US4870248A
Expired / Lapsed
US
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Arc welder with improved arc striking capability
Assignee: Individual
•
Filing: 1988-04-15
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Granted: 1989-09-26
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Expires: 2008-04-15
Abstract
Abstract A pulse type arc welder with improved arc starting characteristics. An output voltage level sensor (2017) monitors the output voltage to determine whether the arc has been struck. If the arc has not been struck, a first oscillator (2000) gates a second, higher frequency oscillator (2002) so that the input to the driver (2010) is a chopped, pulsed, high duty cycle waveform. Also, the bandwidth of the output current level sensor (2012) is reduced so that the high value, short lived arc starting transient current does not cause the output current level sensor (2012) to improperly shut down the driver (2010). Additional current limiting protection is provided during this period since the high chopping frequency causes the reactor (2010a) to have a high impedance. After the arc has been struck, the output voltage will drop to the arc sustaining voltage and the output voltage level sensor (2017) will de-energize relay (2003). The first oscillator (2000) then provides the driver (2010) with an input signal having the characteristics selected for the particular welding operation. Also, the bandwidth of the output current level sensor (2012) is restored to its full value.
Inventors
- 👤 Malcolm T. Gilliland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:15
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/10; B23K9/1006; B23K9/1043; B23K9/1068; B23K9/1087
Claims Analysis
Total Claims: 55
Claim 1
Independent Claim
118 words
An electronic welder with an improved capability for striking an arc, comprising: oscillation means for providing a first signal; chopping means for chopping said first signal to provide a chopped first signal; drive means responsive to a drive signal for providing an output voltage and an output current to a welding operation; switching means responsive to a second signal for providing a selected one of said first signal and said chopped first signal as said drive signal to said drive means; and sensing means responsive to said output voltage for providing said second signal; whereby said switching means provides said chopped first signal before said arc is struck and provides said first signal after said arc is struck.
Claim 2
Dependent Claim
118 words
An electronic welder with an improved capability for striking an arc, comprising: oscillation means for providing a first signal; chopping means for chopping said first signal to provide a chopped first signal; drive means responsive to a drive signal for providing an output voltage and an output current to a welding operation; switching means responsive to a second signal for providing a selected one of said first signal and said chopped first signal as said drive signal to said drive means; and sensing means responsive to said output voltage for providing said second signal; whereby said switching means provides said chopped first signal before said arc is struck and provides said first signal after said arc is struck.
Claim 3
Dependent Claim
29 words
The welder of claim 1 wherein said chopping means comprises a second oscillation means, said second oscillation means being active when said first signal is in a predetermined state.
Claim 4
Dependent Claim
27 words
The welder of claim 2 wherein said second signal causes said switching means to provide said chopped first signal when said output voltage exceeds a predetermined value.
Claim 5
Dependent Claim
27 words
The welder of claim 1 wherein said second signal causes said switching means to provide said chopped first signal when said output voltage exceeds a predetermined value.
Claim 6
Dependent Claim
36 words
The welder of claim 1 wherein said first signal has a first set of characteristics and said oscillation means is responsive to said second signal for providing said first signal with a second set of characteristics.
Claim 7
Dependent Claim
26 words
The welder of claim 5 wherein said first set of characteristics comprises a first frequency and said second set of characteristics comprises a second, higher frequency.
Claim 8
Dependent Claim
28 words
The welder of claim 6 wherein said first set of characteristics comprises a first duty cycle and said second set of characteristics comprises a second, larger duty cycle.
Claim 9
Dependent Claim
32 words
The welder of claim 5 wherein said second signal causes said oscillation means to provide said first signal with said second set of characteristics when said output voltage exceeds a predetermined value.
Claim 10
Dependent Claim
37 words
The welder of claim 1 and further comprising: current sensing means responsive to said output current for providing a third signal, which disables said drive means, when a characteristic of said output current exceeds a predetermined value.
Claim 11
Dependent Claim
12 words
The welder of claim 9 wherein said characteristic is the instantaneous value.
Claim 12
Dependent Claim
46 words
The welder of claim 9 and further comprising: means for reducing the bandwidth of said current sensing means; wherein said bandwidth reducing means is responsive to said second signal for reducing said bandwidth of said current sensing means when said output voltage exceeds a predetermined value.
Claim 13
Dependent Claim
118 words
An electronic welder with an improved capability for striking an arc, comprising: oscillation means for providing a first signal; chopping means for chopping said first signal to provide a chopped first signal; drive means responsive to a drive signal for providing an output voltage and an output current to a welding operation; switching means responsive to a second signal for providing a selected one of said first signal and said chopped first signal as said drive signal to said drive means; and sensing means responsive to said output current for providing said second signal; whereby said switching means provides said chopped first signal before said arc is struck and provides said first signal after said arc is struck.
Claim 14
Dependent Claim
118 words
An electronic welder with an improved capability for striking an arc, comprising: oscillation means for providing a first signal; chopping means for chopping said first signal to provide a chopped first signal; drive means responsive to a drive signal for providing an output voltage and an output current to a welding operation; switching means responsive to a second signal for providing a selected one of said first signal and said chopped first signal as said drive signal to said drive means; and sensing means responsive to said output current for providing said second signal; whereby said switching means provides said chopped first signal before said arc is struck and provides said first signal after said arc is struck.
Claim 15
Dependent Claim
29 words
The welder of claim 12 wherein said chopping means comprises a second oscillation means, said second oscillation means being active when said first signal is in a predetermined state.
Claim 16
Dependent Claim
26 words
The welder of claim 13 wherein said second signal causes said switching means to provide said first signal when said output current exceeds a predetermined value.
Claim 17
Dependent Claim
26 words
The welder of claim 12 wherein said second signal causes said switching means to provide said first signal when said output current exceeds a predetermined value.
Claim 18
Dependent Claim
36 words
The welder of claim 12 wherein said first signal has a first set of characteristics and said oscillation means is responsive to said second signal for providing said first signal with a second set of characteristics.
Claim 19
Dependent Claim
26 words
The welder of claim 16 wherein said first set of characteristics comprises a first frequency and said second set of characteristics comprises a second, higher frequency.
Claim 20
Dependent Claim
28 words
The welder of claim 16 wherein said first set of characteristics comprises a first duty cycle and said second set of characteristics comprises a second, larger duty cycle.
Claim 21
Dependent Claim
34 words
The welder of claim 16 wherein said second signal causes said oscillation means to provide said first signal with said second set of characteristics when said output current is less than a predetermined value.
Claim 22
Dependent Claim
37 words
The welder of claim 12 wherein said sensing means is further responsive to said output current for providing a third signal, which disables said drive means, when a characteristic of said output current exceeds a predetermined value.
Claim 23
Dependent Claim
12 words
The welder of claim 20 wherein said characteristic is the instantaneous value.
Claim 24
Dependent Claim
46 words
The welder of claim 20 and further comprising: means for reducing the bandwidth of said sensing means; wherein said bandwidth reducing means is responsive to said second signal for reducing said bandwidth of said sensing means when said output current is less than a predetermined value.
Claim 25
Dependent Claim
118 words
An electronic welder with an improved capability for striking an arc, comprising: oscillation means for providing a first signal; chopping means for chopping said first signal to provide a chopped first signal; drive means responsive to a drive signal for providing an output voltage and an output current to a welding operation; switching means responsive to a second signal for providing a selected one of said first signal and said chopped first signal as said drive signal to said drive means; and sensing means for providing said second signal when said arc is present; whereby said switching means provides said chopped first signal before said arc is struck and provides said first signal after said arc is struck.
Claim 26
Dependent Claim
118 words
An electronic welder with an improved capability for striking an arc, comprising: oscillation means for providing a first signal; chopping means for chopping said first signal to provide a chopped first signal; drive means responsive to a drive signal for providing an output voltage and an output current to a welding operation; switching means responsive to a second signal for providing a selected one of said first signal and said chopped first signal as said drive signal to said drive means; and sensing means for providing said second signal when said arc is present; whereby said switching means provides said chopped first signal before said arc is struck and provides said first signal after said arc is struck.
Claim 27
Dependent Claim
29 words
The welder of claim 23 wherein said chopping means comprises a second oscillation means, said second oscillation means being active when said first active is in a predetermined state.
Claim 28
Dependent Claim
24 words
The welder of claim 24 wherein said second signal causes said switching means to provide said chopped first signal when said arc is absent.
Claim 29
Dependent Claim
24 words
The welder of claim 23 wherein said second signal causes said switching means to provide said chopped first signal when said arc is absent.
Claim 30
Dependent Claim
36 words
The welder of claim 23 wherein said first signal has a first set of characteristics and said oscillation means is responsive to said second signal for providing said first signal with a second set of characteristics.
Claim 31
Dependent Claim
26 words
The welder of claim 27 wherein said first set of characteristics comprises a first frequency and said second set of characteristics comprises a second, higher frequency.
Claim 32
Dependent Claim
28 words
The welder of claim 27 wherein said first set of characteristics comprises a first duty cycle and said second set of characteristics comprises a second, larger duty cycle.
Claim 33
Dependent Claim
28 words
The welder of claim 27 wherein said second signal causes said oscillation means to provide said first signal with said second of characteristics when said arc is absent.
Claim 34
Dependent Claim
37 words
The welder of claim 23 and further comprising: current sensing means responsive to said output current for providing a third signal, which disables said drive means, when a characteristic of said output current exceeds a predetermined value.
Claim 35
Dependent Claim
12 words
The welder of claim 31 wherein said characteristic is the instantaneous value.
Claim 36
Dependent Claim
43 words
The welder of claim 31 and further comprising: means for reducing the bandwidth of said current sensing means; wherein said bandwidth reducing means is responsive to said second signal for reducing said bandwidth of said current sensing means when said arc is absent.
Claim 37
Dependent Claim
151 words
In an electronic welder containing a drive circuit having an output for providing an output voltage and an output current to a welding operation, a frequency setting circuit for setting the pulse repetition rate and the pulse width of said output voltage, said drive circuit containing at least one inductor in series with said output and a protection circuit for protecting said drive circuit in the event that a predetermined characteristic of said output current exceeds a predetermined value, an improvement for improving the arc starting characteristics of said electronic welder for starting an arc, comprising: sensing means for providing a first signal when said arc is absent; and disabling means responsive to said first signal for at least partially disabling said protection circuit; wherein said protection circuit is at least partially disabled when said arc is absent so that said protection circuit is less responsive to arc starting transient currents.
Claim 38
Dependent Claim
151 words
In an electronic welder containing a drive circuit having an output for providing an output voltage and an output current to a welding operation, a frequency setting circuit for setting the pulse repetition rate and the pulse width of said output voltage, said drive circuit containing at least one inductor in series with said output and a protection circuit for protecting said drive circuit in the event that a predetermined characteristic of said output current exceeds a predetermined value, an improvement for improving the arc starting characteristics of said electronic welder for starting an arc, comprising: sensing means for providing a first signal when said arc is absent; and disabling means responsive to said first signal for at least partially disabling said protection circuit; wherein said protection circuit is at least partially disabled when said arc is absent so that said protection circuit is less responsive to arc starting transient currents.
Claim 39
Dependent Claim
35 words
The improvement of claim 34 wherein said protection circuit contains a filter having an upper cutoff frequency and said disabling means partially disables said protection circuit by reducing said upper cutoff frequeny of said filter.
Claim 40
Dependent Claim
23 words
The improvement of claim 34 wherein said protection circuit is responsive to the instantaneous value of said output current exceeding said predetermined value.
