US3899653A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical resistance weld method and apparatus
Assignee: ORALTECHNIC ANSTALT
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Filing: 1974-04-24
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Granted: 1975-08-12
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Expires: 1994-04-24
Abstract
Abstract The metallic parts to be welded are first pressed together at the welding point between the electrodes of a welding tool. Thereafter the weld current is furnished to the electrodes in form of at least two subsequent pulses. The first pulse is set at a lower energy than the successive one and serves to pre-seat the metallic parts for the second pulse.
Inventors
- 👤 Gaetano Emanuele Spinnato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:48
CPC Classifications
B; B23; B23K; B23K11/00; B23K11/24; B23K11/26; A; A61; A61C; A61C13/00; A61C13/20; B23K11/10; B23K11/30; B23K11/31
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
216 words
An apparatus for welding together metallic parts comprising: a. first and second variable transformers, b. a rectifier, c. a condenser, d. a pulse transformer, e. first switch means for cyclically and alternately connecting said first and second variable transformers to said rectifier; f. second switch means for selectively connecting said rectifier to said condenser; g. third switch means for selectively connecting said condenser to said pulse transformer; h. programmer means, which controls said switch means at each welding cycle, for, in sequence, during each cycle, connecting said first variable transformer to said rectifier, and said rectifier to said condenser, and disconnecting said condenser from said pulse transformer for a time sufficient to charge said condenser to a first weld charge; disconnecting said rectifier from said condenser and connecting said condenser to the said pulse transformer for a time sufficient to discharge said condenser and connecting said second variable transformer to said rectifier, connecting said rectifier to said condenser, and disconnecting said condenser from said pulse transformer for a time sufficient to charge said condenser to a second weld charge and then disconnecting said rectifier from said condenser and connecting said condenser to said pulse transformer, for a time sufficient to discharge said condenser; i. and a welding tool connected to the output of said pulse transformer.
Claim 2
Independent Claim
216 words
An apparatus for welding together metallic parts comprising: a. first and second variable transformers, b. a rectifier, c. a condenser, d. a pulse transformer, e. first switch means for cyclically and alternately connecting said first and second variable transformers to said rectifier; f. second switch means for selectively connecting said rectifier to said condenser; g. third switch means for selectively connecting said condenser to said pulse transformer; h. programmer means, which controls said switch means at each welding cycle, for, in sequence, during each cycle, connecting said first variable transformer to said rectifier, and said rectifier to said condenser, and disconnecting said condenser from said pulse transformer for a time sufficient to charge said condenser to a first weld charge; disconnecting said rectifier from said condenser and connecting said condenser to the said pulse transformer for a time sufficient to discharge said condenser and connecting said second variable transformer to said rectifier, connecting said rectifier to said condenser, and disconnecting said condenser from said pulse transformer for a time sufficient to charge said condenser to a second weld charge and then disconnecting said rectifier from said condenser and connecting said condenser to said pulse transformer, for a time sufficient to discharge said condenser; i. and a welding tool connected to the output of said pulse transformer.
Claim 3
Dependent Claim
40 words
The apparatus according to claim 1, in which the said rectifier comprises two transformers having Their primary windings connected in anti-parallel and their secondary windings connected in series with one another and in series with a number of rectifying diodes.
Claim 4
Dependent Claim
32 words
The apparatus according to claim 1 in which the said condenser has a discharge energy in the range between 1.5 to 150 watt-second at a charge voltage between 100 to 1000 volts.
Claim 5
Dependent Claim
23 words
The apparatus according to claim 1, in which the said pulse transformer has a maximum secondary voltage in the range of 10 volts.
Claim 6
Dependent Claim
85 words
The apparatus according to claim 1, in which the said welding tool is in the form of a pair of tongs and comprises two scissors-like arms, hingedly connected at their middle point; an insulated electrode holder located at one end of each of said arms, and electrically connected to the secondary terminals of said pulse transformer; a pair of electrodes located in said electrode holders; and means for maintaining the said electrodes in engagement against the parts to be welded during the whole welding cycle.
Claim 7
Dependent Claim
33 words
The apparatus according to claim 5, in which the said means for maintaining the said electrodes in engagement comprise a rack and pawl fastener, connected to the arms of the said welding tool.
References Cited (Backward Citations)
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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) | 1978-08-11 | 1979-02-10 | 1979-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-11 | 1983-02-10 | 1983-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-11 | 1987-02-10 | 1987-08-12 | $7700.00 | Window Closed / Lapsed |