Patent US3640586A successfully refreshed from Google Patents.
US3640586A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tachometer amplifier
Assignee: PepsiAmericas Inc
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Filing: 1970-03-09
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Granted: 1972-02-08
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Expires: 1990-03-09
Abstract
Abstract A tachometer amplifier for an antiskid brake system controlling skid conditions on a plurality of vehicle axles which includes circuitry receiving signals from a plurality of tachometer pickups, one on each wheel. The amplifier compensates for difference in wheel diameters due to wear by tracking the signal voltages of the pickups and adjusting same to produce equal voltage signals out for equal speeds, and thereby permit skid detection during braking based on a difference in wheel speed.
Inventors
- 👤 William H Kohler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:13
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/172; B60T2240/00; B60T2240/08
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
229 words
In an antiskid brake system for a vehicle including a tachometer pickup for each wheel or axle for producing a speed voltage having a frequency directly proportional to the speed of the wheel or axle, a plurality of tachometer amplifiers one for each pickup to receive the output therefrom, an antiskid control receiving the outputs of each tachometer amplifier for comparing the speed voltages during braking to detect a skid condition based upon a difference in wheel or axle speed, and brake units having controls responding to the output of the antiskid control, the improvement in said tachometer amplifiers each of which includes means for amplifying the input signal from the respective pickup and converting it to a direct current speed voltage output proportional to the frequency of the respective input signal, each of said tachometer amplifiers except one including a comparison and gain adjusting means for automatically and continuously adjusting the speed voltage outputs thereoF in response to each initiation of a brake command to equal that of said one tachometer amplifier, and said comparison and gain adjusting means of a tachometer amplifier including means comparing the speed voltage output thereof with that of said one tachometer amplifier and compensating for differences in wheel diameter due to wear by adjusting the gain thereof so that its speed voltage output is equal to that of said one tachometer amplifier.
Claim 2
Dependent Claim
229 words
In an antiskid brake system for a vehicle including a tachometer pickup for each wheel or axle for producing a speed voltage having a frequency directly proportional to the speed of the wheel or axle, a plurality of tachometer amplifiers one for each pickup to receive the output therefrom, an antiskid control receiving the outputs of each tachometer amplifier for comparing the speed voltages during braking to detect a skid condition based upon a difference in wheel or axle speed, and brake units having controls responding to the output of the antiskid control, the improvement in said tachometer amplifiers each of which includes means for amplifying the input signal from the respective pickup and converting it to a direct current speed voltage output proportional to the frequency of the respective input signal, each of said tachometer amplifiers except one including a comparison and gain adjusting means for automatically and continuously adjusting the speed voltage outputs thereoF in response to each initiation of a brake command to equal that of said one tachometer amplifier, and said comparison and gain adjusting means of a tachometer amplifier including means comparing the speed voltage output thereof with that of said one tachometer amplifier and compensating for differences in wheel diameter due to wear by adjusting the gain thereof so that its speed voltage output is equal to that of said one tachometer amplifier.
Claim 3
Dependent Claim
34 words
The combination as defined in claim 1, and means responsive to the initiation of a brake command for activating the comparison and gain adjusting means of each tachometer amplifier to adjust the gains thereof.
Claim 4
Dependent Claim
17 words
The combination as defined in claim 1, and diode limiting means for limiting the input signal amplitude.
Claim 5
Dependent Claim
65 words
The combination as defined in claim 3, wherein said amplifying and converting means includes an amplifier for amplifying the input signal, means for receiving the amplified input signal and producing a square wave output, means for differentiating the square wave output, means for rectifying the differentiated square wave output, means for time averaging the rectified voltage, and means for further amplifying the time averaged voltage.
Claim 6
Dependent Claim
18 words
The combination as defined in claim 4, wherein said square wave output producing means comprises a Schmitt trigger.
Claim 7
Dependent Claim
21 words
The combination as defined in claim 5, wherein said time averaging means includes a capacitor ahead of said further amplifying means.
Claim 8
Dependent Claim
84 words
The combination as defined in claim 6, wherein each comparison and gain adjusting means includes a comparison amplifier receiving as one input the speed voltage output from the amplifying and converting means of said one tachometer amplifier and as another input the speed voltage output of a respective amplifying and converting means, and means responding to the output of the comparison amplifier to change the amplitude of the pulse out of the Schmitt trigger if the comparison amplifier detects a difference in its inputs.
Claim 9
Dependent Claim
25 words
The combination as defined in claim 7, wherein said amplitude changing means includes a field effect transistor having its drain connected to the Schmitt trigger.
Claim 10
Dependent Claim
37 words
The combination as defined in claim 8, wherein a capacitor receives the output of the comparison amplifier and discharges through the gate of the field effect transistor and a gate to control the conduction of the transistor.
Claim 11
Dependent Claim
84 words
The combination as defined in claim 7, wherein each comparison and gain adjusting means includes a comparison amplifier receiving as one input the speed voltage output from the amplifying and converting means of said one tachometer amplifier and as another input the speed voltage output of a respective amplifying and converting means, and means responding to the output of the comparison amplifier to change the amplitude of the pulse out of the Schmitt trigger if the comparison amplifier detects a difference in its inputs.
Claim 12
Dependent Claim
25 words
The combination as defined in claim 10, wherein said amplitude changing means includes a field effect transistor having its drain connected to the Schmitt trigger.
Claim 13
Dependent Claim
37 words
The combination as defined in claim 11, wherein a capacitor receives the output of the comparison amplifier and discharges through the gate of the field effect transistor and a gate to control the conduction of the transistor.
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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |