US5661887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blind rivet set verification system and method
Assignee: Newfrey LLC
•
Filing: 1995-04-20
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Granted: 1997-09-02
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Expires: 2015-04-20
Abstract
Abstract A blind rivet set verification system for setting a blind rivet assessing the acceptability of the rivet set. The system includes a remote intensified rivet setting tool and computer hardware and software. The tool comprises a displacement transducer that produces a displacement signal and a pressure transducer that produces a pressure signal. The transducers are connected to the computer which receives the distinct signals. These signals are interpreted to plot a displacement-versus pressure waveform and to determine the velocity of the movement of an air piston that responds to the rivet set by hydraulic pressure. Using the combined date of the velocity waveform and the displacement-versus pressure waveform, the breakload is identified and compared against predetermined ideal data to assess the acceptability of the set. The displacement reading at break is corrected for jaw slippage and offset of the air piston.
Inventors
- 👤 Darren S. Byrne
- 👤 Eymard J. Chitty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:04
CPC Classifications
B; B21; B21J; B21J15/00; B21J15/10; B21J15/28; B21J15/285; B21J15/105; Y; Y10; Y10T; Y10T29/00; Y10T29/53; Y10T29/53709; Y10T29/53717; Y10T29/53726; Y10T29/5373; Y10T29/53739; Y10T29/53743; Y10T29/53748
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
267 words
A system for setting a blind rivet and evaluating the acceptability of the set, said rivet being of the type having a frangible tubular body and an elongated mandrel that includes an enlarged head and a stem extending rearwardly of the head and through said frangible tubular body, said system comprising: a hydraulically operated blind rivet setting tool, said tool including a rivet engaging assembly for engaging said stem of said mandrel and an axially movable piston assembly operatively coupled to said rivet engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; a first transducer for monitoring the pressure of the hydraulic fluid applied to said, piston assembly during a rivet setting process and producing pressure output signals related thereto; a second transducer operatively associated with said tool for producing displacement output signals related to the movement of said piston assembly in the axial direction during the rivet setting process; and a control circuit, said control circuit having circuitry to: (a) receive a series of said pressure output signals and a series of said displacement output signals during the rivet setting process; (b) determine from said series of displacement output signals the velocity of said piston assembly during the rivet setting process; (c) identify the occurrence during the rivet setting process of the highest value of velocity; (d) use the occurrence of the highest value of velocity to identify the mandrel breakpoint; and (e) compare a breakpoint load value determined from the value of the pressure output signal at the mandrel breakpoint with a predetermined desired value.
Claim 2
Independent Claim
267 words
A system for setting a blind rivet and evaluating the acceptability of the set, said rivet being of the type having a frangible tubular body and an elongated mandrel that includes an enlarged head and a stem extending rearwardly of the head and through said frangible tubular body, said system comprising: a hydraulically operated blind rivet setting tool, said tool including a rivet engaging assembly for engaging said stem of said mandrel and an axially movable piston assembly operatively coupled to said rivet engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; a first transducer for monitoring the pressure of the hydraulic fluid applied to said, piston assembly during a rivet setting process and producing pressure output signals related thereto; a second transducer operatively associated with said tool for producing displacement output signals related to the movement of said piston assembly in the axial direction during the rivet setting process; and a control circuit, said control circuit having circuitry to: (a) receive a series of said pressure output signals and a series of said displacement output signals during the rivet setting process; (b) determine from said series of displacement output signals the velocity of said piston assembly during the rivet setting process; (c) identify the occurrence during the rivet setting process of the highest value of velocity; (d) use the occurrence of the highest value of velocity to identify the mandrel breakpoint; and (e) compare a breakpoint load value determined from the value of the pressure output signal at the mandrel breakpoint with a predetermined desired value.
Claim 3
Dependent Claim
85 words
The system for setting a blind rivet of claim 1 wherein said control circuit further includes circuitry to: produce from said series of pressure output signals and said series of displacement output signals received over the rivet setting process a pressure-versus-displacement waveform and a velocity waveform; scan said velocity waveform to determine the location in the velocity waveform of the highest value of velocity; and use the determined location of the highest value of velocity to scan said pressure-versus-displacement waveform to identify the mandrel breakpoint.
Claim 4
Dependent Claim
57 words
The system of claim 1 further including a hydraulic intensifier assembly and a hydraulic line fluidly connecting said hydraulic intensifier assembly to said piston assembly of said rivet setting tool, said hydraulic intensifier assembly including a second axially movable piston assembly; and further wherein said first and second transducers are operatively coupled to said hydraulic intensifier assembly.
Claim 5
Dependent Claim
44 words
The system for setting a blind rivet of claim 1 further including an indicator operatively connected to said control circuit for signalling to an operator the acceptability of the set based on said comparison of said breakpoint load value against said predetermined desired value.
Claim 6
Dependent Claim
25 words
The system of claim 1 wherein said first transducer is an electrical pressure transducer and wherein said second transducer is a linear variable differential transformer.
Claim 7
Dependent Claim
26 words
The system of claim 1 wherein said control circuit includes an integrator, a comparator connected with said integrator, and a programmable memory connected with said comparator.
Claim 8
Independent Claim
183 words
A method of setting a blind rivet having a mandrel with a setting tool having a mandrel engaging assembly for engaging said mandrel and an axially movable piston assembly operatively coupled to said engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; said method including the steps of: (a) monitoring the pressure of the hydraulic fluid applied to said piston assembly during a rivet setting process and producing a series of pressure signals related thereto; (b) monitoring the movement of said piston assembly in the axial direction during said rivet setting process and producing a series of displacement signals related thereto; (c) determining from said series of displacement signals the velocity of said piston assembly during the rivet setting process; (d) identifying the occurrence during the rivet setting process of the highest value of velocity; (e) using the occurrence of the highest value of velocity to identify the mandrel breakpoint; (f) comparing a breakpoint load value determined from the value of the pressure signal at the mandrel breakpoint with a predetermined desired value.
Claim 9
Independent Claim
183 words
A method of setting a blind rivet having a mandrel with a setting tool having a mandrel engaging assembly for engaging said mandrel and an axially movable piston assembly operatively coupled to said engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; said method including the steps of: (a) monitoring the pressure of the hydraulic fluid applied to said piston assembly during a rivet setting process and producing a series of pressure signals related thereto; (b) monitoring the movement of said piston assembly in the axial direction during said rivet setting process and producing a series of displacement signals related thereto; (c) determining from said series of displacement signals the velocity of said piston assembly during the rivet setting process; (d) identifying the occurrence during the rivet setting process of the highest value of velocity; (e) using the occurrence of the highest value of velocity to identify the mandrel breakpoint; (f) comparing a breakpoint load value determined from the value of the pressure signal at the mandrel breakpoint with a predetermined desired value.
Claim 10
Dependent Claim
82 words
The method of claim 7 further including the steps of: producing a pressure-versus-displacement waveform based on said series of pressure signals and said series of displacement signals produced over the rivet setting process; producing a velocity waveform based on said series of displacement signals; scanning said velocity waveform to determine the point in time during the rivet setting process when the highest value of velocity occurred; using said determined point in time to scan said pressure-versus-displacement waveform to identify the mandrel breakpoint.
Claim 11
Independent Claim
246 words
A system for setting a blind rivet and evaluating the acceptability of the set, said rivet being of the type having a frangible tubular body and an elongated mandrel that includes an enlarged head and a stem extending rearwardly of the head and through said frangible tubular body, said system comprising: a hydraulically operated blind rivet setting tool, said tool including a rivet engaging assembly for engaging said stem of said mandrel and an axially movable piston assembly operatively coupled to said rivet engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; a first transducer for monitoring the pressure of the hydraulic fluid applied to said piston assembly during a rivet setting process and producing pressure output signals related thereto; a second transducer operatively associated with said tool for producing displacement output signals related to the movement of said piston assembly in the axial direction during the rivet setting process; and a control circuit, said control circuit having circuitry to: (a) receive a series of said pressure output signals and a series of said displacement output signals during the rivet setting process; (b) identify the occurrence during the rivet setting process of the peak pressure; (c) use the occurrence of the pressure peak to identify the break of the mandrel; (d) determine the total displacement of said piston assembly at the break of the mandrel; and (e) compare said total displacement with a predetermined desired value.
Claim 12
Independent Claim
246 words
A system for setting a blind rivet and evaluating the acceptability of the set, said rivet being of the type having a frangible tubular body and an elongated mandrel that includes an enlarged head and a stem extending rearwardly of the head and through said frangible tubular body, said system comprising: a hydraulically operated blind rivet setting tool, said tool including a rivet engaging assembly for engaging said stem of said mandrel and an axially movable piston assembly operatively coupled to said rivet engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; a first transducer for monitoring the pressure of the hydraulic fluid applied to said piston assembly during a rivet setting process and producing pressure output signals related thereto; a second transducer operatively associated with said tool for producing displacement output signals related to the movement of said piston assembly in the axial direction during the rivet setting process; and a control circuit, said control circuit having circuitry to: (a) receive a series of said pressure output signals and a series of said displacement output signals during the rivet setting process; (b) identify the occurrence during the rivet setting process of the peak pressure; (c) use the occurrence of the pressure peak to identify the break of the mandrel; (d) determine the total displacement of said piston assembly at the break of the mandrel; and (e) compare said total displacement with a predetermined desired value.
Claim 13
Dependent Claim
90 words
The system for setting a blind rivet of claim 9 wherein said control circuit further includes circuitry to: produce from said series of pressure output signals and said series of displacement output signals received over the rivet setting process a pressure-versus-displacement waveform; scan said pressure-versus-displacement waveform to identify the location of the pressure peak in the waveform; use the identified location of the pressure peak to identify the break of the mandrel; and determine from said waveform the total displacement of said piston assembly at the break of the mandrel.
Claim 14
Dependent Claim
102 words
The system for setting a blind rivet of claim 10 wherein said control circuit further includes circuitry for scanning said pressure-versus-displacement waveform for slippage of said mandrel within said rivet engaging assembly by scanning said waveform for a drop in pressure, determining a first displacement value from the point on said waveform where said drop in pressure occurs, scanning said waveform for a subsequent rise in pressure, determining a second displacement value from the point on said waveform where said rise in pressure occurs, determining the difference between said first and second displacement values, and subtracting said difference from said total displacement.
Claim 15
Dependent Claim
42 words
The system for setting a blind rivet of claim 11 wherein said control circuit further includes circuitry for scanning said pressure-versus-displacement waveform for all occurrences of slippage and subtracting the amount of displacement determined for each slippage occurrence from said total displacement.
Claim 16
Dependent Claim
42 words
The system for setting a blind rivet of claim 10 wherein said control circuit further includes circuitry for identifying the value any offset of said piston assembly between sets of rivets and for subtracting said identified offset value from said total displacement.
Claim 17
Dependent Claim
44 words
The system for setting a blind rivet of claim 9 further including an indicator operatively connected to said control circuit for signalling to an operator the acceptability of the rivet set based on said comparison of said total displacement to said predetermined desired value.
Claim 18
Dependent Claim
57 words
The system of claim 9 further including a hydraulic intensifier assembly and a hydraulic line fluidly connecting said hydraulic intensifier assembly to said piston assembly of said rivet setting tool, said hydraulic intensifier assembly including a second axially movable piston assembly; and further wherein said first and second transducers are operatively coupled to said hydraulic intensifier assembly.
Claim 19
Dependent Claim
30 words
The system for setting a blind rivet of claim 15 wherein said first transducer is an electrical pressure transducer and wherein said second transducer is a linear variable differential transformer.
Claim 20
Independent Claim
163 words
A method of setting a blind rivet having a mandrel with a setting tool having a mandrel engaging assembly for engaging said mandrel and an axially movable piston assembly operatively coupled to said engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; said method including the steps of: (a) monitoring the pressure of the hydraulic fluid applied to said piston assembly during a rivet setting process and producing a series of pressure signals related thereto; (b) monitoring the movement of said piston assembly in the axial direction during said rivet setting process and producing a series of displacement signals related thereto; (c) identifying the occurrence during the rivet setting process of a peak pressure; (d) using the occurrence of the peak pressure to identify the breakpoint of the mandrel; (e) determining the total displacement of the piston assembly at the mandrel breakpoint; and (f) comparing the total displacement with a predetermined desired value.
Claim 21
Independent Claim
163 words
A method of setting a blind rivet having a mandrel with a setting tool having a mandrel engaging assembly for engaging said mandrel and an axially movable piston assembly operatively coupled to said engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; said method including the steps of: (a) monitoring the pressure of the hydraulic fluid applied to said piston assembly during a rivet setting process and producing a series of pressure signals related thereto; (b) monitoring the movement of said piston assembly in the axial direction during said rivet setting process and producing a series of displacement signals related thereto; (c) identifying the occurrence during the rivet setting process of a peak pressure; (d) using the occurrence of the peak pressure to identify the breakpoint of the mandrel; (e) determining the total displacement of the piston assembly at the mandrel breakpoint; and (f) comparing the total displacement with a predetermined desired value.
Claim 22
Dependent Claim
70 words
The method of claim 17 further including the steps of: producing a pressure-versus-displacement waveform based on said series of pressure signals and said series of displacement signals produced over the rivet setting process; scanning said pressure-versus-displacement waveform to identify the location of a pressure peak in said waveform; using the location of the pressure peak to identify the total displacement of the piston assembly at the breakpoint of the mandrel.
Claim 23
Dependent Claim
99 words
The method for setting a blind rivet according to claim 18 including the additional steps of: scanning said pressure-versus-displacement waveform for slippage of said mandrel within said jaw assembly by scanning said waveform for a drop in pressure; determining a first displacement value from the point on said waveform where said drop in pressure occurs; scanning said waveform for a subsequent rise in pressure; determining a second displacement value from the point on the waveform where said rise in pressure occurs; determining the difference between said first and second displacement values; and subtracting said difference from said total displacement.
Claim 24
Dependent Claim
40 words
The method for setting a blind rivet according to claim 19 including the additional steps of: scanning said pressure-versus-displacement waveform for all occurrences of slippage; and subtracting the amount of displacement determined for each slippage occurrence from said total displacement.
Claim 25
Dependent Claim
50 words
The method for setting a blind rivet according to claim 18 including the additional steps of: noting the occurrence of piston offset between sets of rivet sets; assigning an offset value representing the amount of offset at said piston offset occurrence; and subtracting said offset value from said total displacement.
Claim 26
Independent Claim
218 words
A system for setting a blind rivet and evaluating the acceptability of the set, said rivet being of the type having a frangible tubular body and an elongated mandrel that includes an enlarged head and a stem extending rearwardly of the head and through said frangible tubular body, said system comprising: a hydraulically operated blind rivet setting tool, said tool including a rivet engaging assembly for engaging said stem of said mandrel and an axially movable piston assembly operatively coupled to said rivet engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; a transducer operatively associated with said tool for producing displacement output signals related to the movement of said piston assembly in the axial direction during the rivet setting process; and a control circuit, said control circuit having circuitry to: (a) receive a series of said displacement output signals over time; (b) determine from said series of displacement output signals the velocity of said piston assembly during the rivet setting process; (c) determine a lowest initial velocity value; (d) determine a peak velocity value subsequent to said lowest initial velocity value; (e) determine the difference between said lowest initial velocity value and said peak velocity value; and (f) compare the determined difference with a predetermined desired value.
Claim 27
Independent Claim
218 words
A system for setting a blind rivet and evaluating the acceptability of the set, said rivet being of the type having a frangible tubular body and an elongated mandrel that includes an enlarged head and a stem extending rearwardly of the head and through said frangible tubular body, said system comprising: a hydraulically operated blind rivet setting tool, said tool including a rivet engaging assembly for engaging said stem of said mandrel and an axially movable piston assembly operatively coupled to said rivet engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; a transducer operatively associated with said tool for producing displacement output signals related to the movement of said piston assembly in the axial direction during the rivet setting process; and a control circuit, said control circuit having circuitry to: (a) receive a series of said displacement output signals over time; (b) determine from said series of displacement output signals the velocity of said piston assembly during the rivet setting process; (c) determine a lowest initial velocity value; (d) determine a peak velocity value subsequent to said lowest initial velocity value; (e) determine the difference between said lowest initial velocity value and said peak velocity value; and (f) compare the determined difference with a predetermined desired value.
Claim 28
Dependent Claim
26 words
The system of claim 22 wherein the circuitry for determining the velocity of said piston assembly measures the intervals between receipt of successive displacement output signals.
Claim 29
Dependent Claim
66 words
The system of claim 22 wherein said control circuit further includes circuitry to: produce from said displacement output signals a velocity waveform; scan said velocity waveform to determine the lowest initial value of velocity; scan said velocity waveform to determine a peak of said waveform subsequent to said lowest initial value of velocity; and determine the difference between said lowest initial value and said subsequent peak.
Claim 30
Dependent Claim
44 words
The system for setting a blind rivet of claim 22 further including an indicator operatively connected to said control circuit for signalling to an operator the acceptability of the set based on said comparison of said actual determined difference against said predetermined desired value.
Claim 31
Dependent Claim
57 words
The system of claim 22 further including a hydraulic intensifier assembly and a hydraulic line fluidly connecting said hydraulic intensifier assembly to said piston assembly of said rivet setting tool, said hydraulic intensifier assembly including a second axially movable piston assembly; and further wherein said first and second transducers are operatively coupled to said hydraulic intensifier assembly.
Claim 32
Dependent Claim
19 words
The system for setting a blind rivet of claim 26 wherein said transducer is a linear variable differential transformer.
Claim 33
Independent Claim
142 words
A method of setting a blind rivet having a mandrel with a setting tool having a mandrel engaging assembly for engaging said mandrel and an axially movable piston assembly operatively coupled to said engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; said method including the steps of: (a) monitoring the movement of said piston assembly in the axial direction during the rivet setting process and producing a series of displacement signals; (b) determining from said series of displacement signals the velocity of said piston assembly; (c) determining a lowest initial value of velocity; (d) determining a peak velocity value subsequent to said lowest initial velocity value; (e) determining the difference between said lowest initial velocity value and said peak velocity value; and (f) comparing said difference to a predetermined desired value.
Claim 34
Independent Claim
142 words
A method of setting a blind rivet having a mandrel with a setting tool having a mandrel engaging assembly for engaging said mandrel and an axially movable piston assembly operatively coupled to said engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; said method including the steps of: (a) monitoring the movement of said piston assembly in the axial direction during the rivet setting process and producing a series of displacement signals; (b) determining from said series of displacement signals the velocity of said piston assembly; (c) determining a lowest initial value of velocity; (d) determining a peak velocity value subsequent to said lowest initial velocity value; (e) determining the difference between said lowest initial velocity value and said peak velocity value; and (f) comparing said difference to a predetermined desired value.
Claim 35
Dependent Claim
27 words
The method of claim 28 wherein said step of determining the velocity of said piston assembly includes measuring the intervals between successive displacement signals in said series.
Claim 36
Dependent Claim
52 words
The method of claim 28 further including the steps of: determining from said series of displacement signals a velocity waveform; scanning said velocity waveform to determine a lowest initial value of velocity; and scanning said velocity waveform to determine a peak in said waveform subsequent to said lowest initial value of velocity.
Claim 37
Independent Claim
271 words
A system for setting a blind rivet and evaluating the acceptability of the set, said rivet being of the type having a frangible tubular body and an elongated mandrel that includes an enlarged head and a stem extending rearwardly of the head and through said frangible tubular body, said system comprising: a hydraulically operated blind rivet setting tool, said tool including a rivet engaging assembly for engaging said stem of said mandrel and an axially movable piston assembly operatively coupled to said rivet engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; a first transducer for monitoring the pressure of the hydraulic fluid applied to said piston assembly during a rivet setting process and producing pressure output signals related thereto; a second transducer operatively associated with said tool for producing displacement output signals related to the movement of said piston assembly in the axial direction during the rivet setting process; and a control circuit, said control circuit having circuitry to: (a) receive a series of said pressure output signals and a series of said displacement output signals; (b) determine from said series of displacement output signals the velocity of said piston assembly during the rivet setting process; (c) determine the occurrence of a lowest initial value of velocity, this value representing the point in time during the rivet setting process when the mandrel head enters the rivet body; (d) determine the value of the pressure output signal at said point in time when the mandrel head enters the rivet body; and (e) compare said pressure value with a predetermined desired value.
Claim 38
Independent Claim
271 words
A system for setting a blind rivet and evaluating the acceptability of the set, said rivet being of the type having a frangible tubular body and an elongated mandrel that includes an enlarged head and a stem extending rearwardly of the head and through said frangible tubular body, said system comprising: a hydraulically operated blind rivet setting tool, said tool including a rivet engaging assembly for engaging said stem of said mandrel and an axially movable piston assembly operatively coupled to said rivet engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; a first transducer for monitoring the pressure of the hydraulic fluid applied to said piston assembly during a rivet setting process and producing pressure output signals related thereto; a second transducer operatively associated with said tool for producing displacement output signals related to the movement of said piston assembly in the axial direction during the rivet setting process; and a control circuit, said control circuit having circuitry to: (a) receive a series of said pressure output signals and a series of said displacement output signals; (b) determine from said series of displacement output signals the velocity of said piston assembly during the rivet setting process; (c) determine the occurrence of a lowest initial value of velocity, this value representing the point in time during the rivet setting process when the mandrel head enters the rivet body; (d) determine the value of the pressure output signal at said point in time when the mandrel head enters the rivet body; and (e) compare said pressure value with a predetermined desired value.
Claim 39
Dependent Claim
61 words
The system of claim 31 wherein said control circuit further includes circuitry to: produce from said series of pressure output signals and said series of displacement output signals a pressure-versus-displacement waveform and a velocity waveform; determine the point on said velocity waveform of a lowest initial velocity value; and determine the pressure value at the corresponding point on said pressure-versus-displacement waveform.
Claim 40
Dependent Claim
43 words
The system for setting a blind rivet of claim 31 further including an indicator operatively connected to said control circuit for signalling to an operator the acceptability of the set based on said comparison of said pressure value with said predetermined desired value.
Claim 41
Dependent Claim
57 words
The system of claim 31 further including a hydraulic intensifier assembly and a hydraulic line fluidly connecting said hydraulic intensifier assembly to said piston assembly of said rivet setting tool, said hydraulic intensifier assembly including a second axially movable piston assembly; and further wherein said first and second transducers are operatively coupled to said hydraulic intensifier assembly.
Claim 42
Dependent Claim
30 words
The system for setting a blind rivet of claim 34 wherein said first transducer is an electrical pressure transducer and wherein said second transducer is a linear variable differential transformer.
Claim 43
Independent Claim
214 words
A method of setting a blind rivet having a tubular body and a mandrel with an enlarged head portion and an elongated stem portion extending through said body, with a setting tool having a mandrel engaging assembly for engaging said mandrel and an axially movable piston assembly operatively coupled to said engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; said method including the steps of: (a) monitoring the pressure of the hydraulic fluid applied to said piston assembly during a rivet setting process and producing a series of pressure signals related thereto; (b) monitoring the movement of said piston assembly in the axial direction during said rivet setting process and producing a series of displacement signals related thereto; (c) determining from said series of displacement signals the velocity of said piston assembly during the rivet setting process; (d) determining the occurrence of a lowest initial velocity value, said lowest initial velocity value representing the point in time during the rivet setting process when the mandrel head enters the rivet body; (e) determining the value of said pressure output signal at said point in time when the mandrel head enters the rivet body; and (f) comparing said pressure value to a predetermined desired value.
Claim 44
Independent Claim
214 words
A method of setting a blind rivet having a tubular body and a mandrel with an enlarged head portion and an elongated stem portion extending through said body, with a setting tool having a mandrel engaging assembly for engaging said mandrel and an axially movable piston assembly operatively coupled to said engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly; said method including the steps of: (a) monitoring the pressure of the hydraulic fluid applied to said piston assembly during a rivet setting process and producing a series of pressure signals related thereto; (b) monitoring the movement of said piston assembly in the axial direction during said rivet setting process and producing a series of displacement signals related thereto; (c) determining from said series of displacement signals the velocity of said piston assembly during the rivet setting process; (d) determining the occurrence of a lowest initial velocity value, said lowest initial velocity value representing the point in time during the rivet setting process when the mandrel head enters the rivet body; (e) determining the value of said pressure output signal at said point in time when the mandrel head enters the rivet body; and (f) comparing said pressure value to a predetermined desired value.
Claim 45
Dependent Claim
80 words
The method of claim 36 further including the steps of: producing a pressure-versus-displacement waveform based on said series of pressure signals and said series of displacement signals; producing a velocity waveform based on said series of displacement signals over time; determining the point on said velocity waveform of the lowest initial velocity value, this value representing the point at which the mandrel head enters the rivet body; and determining the pressure value at the corresponding point on said pressure-versus-displacement waveform.
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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) | 2000-09-01 | 2001-03-03 | 2001-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-09-01 | 2005-03-03 | 2005-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-09-01 | 2009-03-03 | 2009-09-02 | $7700.00 | Window Closed / Lapsed |