US3837694A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic head closure mechanism
Assignee: Westinghouse Electric Corp
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Filing: 1970-07-08
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Granted: 1974-09-24
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Expires: 1990-07-08
Abstract
Abstract In order to reduce the time required for removal and replacement of a reactor vessel closure head, previously used studs for securing the closure head are replaced with a reduced member of larger diameter bolts located in radial slots in vessel and head flanges. All bolts are provided with individual hydraulic tensioning and tilting devices mounted on the head flange. The devices are operated simultaneously to preload the bolts and to actuate the bolts and the devices to an inclined position to permit the head to be removed when the tension load on the bolts is released.
Inventors
- 👤 H Andrews
- 👤 E Frisch
- 👤 D Frisch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:59
CPC Classifications
B; B25; B25B; B25B29/00; B25B29/02; B23; B23P; B23P19/00; B23P19/04; B23P19/06; B23P19/067; G; G21; G21C; G21C13/00; G21C13/02; G21C13/06; Y; Y02; Y02E; Y02E30/00; Y02E30/30; Y10; Y10S; Y10S411/00; Y10S411/916; Y10T; Y10T292/00; Y10T292/20; Y10T292/221; Y10T292/223
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
202 words
A head closure mechanism for a nuclear reactor comprising: a generally cylindrical reactor vessel and a closure head each having an outwardly extending flange with a plurality of vertically aligned radial slots in the periphery of the flanges, bolts disposed in said slots to retain the closure head on the vessel, each bolt having a head engaging the bottom surface of the vessel flange, a hydraulic pressure bolt tensioning device surrounding each bolt and mounted on the top surface of the closure head flange, said bolt extending continuously through the device with a threaded portion at its upper end, thrust means fixed on the bolt axially outward from the tensioning device, said tensioning device being located between the thrust means and the head flange, said tensioning device applying force in one axial direction against the head flange and in the other axial direction against the thrust means on the bolt for elongating the bolt between the bottom of the vessel flange and said thrust means on the bolt, and adjustable means threaded on the threaded portion axially outward from the tensioning device and the thrust means for maintaining the bolt under tension when the hydraulic pressure is removed from the tensioning device.
Claim 2
Dependent Claim
202 words
A head closure mechanism for a nuclear reactor comprising: a generally cylindrical reactor vessel and a closure head each having an outwardly extending flange with a plurality of vertically aligned radial slots in the periphery of the flanges, bolts disposed in said slots to retain the closure head on the vessel, each bolt having a head engaging the bottom surface of the vessel flange, a hydraulic pressure bolt tensioning device surrounding each bolt and mounted on the top surface of the closure head flange, said bolt extending continuously through the device with a threaded portion at its upper end, thrust means fixed on the bolt axially outward from the tensioning device, said tensioning device being located between the thrust means and the head flange, said tensioning device applying force in one axial direction against the head flange and in the other axial direction against the thrust means on the bolt for elongating the bolt between the bottom of the vessel flange and said thrust means on the bolt, and adjustable means threaded on the threaded portion axially outward from the tensioning device and the thrust means for maintaining the bolt under tension when the hydraulic pressure is removed from the tensioning device.
Claim 3
Dependent Claim
46 words
The mechanism defined in claim 1, wherein the adjustable means is movable into contact with the tensioning device when the bolt is elongated to transfer the tension load on the bolt from the fixed thrust means to the adjustable means when the hydraulic pressure is removed.
Claim 4
Dependent Claim
73 words
The mechanism defined in claim 1, wherein the tensioning device includes at least one cylinder containing a reciprocable piston for applying a tension load on the bolt through said fixed thrust means, and the adjustable means is operable movable to a position in which the tension load on the bolt is transmitted to the closure head flange through the adjustable means and the cylinder when the hydraulic pressure is removed from the piston.
