Patent US4358945A successfully refreshed from Google Patents.
US4358945A
Expired / Lapsed
US
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Gag press
Assignee: ZF Friedrichshafen AG
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Filing: 1980-07-16
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Granted: 1982-11-16
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Expires: 2000-07-16
Abstract
Abstract Piezoelectric transducers are mounted on support members of a gag press for sensing pressure vibrations arising in a workpiece in part as reflections of an initial pulse produced by the striking of the workpiece by a press ram at the initiation of a straightening operation. An electrical circuit is connected to the transducers for analyzing the sensed pressure waves and for comparing the analyzed waves to pre-established sound-threshold data stored in a memory. Upon detecting pressure waves indicative of an internal structural flaw in the workpiece, a microprocessor in the electrical circuit signals a ram drive to raise the ram and thereby terminate straightening operations, the defect-bearing workpiece being transferred to a scrap store or to a heat treatment plant by a sorter according to signals from the microprocessor. The press assembly includes position monitors juxtaposable to the workpiece in the press for determining workpiece curvature, the microprocessor being connected to these monitors and to a ram mount for adjusting in response to signals from the monitors the horizontal position of the ram prior to a downward workpiece-bending stroke thereof. Upon detecting the straightening of the workpiece according to stored tolerance data, the microprocessor elevates the ram and has the workpiece conveyed away for further finishing operations. The press assembly includes in a feeder an automatic centering or grinding apparatus and an oiling device for preparing a workpiece for sound-wave transmission over the supports to the transducers.
Inventors
- 👤 Karl-Heinz Partzel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:56
CPC Classifications
B; B21; B21D; B21D3/00; B21D3/10; G; G01; G01N; G01N2291/00; G01N2291/02; G01N2291/028; G01N2291/02872
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
211 words
In a gag press for straightening a metal workpiece, comprising: a frame; support means on said frame at a pressing station for holding said workpiece during straightening operations in a position wherein the workpiece is straightened; feed means extending to said pressing station for conveying said workpiece to said support means prior to said straightening operations; stressing means including a ram reciprocatably mounted on said frame at said pressing station for striking said workpiece to generate an initial sound-producing pulse and for subsequently coacting with said support means to bend said workpiece; drive means on said frame connected to said stressing means for reciprocating said ram in said mounting means; extracting means for removing said workpiece from said pressing station upon the termination of said straightening operations, the improvement which comprises the combination therewith of: sensor means including an acoustic-electric transducer mounted on said frame for detecting pressure waves including ultrasonic waves generated by internal structural irregularities in said workpiece in response to said pulse; adjustable mounting means on said frame for holding said ram in a preselected one of a plurality of positions; and electrical circuit means connected to said sensor means for analyzing signals therefrom to determine the presence, location and extent of internal structural irregularities in said workpiece.
Claim 2
Dependent Claim
211 words
In a gag press for straightening a metal workpiece, comprising: a frame; support means on said frame at a pressing station for holding said workpiece during straightening operations in a position wherein the workpiece is straightened; feed means extending to said pressing station for conveying said workpiece to said support means prior to said straightening operations; stressing means including a ram reciprocatably mounted on said frame at said pressing station for striking said workpiece to generate an initial sound-producing pulse and for subsequently coacting with said support means to bend said workpiece; drive means on said frame connected to said stressing means for reciprocating said ram in said mounting means; extracting means for removing said workpiece from said pressing station upon the termination of said straightening operations, the improvement which comprises the combination therewith of: sensor means including an acoustic-electric transducer mounted on said frame for detecting pressure waves including ultrasonic waves generated by internal structural irregularities in said workpiece in response to said pulse; adjustable mounting means on said frame for holding said ram in a preselected one of a plurality of positions; and electrical circuit means connected to said sensor means for analyzing signals therefrom to determine the presence, location and extent of internal structural irregularities in said workpiece.
Claim 3
Dependent Claim
13 words
The improvement defined in claim 1 wherein said transducer contacts said support means.
Claim 4
Dependent Claim
18 words
The improvement defined in claim 2 wherein said sensor means includes an additional acoustic-electric transducer contacting said ram.
Claim 5
Dependent Claim
14 words
The improvement defined in claim 2 wherein said transducer is of the piezoelectric-crystal type.
Claim 6
Dependent Claim
38 words
The improvement defined in claim 2 wherein said electrical circuit means is operatively connected to said drive means for controlling the actuation and disengagement of said ram at least partially in response to signal from said sensor means.
Claim 7
Dependent Claim
50 words
The improvement defined in claim 5 wherein said sensor means further includes at least two workpiece-position monitors, said electrical circuit means being operatively connected to said mounting means for adjusting the position of said ram relative to said workpiece at least partially in response to signals from said workpiece-position monitors.
Claim 8
Dependent Claim
62 words
The improvement defined in claim 5 or 6 wherein said electrical circuit means includes a memory for storing coded sound-threshold values pre-established for said workpiece and control means connected to said memory and to said sensor means for comparing signals from said sensor means with said threshold values, thereby determining the presence, location and extent of internal structural irregularities in said workpiece.
Claim 9
Dependent Claim
38 words
The improvement defined in claim 7 wherein said extracting means includes sorting means operatively connected to said electrical circuit means for selecting under the control thereof workpieces to be scrapped and workpieces to be subjected to further treatment.
Claim 10
Dependent Claim
31 words
The improvement defined in claim 8, wherein said extracting means includes means for applying to a workpiece a mark indicating at least in part the internal structural state of such workpiece.
Claim 11
Dependent Claim
49 words
The improvement defined in claim 9 wherein said feed means includes means for applying an oil film to at least part of the external surface of a workpiece prior to the delivery thereof to said support means, thereby facilitating a sound-transmitting coupling between such workpiece and said support means.
Claim 12
Dependent Claim
64 words
The improvement defined in claim 10 wherein said electrical circuit means is operatively connected to said workpiece-position monitors at least in part for detecting the completion of bending operations on a workpiece, further comprising signal-converting means operatively connected to said electrical circuit means and to said feed means for controlling the functioning thereof at least partially in response to signals from said workpiece-position monitors.
Claim 13
Dependent Claim
29 words
The improvement defined in claim 11 wherein said feed means includes centering means for grinding support-contact areas on a workpiece prior to the delivery thereof to said pressing station.
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) | 1985-11-15 | 1986-05-17 | 1986-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-15 | 1990-05-17 | 1990-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-15 | 1994-05-17 | 1994-11-16 | $7700.00 | Window Closed / Lapsed |