Digital oil level sensor
First Claim
1. An oil level sensor suitable for use with internal combustion engines, transmissions, differentials, vehicular oil systems, and the like comprising:
- a sensor body adapted to be mounted to the block, casing or the like of an oil-containing reservoir;
a probe including a pair of electrodes forming a capacitor, said probe extending from said sensor body so as to at least partially immerse the capacitor in oil during normal conditions of use to detect the level thereof, at least one of said electrodes being substantially insulated so that the apparent capacitance of the capacitor is relatively insensitive to any change in the conductivity of the oil a high temperatures; and
means responsive to the capacitance of said capacitor for signalling the level of the oil, said capacitance being a function of said oil level.
4 Assignments
0 Petitions
Accused Products
Abstract
An oil level sensor includes a sensor body adapted to be mounted to the block or casing of an oil-containing reservoir. A probe including a pair of electrodes forming a capacitor extends from the sensor body so that the capacitor will be at least partially immersed in the oil to detect the level thereof. At least one of the electrodes is insulated so that the apparent capacitance of the capacitor is relatively insensitive to any change in the conductivity of the oil at high temperatures. Circuitry is provided in response to the capacitance of the capacitor for signalling the level of the oil, which capacitance is a function of the oil level. The sensor body is mounted to the block by external threads on the probe. The electrodes of the probe extend proximally past the threads to provide an increased capacitance for the sensor. The electrodes of the probe are concentric and the inner electrode is supported at both ends to reduce fatigue. Circuitry is also provided for automatically testing the proper operation of the sensor.
-
Citations
26 Claims
-
1. An oil level sensor suitable for use with internal combustion engines, transmissions, differentials, vehicular oil systems, and the like comprising:
-
a sensor body adapted to be mounted to the block, casing or the like of an oil-containing reservoir; a probe including a pair of electrodes forming a capacitor, said probe extending from said sensor body so as to at least partially immerse the capacitor in oil during normal conditions of use to detect the level thereof, at least one of said electrodes being substantially insulated so that the apparent capacitance of the capacitor is relatively insensitive to any change in the conductivity of the oil a high temperatures; and means responsive to the capacitance of said capacitor for signalling the level of the oil, said capacitance being a function of said oil level. - View Dependent Claims (2, 3, 4, 5)
-
-
6. An oil level sensor suitable for use with internal combustion engines, transmissions, differentials, vehicular oil systems, and the like comprising:
-
a sensor body; means for mounting the sensor body to the block, casing, or the like of an oil-containing reservoir; a probe including a pair of electrodes forming a capacitor, said probe extending from said sensor body so as to at least partially immerse the capacitor in oil during normal conditions of use to detect the level thereof, said mounting means being disposed exteriorly about the proximal end of the probe adjacent the main portion of the sensor body; said electrodes defining a gap therebetween and extending proximally toward the main portion of the sensor body at least a significant distance past the distal end of the mounting means; and means responsive to the capacitance of said capacitor for signalling the level of the oil, said capacitance being a function of said oil level. - View Dependent Claims (7, 8, 9)
-
-
10. An oil level sensor suitable for use with internal combustion engines, transmissions, differentials, vehicular oil systems, and the like comprising:
-
a sensor body adapted to be mounted to the block, casing, or the like of an oil-containing reservoir; a probe including a pair of electrodes forming a capacitor, said probe extending from said sensor body so as to at least partially immerse the capacitor in oil during normal conditions of use to detect the level thereof, said electrodes defining a gap therebetween and extending distally from the main portion of the sensor body generally to the end of the probe; means for securing the electrodes against relative movement with respect to each other, said means being disposed at each end of at least one of the electrodes; and means electrically connected to the capacitor and responsive to the capacitance of said capacitor for signalling the level of the oil, said capacitance being a function of said oil level. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
-
-
19. An oil level sensor suitable for use with internal combustion engines, transmissions, differentials, vehicular oil systems, and the like comprising:
-
a sensor body adapted to be mounted to the block, casing, or the like of an oil-containing reservoir; a probe including a pair of electrodes forming a capacitor, said probe extending from said sensor body so as to at least partially immerse the capacitor in oil during normal conditions of use to detect the level thereof; means disposed in the sensor body and responsive to the capacitance of said capacitor for signalling the level of the oil, said capacitance being a function of said oil level; and means for automatically testing the proper operation of the signalling means for both the presence and the absence of oil at a predetermined level. - View Dependent Claims (20, 21, 22, 23, 24, 25)
-
-
26. An oil level sensor suitable for use with internal combustion engines, transmissions, differentials, vehicular oil systems, and the like comprising:
-
a sensor body; means for mounting the sensor body to the block, casing, or the like of an oil-containing reservoir; a probe including a pair of electrodes forming a capacitor, said probe extending from said sensor body so as to at least partially immerse the capacitor in oil during normal conditions of use to detect the level thereof, said mounting means being disposed exteriorly about the proximal end of the probe; said electrodes defining a gap therebetween and extending proximally toward the main portion of the sensor body at least a significant distance past the distal end of the mounting means, at least one of said electrodes being insulated so that the apparent capacitance of the capacitor is relatively insensitive to any change in the conductivity of the oil at high temperatures; means responsive to the capacitance of said capacitor for signalling the level of the oil, said capacitance being a function of said oil level; and means for automatically testing the proper operation of the signalling means for both the presence and absence of oil at a predetermined level.
-
Specification