EP0481971B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Signature analysis control system for a stamping press
Assignee: Signature Technologies Inc
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Filing: 1989-02-21
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Granted: 1994-09-07
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Expires: 2009-02-21
Abstract
Abstract A control system for a stamping press having a ram adapted to cooperate with a tool for controllably moving through a cycle to generate forces at the tool includes storing, as a reference signature, a set of data bytes corresponding to a first ram cycle, storing, as a current signature, a set of data bytes corresponding to a subsequent ram cycle, comparing the current and reference signatures and generating control signals to the press in accordance with the comparison to disable the press in the event of unacceptable force variations.
Inventors
- 👤 Michael J. O'brien
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 16:22
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/04; G05B19/042; G05B19/0428; B; B30; B30B; B30B15/00; B30B15/0094; B30B15/26; B30B15/28; G05B2219/00; G05B2219/20; G05B2219/24; G05B2219/24042
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
279 words
A method for controlling the operation of a stamping press (12), said press including a first press member (21), adapted to cooperate with a second press member (22), for controllably moving through a cycle to generate forces at said second press member (22), the method being of the type including the steps of generating a first analog signal indicative of a first force associated with said first press member (21) during a reference cycle, and generating a position signal indicative of cyclical incremental advancement of the first press member (21), said method characterized in that it comprises the steps of: sampling said first analog signal at a rate dependent upon said position signal and generating a first signature array of successive data bytes indicative of instantaneous values of said first force; generating first and second reference arrays of data bytes from said first signature array, wherein the data bytes of said first reference array are indicative of said instantaneous values having a first offset value added thereto and the data bytes of said second reference array are indicative of said instantaneous values having a second offset value subtracted therefrom; generating a second analog signal indicative of a second force associated with said first press member (21) during an operation cycle subsequent to said reference cycle; sampling said second analog signal at a rate dependent upon said position signal and generating a second signature array of successive data bytes indicative of instantaneous values of said second force; comparing the data bytes of said second signature array with the data bytes of said first and second reference arrays; and generating control signals to control said press in accordance with said comparison.
Claim 2
Dependent Claim
49 words
The method as claimed in claim 1, further including the steps of providing a trigger signal based on the progression of said stamping press (12) past a definable point in an operational cycle, and initiating the acquisition of said first and second analog signals based on said trigger signal.
Claim 3
Dependent Claim
49 words
The method as claimed in claim 1, further including the steps of generating a position signal based on the progression of said stamping press (12) past a definable point in an operational cycle, and terminating the acquisition of said first and second analog signals based on said position signal.
Claim 4
Dependent Claim
17 words
The method as claimed in claim 1, wherein the first offset value equals the second offset value.
Claim 5
Dependent Claim
55 words
The method of claim 1, further comprising the step of permanently storing said signature array and said first and second reference arrays in a mass storage area (38) when data bytes of the said current signature array are found to deviate unacceptably from the corresponding data bytes in said reference arrays based on said comparison.
Claim 6
Independent Claim
260 words
An apparatus for controlling the operating of a stamping press (12), said press including a ram (21) adapted to cooperate with a tool (22) for controllably moving through a cycle to generate forces at said tool (22), the apparatus being of the type including means (34) for generating a position signal indicative of the position of the ram during a cycle, signal means (32) for generating a first analog signal indicative of a first force associated with said ram during a reference cycle and a second analog signal indicative of a second force associated with said ram during a subsequent cycle, and sampling means (108) for sampling said first and second analog signals in response to the position signal, and respectively generating first and second signature arrays of successive data bytes indicative of instantaneous values of said first and second force, said apparatus characterized in that it comprises: process means (112) for generating first and second reference arrays of data bytes from said first signature array, wherein the data bytes of said first reference array are indicative of said instantaneous values having a first offset value added thereto and the data bytes of said second reference array are indicative of said instantaneous value having a second offset value subtracted therefrom; comparison means (110, 112) for comparing the data bytes of said second signature array with the data bytes of said first and second reference arrays and generating a comparison signal; and control means (112, 116) for generating control signals to control said press (12) in response to said comparison signal.
Claim 7
Dependent Claim
54 words
An apparatus as claim in claim 6, further comprising means for generating a trigger signal (101) based on the progression of said stamping press (12) past a definable point in an operational cycle, wherein said signal means (101) initiates the acquisition of said first and second analog signals in response to said trigger signal.
Claim 8
Dependent Claim
54 words
An apparatus as claimed in claim 7, further comprising means (105) for generating a position signal based on the progression of said stamping press (12) past a definable point in an operational cycle, wherein said signal means (105) terminates the acquisition of said first and second analog signals in response to said position signal.
Claim 9
Dependent Claim
91 words
An apparatus as claimed in claim 8, further comprising a drive mechanism (18) for moving the ram (21) through the cycle, wherein: means for generating a position signal includes an encoder (34) coupled to the drive mechanism (18) for generating a series of pulses, each pulse corresponding to an incremental change in the position of the ram (21); the sampling means includes an analog-to-digital convertor (108); and the encoder (34) is coupled to the analog-to-digital convertor (108) such that one sample occurs in response to one pulse of the position signal.
Claim 10
Dependent Claim
54 words
The apparatus of claim 6, further comprising means for permanently storing said signature array and said first and second reference arrays in a mass storage area (38) when data bytes of the said current signature array are found to deviate unacceptably from the corresponding data bytes in said reference arrays based on said comparison.
References Cited (Backward Citations)
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