Claim 5
Dependent Claim
128 words
The mechanism defined in claim 1, wherein the tensioning device includes a base plate mounted on the top surface of the closure head flange, a top plate spaced from the base plate, at least one cylinder disposed between the plates, a reciprocable piston within the cylinder for applying a tension load on the bolt through said thrust means when hydraulic pressure is applied to the piston, and said adjustable means being operable to a position with respect to the top plate to transfer the tension load on the bolt from the thrust means to the adjustable means and transmit the bolt tension load through the top plate and the cylinder and the base plate to the closure head flange when the hydraulic pressure is removed from the piston.
Claim 6
Dependent Claim
42 words
The mechanism defined in claim 1, wherein the thrust means includes a nut affixed on the bolt substantially at the top of the tensioning device, and the adjustable means includes a nut having a handwheel attached thereto for manually rotating the nut.
Claim 7
Dependent Claim
63 words
The mechanism defined in claim 1, wherein the tensioning device is operable to permit disengagement of the bolt head from the vessel flange, and including a tilting device mounted on the closure head flange for actuating the bolt and its tensioning device to an inclined position to permit the closure head to be lifted vertically without the bolt interferring with the vessel flange.
Claim 8
Dependent Claim
28 words
The mechanism defined in claim 6 wherein the tensioning device and the bolt are actuated about a pivot line on the top surface of the closure head flange.
Claim 9
Dependent Claim
30 words
The mechanism defined in claim 7, including a lever on the tensioning device engaged by the tilting device to actuate the tensioning device and the bolt abouT the pivot line.
Claim 10
Dependent Claim
35 words
The mechanism defined in claim 8, including a swivel support for the tilting device permitting it to move to an inclined position when the tensioning device and the bolt are actuated to the inclined position.
Claim 11
Dependent Claim
24 words
The mechanism defined in claim 9, including spring means for returning the tilting device to a vertical position when the tilting device is deenergized.
Claim 12
Dependent Claim
40 words
The mechanism defined in claim 8, wherein the tilting device comprises a fluid pressure actuated piston, a bifurcated member having arms straddling said lever, and a cross pin in the arms engaging the lever when the piston is actuated downwardly.
Claim 13
Dependent Claim
25 words
The mechanism defined in claim 11, including a spring for returning the piston to its original position when fluid pressure is released from the piston.
Claim 14
Dependent Claim
130 words
A head closure mechanism for a vessel member and a closure head member each having an outwardly extending flange with a plurality of vertically aligned openings therein, comprising bolts disposed in said openings to retain the closure head member on the vessel member, a hydraulic pressure tensioning device surrounding each bolt and mounted on a surface of the flange on one of said members, said bolt extending continuously through the device with a threaded portion at one end, thrust means fixed on the bolt, said tensioning device applying force between the thrust means and said flange for tensioning the bolt, and adjustable means threaded on said threaded portion axially outward of the tensioning device for maintaining the bolt under tension when the hydraulic pressure is removed from the tensioning device.
Claim 15
Dependent Claim
130 words
A head closure mechanism for a vessel member and a closure head member each having an outwardly extending flange with a plurality of vertically aligned openings therein, comprising bolts disposed in said openings to retain the closure head member on the vessel member, a hydraulic pressure tensioning device surrounding each bolt and mounted on a surface of the flange on one of said members, said bolt extending continuously through the device with a threaded portion at one end, thrust means fixed on the bolt, said tensioning device applying force between the thrust means and said flange for tensioning the bolt, and adjustable means threaded on said threaded portion axially outward of the tensioning device for maintaining the bolt under tension when the hydraulic pressure is removed from the tensioning device.
Claim 16
Dependent Claim
55 words
The mechanism defined in claim 13, wherein the thrust means is mounted on the bolt internally of the tensioning device, and the adjustable means is movable into contact with the tensioning device to transfer the tension load on the bolt from the fixed thrust means to the adjustable means when the hydraulic pressure is removed.
Claim 17
Dependent Claim
37 words
The mechanism defined in claim 14, wherein the tension load on the bolt is transmitted to the flange on one of said members through the adjustable means and the tensioning device when the hydraulic pressure is removed.
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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) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |