US3630074A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rate control for tools
Assignee: Research Derivatives Inc
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Filing: 1969-03-20
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Granted: 1971-12-28
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Expires: 1989-03-20
Abstract
Abstract The first time derivative of the output voltage of a measuring transducer in a machine, which is a measure of the velocity of some parameter affected by the machine, such as the machine displacement, is compared with a fixed voltage standard. For a given velocity, the derivative output is fixed and if equal to the fixed reference, exactly balances out in the differential voltage comparator. If a velocity error is present, the comparator produces an error signal which is then amplified in a servocontrol arrangement, to force the machine to minimize the error signal and maintain a uniform rate of travel.
Inventors
- 👤 William Herbert Hartman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:16
CPC Classifications
B; B30; B30B; B30B15/00; B30B15/14; B30B15/148; B30B15/26; G; G01; G01N; G01N3/00; G01N3/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
214 words
In a testing device for hard material, power means for operating the testing device having parameters such as the amount of force applied to the material and the velocity of the force applying means, at least one of said parameters being controllable, the power means being capable of applying forces greater than 1,000 lbs. to the material with movement of distances less than 1 mil from zero to full load, an electrical transducer responsive to the operation of the device for sensing the controllable parameter and providing an output voltage which varies in linear proportion to variations of the controllable parameter, electrical differentiating means for extracting the time derivative of the transducer output voltage which is applied to its input, an adjustable reference voltage source settable to an amplitude representative of a selected rate of change of the controllable parameter, means for comparing the output of the differentiating means and the reference voltage to obtain an error voltage of an amplitude and polarity representing the rate and direction of departure from the selected rate, and modulating means responsive to said error voltage for controlling the power applied to the testing device in an amount and a direction to correct the amount and direction of departure of the said controllable parameter from the selected rate.
Claim 2
Dependent Claim
214 words
In a testing device for hard material, power means for operating the testing device having parameters such as the amount of force applied to the material and the velocity of the force applying means, at least one of said parameters being controllable, the power means being capable of applying forces greater than 1,000 lbs. to the material with movement of distances less than 1 mil from zero to full load, an electrical transducer responsive to the operation of the device for sensing the controllable parameter and providing an output voltage which varies in linear proportion to variations of the controllable parameter, electrical differentiating means for extracting the time derivative of the transducer output voltage which is applied to its input, an adjustable reference voltage source settable to an amplitude representative of a selected rate of change of the controllable parameter, means for comparing the output of the differentiating means and the reference voltage to obtain an error voltage of an amplitude and polarity representing the rate and direction of departure from the selected rate, and modulating means responsive to said error voltage for controlling the power applied to the testing device in an amount and a direction to correct the amount and direction of departure of the said controllable parameter from the selected rate.
Claim 3
Dependent Claim
16 words
The structure of claim 1 wherein the controllable parameter is the force applied to the material.
Claim 4
Dependent Claim
19 words
The structure of claim 2 wherein the transducer is a strain gage load cell providing a linear output voltage.
Claim 5
Dependent Claim
38 words
The structure of claim 3 wherein said reference voltage source is adjuStable during operation of said device, so that operation of the ram can be arrested, reversed or continued at will by adjustment of said reference voltage source.
Claim 6
Dependent Claim
59 words
The structure of claim 3 including a ram for applying the force and operated by the power means to move forward and back throughout a range of positions, a supporting frame supporting said ram and capable of restraining said ram and for providing support for a sample specimen of material to be compressionably and extensionably tested in said device.
Claim 7
Dependent Claim
18 words
The structure of claim 1 wherein the controllable parameter is that rate of movement of the force-applying means.
Claim 8
Dependent Claim
42 words
The structure of claim 6 wherein the force-applying means is a movable ram and the transducer is of the linear displacement type and provides a linear output voltage of an amplitude which is a measure of the relative position of the ram.
Claim 9
Dependent Claim
36 words
The structure of claim 1 in which the modulating means is a servo valve capable of controlling the power means to operate the testing device in amounts and direction for effecting reduction in the rate error.
Claim 10
Dependent Claim
51 words
The structure of claim 1 having signal amplifier means connected to said transducer means and capable of a voltage gain and a voltage loss for scaling the output of said transducer means to a desired level of voltage amplitude, said signal amplifier means having its output connected to said differentiator means.
Claim 11
Dependent Claim
41 words
The structure of claim 1 wherein said means for modulating is a linear servo valve capable of applying power to the controlled device proportionally in an amount and in either direction so as to effect a reduction in the rate error.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |