US3895384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Distance measuring apparatus
Assignee: FLEET CREDIT Corp A CORP OF RI
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Filing: 1973-04-23
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Granted: 1975-07-15
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Expires: 1993-04-23
Abstract
Abstract The embodiment of the invention disclosed herein is directed to distance measuring apparatus which includes a directive antenna mounted to a vehicle for directing RF energy toward the surface over which the vehicle is moving. Reflected portions of the RF energy signals are received by the antenna and are mixed in an oscillator-mixer circuit for producing Doppler signals having a repetition rate proportional to the rate of travel of the vehicle. A preamplifier having substantially zero input impedance is connected to the output of the oscillator-mixer circuit. Each Doppler cycle so generated represents a predetermined distance traveled and is delivered to a counter to indicate that distance. The Doppler signal is processed to produce time rate information corresponding to the miles per hour of the vehicle.
Inventors
- 👤 George H Fathauer
- 👤 Wesley J Bachman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:45
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/58; G01S13/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
204 words
A distance measuring apparatus for vehicles, comprising: antenna means to be mounted to a vehicle for directing RF energy towards the surface over which the vehicle is moving and for receiving reflected signals of said RF energy from the surface, oscillator-mixer means for generating said RF energy and for mixing therewith the reflected portions of said RF energy to produce a Doppler signal which has a component proportional to the rate of travel of the vehicle over the surface, said Doppler signal so generated representing predetermined increments of distances traveled, a low input impedance amplifier circuit having the input thereof connected to said oscillator-mixer means to receive said Doppler signal, said low input impedance amplifier circuit comprising a pair of transistors, one of said transistors having a grounded emitter with its base coupled to said oscillator-mixer means, the other transistor having the base thereof connected to the collector of said one transistor and the emitter thereof connected to the base of said one transistor, circuit means for developing said amplifier Doppler signal and translating the same to output terminal means, and indicator readout means connected to said output terminal means for receiving said Doppler signal to produce a visual reading of the distance traveled.
Claim 2
Dependent Claim
204 words
A distance measuring apparatus for vehicles, comprising: antenna means to be mounted to a vehicle for directing RF energy towards the surface over which the vehicle is moving and for receiving reflected signals of said RF energy from the surface, oscillator-mixer means for generating said RF energy and for mixing therewith the reflected portions of said RF energy to produce a Doppler signal which has a component proportional to the rate of travel of the vehicle over the surface, said Doppler signal so generated representing predetermined increments of distances traveled, a low input impedance amplifier circuit having the input thereof connected to said oscillator-mixer means to receive said Doppler signal, said low input impedance amplifier circuit comprising a pair of transistors, one of said transistors having a grounded emitter with its base coupled to said oscillator-mixer means, the other transistor having the base thereof connected to the collector of said one transistor and the emitter thereof connected to the base of said one transistor, circuit means for developing said amplifier Doppler signal and translating the same to output terminal means, and indicator readout means connected to said output terminal means for receiving said Doppler signal to produce a visual reading of the distance traveled.
Claim 3
Dependent Claim
24 words
The distance measuring apparatus for vehicles according to claim 1, wherein said indicator readout means is a counter to show the accumulative distance traveled.
Claim 4
Dependent Claim
29 words
The distance measuring apparatus for vehicles according to claim 1, wherein said indicator readout means is a speedometer to show the time rate of measurement of the distance traveled.
Claim 5
Dependent Claim
21 words
The distance measuring apparatus for vehicles according to claim 3, wherein the said time rate measurement is in miles per hour.
Claim 6
Dependent Claim
91 words
The distance measuring apparatus for vehicles according to claim 1, wherein said circuit means for developing said amplified Doppler signal include a multivibrator circuit, an integrating circuit connected thereto, and a milliameter connected to said integrating circuit to produce a current reading which is calibrated and indicative of the time rate of travel of the vehicle, and further including a trigger circuit also for receiving said amplified Doppler signal to produce a count pulse at an output terminal for energizing a counter to produce an accumulative indication of the distance traveled.
Claim 7
Dependent Claim
38 words
The distance measuring apparatus for vehicles according to claim 1, wherein said antenna means is arranged for connection to a vehicle to be at all times relatively close to the ground surface over which the vehicle is moving.
Claim 8
Dependent Claim
37 words
The distance measuring apparatus for vehicles according to claim 1, further including clamp circuit means coupled between said low input impedance amplifier circuit and said circuit means to maintain said Doppler signal withIn a predetermined voltage range.
Claim 9
Dependent Claim
82 words
The distance measuring apparatus for vehicles according to claim 7, wherein said clamp circuit means includes a pair of parallel connected back-to-back diodes, a series connected capacitor connected between said low input impedance amplifier circuit and one end of said diodes, the other end of said diodes being connected to a source of DC voltage, whereby the variation of said Doppler signal is limited by the inherent voltage drop across said diodes above and below the value of said DC voltage source.
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) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |