US4845486A — Residential fuel-oil level reporting and alarm sy…

Claim 1

Independent Claim 179 words

In a system for reporting a fuel-oil level in a residential tank to a central location, a sensor unit located near said tank, said sensor unit comprising: means located near said tank for generating a fuel-oil level sense signal, detector means responsive to said sense signal for producing a reorder signal when the fuel-oil in said tank reaches a predetermined level, an oscillator for generating an output signal, said output signal having a frequency variation, and controller means responsive to said reorder signal and to said output signal for transmitting a data word encoded by digital bits consisting of pulses of said output signal to said central location, said data word comprising a fixed, predetermined header pattern of bits, followed by a plurality of data bits including at least one bit indicating the status of said reorder signal and a plurality of identification number bits, said identification number bits representing an identification number unique to said sensor unit, followed by a checksum code bit pattern encoding a checksum derived by logically combining said identification number bits with each other.

Claim 2

Dependent Claim 179 words

In a system for reporting a fuel-oil level in a residential tank to a central location, a sensor unit located near said tank, said sensor unit comprising: means located near said tank for generating a fuel-oil level sense signal, detector means responsive to said sense signal for producing a reorder signal when the fuel-oil in said tank reaches a predetermined level, an oscillator for generating an output signal, said output signal having a frequency variation, and controller means responsive to said reorder signal and to said output signal for transmitting a data word encoded by digital bits consisting of pulses of said output signal to said central location, said data word comprising a fixed, predetermined header pattern of bits, followed by a plurality of data bits including at least one bit indicating the status of said reorder signal and a plurality of identification number bits, said identification number bits representing an identification number unique to said sensor unit, followed by a checksum code bit pattern encoding a checksum derived by logically combining said identification number bits with each other.

Claim 3

Dependent Claim 56 words

In a fuel-oil level reporting system, the sensor unit according to claim 1 wherein said digital bits consist of a mark bit comprising a predetermined number of cycles of said single frequency signal and a space bit comprising a period of time equal to the time period of said mark in which no signal is transmitted.

Claim 4

Dependent Claim 27 words

In a fuel-oil level reporting system, the sensor unit according to claim 2 wherein said header pattern of bits comprises a predetermined number of sequential mark bits.

Claim 5

Dependent Claim 245 words

In a system for reporting a fuel-oil level in a residential tank to a central location, said tank having a mechanical level gauge attached thereto, said mechanical level gauge comprised of a movable mechanical arm with a float attached thereto, said float and arm moving in response to changes in fuel-oil level, and an indicator vial located on the outside of said tank containing an indicator button attached to said arm, a sensor unit comprising: a magnet attached to said indicator button, a magnetic reed switch located in close proximinity to said gauge vial, said reed switch containing a contact which closes to indicate a low-oil condition when said magnet moves close to said reed switch, an oscillator for generating an output signal, said output signal having a frequency variation, and controller means responsive to a closure of said reed switch contact and to said output signal for transmitting a data word encoded by digital bits consisting of pulses of said output signal to said central location, said data word comprising a fixed, predetermined header pattern of bits, followed by a plurality of data bits comprising a plurality of status bits including at least one bit indicating the status of said reed switch contact and a plurality of identification number bits, said identification number bits representing an identification number unique to said sensor unit followed by a checksum code pit pattern encoding a checksum derived by logically combining said identification number bits with each other.

Claim 6

Dependent Claim 245 words

In a system for reporting a fuel-oil level in a residential tank to a central location, said tank having a mechanical level gauge attached thereto, said mechanical level gauge comprised of a movable mechanical arm with a float attached thereto, said float and arm moving in response to changes in fuel-oil level, and an indicator vial located on the outside of said tank containing an indicator button attached to said arm, a sensor unit comprising: a magnet attached to said indicator button, a magnetic reed switch located in close proximinity to said gauge vial, said reed switch containing a contact which closes to indicate a low-oil condition when said magnet moves close to said reed switch, an oscillator for generating an output signal, said output signal having a frequency variation, and controller means responsive to a closure of said reed switch contact and to said output signal for transmitting a data word encoded by digital bits consisting of pulses of said output signal to said central location, said data word comprising a fixed, predetermined header pattern of bits, followed by a plurality of data bits comprising a plurality of status bits including at least one bit indicating the status of said reed switch contact and a plurality of identification number bits, said identification number bits representing an identification number unique to said sensor unit followed by a checksum code pit pattern encoding a checksum derived by logically combining said identification number bits with each other.

Claim 7

Dependent Claim 21 words

A sensor according to claim 4 further comprising a clamp unit for slidably holding said reed switch on said indicator vial.

Claim 8

Dependent Claim 21 words

In a fuel-oil level reporting system, the sensor unit according to claim 1 wherein said generating means is a capacitive sensor.

Claim 9

Dependent Claim 28 words

In a fuel-oil level reporting system, the sensor unit according to claim 6 wherein said detector means compares the capacitance of said capacitive sensor to a known capacitance.

Claim 10

Dependent Claim 20 words

In a fuel-oil level reporting system, the sensor unit according to claim 1 wherein said oscillator is a resistance/capacitance oscillator.

Claim 11

Dependent Claim 20 words

In a fuel-oil level reporting system, the sensor unit according to claim 1 wherein said oscillator is a crystal oscillator.

Claim 12

Dependent Claim 34 words

In a fuel-oil level reporting system according to claim 1 further having a mechanical fuel-oil level gauge, wherein said fuel-oil level sense signal generating means is an electrical switch controlled by said mechanical gauge.

Claim 13

Dependent Claim 33 words

In a fuel-oil level reporting system, the sensor unit according to claim 10 wherein said electrical switch is a magnetic reed switch which is controlled by a magnet attached to said mechanical gauge.

Claim 14

Dependent Claim 44 words

In a fuel-oil level reporting system, the sensor unit according to claim 1 further comprising means for sensing additional alarm conditions and for generating an alarm signal when said additional alarm conditions occur and means for encoding said alarm signal into said data word.

Claim 15

Independent Claim 240 words

A system for reporting a fuel-oil level in a residential tank to a central location comprising: a sensor unit located near said tank comprising: means located near said tank for generating a fuel-oil level sense signal, detector means responsive to said sense signal for producing a reorder signal when the fuel-oil in said tank reaches a predetermined level, an oscillator for generating an output signal, said output signal having a frequency variation, controller means responsive to said reorder signal and to said output signal for transmitting a data word encoded by digital bits consisting of pulses of said output signal to said central location, said data word comprising a fixed, predetermined header pattern of bits, followed by a plurality of data bits followed by a checksum code bit pattern wherein said data bits comprise a plurality of status bits including at least one bit indicating the status of said reorder signal and a plurality of identification number bits, said identification number bits representing an identification number unique to said sensor unit and wherein said checksum code bit pattern encodes a checksum derived by logically combining said identification number bits with each other, a receiving unit located at said central location comprising, means for receiving said data word, means responsive to said header pattern of bits in said data word for determining the bit time duration by calculating the average time duration of the bits in said header pattern of bits.

Claim 16

Independent Claim 240 words

A system for reporting a fuel-oil level in a residential tank to a central location comprising: a sensor unit located near said tank comprising: means located near said tank for generating a fuel-oil level sense signal, detector means responsive to said sense signal for producing a reorder signal when the fuel-oil in said tank reaches a predetermined level, an oscillator for generating an output signal, said output signal having a frequency variation, controller means responsive to said reorder signal and to said output signal for transmitting a data word encoded by digital bits consisting of pulses of said output signal to said central location, said data word comprising a fixed, predetermined header pattern of bits, followed by a plurality of data bits followed by a checksum code bit pattern wherein said data bits comprise a plurality of status bits including at least one bit indicating the status of said reorder signal and a plurality of identification number bits, said identification number bits representing an identification number unique to said sensor unit and wherein said checksum code bit pattern encodes a checksum derived by logically combining said identification number bits with each other, a receiving unit located at said central location comprising, means for receiving said data word, means responsive to said header pattern of bits in said data word for determining the bit time duration by calculating the average time duration of the bits in said header pattern of bits.

Claim 17

Dependent Claim 62 words

A fuel-oil level reporting system according to claim 13 wherein said digital bits consist of a mark bit comprising a predetermined number of cycles of said output signal and a space bit comprising a period of time equal to the time period of said mark in which no signal is transmitted and said header pattern of bits comprises eight sequential mark bits.

Claim 18

Dependent Claim 35 words

A fuel-oil level reporting system according to claim 13 wherein said data bits comprise at least one bit indicating the status of an alarm signal indicating an alarm condition other than a low fuel-oil condition.

Claim 19

Dependent Claim 44 words

A fuel-oil level reporting system according to claim 13 wherein said checksum code bit pattern encodes a checksum derived from logically combining all bits sent in the entire transmission with each other, said bits including said header bits, identification number bits and data bits.

Claim 20

Dependent Claim 21 words

A fuel-oil level reporting system according to claim 13 wherein said fuel-oil level sense signal generating means is a capacitive sensor.

Claim 21

Dependent Claim 16 words

A fuel-oil level reporting system according to claim 13 wherein said oscillator is a resistance/capacitance oscillator.

Claim 22

Dependent Claim 16 words

A fuel-oil level reporting system according to claim 13 wherein said oscillator is a crystal oscillator.

Claim 23

Dependent Claim 42 words

A fuel-oil level reporting system according to claim 13 further having a mechanical fuel-oil level gauge, wherein said fuel-oil level sense signal generating means is a magnetic reed switch which is controlled by a magnet attached to said mechanical fuel-oil level gauge.

Claim 24

Dependent Claim 162 words

In a system for reporting an alarm condition in a remote location to a central location, a sensor unit located at said remote location, said sensor unit comprising: detector means responsive to an alarm condition in said remote location for producing an alarm signal, an oscillator for generating an output signal, said output signal having a frequency variation, and controller means responsive to said alarm signal and to said output signal for transmitting a data word encoded by digital bits consisting of pulses of said output signal to said central location, said data word comprising a fixed, predetermined header pattern of bits, followed by a plurality of data bits including at least one bit indicating the status of said alarm signal and a plurality of identification number bits, said identification number bits representing an identification number unique to said sensor unit, followed by a checksum code bit pattern encoding a checksum derived by logically combining said identification number bits with each other.

Claim 25

Dependent Claim 162 words

In a system for reporting an alarm condition in a remote location to a central location, a sensor unit located at said remote location, said sensor unit comprising: detector means responsive to an alarm condition in said remote location for producing an alarm signal, an oscillator for generating an output signal, said output signal having a frequency variation, and controller means responsive to said alarm signal and to said output signal for transmitting a data word encoded by digital bits consisting of pulses of said output signal to said central location, said data word comprising a fixed, predetermined header pattern of bits, followed by a plurality of data bits including at least one bit indicating the status of said alarm signal and a plurality of identification number bits, said identification number bits representing an identification number unique to said sensor unit, followed by a checksum code bit pattern encoding a checksum derived by logically combining said identification number bits with each other.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1992-07-03	1993-01-02	1993-07-04	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1996-07-03	1997-01-02	1997-07-04	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2000-07-03	2001-01-02	2001-07-04	$7700.00	Window Closed / Lapsed

Residential fuel-oil level reporting and alarm system

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