US4185504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for measuring the pre-tension of a threaded bolt
Assignee: Kraftwerk Union AG
•
Filing: 1978-10-26
•
Granted: 1980-01-29
•
Expires: 1998-10-26
Abstract
Abstract An apparatus for measuring the pre-tension of a threaded bolt by means of a two part measuring rod introduced into a central hole of the threaded bolt and of a length measuring device. The measuring rod includes an upper rod threaded to a lower tube which is secured against rotation. Rotation of the threaded rod by a motor moves the end of the measuring rod in or out of the central hole.
Inventors
- 👤 Gerhard Exner
- 👤 Volfango Festinori
- 👤 Detlef Luckschus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:09
CPC Classifications
G; G01; G01L; G01L5/00; G01L5/24; F; F16; F16B; F16B31/00; F16B31/02; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
173 words
In an apparatus for measuring the pre-tension of a threaded bolt useful with a portable tensioning device for closing a reactor pressure vessel and having a measuring rod for insertion through the tensioning device and any associated tensioning bolt to the lowest point of a central, closed hole in the threaded bolt and a measuring device for determining the difference in length between the threaded bolt and the measuring rod, the improvement comprising: a two-part measuring rod having an upper threaded rod part and a lower tube threadedly engaged with the upper part and secured against rotation, a guide rail connected to the tensioning device and supporting a mounting for motion in the longitudinal direction of the threaded rod, a motor having a housing and a braking device carried on the mounting, the motor being connected to the measuring rod for turning it, and a length measuring device fastened on the mounting and having a part resting on an end face of an extension part directly or indirectly connected to the threaded bolt.
Claim 2
Dependent Claim
173 words
In an apparatus for measuring the pre-tension of a threaded bolt useful with a portable tensioning device for closing a reactor pressure vessel and having a measuring rod for insertion through the tensioning device and any associated tensioning bolt to the lowest point of a central, closed hole in the threaded bolt and a measuring device for determining the difference in length between the threaded bolt and the measuring rod, the improvement comprising: a two-part measuring rod having an upper threaded rod part and a lower tube threadedly engaged with the upper part and secured against rotation, a guide rail connected to the tensioning device and supporting a mounting for motion in the longitudinal direction of the threaded rod, a motor having a housing and a braking device carried on the mounting, the motor being connected to the measuring rod for turning it, and a length measuring device fastened on the mounting and having a part resting on an end face of an extension part directly or indirectly connected to the threaded bolt.
Claim 3
Dependent Claim
26 words
In a measuring apparatus in accordance with claim 1, the further improvement comprising the threaded rod being driven by an electric motor having an electric brake.
Claim 4
Dependent Claim
26 words
In a measuring apparatus in accordance with claim 1, the further improvement comprising the threaded rod being in engagement with the tube via a threaded bushing.
Claim 5
Dependent Claim
35 words
In a measuring apparatus in accordance with claim 1, the further improvement comprising a key guided in the tensioning bolt and engaging an outer longitudinal slot of the tube for securing the tube against rotation.
Claim 6
Dependent Claim
30 words
In a measuring apparatus in accordance with claim 1, the further improvement comprising a bushing supported on the end face of the extension part for supporting the length measuring device.
References Cited (Backward Citations)
US2562831A
Cited
US2995033A
Cited
US3162071A
Cited
US3837694A
Cited
US3877326A
Cited
US3943819A
Cited
US3995828A
Cited
DE2604510A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-28 | 1983-07-30 | 1984-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-28 | 1987-07-30 | 1988-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-28 | 1991-07-30 | 1992-01-29 | $7700.00 | Window Closed / Lapsed |