ENGINE COOLANT LEVEL WARNING SYSTEM

• US 3,614,730 A
• Filed: 06/25/1970
• Issued: 10/19/1971
• Est. Priority Date: 06/25/1970
• Status: Expired due to Term

• Current Assignee: Michael Bozoian
• Original Assignee: Michael Bozoian
• Inventors: Bozoian, Michael
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/049,691
• Time in Patent Office: 481 Days
• Field of Search: 340/52,59,244,282 315/129,194 73/290
• US Class Current: 340/450
• CPC Class Codes: F01P 11/18 concerning coolant pressure, coolant flow, or liquid-coolant level
• CPC Class Codes: G01F 23/265 for discrete levels

Abstract

A system for indicating lack of or severe reduction of coolant flow through a coolant system for an internal combustion engine that warns the vehicle operator of catastrophic failure or loss of fluid in the engine cooling system, as well as apprising the operator that the engine coolant thermostat has opened. A metal band, for example, a hose clamp, is placed on one of the radiator hoses, preferably the upper hose, and a signal generator generating a high-frequency electrical signal is coupled to this metal band. An indication means in the form of a lamp driver circuit and a warning lamp is also connected to the metal band. When coolant is flowing through the radiator hose, the capacitance between the metal band and the engine is at a predetermined level, but when flow of coolant through the hose is reduced substantially, the capacitance is reduced substantially. This change of capacitance is sensed by the lamp driver circuit and will cause the warning lamp coupled to the lamp driver circuit to become illuminated when coolant flow through the radiator hose is at a low or nonexistent level.

Claims

1. In a system for indicating a low level of coolant flowing through an engine coolant system, the combination comprising an engine requiring a liquid coolant, cooling means for cooling the engine coolant, and means including a conduit comprised of a nonconducting material coupling the engine and the cooling means for circulating engine coolant through the engine and the cooling means, a source of electrical energy, means coupled to said source of electrical energy for producing an alternating electrical signal, a warning means coupled to said source of electrical energy, and means coupled to said warning means, said source of electrical energy and to said conduit for sensing coolant flow through said conduit and giving a warning to the vehicle operator when coolant flow through said conduit is at a low level.

2. The combination of claim 1 in which said last-mentioned means comprises a metal band positioned around said conduit, said metal band being electrically connected to said warning means and to said means for producing said alternating electrical signal.

3. The combination of claim 2 in which said means for circulating engine coolant comprises an engine-driven pump coupling said engine and said cooling means comprises a radiator.

4. The combination of claim 1 in which said means coupled to said means for producing an alternating electrical signal, said warning means and to said conduit comprises a conductive band positioned around said conduit.

5. The combination of claim 4 in which said means for circulating engine coolant through said engine and said engine coolant means comprises a pump having an inlet and an outlet, said conduit being connected between the outlet of said pump and said cooling means.

6. The combination of claim 5 in which a thermostat is positioned in said conduit between said outlet of said pump and in a position between said metal band and the outlet of said pump.

7. The combination of claim 1 in which said last-mentioned means comprises a low-pass filter.

8. The combination of claim 1 in which said means for generating an alternating frequency signal comprises a first transistor having emitter and collector output electrodes and an input electrode, a second transistor comprising emitter and collector output electrodes and an input electrode, a series circuit comprised of a capacitor and a resistor connecting the emitter electrodes of said two transistors and a resistive network coupling the emitter electrode of said second transistor with the input electrode of said first transistor, and said means for sensing coolant flow through said conduit is connected to the emitter electrode of said second transistor.

9. The combination of claim 1 and comprising further a first transistor and a second transistor, each of said transistors having an emitter, a collector and a base electrode, said warning means being connected between said source of electrical energy and the collector electrodes of said transistors, said emitter electrode of said first transistor being directly coupled to the base electrode of said second transistor and the emitter electrode of said second transistor being connected to the other terminal of said source of electrical energy, and a capacitor coupling said means for sensing coolant flow and the base electrode of said first transistor.