Method and apparatus for welding metallic parts
First Claim
1. An apparatus for spot welding metallic parts, said apparatus comprising:
- (a) means for forming an electrical contact region of increasing size between said parts;
(b) means for generating a series of measurement current pulses having a predetermined magnitude through said contact region;
(c) means for comparing the magnitude of the voltage across said contact region prior to the application of each of said measurement current pulses with the magnitude of the voltage there across during the application of each of said measurement current pulses, and generating an output voltage which is a function of the difference between said compared voltage magnitudes; and
(d) means for applying an electrical weld current having a predetermined magnitude through said contact region for a predetermined period of time when the magnitude of said output voltage attains a predetermined value.
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Accused Products
Abstract
A method and apparatus is provided for applying an electrical welding current between contacting members upon detecting a predetermined electrical resistance therebetween. Measurement current pulses are applied through the contacting members prior to the initiation of a weld current therethrough. Measurement voltage pulses, induced by the applied measurement current pulses, are compared against a reference voltage level. When the magnitude of the voltage pulses decreases to a value less than the reference voltage level, a weld signal is generated which causes the application of the weld current through the contacting members for a predetermined period of time.
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Citations
12 Claims
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1. An apparatus for spot welding metallic parts, said apparatus comprising:
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(a) means for forming an electrical contact region of increasing size between said parts; (b) means for generating a series of measurement current pulses having a predetermined magnitude through said contact region; (c) means for comparing the magnitude of the voltage across said contact region prior to the application of each of said measurement current pulses with the magnitude of the voltage there across during the application of each of said measurement current pulses, and generating an output voltage which is a function of the difference between said compared voltage magnitudes; and (d) means for applying an electrical weld current having a predetermined magnitude through said contact region for a predetermined period of time when the magnitude of said output voltage attains a predetermined value. - View Dependent Claims (2, 3)
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4. A method of spot welding metallic parts, said method comprising the steps of:
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(a) forming an electrical contact region of increasing size between said parts; (b) generating a series of measurement current pulses having a predetermined magnitude and applying said pulses through said contact region; (c) comparing the magnitude of the voltage across said contact region prior to the application of each of said measurement current pulses with the magnitude voltage there across during the application of each of said measurement current pulses; (d) generating an output voltage which is the function of the difference between said compared voltage magnitudes; and (e) applying an electrical weld current having a predetermined magnitude through said contact region for a predetermined period of time when the magnitude of said output voltage attains a predetermined value. - View Dependent Claims (5, 6)
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7. An apparatus for welding lead parts, disposed on opposite sides of a partition of a battery case, through an aperture in said partition, said apparatus comprising:
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(a) means for forming an electrical contact region of increasing size between said parts through said aperture; (b) means for generating a series of measurement current pulses having a predetermined magnitude and applying said pulses through said contact region; (c) means for comparing the magnitude of the voltage across said contact region prior to the application of each of said measurement current pulses with the magnitude of the voltage there across during the application of each of said measurement current pulses, and generating an output voltage which is a function of a difference between said compared voltage magnitude; and (d) means for applying an electrical welding current having a predetermined magnitude through said contact region for a predetermined period of time when the magnitude of said output voltage attains a predetermined value. - View Dependent Claims (8, 9)
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10. A method for welding lead parts, disposed on opposite sides of a partition of a battery case, through an aperture in said partition, said method comprising the steps of:
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(a) forming an electrical contact region of increasing size between said parts through said aperture; (b) generating a series of measurement current pulses having a predetermined magnitude and applying said pulses through said contact region; (c) comparing the magnitude of the voltage across said contact region prior to the application of each of said measurement current pulses with the magnitude of the voltage there across during the application of each of said measurement current pulses; (d) generating an output voltage which is a function of the difference between said compared voltage magnitude; and (e) applying an electrical weld current having a predetermined magnitude through said contact region for a predetermined period of time when the magnitude of said output voltage attains a predetermined value. - View Dependent Claims (11, 12)
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Specification