Claim 41
Dependent Claim
29 words
The improvement of claim 34 and further comprising: switching means responsive to said first signal for causing said frequency setting circuit to shift to a higher pulse repetition rate.
Claim 42
Dependent Claim
28 words
The improvement of claim 34 and further comprising: switching means responsive to said first signal for causing said frequency setting circuit to shift to a higher duty cycle.
Claim 43
Dependent Claim
33 words
The improvement of claim 34 and further comprising chopping means responsive to said first signal for causing said output voltage to be chopped at a chopping frequency which exceeds said pulse repetition rate.
Claim 44
Dependent Claim
18 words
The improvement of claim 34 wherein said sensing means comprises voltage sensing means responsive to said output voltage.
Claim 45
Dependent Claim
22 words
The improvement of claim 40 wherein said voltage sensing means provides said first signal when said output voltage exceeds a predetermined value.
Claim 46
Dependent Claim
24 words
The improvement of claim 40 wherein said current sensing means provides said first signal when said output current is less than a predetermined value.
Claim 47
Dependent Claim
18 words
The improvement of claim 34 wherein said sensing means comprises current sensing means responsive to said output current.
Claim 48
Dependent Claim
125 words
For use with a low frequency pulse arc welder of the type comprising a low frequency oscillator having an output characterized by a pulse repetition rate and a pulse width, a driver circuit for providing an output voltage and an output current to a welding operation, and an inductor in series between said driver circuit and said welding operation, a method for improving the characteristics of said welder for starting an arc, comprising the steps of: (a) determining if said arc is present; and (b) if said arc is not present, then: (i) increasing at least a selected one of said pulse repetition rate and said pulse width; and (ii) chopping said output of said oscillator at a chopping rate exceeding said pulse repetition rate.
Claim 49
Dependent Claim
125 words
For use with a low frequency pulse arc welder of the type comprising a low frequency oscillator having an output characterized by a pulse repetition rate and a pulse width, a driver circuit for providing an output voltage and an output current to a welding operation, and an inductor in series between said driver circuit and said welding operation, a method for improving the characteristics of said welder for starting an arc, comprising the steps of: (a) determining if said arc is present; and (b) if said arc is not present, then: (i) increasing at least a selected one of said pulse repetition rate and said pulse width; and (ii) chopping said output of said oscillator at a chopping rate exceeding said pulse repetition rate.
Claim 50
Dependent Claim
20 words
The method of claim 44 wherein, at step (b)(i), both said pulse repetition rate and said pulse width are increased.
Claim 51
Dependent Claim
57 words
The method of claim 44 wherein said welder further comprises an over-current protection circuit for at least partially disabling said driver circuit if a selected characteristic of said output current exceeds a predetermined value, and further comprising the step of: (b) (iii) reducing the sensitivity of said protection circuit to said selected characteristic of said output current.
Claim 52
Dependent Claim
20 words
The method of claim 46 wherein, at step (b)(i), both said pulse repetition rate and said pulse width are increased.
Claim 53
Dependent Claim
35 words
The method of claim 46 wherein said over-current protection circuit is responsive to the instantaneous value of said output current and said sensitivity is reduced by lowpass filtering a signal corresponding to said output current.
Claim 54
Dependent Claim
33 words
The method of claim 44 wherein said step (a) comprises: (i) monitoring said output voltage; and (ii) declaring said arc to be present if said output voltage is less than a predetermined value.
Claim 55
Dependent Claim
33 words
The method of claim 44 wherein said step (a) comprises: (i) monitoring said output current; and (ii) declaring said arc to be present if said output current is greater than a predtermined value.
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) | 1992-09-25 | 1993-03-27 | 1993-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-25 | 1997-03-27 | 1997-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-25 | 2001-03-27 | 2001-09-26 | $7700.00 | Window Closed / Lapsed |