Patent US3815874A successfully refreshed from Google Patents.
US3815874A
Expired / Lapsed
US
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Bolt tensioning device especially adapted for use with nuclear reactor pressure vessel
Assignee: UNC NUCLEAR INDUSTRIES Inc A CORP OF
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Filing: 1971-10-18
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Granted: 1974-06-11
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Expires: 1991-10-18
Abstract
Abstract An improved bolt tensioning device for use for loosening or tightening the bolts which secure the pressure head to a nuclear reactor pressure vessel is described. The improved tensioner comprises a head bearing member which surrounds the bolt nut and has an annular ledge defining with an overlying complementary mating piston member an annular pressurized fluid receiving chamber. A connection to the bolt stud is constituted by a split sleeve or ring which is placed in threaded engagement with the stud above the fluid receiving chamber and held in place therein by a surrounding retainer sleeve via matching tapered surfaces. A bearing washer with curved bearing surface is interposed between the upwardly urged complementary member and the split ring for transmitting the upward force to the latter and via the latter to the stud.
Inventors
- 👤 C Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:35
CPC Classifications
B; B25; B25B; B25B29/00; B25B29/02
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
218 words
A bolt tensioning device for loosening or tightening a nut on a threaded stud used for bolting the head flange to a nuclear reactor pressure vessel, comprising a flange bearing member having means for positioning same on the head flange and surrounding the nut and an internal ledge providing an upwardly facing surface, a complementary piston member seated on the flange bearing member and having a surface opposed to the upwardly facing surface on the latter, said complementary member having an upwardly facing surface, means for removably engaging a threaded portion of the stud, means for removably securing the stud thread engaging means to the stud, said stud thread engaging means having a downwardly facing bearing surface, force transmitting means coupling the upwardly facing surface of the complementary member to the downwardly facing bearing surface of the thread engaging means, means for introducing pressurized fluid between the upwardly facing surface of the flange bearing member and the opposing surface on the complementary member, said flange bearing member having a portion extending over the complementary member, first valve means in the flange bearing portion and adapted to be actuated when the complementary member elevation exceeds a predetermined amount, and means responsive to the actuated first valve means for relieving high fluid pressure between the flange bearing and complementary members.
Claim 2
Dependent Claim
218 words
A bolt tensioning device for loosening or tightening a nut on a threaded stud used for bolting the head flange to a nuclear reactor pressure vessel, comprising a flange bearing member having means for positioning same on the head flange and surrounding the nut and an internal ledge providing an upwardly facing surface, a complementary piston member seated on the flange bearing member and having a surface opposed to the upwardly facing surface on the latter, said complementary member having an upwardly facing surface, means for removably engaging a threaded portion of the stud, means for removably securing the stud thread engaging means to the stud, said stud thread engaging means having a downwardly facing bearing surface, force transmitting means coupling the upwardly facing surface of the complementary member to the downwardly facing bearing surface of the thread engaging means, means for introducing pressurized fluid between the upwardly facing surface of the flange bearing member and the opposing surface on the complementary member, said flange bearing member having a portion extending over the complementary member, first valve means in the flange bearing portion and adapted to be actuated when the complementary member elevation exceeds a predetermined amount, and means responsive to the actuated first valve means for relieving high fluid pressure between the flange bearing and complementary members.
Claim 3
Dependent Claim
38 words
A bolt tensioning device as set forth in claim 1 wherein the force transmitting means comprises a bearing washer disposed entirely between the complementary member upwardly facing surface and the stud thread engaging means downwardly facing bearing surface.
Claim 4
Dependent Claim
42 words
A device as set forth in claim 2 wherein the stud thread engaging means downwardly facing bearing surface is convex, and the opposed surface of the bearing washer is concave, the convex surface curvature being greater than that of the concave surface.
Claim 5
Dependent Claim
91 words
A device as set forth in claim 1 wherein the flange bearing member comprises a generally annular body having an inward annular ledge providing the upwardly facing surface, the complementary member comprises a main body portion seated on the said ledge and a depending skirt portion, the complementary member opposed surface and the ledge surface defining the fluid receiving annular chamber located below the stud thread engaging means, annular seal means sealing off the annular chamber, and means in the flange bearing member for introducing pressurized fluid into the annular chamber.
Claim 6
Dependent Claim
37 words
A device as set forth in claim 4 wherein the annular chamber is laterally offset outwardly of the stud thread engaging means, and the force transmitting member comprises a spherical bearing surface for transmitting the upward force.
Claim 7
Dependent Claim
135 words
A bolt tensioning device adapted for loosening or tightening a nut on a threaded stud used for bolting the head flange to a nuclear reactor pressure vessel, comprising means for removably engaging the stud threads above the nut, hydraulic means for imparting an upward force to the stud engaging means, said hydraulic means comprising mating parts forming a hydraulic piston and cylinder assembly, means coupling one of the mating parts to the stud-engaging means, said mating parts tending to separate when imparting the said upward force, and means forming an auxiliary hydraulic chamber for assembling the mating parts upon the introduction of pressurized fluid into the auxiliary chamber, said auxiliary chamber being located above the said one mating part and driving same downward toward the other of the mating parts upon introduction of pressuriZed fluid.
Claim 8
Dependent Claim
135 words
A bolt tensioning device adapted for loosening or tightening a nut on a threaded stud used for bolting the head flange to a nuclear reactor pressure vessel, comprising means for removably engaging the stud threads above the nut, hydraulic means for imparting an upward force to the stud engaging means, said hydraulic means comprising mating parts forming a hydraulic piston and cylinder assembly, means coupling one of the mating parts to the stud-engaging means, said mating parts tending to separate when imparting the said upward force, and means forming an auxiliary hydraulic chamber for assembling the mating parts upon the introduction of pressurized fluid into the auxiliary chamber, said auxiliary chamber being located above the said one mating part and driving same downward toward the other of the mating parts upon introduction of pressuriZed fluid.
Claim 9
Dependent Claim
27 words
A device as set forth in claim 6 wherein the stud thread engaging means comprises a split sleeve with an inside thread matching that of the stud.
Claim 10
Dependent Claim
36 words
A device as set forth in claim 7 wherein the securing means comprises a sleeve adapted to fit over the split sleeve, said securing means and split sleeve being provided with complementary tapered smooth contacting surfaces.
Claim 11
Dependent Claim
43 words
A device as set forth in claim 8 wherein the securing means sleeve has an aperture at its top for receiving a wedge shaped element which when inserted will impart to it an upward force relative to the stud for removing the sleeve.
Claim 12
Dependent Claim
26 words
A bolt tensioning device as claimed in claim 6 wherein means are provided responsive to movement of the hydraulic piston to interrupt introduction of pressurized fluid.
Claim 13
Dependent Claim
90 words
A device as set forth in claim 1 and comprising second valve means in the flange bearing member and adapted to be actuated when the complementary member is moved downward toward the flange bearing member, means providing a pressurized fluid receiving chamber located between a top surface of the complementary member and the flange bearing portion overlying same, means for introducing pressurized fluid into the last-named chamber for driving the complementary member downward, and means responsive to actuation of the second valve for relieving high fluid pressure in said chamber.
Claim 14
Dependent Claim
19 words
A bolt tensioning device as claimed in claim 1 and further including means for hydraulically assembling the complementary member.
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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) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |