Roller electrodes for electric-resistance welding machine

Claim 2

In a roller electrode adapted for use in electric resistance seam welding apparatus to weld overlapped edges of a metal blank, the roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components, the improvement comprising the combination of said conductive liquid being of a composite eutectic mixture of gallium (Ga), indium (In), tin (Sn) and zinc (Zn), by weight, being substantially 61% Ga, 25% In, 13% Sn, and 1% Zn.

Claim 3

A roller electrode combination according to claim 1, further wherein said metal blank is curved over a full 360 degrees to a tubular configuration; the roller electrode being adapted to be disposed inside of the tubular configuration; and said rotor having an exterior peripherial face adapted to cooperate with the overlapped blank edges and said exterior peripherial face being opposite portions of said annular rotor surfaces, and a protective coating being formed on said portions of the annular rotor surfaces, and said protective coating being of rhodium (Rh).

Claim 4

A roller electrode combination according to claim 2, wherein said protective coating includes gold (Au) plated directly on the rotor and the said rhodium (Rh) plated on the gold.

Claim 5

A roller electrode combination according to claim 2, wherein another protective coating is formed on said rotor, on the exterior peripherial rotor face adapted to cooperate with the overlapped blank edges, and said protective coating being of rhodium (Rh).

Claim 6

A roller electrode combination according to claim 4, wherein each of said protective coatings includes gold (Au) plated directly on the rotor and the said rhodium (Rh) plated on the gold.

Claim 7

A roller electrode combination according to claim 1, wherein the roller electrode has coolant flow passages defined therein; means to circulate coolant through the flow passages including via an inlet to the passages and an outlet from the passages; flow control means located outside of the roller electrode and connected substantially in a series flow connection with the inlet; and means to sense the coolant temperature at the outlet and to change the flow control means to direct greater relative coolant flow to the roller electrode when the coolant temperature at the outlet increases.

Claim 8

A roller electrode combination according to claim 1, wherein the roller electrode has coolant flow passages defined therein; means to circulate coolant through the flow passages including via an inlet to the passages and an outlet from the passages; flow control means located outside of the roller electrode and connected substantially in a series flow connection with the inlet; and means to sense the coolant temperature and to change the flow control means to direct lesser relative coolant flow to the roller electrode when the coolant temperature becomes too cold for the conductive liquid.

Claim 9

A roller electrode combination according to claim 7, further including bypass line means located outside of the roller electrode and connected substantially in a parallel flow connection therewith between the flow control means and outlet; and said flow control means being operable to vary the relative coolant flow directed to the roller electrode and to the bypass line means, responsive to changes of the coolant temperature.

Claim 10

In a roller electrode adapted for use in electric resistance seam welding apparatus to weld overlapped edges of a metal blank, the roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components, the improvement comprising a thin protective coating formed on certain of said annular rotor surfaces that would contact the conductive liquid, and said protective coating being of gold (Au) and/or material from the platinum (Pt) family.

Claim 11

In a roller electrode adapted for use in electric resistance seam welding apparatus to weld overlapped edges of a metal blank, the roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components, the improvement comprising a thin protective coating formed on certain of said annular rotor surfaces that would contact the conductive liquid, and said protective coating being of gold (Au) and/or material from the platinum (Pt) family.

Claim 12

A roller electrode combination according to claim 9, wherein said protective coating is formed only on said annular rotor surfaces, and the annular surfaces of said stator adjacent the said thin gaps and that would contact the conductive liquid are without any protective coating.

Claim 13

A roller electrode combination according to claim 10, wherein said protective coating includes gold (Au) plated directly on the said annular rotor surfaces and said material from the platinum (Pt) family then being plated on the gold.

Claim 14

A roller electrode combination according to claim 10, further wherein the platinum family material of said protective coating is rhodium (Rh), and the protective coating is of rhodium plated directly on the annular rotor surfaces.

Claim 15

A roller electrode combination according to claim 10, wherein said protective coating includes gold (Au) plated directly on the annular rotor surfaces and the platinum (Pt) family material is rhodium (Rh) and it is plated on the gold.

Claim 16

A roller electrode combination according to claim 13, further wherein said rotor has an exterior peripherial face adapted to cooperate closely adjacent the overlapped blank edges during welding; certain of said annular surfaces of the rotor being opposite to the peripherial rotor face; and said protective coating being formed on those certain annular rotor surfaces opposite to the peripherial rotor face.

Claim 17

A roller electrode combination according to claim 9, further wherein said rotor and stator are formed of different materials, said rotor being formed of a material durable under high temperatures and pressures, and electrically and thermally conductive; and said stator being formed of a material having less durability under high temperatures and pressures, but having greater electrical and thermal conductivity, than the material forming the rotor.

Claim 18

A roller electrode combination according to claim 15, further wherein said rotor material is a copper alloy having approximately 0.3-.7% Beryllium (Be), 1.5-2.0% Nickel (Ni), with the balance Copper (Cu); and said stator material is copper alloy having approximately 1% Chromium (Cr) and the balance Copper (Cu).

Claim 19

A roller electrode combination according to claim 16, wherein said protective coating includes gold (Au) plated directly on the annular surfaces of the rotor and the platinum (Pt) family material being rhodium (Rh) and being plated on the gold, and further wherein said electrically conductive liquid is of a composite eutectic mixture of gallium (Ga), indium (In), tin (Sn) and zinc (Zn), by weight, being substantially 61% Ga, 25% In, 13% Sn, and 1% Zn.

Claim 20

A roller electrode combination according to claim 15, further wherein said rotor has an exterior peripherial face adapted to be closely adjacent the overlapped edges of the blank; certain of said annular surfaces of the rotor being opposite to the peripherial rotor face, and the rotor in this region between said certain annular surfaces and the peripherial face being structural and being formed only of a composite sintered mixture of copper (Cu) and tungsten (W), in the range of 60-70% tungsten and 40-30% copper, by weight.

Claim 21

In a roller electrode adapted for use in electric resistance seam welding apparatus to weld overlapped edges of a metal blank, the roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components, the improvement comprising said rotor having an exterior peripherial face adapted to be closely adjacent the overlapped blank edges during welding; certain of said annular surfaces of the rotor being opposite to the peripherial rotor face, and the rotor in this region between said certain annular surfaces and the peripherial face being structural and being formed only of a composite sintered mixture of copper (Cu) and tungsten (W), in the range of 60-70% tungsten and 40-30% copper, by weight.

Claim 22

In a roller electrode adapted for use in electric resistance seam welding apparatus to weld overlapped edges of a metal blank, the roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components, the improvement comprising said rotor having an exterior peripherial face adapted to be closely adjacent the overlapped blank edges during welding; certain of said annular surfaces of the rotor being opposite to the peripherial rotor face, and the rotor in this region between said certain annular surfaces and the peripherial face being structural and being formed only of a composite sintered mixture of copper (Cu) and tungsten (W), in the range of 60-70% tungsten and 40-30% copper, by weight.

Claim 23

In a roller electrode adapted for use in electric resistance seam welding apparatus to weld overlapped edges of a metal blank, the roller electrode having stator and rotor components, the rotor surrounding the stator and these components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components and to thermally cool said rotor from a cooled stator, the improvement comprising said rotor having an exterior peripherial face adapted to be closely adjacent the overlapped blank edges, and certain of said annular rotor surfaces being opposite to the peripherial rotor face; and said stator having coolant flow passages defined therein including: axial inlet and outlet passages located on opposite axial sides of the stator; separate annular passages disposed circumferentially of the stator closely adjacent the said certain stator annular surfaces and the defined gaps; a plurality of separate circumferentially spaced inlet and outlet radial passages respectively located on opposite axial sides of the stator and communicating with the respective inlet and outlet passages and with the respective annular passages, said radial passages each being of a substantially small cross section and being circumferentially offset from one another; and through openings communicating between the separate annular passages, at locations between the radial passages, thereby defining tortious paths through the stator between the inlet and outlet passages and causing circumferential flow over all of the separate annular passages, for high cooling effectiveness of the certain annular stator surfaces at the defined gaps and particularly opposite said certain annular rotor surfaces, for high cooling effectiveness of the peripherial rotor face via the rotor and the conductive liquid across the gaps.

Claim 24

In a roller electrode adapted for use in electric resistance seam welding apparatus to weld overlapped edges of a metal blank, the roller electrode having stator and rotor components, the rotor surrounding the stator and these components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components and to thermally cool said rotor from a cooled stator, the improvement comprising said rotor having an exterior peripherial face adapted to be closely adjacent the overlapped blank edges, and certain of said annular rotor surfaces being opposite to the peripherial rotor face; and said stator having coolant flow passages defined therein including: axial inlet and outlet passages located on opposite axial sides of the stator; separate annular passages disposed circumferentially of the stator closely adjacent the said certain stator annular surfaces and the defined gaps; a plurality of separate circumferentially spaced inlet and outlet radial passages respectively located on opposite axial sides of the stator and communicating with the respective inlet and outlet passages and with the respective annular passages, said radial passages each being of a substantially small cross section and being circumferentially offset from one another; and through openings communicating between the separate annular passages, at locations between the radial passages, thereby defining tortious paths through the stator between the inlet and outlet passages and causing circumferential flow over all of the separate annular passages, for high cooling effectiveness of the certain annular stator surfaces at the defined gaps and particularly opposite said certain annular rotor surfaces, for high cooling effectiveness of the peripherial rotor face via the rotor and the conductive liquid across the gaps.

Claim 25

In a roller electrode adapted for use in electric resistance seam welding apparatus to weld overlapped edges of a metal blank, the roller electrode having stator and rotor components, the rotor surrounding the stator and these components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components and to thermally cool said rotor from a cooled stator, the improvement comprising said rotor having an exterior peripherial face adapted to be closely adjacent the overlapped blank edges, and certain of said annular rotor surfaces being opposite to the peripherial rotor face; a protective coating formed on said annular rotor surfaces in the region of the defined gaps that contact the conductive liquid, said protective coating being of gold (Au) and/or material from the platinum (Pt) family, and said annular stator surfaces in the region of the defined gaps that contact the conductive liquid, being void of any protective coating; and said stator having coolant flow passages defined therein including: axial inlet and outlet passages located on opposite axial sides of the stator; annular passages disposed circumferentially of the stator; separate inlet and outlet radial passages located on opposite axial sides of the stator and communicating with the respective inlet and outlet passages and with the annular passages, said radial passages being circumferentially offset from one another; and through openings communicating between the annular passages, at locations between the radial passages, thereby defining tortious paths through the stator between the inlet and outlet passages and causing circumferential flow over all of the annular passages, for high cooling effectiveness of the annular stator surfaces at the defined gaps and particularly opposite said certain annular rotor surfaces, for high cooling effectiveness of the peripherial rotor face via the rotor and the conductive liquid across the gaps.

Claim 26

In a roller electrode adapted for use in electric resistance seam welding apparatus to weld overlapped edges of a metal blank, the roller electrode having stator and rotor components, the rotor surrounding the stator and these components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components and to thermally cool said rotor from a cooled stator, the improvement comprising said rotor having an exterior peripherial face adapted to be closely adjacent the overlapped blank edges, and certain of said annular rotor surfaces being opposite to the peripherial rotor face; a protective coating formed on said annular rotor surfaces in the region of the defined gaps that contact the conductive liquid, said protective coating being of gold (Au) and/or material from the platinum (Pt) family, and said annular stator surfaces in the region of the defined gaps that contact the conductive liquid, being void of any protective coating; and said stator having coolant flow passages defined therein including: axial inlet and outlet passages located on opposite axial sides of the stator; annular passages disposed circumferentially of the stator; separate inlet and outlet radial passages located on opposite axial sides of the stator and communicating with the respective inlet and outlet passages and with the annular passages, said radial passages being circumferentially offset from one another; and through openings communicating between the annular passages, at locations between the radial passages, thereby defining tortious paths through the stator between the inlet and outlet passages and causing circumferential flow over all of the annular passages, for high cooling effectiveness of the annular stator surfaces at the defined gaps and particularly opposite said certain annular rotor surfaces, for high cooling effectiveness of the peripherial rotor face via the rotor and the conductive liquid across the gaps.

Claim 27

A roller electrode combination according to claim 21, wherein said protective coating includes gold (Au) plated directly on the annular rotor surfaces, and rhodium (Rh) plated on the gold.

Claim 28

A roller electrode combination according to claim 20, further wherein said rotor and stator are formed of different materials, said rotor being formed of a material durable under high temperatures and pressures, and electrically and thermally conductive; and said stator being formed of a material having less durability under high temperatures and pressures, but having greater electrical and thermal conductivity, than the material forming the rotor.

Claim 29

In a roller electrode adapted for use in electric resistance seam welding apparatus to weld overlapped edges of a metal blank, the roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components, the improvement comprising the combination of said rotor and stator being formed of different materials, said rotor being formed of a copper alloy having approximately 0.3-.7% Beryllium (Be), 1.5-2.0% Nickel (Ni), with the balance Copper (Cu), thereby being durable under high temperatures and pressures, and electrically and thermally conductive; and said stator being formed of a copper alloy having approximately 1% Chromium (Cr) and the balance Copper (Cu), thereby having less durability under high temperatures and pressures, but having greater electrical and thermal conductivity than the rotor.

Claim 30

In a roller electrode adapted for use in electric resistance seam welding apparatus to weld overlapped edges of a metal blank, the roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components, the improvement comprising the combination of said rotor and stator being formed of different materials, said rotor being formed of a copper alloy having approximately 0.3-.7% Beryllium (Be), 1.5-2.0% Nickel (Ni), with the balance Copper (Cu), thereby being durable under high temperatures and pressures, and electrically and thermally conductive; and said stator being formed of a copper alloy having approximately 1% Chromium (Cr) and the balance Copper (Cu), thereby having less durability under high temperatures and pressures, but having greater electrical and thermal conductivity than the rotor.

Claim 31

A roller electrode combination according to claim 24, further wherein the conductive liquid is of a composite eutectic mixture of gallium (Ga), indium (In), tin (Sn) and zinc (Zn), by weight, being substantially 61% Ga, 25% In, 13% Sn, and 1% Zn.

Claim 32

In an electric resistance seam welding apparatus to weld overlapped edges of a metal blank, including a roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components, the improvement comprising the combination of the stator having coolant flow passages defined therein; means to circulate coolant through the stator passages including via an inlet to the passages and an outlet from the passages; flow control means in a series connection with the inlet operable to vary the relative coolant flow to the stator; and means to sense the coolant temperature and to change the flow control means to direct lesser relative coolant flow when the coolant temperature becomes too cold for the conductive liquid.

Claim 33

In an electric resistance seam welding apparatus to weld overlapped edges of a metal blank, including a roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, a conductive liquid simultaneously contacting said annular surfaces to electrically conduct a welding current across said gaps between the components, the improvement comprising the combination of the stator having coolant flow passages defined therein; means to circulate coolant through the stator passages including via an inlet to the passages and an outlet from the passages; flow control means in a series connection with the inlet operable to vary the relative coolant flow to the stator; and means to sense the coolant temperature and to change the flow control means to direct lesser relative coolant flow when the coolant temperature becomes too cold for the conductive liquid.

Claim 34

A roller electrode combination according to claim 26, further wherein the conductive liquid is of a composite eutectic mixture of gallium (Ga), indium (In), tin (Sn) and zinc (Zn), by weight, being substantially 61% Ga, 25% In, 13% Sn, and 1% Zn, and wherein said means to sense the coolant temperature is set to direct lesser relative coolant flow to the roller electrode so as to preclude a coolant temperature of the order of less than 3 degrees C. at the roller electrode.

Claim 35

A roller electrode combination according to claim 27, wherein the means to sense the coolant temperature at the outlet and flow control means further are effective to direct greater relative coolant flow to the roller electrode when the coolant temperature at the outlet increases during welding operation, to above approximately 20 degrees C.

Claim 36

An electric resistance seam welding apparatus combination according to claim 27, further wherein the stator passages include annular passages disposed circumferentially of the stator; separate inlet and outlet radial passages located on opposite axial sides of the stator and communicating respectively with the inlet and outlet and with the annular passages, said radial passages being circumferentially offset from one another; and through openings communicating between the annular passages, at locations between the radial passages, thereby defining tortious paths through the stator and causing circumferential flow over all of the annular passages, for high cooling effectiveness of the annular stator surfaces at the defined gaps and particularly opposite said certain annular rotor surfaces, for high cooling effectiveness of the peripherial rotor face via the rotor and the conductive liquid across the gaps.

Claim 37

A roller electrode combination according to claim 9, further wherein the protective coating includes gold (Au) plated directly on the annular rotor surfaces and said material from the platinum (Pt) family then being plated on the gold; and wherein said conductive liquid is mercury (Hg).

Claim 38

A roller electrode combination according to claim 20, further wherein a thin coating of silver is applied to the walls of the coolant passages, the thickness of the silver coating being between 0.001 and 0.0125 of a millimeter.

Claim 39

In an electric resistance seam welding apparatus to weld overlapped edges of a metal blank, including a roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid adapted to simultaneously contact said annular surfaces operable to electrically conduct a welding current across said gaps between the stator and rotor components, the improvement comprising the combination of a protective coating formed on said rotor, on the exterior peripherial rotor face adapted to cooperate with the overlapped blank edges, and said protective coating being of rhodium (Rh).

Claim 40

In an electric resistance seam welding apparatus to weld overlapped edges of a metal blank, including a roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid adapted to simultaneously contact said annular surfaces operable to electrically conduct a welding current across said gaps between the stator and rotor components, the improvement comprising the combination of a protective coating formed on said rotor, on the exterior peripherial rotor face adapted to cooperate with the overlapped blank edges, and said protective coating being of rhodium (Rh).

Claim 41

A roller electrode combination according to claim 32, wherein said exterior peripherial rotor face has a continuous circumferential groove formed therein adapted to receive and guide a continuous copper wire electrode that in turn is adapted to be urged against the overlapped blank edges, and said protective coating being formed on the faces of the rotor groove, to engage the wire electrode.

Claim 42

A roller electrode combination according to claim 33, wherein said protective coating includes gold (Au) plated directly on the rotor and the said rhodium (Rh) plated on the gold.

Claim 43

In an electric resistance seam welding apparatus to weld overlapped edges of a metal blank, including a roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid adapted to simultaneously contact said annular surfaces operable to electrically conduct a welding current across said gaps between the stator and rotor components, the improvement comprising the combination of using a conductive liquid that remains semi-fluid and/or gelatinous throughout and even beyond its useful life, said conductive liquid being of a composite eutectic mixture of gallium (Ga), indium (In), tin (Sn) and zinc (Zn), by weight, being substantially 61% Ga, 25% In, 13% Sn, and 1% Zn; and of disassemblying the rotor and stator components of the used roller electrode including removing the used conductive liquid; of cleaning the annular surfaces of the stator and rotor components of all traces of the used conductive liquid; of reassemblying the cleaned stator and rotor components including providing bearing means; and of providing a charge of fresh conductive liquid of the same type for the roller electrode, for simultaneously contacting said annular surfaces of the stator and rotor components.

Claim 44

In an electric resistance seam welding apparatus to weld overlapped edges of a metal blank, including a roller electrode having stator and rotor components, the rotor and stator components having annular surfaces spaced apart across thin gaps, bearing means for mounting said rotor to rotate relative to said stator with movement via said gaps, and a conductive liquid adapted to simultaneously contact said annular surfaces operable to electrically conduct a welding current across said gaps between the stator and rotor components, the improvement comprising the combination of using a conductive liquid that remains semi-fluid and/or gelatinous throughout and even beyond its useful life, said conductive liquid being of a composite eutectic mixture of gallium (Ga), indium (In), tin (Sn) and zinc (Zn), by weight, being substantially 61% Ga, 25% In, 13% Sn, and 1% Zn; and of disassemblying the rotor and stator components of the used roller electrode including removing the used conductive liquid; of cleaning the annular surfaces of the stator and rotor components of all traces of the used conductive liquid; of reassemblying the cleaned stator and rotor components including providing bearing means; and of providing a charge of fresh conductive liquid of the same type for the roller electrode, for simultaneously contacting said annular surfaces of the stator and rotor components.

Claim 45

A roller electrode combination according to claim 35, further providing the component surfaces that were exposed to the conductive liquid are cleaned by blasting them with glass beads or aluminum oxide, to clean them without removing component material.

Claim 46

A roller electrode combination according to claim 35, further providing the stator component has coolant flow passages defined therein, and the coolant passages being cleaned by flushing them with an acetic acid, including with abrasive such as glass beads or aluminum oxide.

Claim 47

A roller electrode combination according to claim 37, further providing the component surfaces that were exposed to the conductive liquid are cleaned by blasting them with glass beads or aluminum oxide, to clean them without removing component material.