US3899384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for manufacturing a tendon
Assignee: Individual
•
Filing: 1972-01-03
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Granted: 1975-08-12
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Expires: 1992-01-03
Abstract
Abstract This invention is a tendon for post-tensioning concrete which includes a strand of wire which is encased in a grease lubricant of predetermined thickness, the lubricant being covered by a loose-fitting plastic jacket which is in spaced relation determined by the grease thickness, to the strand of wire. The tendon is manufactured in a continuous process by passing the strand of wire through a grease applicator and then through a die sized to control grease thickness for impacting the strand with grease lubricant forming an envelope around the strand, following which the grease-encased strand is passed through an extruder having a die for applying a thermoplastic material to the outer surface of the grease envelope. The thermoplastic material is water cooled upon engagement with the grease envelope, causing the material to congeal, thus forming a continuous protective jacket around the grease envelope.
Inventors
- 👤 William F Kelly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:33
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/15; B29C48/03; B29C48/05
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
193 words
APPARATUS FOR MANUFACTURING A TENDON EMBODYING A STAND OF WIRE ENCASED IN A LUBRICANT COVERED BY A PROTECTIVE JACKET FOR USE IN THE POST LUBRICANT COVERED BY A PROTECTIVE SAID APPARATUS INCLUDING: A. FEED MEANS FOR ADVANCING THE STAND OF WIRE AT A CONSTANT, PREDDETERMINED SPEED, B. MEANS FOR APPLYING A LUBRICANT OF GREESE-LIKE CONSISTENCY AND PREDETERMINED THICKNESS TO THE PERIPHERY OF SAID STAND OF WIRE, C. SAID MEANS COMPRISING AN ELONAGATED HOUSING PROVIDING A LUBRICANT RESERVIOR, D. MEANS FOR FORCING LUBRICANT UNDER PRESSURE INTO RESERVIOR, E. NLET AND OUTLET MEANS AT OPPOSITE ENDS OF SAID HOUSING FOR PASSING THE STAND OF WIRE LONGITUDINALLY THROUGH THE RESERVIOR, WHEREBY THE LUBRICANT ADERES TO THE OUTER PERIPHERY THEREOF, F. DIE MEANS WITHIN SAID HOUSING ADJACENT SAID OUTLET MEANS FOR GAUGING A LUBRICANT ENVELOPE OF UNIFORM PREDETERMINED THICKNESS TO THE STAND OF WIRE PRIOR TO PASSING FROM SAID HOUSING. G. GUIDE MEANS WHITHIN SAID HOUSING RESERVIOR ADJACENT SAID DIE MEANS FP URGING THE LUBRICANT IN THE DIRECTION OF THE STAND OF WIRE, AND H. MEANS FOR APPLYING A PROTECTIVE JACKET TO THE OUTER PEREPHERY OF THE LUBRICANT ENVELOPE IN SPACED RELATION TO THE STAND OF WIRE.
Claim 2
Dependent Claim
193 words
APPARATUS FOR MANUFACTURING A TENDON EMBODYING A STAND OF WIRE ENCASED IN A LUBRICANT COVERED BY A PROTECTIVE JACKET FOR USE IN THE POST LUBRICANT COVERED BY A PROTECTIVE SAID APPARATUS INCLUDING: A. FEED MEANS FOR ADVANCING THE STAND OF WIRE AT A CONSTANT, PREDDETERMINED SPEED, B. MEANS FOR APPLYING A LUBRICANT OF GREESE-LIKE CONSISTENCY AND PREDETERMINED THICKNESS TO THE PERIPHERY OF SAID STAND OF WIRE, C. SAID MEANS COMPRISING AN ELONAGATED HOUSING PROVIDING A LUBRICANT RESERVIOR, D. MEANS FOR FORCING LUBRICANT UNDER PRESSURE INTO RESERVIOR, E. NLET AND OUTLET MEANS AT OPPOSITE ENDS OF SAID HOUSING FOR PASSING THE STAND OF WIRE LONGITUDINALLY THROUGH THE RESERVIOR, WHEREBY THE LUBRICANT ADERES TO THE OUTER PERIPHERY THEREOF, F. DIE MEANS WITHIN SAID HOUSING ADJACENT SAID OUTLET MEANS FOR GAUGING A LUBRICANT ENVELOPE OF UNIFORM PREDETERMINED THICKNESS TO THE STAND OF WIRE PRIOR TO PASSING FROM SAID HOUSING. G. GUIDE MEANS WHITHIN SAID HOUSING RESERVIOR ADJACENT SAID DIE MEANS FP URGING THE LUBRICANT IN THE DIRECTION OF THE STAND OF WIRE, AND H. MEANS FOR APPLYING A PROTECTIVE JACKET TO THE OUTER PEREPHERY OF THE LUBRICANT ENVELOPE IN SPACED RELATION TO THE STAND OF WIRE.
Claim 3
Dependent Claim
66 words
The apparatus of claim 1, wherein: a. said means for applying a jacketing material to the lubricant envelope includes a plastic extruder through which the lubricant-encased wire passes, and b. means for directing a plastic film towards the strand of wire at a speed less than the speed of the strand of wire, whereby ''''necking down'''' of the plastic film on the lubricant envelope is effected.
Claim 4
Dependent Claim
48 words
The apparatus of claim 3, with the addition of: a. a cooling station embodying a water trough through which the tendon passes, b. said trough including means for directing water on the plastic film substantially simultaneous with engagement with the lubricant envelope, to prevent breakdown of the lubricant.
Claim 5
Dependent Claim
54 words
The apparatus of claim 4, wherein: a. said trough includes a main body portion, and b. a throat at one end of said trough in communication with said main body portion, whereby water is permitted to run from the main portion of the trough through the throat into cooling engagement with the plastic film.
Claim 6
Dependent Claim
73 words
The apparatus of claim 4, with the addition of: a. a vibration dampener for receiving the tendon from the cooling station, b. said vibration dampener including a stationary support member, c. superimposed block members on said support member, d. the opposed faces of said block members being provided with opposed longitudinal recesses through which the strand of wire extends, and e. means for clamping said block members together and to said support member.
Claim 7
Dependent Claim
17 words
The apparatus of claim 6, with the addition of: a. means for collecting the tendon for storage.
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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) | 1978-08-11 | 1979-02-10 | 1979-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-11 | 1983-02-10 | 1983-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-11 | 1987-02-10 | 1987-08-12 | $7700.00 | Window Closed / Lapsed |