Patent US3597830A successfully refreshed from Google Patents.
US3597830A
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Method and apparatus for post tensioning and anchoring prestressing tendons
Assignee: Individual
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Filing: 1968-11-29
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Granted: 1971-08-10
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Expires: 1988-11-29
Abstract
Abstract A method and apparatus for post tensioning a prestressing tendon disposed in a concrete structure through the employment of a first jack to impart a uniform predetermined tension to the tendon, and a second jack used in conjunction with an engageable anchor to selectively engage the anchor to the prestressing tendon and place he anchor in abutment with the concrete structure. The jacks are separate and separable from each other to facilitate preassembly of the second jack nd anchor on a tendon prior to the application of the first jack.
Inventors
- 👤 Lawrence R Yegge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:48
CPC Classifications
E; E04; E04G; E04G21/00; E04G21/12; E04G21/121; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49863; Y10T29/49874
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
159 words
An assemblage for applying tension to and anchoring the end of a prestressing tendon extending from a concrete structure, said assemblage comprising: a. anchoring means disposed around said tendon for seating engagement with said structure and selective gripping engagement of said tendon upon the application of compressive force to said means; b. a first jack having a base member disposed in compression imparting relationship to said structure and a ram selectively expansible relative to said base member disposed in gripping engagement with said tendon; and c. a separable second jack releasably connected to said first jack, said second jack having a base member restrained against movement away from said structure by said first jack base member and a ram selectively expansible relative to said second jack base member and disposed for movement towards and into abutting engagement with said anchoring means to impart compressive force thereto to effect gripping said tendon and seating said anchoring means against said structure.
Claim 2
Dependent Claim
159 words
An assemblage for applying tension to and anchoring the end of a prestressing tendon extending from a concrete structure, said assemblage comprising: a. anchoring means disposed around said tendon for seating engagement with said structure and selective gripping engagement of said tendon upon the application of compressive force to said means; b. a first jack having a base member disposed in compression imparting relationship to said structure and a ram selectively expansible relative to said base member disposed in gripping engagement with said tendon; and c. a separable second jack releasably connected to said first jack, said second jack having a base member restrained against movement away from said structure by said first jack base member and a ram selectively expansible relative to said second jack base member and disposed for movement towards and into abutting engagement with said anchoring means to impart compressive force thereto to effect gripping said tendon and seating said anchoring means against said structure.
Claim 3
Dependent Claim
85 words
The assemblage as described in claim 1 wherein the anchoring means comprises: a. an anchoring plate in abutting engagement with said second jack base member and having a truncated conical hole through which the tendon is directed; and, b. internally toothed collar-shaped wedges received around the tendon, said wedges being adapted, under the application of compressive force thereto by said second jack ram upon expansion thereof relative to said second jack base member, to wedge into the anchor plate hole and grippingly engage said tendon.
Claim 4
Dependent Claim
42 words
a surface within said cavity and spaced from the open end thereof against which an independent jack received therein may bear whereby, upon expansion, movement of said independent jack away from a structure against which said base member is seated is restrained;
Claim 5
Dependent Claim
42 words
a surface within said cavity and spaced from the open end thereof against which an independent jack received therein may bear whereby, upon expansion, movement of said independent jack away from a structure against which said base member is seated is restrained;
Claim 6
Dependent Claim
105 words
The assemblage as described in claim 2 wherein: a. the second jack base member defines a cavity; b. the tendon is comprised of a plurality of strands; c. the anchoring plate is at least partially disposed within said cavity and in abutting engagement with the wall of said second jack base member defining said cavity, said anchoring plate having at least one such truncated conical hole for each strand of said tendon, said holes disposed in a uniform pattern across said plate; and, d. toothed collar-shaped wedges are provided for each strand to grippingly engage each strand responsive to a common compressive force applied thereto.
Claim 7
Dependent Claim
23 words
an open area within said cavity and communicating with the open end thereof through which an independent jack received therein may expand; and,
Claim 8
Dependent Claim
23 words
an open area within said cavity and communicating with the open end thereof through which an independent jack received therein may expand; and,
Claim 9
Dependent Claim
218 words
An assemblage for applying tension to and anchoring the end of a prestressing tendon extending from a concrete structure, said assemblage comprising: a. anchoring means disposed around said tendon for seating engagement with said structure and selective gripping engagement of said tendon upon the application of compressive force to said means; b. a first jack having a base member disposed in compression-imparting relationship to said structure and a ram selectively expansible relative to said base member disposed in gripping engagement with said tendon; and c. a second jack interposed between said first jack and said anchoring means, said second jack having a base member restrained against movement away from said structure and a ram selectively expansible relative to said base member and disposed for movement towards and into abutting engagement with said anchoring means to impart compressive force thereto to effect gripping said tendon and seating said anchoring means against said structure; said first jack being of the center hole type and formed with a cavity within the base member thereof to receive said anchoring means and said second jack and said second jack being restrained from movement away from the structure by an abutting engagement between the base member of said second jack and a wall of the cavity in the base member of said first jack.
Claim 10
Dependent Claim
218 words
An assemblage for applying tension to and anchoring the end of a prestressing tendon extending from a concrete structure, said assemblage comprising: a. anchoring means disposed around said tendon for seating engagement with said structure and selective gripping engagement of said tendon upon the application of compressive force to said means; b. a first jack having a base member disposed in compression-imparting relationship to said structure and a ram selectively expansible relative to said base member disposed in gripping engagement with said tendon; and c. a second jack interposed between said first jack and said anchoring means, said second jack having a base member restrained against movement away from said structure and a ram selectively expansible relative to said base member and disposed for movement towards and into abutting engagement with said anchoring means to impart compressive force thereto to effect gripping said tendon and seating said anchoring means against said structure; said first jack being of the center hole type and formed with a cavity within the base member thereof to receive said anchoring means and said second jack and said second jack being restrained from movement away from the structure by an abutting engagement between the base member of said second jack and a wall of the cavity in the base member of said first jack.
Claim 11
Dependent Claim
28 words
an elongated throughbore formed in said base member and communicating with said cavity, said surface surrounding said throughbore; and b. a ram expansible relative to said base member.
Claim 12
Dependent Claim
28 words
an elongated throughbore formed in said base member and communicating with said cavity, said surface surrounding said throughbore; and b. a ram expansible relative to said base member.
Claim 13
Dependent Claim
36 words
A center hole pulling jack for use in imparting tension to a tendon extending from a concrete structure, said jack coMprising: a. a base member adapted to be seated against the structure, said base member having:
Claim 14
Dependent Claim
36 words
A center hole pulling jack for use in imparting tension to a tendon extending from a concrete structure, said jack coMprising: a. a base member adapted to be seated against the structure, said base member having:
Claim 15
Dependent Claim
34 words
The jack as described in claim 5 wherein, an opening extends laterally through said base member and into communication with the cavity therein to permit access to an independent jack received in said cavity.
Claim 16
Independent Claim
228 words
A method of posttensioning and anchoring the end of a prestressing tendon extending from a concrete structure by means of an engageable collet which grips said tendon responsive to application of a compressive force thereto and anchors the tendon to the structure, comprising: a. positioning the engageable collet adjacent said structure and around the emerging end of the prestressing tendon; b. positioning an engaging jack having two portions selectively expansible relative to each other to restrain one of said portions against movement away from said structure and dispose the other for selective movement toward and into abutment with said engageable collet to effect the gripping engagement of said collet with said tendon and force said collet into bearing interrelationship with said structure; c. positioning around the tendon, the engaging jack and engageable collet, a center hole pulling jack having two hollow portions selectively expansible relative to each other, with one portion disposed in compression imparting relationship to said structure, and the other portion disposed in gripping engagement to the end of said tendon; d. expanding said pulling jack to impart a predetermined tension to said tendon; e. expanding said engaging jack to force the collet into gripping engagement with the tendon and bearing interrelationship with the structure; f. collapsing the engaging jack; g. collapsing the pulling jack; h. removing the pulling jack; and i. removing the engaging jack.
Claim 17
Independent Claim
228 words
A method of posttensioning and anchoring the end of a prestressing tendon extending from a concrete structure by means of an engageable collet which grips said tendon responsive to application of a compressive force thereto and anchors the tendon to the structure, comprising: a. positioning the engageable collet adjacent said structure and around the emerging end of the prestressing tendon; b. positioning an engaging jack having two portions selectively expansible relative to each other to restrain one of said portions against movement away from said structure and dispose the other for selective movement toward and into abutment with said engageable collet to effect the gripping engagement of said collet with said tendon and force said collet into bearing interrelationship with said structure; c. positioning around the tendon, the engaging jack and engageable collet, a center hole pulling jack having two hollow portions selectively expansible relative to each other, with one portion disposed in compression imparting relationship to said structure, and the other portion disposed in gripping engagement to the end of said tendon; d. expanding said pulling jack to impart a predetermined tension to said tendon; e. expanding said engaging jack to force the collet into gripping engagement with the tendon and bearing interrelationship with the structure; f. collapsing the engaging jack; g. collapsing the pulling jack; h. removing the pulling jack; and i. removing the engaging jack.
Claim 18
Dependent Claim
71 words
The method as described in claim 7, wherein: a. prior to engaging the engageable collet, the pulling jack is expanded to impart a tension in excess of the predetermined amount ultimately desired to overcome frictional effects along the length of the tendon; b. the pulling jack is partially collapsed to impart a uniform predetermined tension to the tendon; and, c. the engaging jack is then expanded to engage the engageable collet.
Claim 19
Dependent Claim
104 words
The method as described in claim 7, wherein: a. the tendon is composed of a plurality of strands; b. the engageable collet is of the type adapted to individually accommodate a plurality of strands and is positioned so that each strand of the tendon is individually surrounded thereby; c. a single pulling jack is employed to simultaneously engage and tension all of the strands; and, d. a single engaging jack is employed to simultaneously engage the collet to all of the strands; e. the one portion of said engaging jack is restrained against movement away from the structure by abutment with said pulling jack.
Claim 20
Dependent Claim
71 words
The method as described in claim 9, wherein: a. prior to engaging the engageable collet, the pulling jack is expanded to impart a tension in excess of the predetermined amount ultimately desired to overcome frictional effects along the length of the tendon; b. the pulling jack is partially collapsed to impart a uniform predetermined tension to the tendon; and, c. the engaging jack is then expanded to engage the engageable collet.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-09 | 1975-02-08 | 1975-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-09 | 1979-02-08 | 1979-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-09 | 1983-02-08 | 1983-08-10 | $7700.00 | Window Closed / Lapsed |