US3897659A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultrasonic-acoustic grinding wheel setting station for automatic numerically-controlled machines
Assignee: United States Department of Energy
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Filing: 1974-08-30
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Granted: 1975-08-05
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Expires: 1994-08-30
Abstract
Abstract An ultrasonic-acoustic grinding wheel setting station for a numerically controlled machine has been provided. A precisely machined metal ball is supported at a reference position on a numerically controlled grinding machine. The ball is displaceably carried by a metal holder having a conical shaped seat machined to support the ball. The holder is mounted at the reference position on the machine by means of a phenolic support to attenuate extraneous ultrasonic vibrations induced in the machine base. A piezoelectric crystal is acoustically coupled to the ball holder to sense ultrasonic vibrations induced in the ball and transmitted through the holder when the grinding wheel touches the reference ball. The ultrasonic frequency electrical signal output of the crystal is sensed by an ultrasonic detection circuit which produces a DC output signal having an amplitude proportional to the ultrasonic signal amplitude. The DC signal may be used to signal the numerical controller to stop the grinding wheel positioning mechanism when a predetermined level DC signal is sensed to indicate that the grinding wheel is positioned at the reference point along the axis.
Inventors
- 👤 John J Henry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:21
CPC Classifications
B; B24; B24B; B24B49/00; B24B49/003; B24B47/00; B24B47/20; Y; Y10; Y10S; Y10S451/00; Y10S451/91
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
220 words
In an automatic grinding machine comprising a grinding wheel, means for positioning said grinding wheel over a programmed path relative to a workpiece from a reference position on said machine, a system for detecting contact between said grinding wheel and a contact member positioned at said reference position, comprising: a support member for displaceably carrying said contact member, said support being made of a material which readily transmits vibrations in the ultrasonic frequency range generated when said grinding wheel contacts said contact member; a holder member for fixedly mounting said support member at said reference position on said machine, said holder member being made of a material which attenuates the transmission extraneous of ultrasonic vibrations therethrough from said machine; an ultrasonic acoustical transducer mechanically coupled to said support member for detecting ultrasonic acoustic vibrations transmitted through said support member from said contact member when said grinding wheel contacts said contact member and generating an AC output signal having an amplitude proportional to the amplitude of the acoustic vibrations detected by said transducer; and a detector circuit means responsive to the AC output signal of said transducer for generating a DC control signal when the amplitude of the output signal of said transducer exceeds a preselected value indicative of a known contact force of said grinding wheel against said contact member.
Claim 2
Dependent Claim
220 words
In an automatic grinding machine comprising a grinding wheel, means for positioning said grinding wheel over a programmed path relative to a workpiece from a reference position on said machine, a system for detecting contact between said grinding wheel and a contact member positioned at said reference position, comprising: a support member for displaceably carrying said contact member, said support being made of a material which readily transmits vibrations in the ultrasonic frequency range generated when said grinding wheel contacts said contact member; a holder member for fixedly mounting said support member at said reference position on said machine, said holder member being made of a material which attenuates the transmission extraneous of ultrasonic vibrations therethrough from said machine; an ultrasonic acoustical transducer mechanically coupled to said support member for detecting ultrasonic acoustic vibrations transmitted through said support member from said contact member when said grinding wheel contacts said contact member and generating an AC output signal having an amplitude proportional to the amplitude of the acoustic vibrations detected by said transducer; and a detector circuit means responsive to the AC output signal of said transducer for generating a DC control signal when the amplitude of the output signal of said transducer exceeds a preselected value indicative of a known contact force of said grinding wheel against said contact member.
Claim 3
Dependent Claim
43 words
The system as set forth in claim 1 wherein said contact member is a precisely formed steel ball and wherein said support member is in the form of a solid metal cylinder having a conical shaped recessed upper portion for carrying said ball.
Claim 4
Dependent Claim
81 words
The system as set forth in claim 2 wherein said detector circuit means includes a tunable bandpass amplifier for amplifying signals corresponding to the ultrasonic resonant frequency of the AC output signal of said transducer; an integrator; a diode connected between the output of said amplifier and said integrator and a discriminator connected to the output of said integrator for producing said DC output signal when the amplitude of the signal at the output of said integrator exceeds a predetermined value.
Claim 5
Dependent Claim
16 words
The system as set forth in claim 3 wherein said holder member is constructed from phenolic.
References Cited (Backward Citations)
US2697347A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |