a resistor is positioned in said plastic tube in series circuit between said probe and said electrical conductor.
Claim 20
Dependent Claim
158 words
In a system for sensing and indicating the liquid lens of liquid cooled internal combustion engines having a radiator with a normal liquid level positioned remotely from the drivers compartment; a probe insulated from its surroundings and projecting below the liquid level of said radiator, a flexible plastic insulating tube one end of which surrounds said carbon probe and the other end of which projects out of the radiator, an electrical conductor inside said tube extending from a point inside said radiator through said tube into the drivers compartment, means mounting said tube to said radiator and deforming said tube radially inwardly for effecting a seal relative to said conductor, said conductor having electrical insulation thereon inside said tube and extending from said means out of the tube into said drivers compartment, said tube being non-wetted by the liquid in said radiator, and whereby the engine and radiator can run submerged in water without said system becoming inoperative.
Claim 21
Dependent Claim
158 words
In a system for sensing and indicating the liquid lens of liquid cooled internal combustion engines having a radiator with a normal liquid level positioned remotely from the drivers compartment; a probe insulated from its surroundings and projecting below the liquid level of said radiator, a flexible plastic insulating tube one end of which surrounds said carbon probe and the other end of which projects out of the radiator, an electrical conductor inside said tube extending from a point inside said radiator through said tube into the drivers compartment, means mounting said tube to said radiator and deforming said tube radially inwardly for effecting a seal relative to said conductor, said conductor having electrical insulation thereon inside said tube and extending from said means out of the tube into said drivers compartment, said tube being non-wetted by the liquid in said radiator, and whereby the engine and radiator can run submerged in water without said system becoming inoperative.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-12 | 1975-01-11 | 1975-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-12 | 1979-01-11 | 1979-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-12 | 1983-01-11 | 1983-07-13 | $7700.00 | Window Closed / Lapsed |