US3679173A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-aligning tensioner
Assignee: Babcock and Wilcox Co
•
Filing: 1970-08-06
•
Granted: 1972-07-25
•
Expires: 1990-08-06
Abstract
Abstract A hydraulic tensioner for preloading threaded studs or bolts has a cylinder and piston assembly at the top with a spherically concaved bottom surface overlying a matching spherically convex top surface of the supporting pedestal. Said assembly is held spaced above the pedestal by counterbalancing springs when the tensioner is unloaded but is pulled down to engage said surfaces when the tensioner is loaded. Said assembly and the drawbar, engagement nut and related components are angularly movable.
Inventors
- 👤 Ronald E Sherrick
- 👤 John C Singleton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:34
CPC Classifications
B; B25; B25B; B25B29/00; B25B29/02; Y; Y10; Y10T; Y10T29/00; Y10T29/53; Y10T29/53796; Y10T29/5383
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
98 words
A stud tensioner including a pedestal adapted to straddle and extend above a nut-carrying stud to be tensioned, and a cylinder, piston and drawbar assembly mounted above the pedestal with the drawbar extending down inside the pedestal for engagement with a stud to be tensioned, and having lateral clearance between the drawbar assembly and the pedestal, characterized by resilient supporting means for said assembly reacting downwardly against the pedestal and upwardly on said assembly with a force exceeding the weight of the assembly, said supporting means permitting limited lateral and vertical movement between the assembly and the pedestal.
Claim 2
Dependent Claim
98 words
A stud tensioner including a pedestal adapted to straddle and extend above a nut-carrying stud to be tensioned, and a cylinder, piston and drawbar assembly mounted above the pedestal with the drawbar extending down inside the pedestal for engagement with a stud to be tensioned, and having lateral clearance between the drawbar assembly and the pedestal, characterized by resilient supporting means for said assembly reacting downwardly against the pedestal and upwardly on said assembly with a force exceeding the weight of the assembly, said supporting means permitting limited lateral and vertical movement between the assembly and the pedestal.
Claim 3
Dependent Claim
72 words
A tensioner as defined in claim 1 including an upward facing convex spherical seat area on the top of the pedestal surrounding and outspaced from the drawbar, a matching downward facing concave spherical seat area on the bottom of the cylinder and overlying the first mentioned seat area, said resilient supporting means holding said seat areas apart a distance which is less than the travel of the piston during a tensioning operation.
Claim 4
Dependent Claim
28 words
A tensioner as defined in claim 2 wherein said spherical seat areas are concentric with a common center located centrally of and near the bottom of the pedestal.
Claim 5
Dependent Claim
38 words
A tensioner as defined in claim 1 including an upwardly yieldably retractable centering element carried by and extending downwardly from the drawbar and engageable with a stud in the pedestal prior to engagement between the drawbar and stud.
Claim 6
Dependent Claim
47 words
A tensioner as defined in claim 1 including a centering element carried by the drawbar for engagement with a stud in the pedestal, and biasing spring means urging the centering element downwardly with a force which is relatively light in proportion to the weight of the tensioner.
Claim 7
Dependent Claim
45 words
A tensioner as defined in claim 5 wherein said centering element is axially slidable in and projectable from the bottom of the drawbar, and a rod actuatable by the centering element and extending to a position near and accessible from the top of the tensioner.
Claim 8
Dependent Claim
122 words
In a tensioner as defined in claim 1, means for attaching the drawbar to and detaching it from a stud in the pedestal comprising a tensioning nut threadedly attached to and extensible from the bottom of the drawbar to threadedly engage a stud while still threadedly enGaged with the drawbar, and means for rotating the tensioning nut comprising a cylindrical rotary drive tube journaled in the pedestal and held against unwanted axial movement and of substantially greater internal diameter than the drawbar and tensioning nut, a gimbal ring rockable but non-rotatively attached to the tensioning nut, means slidably and rockably but non-rotatively connecting the gimbal ring to the drive tube, and means for rotating the drive tube to turn the tensioning nut.
Claim 9
Dependent Claim
42 words
A tensioner as defined in claim 7 wherein the drive tube, gimbal ring, and tensioning nut are substantially concentric and substantial radial clearance is provided between the tensioning nut and the gimbal ring, and between the gimbal ring and the drive tube.
Claim 10
Dependent Claim
43 words
A tensioner as defined in claim 2 including spring-retaining flange portions extending outwardly from opposite sides of the cylinder, coacting flange portions extending outwardly from opposite sides of the pedestal, and compression springs trapped between said flanges on opposite sides of the tensioner.
Claim 11
Dependent Claim
133 words
In a tensioner as defined in claim 1, means for rotating a holding nut on the stud comprising a wrench tube journaled in and near the bottom of the pedestal for rotation upon an axis substantially concentric therewith but having substantial radial clearance with respect to the pedestal and the drawbar assembly and adapted to be drivingly interconnected with such a holding nut, and means for rotating the wrench tube to turn the holding nut including axially extending gear teeth on the periphery of the wrench tube and a spur gear meshing therewith journaled on the pedestal, said gear teeth and the teeth of the spur gear being relatively coarse and of a radial length to permit radial displacement of the wrench tube and pedestal to the extent of the effective clearance therebetween.
Claim 12
Dependent Claim
53 words
A tensioner as defined in claim 1 wherein both the piston and drawbar are accurately non-rockably fitted in the cylinder, said resilient supporting means comprising a plurality of helical compression springs peripherally spaced around the cylinder and which are relatively long in proportion to their diameter to permit relatively easy lateral deflection thereof.
Claim 13
Dependent Claim
55 words
A tensioner as defined in claim 2 wherein both the piston and drawbar are accurately non-rockably fitted in the cylinder, said resilient supporting means comprising a plurality of helical compression springs peripherally spaced around the cylinder and reacting upwardly against an upper part of the cylinder and downwardly against an upper part of the pedestal.
References Cited (Backward Citations)
US3099434A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |