Patent US3844533A successfully refreshed from Google Patents.
US3844533A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic stud tensioner
Assignee: UNC NUCLEAR INDUSTRIES Inc A CORP OF
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Filing: 1973-03-12
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Granted: 1974-10-29
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Expires: 1993-03-12
Abstract
Abstract A power operated, automatic, stud tensioner adapted for use with a nuclear reactor pressure vessel is described. Means are included to provide for automatic engagement of a segmented coupling nut with the normal helical stud threads while a retaining ring is being lowered to lock the coupling nut to the stud. Also included are motor actuated means for running off the nut, and means for allowing the tensioner to align itself with the stud.
Inventors
- 👤 J Markiewicz
- 👤 A Yoli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:27
CPC Classifications
B; B25; B25B; B25B29/00; B25B29/02
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
324 words
Apparatus for tensioning a stud having helical threads for assembly or disassembly of a closure nut engaging said helical threads, comprising a pedestal, hydraulic means comprising a piston and cylinder, one of the piston and cylinder being connected to the pedestal, means for introducing pressurized fluid into the hydraulic means, a puller rod connected to the other of the piston and cylinder and having a threaded section, means for detachably coupling to the stud helical threads above the closure nut, said detachable coupling means comprising plural segments carried by the puller rod and each having a first helical threaded section for engaging the stud helical threads and a second threaded section for threaded engagement with the puller rod threaded section, the segments first threaded sections having a smoothy tapered external surface, means for coupling together the plural segments forcing them to move vertically as a unit, means smoothly effecting threaded engagement between the plural first threaded sections and the stud threads above the closure nut and without rotating the plural segments, said engagement effecting means comprising a smoothly tapered lower annular ring for engagement with the tapered external surface of the segments first threaded sections when moved downward for displacing the plural segments laterally inward and means operative upon a non-threaded-engagement meeting of the segments first threaded sections with the stud thrEads to cause a small vertical displacement of the plural segments until complete threaded engagement of the segments first threaded sections and the stud threads occurs, said vertical displacement means comprising an upper annular retaining ring for engagement with the segments second threaded sections, means for driving the smoothly tapered lower annular ring downward, and means operative upon downward motion of the lower annular ring to move downward the upper retaining ring into engagement with the segments second threaded sections, said last-named means not being operative to move the upper retaining ring until the lower annular ring has been displaced a certain distance.
Claim 2
Dependent Claim
324 words
Apparatus for tensioning a stud having helical threads for assembly or disassembly of a closure nut engaging said helical threads, comprising a pedestal, hydraulic means comprising a piston and cylinder, one of the piston and cylinder being connected to the pedestal, means for introducing pressurized fluid into the hydraulic means, a puller rod connected to the other of the piston and cylinder and having a threaded section, means for detachably coupling to the stud helical threads above the closure nut, said detachable coupling means comprising plural segments carried by the puller rod and each having a first helical threaded section for engaging the stud helical threads and a second threaded section for threaded engagement with the puller rod threaded section, the segments first threaded sections having a smoothy tapered external surface, means for coupling together the plural segments forcing them to move vertically as a unit, means smoothly effecting threaded engagement between the plural first threaded sections and the stud threads above the closure nut and without rotating the plural segments, said engagement effecting means comprising a smoothly tapered lower annular ring for engagement with the tapered external surface of the segments first threaded sections when moved downward for displacing the plural segments laterally inward and means operative upon a non-threaded-engagement meeting of the segments first threaded sections with the stud thrEads to cause a small vertical displacement of the plural segments until complete threaded engagement of the segments first threaded sections and the stud threads occurs, said vertical displacement means comprising an upper annular retaining ring for engagement with the segments second threaded sections, means for driving the smoothly tapered lower annular ring downward, and means operative upon downward motion of the lower annular ring to move downward the upper retaining ring into engagement with the segments second threaded sections, said last-named means not being operative to move the upper retaining ring until the lower annular ring has been displaced a certain distance.
Claim 3
Dependent Claim
32 words
Tensioning apparatus as claimed in claim 1 wherein means are provided operative upon initial downward movement of the lower annular ring for biasing the plural segments toward their stud thread engagement position.
Claim 4
Dependent Claim
36 words
Tensioning apparatus as claimed in claim 1 wherein means are provided operative upon upward motion of the retainer driving means for outwardly displacing the plural segments to disengage same from the stud threads and puller rod.
Claim 5
Dependent Claim
218 words
Apparatus for tensioning a stud having helical threads for assembly or disassembly of a closure nut engaging said helical threads, comprising a pedestal, hydraulic means comprising a piston and cylinder, one of the piston and cylinder being connected to the pedestal, means for introducing pressurized fluid into the hydraulic means, means for detachably coupling to the same stud helical threads which can be engaged by the closure nut, said detachable coupling means comprising plural segments each having a first helical threaded section for engaging the stud helical threads, said plural segments being suspended in a vertical position from the other of the piston and cylinder in such manner as to surround the stud and as to enable radial displacement and vertical displacement of the segments relative to the pedestal, means for effecting engagement and disengagement between the plural first threaded sections and the stud threads above the closure nut and without rotating the plural segments, said engagement effecting means including means for displacing the plural segments laterally inward and means operative upon the segments first threaded sections contacting but not entering into theaded engagement relation with the stud threads to cause the plural segments to be displaced vertically until such threaded engagement can occur, and means for retaining the detachable coupling means in engagement with the stud threads.
Claim 6
Dependent Claim
218 words
Apparatus for tensioning a stud having helical threads for assembly or disassembly of a closure nut engaging said helical threads, comprising a pedestal, hydraulic means comprising a piston and cylinder, one of the piston and cylinder being connected to the pedestal, means for introducing pressurized fluid into the hydraulic means, means for detachably coupling to the same stud helical threads which can be engaged by the closure nut, said detachable coupling means comprising plural segments each having a first helical threaded section for engaging the stud helical threads, said plural segments being suspended in a vertical position from the other of the piston and cylinder in such manner as to surround the stud and as to enable radial displacement and vertical displacement of the segments relative to the pedestal, means for effecting engagement and disengagement between the plural first threaded sections and the stud threads above the closure nut and without rotating the plural segments, said engagement effecting means including means for displacing the plural segments laterally inward and means operative upon the segments first threaded sections contacting but not entering into theaded engagement relation with the stud threads to cause the plural segments to be displaced vertically until such threaded engagement can occur, and means for retaining the detachable coupling means in engagement with the stud threads.
Claim 7
Dependent Claim
41 words
Tensioning apparatus as claimed in claim 4 and further comprising a puller rod located above the stud and having a threaded section, and the plural segments each comprise a second threaded section for threaded engagement with the puller rod threaded section.
Claim 8
Dependent Claim
53 words
Tensioning apparatus as claimed in claim 1 wherein the upper retaining ring comprises a groove, and finger means are provided connected to the lower annular ring driving means and engaging the groove in the upper retaining ring, the vertical dimension of the said finger being smaller than the corresponding dimension of the groove.
Claim 9
Dependent Claim
22 words
Tensioning apparatus as claimed in claim 4 and further including means connecting together the segment engagement effecting means and the retaining means.
Claim 10
Dependent Claim
39 words
Tensioning apparatus as claimed in claim 7 and further including means operable upon actuation of the retaining means to effect engagement of the coupling means and the stud threads before the retaining means reach their final segment retaining position.
Claim 11
Dependent Claim
239 words
Apparatus for tensioning a stud having a continuous helical threaded section for assembly or disassembly of a closure nut engaging the threads of said helical threaded section: comprising a pedestal; hydraulic means comprising a piston and cylinder, one of the piston and cylinder being connected to the pedestal, and means for introducing pressurized fluid into the cylinder; means comprising plural segments for detAchably coupling to the same threads of the stud helical threaded section engaged by the closure nut, said plural segments each having a helical threaded section for engaging the stud helical threads, and means for supporting the plural segments on the other one of the piston and cylinder so as to surround the stud, said segment support means enabling lateral and vertical displacement of the segments relative to said other one of the piston and cylinder; and means for causing threaded engagement between the segment threaded sections and the stud helical threads and without rotating the plural segments, said engagement causing means comprising means for biasing the segments inwardly to bring about contact of its threaded sections with the stud threaded section, and means for imparting to the plural segments subsequent to the time they contact the stud threaded section and while they are still being biased inwardly a force capable of vertically displacing the plural segments if they are not in threaded engagement with the stud threads a sufficient distance to bring about said threaded engagement.
Claim 12
Dependent Claim
239 words
Apparatus for tensioning a stud having a continuous helical threaded section for assembly or disassembly of a closure nut engaging the threads of said helical threaded section: comprising a pedestal; hydraulic means comprising a piston and cylinder, one of the piston and cylinder being connected to the pedestal, and means for introducing pressurized fluid into the cylinder; means comprising plural segments for detAchably coupling to the same threads of the stud helical threaded section engaged by the closure nut, said plural segments each having a helical threaded section for engaging the stud helical threads, and means for supporting the plural segments on the other one of the piston and cylinder so as to surround the stud, said segment support means enabling lateral and vertical displacement of the segments relative to said other one of the piston and cylinder; and means for causing threaded engagement between the segment threaded sections and the stud helical threads and without rotating the plural segments, said engagement causing means comprising means for biasing the segments inwardly to bring about contact of its threaded sections with the stud threaded section, and means for imparting to the plural segments subsequent to the time they contact the stud threaded section and while they are still being biased inwardly a force capable of vertically displacing the plural segments if they are not in threaded engagement with the stud threads a sufficient distance to bring about said threaded engagement.
Claim 13
Dependent Claim
46 words
Tensioning apparatus as claimed in claim 9 wherein the supporting means for the plural segments comprises a puller rod having hook means, said segments having finger means engaging the puller rod hook means in such manner as to enable radial and vertical displacement of the segments.
Claim 14
Dependent Claim
76 words
Tensioning apparatus as claimed in claim 10 wherein the puller rod has a threaded section comprising square threads, and the plural segments each have second threaded sections also comprising square threads for engaging the puller rod threaded section, said puller rod square threads and said second section square threads having dimensions such that when centered relative to one another a clearance exists between the threads on each side equal to about one-half the stud thread pitch.
Claim 15
Dependent Claim
25 words
Tensioning apparatus as claimed in claim 9 and further including means for coupling together the plural segments forcing them to move vertically as a unit.
Claim 16
Dependent Claim
30 words
Tensioning apparatus as claimed in claim 9 and further including means for releasably engaging the closure nut, and motor means coupled to the closure nut engaging means for rotating same.
Claim 17
Dependent Claim
50 words
Tensioning apparatus as claimed in claim 13 and including means for lifting the apparatus, the motor means being adapted to rotate the closure nut so as to cause it to be vertically displaced at a rate equal to or in excess of the rate at which the apparatus is lifted.
Claim 18
Dependent Claim
42 words
Tensioning apparatus as claimed in claim 9 and including means coupled to the pedestal for lifting the apparatus, said coupling means including a gimbal mechanism allowing horizontal pivoting action of the pedestal relative to the lifting means about two orthogonal horizontal axes.
Claim 19
Dependent Claim
29 words
Tensioning apparatus as claimed in claim 15 and further including bearing means in the foot of the pedestal allowing for alignment of the apparatus with an off-axially directed stud.
Claim 20
Dependent Claim
63 words
Tensioning apparatus as claimed in claim 1, wherein the puller rod threaded section comprises square threads and the second threaded sections also comprise square threads, said puller rod square threads and said second section square threads having dimensions such that when centered relative to one another a clearance exists between the threads on each side equal to about one-half the stud thread pitch.
Claim 21
Dependent Claim
43 words
Tensioning apparatus as claimed in claim 17 wherein the segments are floatingly suspended within the pedestal such that when the first section threads are exactly aligned with the stud threads, the second section threads are centered with respect to the puller rod threads.
Claim 22
Independent Claim
143 words
A method of tensioning a stud traversing a flange to assemble or disassemble a flange bearing closure nut, comprising the steps of locating over the stud, tensioner apparatus comprising a pedestal having a foot for engaging the flange, alignment means, hydraulic piston and cylinder of which one is connected to the pedestal, and deTachable coupling means for the stud connected to the other of the piston and cylinder, lowering the tensioner apparatus until just before the pedestal foot engages the flange, threadingly engaging the coupling means to the stud while the apparatus remains free of the flange, and then introducing pressurized fluid between the piston and cylinder to cause the pedestal first to move downward until the flange is engaged and then to cause the stud to be tensioned, any misalignment of stud, flange and tensioner being taken up by the alignment means.
Claim 23
Independent Claim
143 words
A method of tensioning a stud traversing a flange to assemble or disassemble a flange bearing closure nut, comprising the steps of locating over the stud, tensioner apparatus comprising a pedestal having a foot for engaging the flange, alignment means, hydraulic piston and cylinder of which one is connected to the pedestal, and deTachable coupling means for the stud connected to the other of the piston and cylinder, lowering the tensioner apparatus until just before the pedestal foot engages the flange, threadingly engaging the coupling means to the stud while the apparatus remains free of the flange, and then introducing pressurized fluid between the piston and cylinder to cause the pedestal first to move downward until the flange is engaged and then to cause the stud to be tensioned, any misalignment of stud, flange and tensioner being taken up by the alignment means.
Claim 24
Dependent Claim
30 words
A method as set forth in claim 19 wherein the alignment means comprises gimbal means for supporting the tensioner, and spherical bearing means located at the foot of the pedestal.
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) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |