US3784778A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for t. i. g. tube welding
Assignee: Atomic Energy of Canada Ltd AECL
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Filing: 1971-03-29
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Granted: 1974-01-08
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Expires: 1991-03-29
Abstract
Abstract A method and apparatus for fully automatically weldjoining lengths of metal instrument tubing employs the TIG welding process to advance a weld puddle about the periphery of the junction of butted aligned ends of straight tubing, respective end portions of which are held in a closed chamber rigidly clamped in spaced seats of a robust metal head to compel elongation into the junction as heat flows into the tubing ends; the unit comprises a handle portion axially separably joined with the head, providing drive to rotate an electrode carrier spool about the work angular interval marking signals being transmitted to a remote control unit from which welding current is supplied to the refractory electrode and gas to the head chamber and tubing interior. A welding cycle commences with a stationary arc developing a weld pool, causing expansion sealing the junction, followed by advance at uniform speed with controlled current levels, the arc being sustained beyond 360* and the complete cycle spanning two revolutions and terminating with a bead-cooling gas flow. Repeatable welds of high quality on a production basis may be obtained, characterized by minimal fall-in of bead, full area fusion of faces, and constant internal diameter.
Inventors
- 👤 N Mcpherson
- 👤 N Hanssmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:18
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/02; B23K9/028; B23K9/0282; B23K9/16; B23K9/167
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
335 words
In a welding device for fusion joining the junction of planar abutting ends of lengths of metal tubing, a housing comprising a hollow metal body of box form having a top wall, a bottom wall, a rear wall, and integral opposed spaced end walls, a frontal opening defined by forward margins of said top, bottom and end walls giving access to an interior space, an insulative spool member rotatably supported in said interior space for rotation about an axis transverse to said end walls, said spool member having an end face, electrode mounting means pivotally supported from said end face, means for rotating said spool member whereby the path of an electrode mounted in said mounting means defines a weld plane, a slot coextensive with said spool member for receiving therewithin through said frontal opening tubing lengths to be welded, tube-seating, tube-holding and tube-locating means carried by said housing comprising aligned transverse seats formed in forward margins of said end walls, said seats being shaped as planar surfaces forming V grooves with included angles of 90* for seating said tubing lengths coaxially of said rotational axis, clamp means carried by said end walls for holding end portions of said lengths located in said seats, said clamps comprising pivoted arms having their one ends pivoted by pivot means carried by respective end walls and disposed laterally of said axis, holding means carried by their other ends separably engageable with said housing and adapted to exert adjustable clamp pressure by said arms on tubing surfaces to restrain axial movement between said tubing and its seat, an aperture in said rear wall intersected by said weld plane, a limit stop member having a locating face selectably insertable within and withdrawable through said aperture, and guide means in said housing for guiding said limit stop member when inserted through said aperture to dispose said locating face normally of said axis to permit locating the end face of one tubing length in said weld plane and clamping in located position.
Claim 2
Dependent Claim
335 words
In a welding device for fusion joining the junction of planar abutting ends of lengths of metal tubing, a housing comprising a hollow metal body of box form having a top wall, a bottom wall, a rear wall, and integral opposed spaced end walls, a frontal opening defined by forward margins of said top, bottom and end walls giving access to an interior space, an insulative spool member rotatably supported in said interior space for rotation about an axis transverse to said end walls, said spool member having an end face, electrode mounting means pivotally supported from said end face, means for rotating said spool member whereby the path of an electrode mounted in said mounting means defines a weld plane, a slot coextensive with said spool member for receiving therewithin through said frontal opening tubing lengths to be welded, tube-seating, tube-holding and tube-locating means carried by said housing comprising aligned transverse seats formed in forward margins of said end walls, said seats being shaped as planar surfaces forming V grooves with included angles of 90* for seating said tubing lengths coaxially of said rotational axis, clamp means carried by said end walls for holding end portions of said lengths located in said seats, said clamps comprising pivoted arms having their one ends pivoted by pivot means carried by respective end walls and disposed laterally of said axis, holding means carried by their other ends separably engageable with said housing and adapted to exert adjustable clamp pressure by said arms on tubing surfaces to restrain axial movement between said tubing and its seat, an aperture in said rear wall intersected by said weld plane, a limit stop member having a locating face selectably insertable within and withdrawable through said aperture, and guide means in said housing for guiding said limit stop member when inserted through said aperture to dispose said locating face normally of said axis to permit locating the end face of one tubing length in said weld plane and clamping in located position.
Claim 3
Dependent Claim
106 words
A tube welding device as set forth in claim 37 wherein said housing further comprises a cover separably secureable over said frontal opening for closing said interior space independently of the clamping state of said clamp means, said cover having apertured end walls adapted to closely engage the exterior forward marginal portions of said end walls and having a convex forward wall joining said end walls, and adapted to closely engage exterior forward marginal surface respectively of said top and bottom housing walls to cover said seats and said clamp means with said tubing seated therein with said cover apeRtures in registry with said tubing lengths.
Claim 4
Dependent Claim
137 words
The device of claim 2 wherein said spool member is rotatably supported in a journal block mounted on said rear wall of said housing, an aperture in said rear wall intersected by the weld plane, an insulative gas-diffuser body fitting in said aperture and extending forwardly into said interior space and having a porous forward wall spaced from and coaxial with the electrode path, and having opposed spaced side walls at least in part transparent to luminosity of an arc, a hollow space in said body enclosed by said walls, and a gas supply conduit in said journal block communicating with said hollow space through a supply aperture in one of said walls, whereby gas led into said conduit is caused to diffuse through said porous wall over a sector having an arcuate length of about 180*.
Claim 5
Dependent Claim
181 words
The device of claim 3 wherein said journal block is an insulative body having spaced parallel end faces perpendicular to the spool axis and a transverse aperture concentric with said axis supporting said spool member rotatably therein but restricting relative axial movement of said spool member, and having a slot communicating with said aperture and opening forwardly of said housing to pass tubing therewithin when said spool slot is registered with said journal block slot, and means to revolve said spool member comprising a drive gear mounted coaxially on an end of the spool remote from said electrode mount and being contiguous with one end face of said journal block, and a transmission supported rearwardly in said housing having an input shaft projecting from said rear wall and a pair of like output pinion gears drivably connected with said input shaft for rotation in the same direction engaging said drive gear, said gear having a slot axially registered with said spool slot, said pinion gears being peripherally spaced a distance at least as great as the opening of said gear slot.
Claim 6
Dependent Claim
119 words
The device of claim 1 wherein the forward marginal portion of said top wall is slotted adjacent respective end walls, said slots each extending rearwardly and opening into a recess giving access thereto from said top, rear and end walls, the junction of a slot and a recess defining a shoulder extending inwardly from said top wall, and wherein said holding means comprise links pivotedly supported by their one ends on said other ends of said clamp arms and having threaded end portions for receiving nuts, said threaded end portions being insertable to lie within said lslots and having a length to project beyond said shoulder for engagement by respective threaded nuts occupying said recesses for exerting clamping pressure.
Claim 7
Dependent Claim
32 words
The device of claim 4 wherein said one length of tubing which is first located to have its end face concentred in the path of said electrode extends through said spool member.
Claim 8
Dependent Claim
139 words
The device of claim 1 wherein the housing is of laminated construction and comprises a base portion having said top, bottom and end walls truncated and the forward margins of said walls lying in a plane parallel to and spaced rearwardly from the tube axis, said forward margins supporting secured thereto an integral slab member of a non-magnetic hardenable metal alloy having a planar rearward face lying conformably on and coextensive with the said forward margins, an opening in said slab member defining said frontal opening and defining extensions of said top, bottom and end walls, hardened seats formed in said extensions of said end walls having angularly disposed planar tubing-locating surfaces with like surfaces of both seats coplanar and disposed to locate respective end portions of straight tubing precisely coaxial with each other and with said tubing axis.
Claim 9
Dependent Claim
38 words
The device of claim 3 wherein said porous wall is apertured for passage of said limit stop member and comprises a perforated strip having a multiplicity of uniformly spaced fine channels extending through the thickness of said strip.
Claim 10
Dependent Claim
52 words
The device of claim 3 wherein said concave surFace of said forward wall is apertured for passage of said limit stop member, areas of said surface adjacent said aperture comprising openings communicating with said hollow space, and said porous surface is formed by sintered refractory curved strip bodies inserted into said openings.
Claim 11
Dependent Claim
62 words
The device of claim 3 wherein said concave surface of said forward wall is apertured for passage of said limit stop member, areas of said concave surface adjacent said limit stop aperture comprising openings communicating with said hollow space, and said porous surface is formed by strips of woven or knitted glass filament cloth material adhered in covering relation over said openings.
Claim 12
Dependent Claim
60 words
The device of claim 3 wherein a passage is formed through said gas-diffuser body opening into the rear wall and the passage has a boundary wall separating it from said hollow space, and a guide means for guiding said tube-locating limit stop member through said body is insertably receivable forwardly along said passage in gas-sealing relation with said boundary wall.
Claim 13
Dependent Claim
209 words
The device of claim 8 further comprising a handle portion having a forward wall, said wall being detachably attached on said rear wall of said housing and said handle portion extending therefrom at right angles to said spool axis, and wherein said limit stop member for locating a tubing length concentred in said electrode path comprises a tubular guide means secured on a side of said handle portion having a forward open end projecting forwardly of said forward wall and disposed for entry within said aperture when said handle portion is attached to said housing, said tubular guide means extending short of said concave wall of said diffuser body, and wherein said limit stop member comprises a rod slidably reciprocable in said guide means and being movable between a rearward retracted position and a forward tube-locating position, and end portion of said rod having a planar side at right angles to said tube axis, said planar side lying in the weld plane and intersecting said spool axis when said rod is in said tube-locating position, whereby said one length of tubing admitted within said spool member may be located with said end face of the tubing end abutting said planar side of said rod precisely in the weld plane.
Claim 14
Dependent Claim
73 words
The device of claim 12 wherein said tubular guide means has a side portion open to the exterior, a protuberance carried by said rod exposed therein for manipulation of said rod into said tube-locating and said retracted positions, said rod carrying detect means, and said tubular guide means carrying spaced recess means engageable by said detent means to restrain sliding when said rod is in either of said tube-locating and said retracted positions.
Claim 15
Dependent Claim
208 words
In a TIG welding device having a housing, tube holding means in said housing for holding a pair of tubing lengths with their axes in mutual alignment and their ends contiguous, a rotatable electrode movable in a weld plane along a path in the periphery of the junction of said tubing lengths, and means for locating the junction in the weld plane, the improvement wherein said housing comprises a rigid unitary metal hollow box structure having end walls spaced axially, a rear wall, a top and bottom wall, forward marginal portions of said top, bottom and end walls defining a frontal opening, a cover releasably secureable over said frontal opening to enclose a welding chamber surrounding said tubing lengths and tube holding means, means to fill said chamber with an inert gas atmosphere comprising a gas-pervious diffusing surface portion formed in said rear wall concentric about said axis and extending axially to either side of said junction and subtending an angle of about 180* about said axis, and means to maintain a predetermined gas pressure difference across said wall portion whereby to cause a highly-diffuse, low-velocity flow of said gas to issue through said gas-pervious surface generally radially toward said axis throughout a zone adjacent said weld plaNe.
Claim 16
Dependent Claim
208 words
In a TIG welding device having a housing, tube holding means in said housing for holding a pair of tubing lengths with their axes in mutual alignment and their ends contiguous, a rotatable electrode movable in a weld plane along a path in the periphery of the junction of said tubing lengths, and means for locating the junction in the weld plane, the improvement wherein said housing comprises a rigid unitary metal hollow box structure having end walls spaced axially, a rear wall, a top and bottom wall, forward marginal portions of said top, bottom and end walls defining a frontal opening, a cover releasably secureable over said frontal opening to enclose a welding chamber surrounding said tubing lengths and tube holding means, means to fill said chamber with an inert gas atmosphere comprising a gas-pervious diffusing surface portion formed in said rear wall concentric about said axis and extending axially to either side of said junction and subtending an angle of about 180* about said axis, and means to maintain a predetermined gas pressure difference across said wall portion whereby to cause a highly-diffuse, low-velocity flow of said gas to issue through said gas-pervious surface generally radially toward said axis throughout a zone adjacent said weld plaNe.
Claim 17
Dependent Claim
142 words
The device of claim 16 wherein said diffusing surface portion is apertured and said guide means comprises a tube extending radially of said axis into said housing from the exterior and fitting closely in said aperture and wherein said means for locating the junction in the weld plane comprises a limit stop member guidedly insertable by said guide means within said housing in a direction normal to said alignment axis, said limit stop member having a planar side face, said side face, when inserted, intersecting said alignment axis and lying in said weld plane, whereby the planar end face of one length of tubing may be precisely located and held abutting said side face, and the end face of a companion length may be inserted along said axis on withdrawal of said limit stop member and fitted against said located end face.
Claim 18
Dependent Claim
127 words
The device of claim 14 wherein said tube locating and holding means comprises tubing seats formed in forward margins of said end walls, said seats being shaped as planar surfaces forming a ''''V'''' groove in a section transverse to said axis, like surfaces of both seats being coplanar and disposed to locate seated tubing lengths coaxial with said alignment axis, and clamp arms having their one ends rotatably supported on pivot means carried by respective end walls and disposed laterally of said axis, arcuate surface portions of said arms adapted to engage seated tubing lengths, the other ends of said arms being adjustably engageable with the exterior of said housing for applying seating pressure to restrain axial elongation of the column formed by clamped abutting tubing lengths.
Claim 19
Dependent Claim
139 words
The device of claim 15 having an insulative electrode mounting, bearing means journalling said electrode mounting for rotation about said axis, a transmission for driving said electrode mounting, and an input shaft exposed in said rear wall, and further comprising a handle portion having a forward wall, a drive motor in said handle portion, means on said forward wall to couple said handle portion to said housing rear wall in perpendicularly extending relation to said alignment axis, and offset from said weld plane, and to couple said drive motor in drive relation with said input shaft, and wherein said guide means is mounted on said handle portion for entry within said aperture on coupling said handle portion with said housing, said limit stop member carrying a protuberance for manipulation of said stop member between said inserted and withdrawn positions.
Claim 20
Dependent Claim
95 words
The device of claim 17 wherein said handle portion includes a speed-reducing gear train driven from said motor having an output shaft, the ratio of rotational speed of said output shaft to the rotational speed of said electrode mounting being an integer larger than unity, a switching means having terminals, and means carried by said output shaft disposed in actuating relation to said switching means whereby to effect an on-off switching sequence between said terminals once per revolution of said output shaft corresponding to an increment of movement of said electrode in said path .
References Cited (Backward Citations)
US3536879A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |