CA1276777C - Method of producing an annular steel wedge formed of a plurality of parts and used for anchoring a tension element in prestressed concrete - Google Patents
Method of producing an annular steel wedge formed of a plurality of parts and used for anchoring a tension element in prestressed concreteInfo
- Publication number
- CA1276777C CA1276777C CA000487360A CA487360A CA1276777C CA 1276777 C CA1276777 C CA 1276777C CA 000487360 A CA000487360 A CA 000487360A CA 487360 A CA487360 A CA 487360A CA 1276777 C CA1276777 C CA 1276777C
- Authority
- CA
- Canada
- Prior art keywords
- wedge
- wedge sections
- teeth
- sections
- anchor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
- G09B29/00—Maps; Plans; Charts; Diagrams, e.g. route diagram
- G09B29/003—Maps
- G09B29/006—Representation of non-cartographic information on maps, e.g. population distribution, wind direction, radiation levels, air and sea routes
- G09B29/008—Touring maps or guides to public transport networks
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
- E04C5/08—Members specially adapted to be used in prestressed constructions
- E04C5/12—Anchoring devices
- E04C5/122—Anchoring devices the tensile members are anchored by wedge-action
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Theoretical Computer Science (AREA)
- Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Ecology (AREA)
- Structural Engineering (AREA)
- Mathematical Physics (AREA)
- Civil Engineering (AREA)
- Business, Economics & Management (AREA)
- Educational Administration (AREA)
- Educational Technology (AREA)
- General Physics & Mathematics (AREA)
- Reinforcement Elements For Buildings (AREA)
- Spinning Or Twisting Of Yarns (AREA)
- Piles And Underground Anchors (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An annular steel anchor grip divided into individual wedge sections is used to anchor a tension element in a prestressed concrete structure. Prior to forming the in-dividual wedge sections from an axially extending annular wedge blank, the inside surface of the blank is threaded forming circumferentially extending teeth so that the wedge can grip the tension element and provide the requisite friction co-efficient in the anchorage. To prevent the sharp teeth formed in the threading step from cutting into the surface of the tension element, the teeth are ground down in a tumbling operation in which the wedge sections are mixed together with ceramic grinding bodies in a tumbling drum. The grinding bodies have bends in at least a portion of their surfaces and the bends have a smaller radius than the radius of the threaded inside surface of the wedge.
An annular steel anchor grip divided into individual wedge sections is used to anchor a tension element in a prestressed concrete structure. Prior to forming the in-dividual wedge sections from an axially extending annular wedge blank, the inside surface of the blank is threaded forming circumferentially extending teeth so that the wedge can grip the tension element and provide the requisite friction co-efficient in the anchorage. To prevent the sharp teeth formed in the threading step from cutting into the surface of the tension element, the teeth are ground down in a tumbling operation in which the wedge sections are mixed together with ceramic grinding bodies in a tumbling drum. The grinding bodies have bends in at least a portion of their surfaces and the bends have a smaller radius than the radius of the threaded inside surface of the wedge.
Description
1276~m The present invention is directed to a method of producing an annular steel anchor grip made up of a number of wedge sections for anchoring a tension member or element in a prestressed concrete structure. The anchor grip is formed of wedge sections separated from one another along axially extending radially directed planes. The inside surface of the wedge sections which contact the tension element are formed with a plurality of circumferentially extending teeth. A wedge blank with a frusto-conical outside surface is cut into the individual wedge sections after the teeth are cut in the in-side surface of the blank forming an axially extending threaded bore.
Numerous prestressing methods with tension elements of steel bars, steel wires or steel wire strands, are used in prestressed concrete construction utilizing the principle of wedge anchors. For individual tension elements, annular anchor grips are used formed of at least two and at most three wedge sections which laterally enclose the tension element to be anchored. In anchoring a prestressed tension element of this type, the wedge sections are drawn into a conically shaped borehole in an anchoring member in the direction of the tension element axis by a tensile force applied to the tension element.
As a result, clamping forces directed at right angles to the tension element axis are developed in the wedge sections and these clamping forces prevent the movement of the tension element. To achieve this effect, the friction coefficient between the tension element and the anchor grip is greater than between the anchor grip and the conical borehole. Accordingly, the inside surface of the wedge sections are shaped so that the wedge can securely grip the surface of the tension element.
Numerous prestressing methods with tension elements of steel bars, steel wires or steel wire strands, are used in prestressed concrete construction utilizing the principle of wedge anchors. For individual tension elements, annular anchor grips are used formed of at least two and at most three wedge sections which laterally enclose the tension element to be anchored. In anchoring a prestressed tension element of this type, the wedge sections are drawn into a conically shaped borehole in an anchoring member in the direction of the tension element axis by a tensile force applied to the tension element.
As a result, clamping forces directed at right angles to the tension element axis are developed in the wedge sections and these clamping forces prevent the movement of the tension element. To achieve this effect, the friction coefficient between the tension element and the anchor grip is greater than between the anchor grip and the conical borehole. Accordingly, the inside surface of the wedge sections are shaped so that the wedge can securely grip the surface of the tension element.
.~ ~
lZ767~ 21182-264 For the sake of simplicity, the shaping of the inside surface is formed as a thread cut into an axial borehole in a frusto-conically shaped wedge blank before it is cut into the in-dividual wedge sections, Great Britain patent 869 923.
Known wedge anchor grips for high-strength smooth wires and strands are sensitive with respect to fatigue strength. In practice, it has been found that the wires and strands always break in the front region of the anchor, that is, at the smaller diameter end of the anchor grips. Such failures are caused substantially by high transverse compression in the region of the introduction of force and by notches, particular-ly formed at the commencement of the anchoring operation and caused by the sharp edges of the thread teeth. Since the diameter of the individual wedge sections is somewhat smaller than the outside diameter of the tension element, the sharp edges on the thread teeth at the axially extending edges of the wedge sections, that is, where the thread teeth end along the elongated edges of the wedge sections, cut into the surface of the tension element.
The present invention provides, in the most economi-cal manner possible, for the improved fatigue strength of a wedge anchor of the aforesaid type.
In particular, the present invention provides method for producing wedge sections for use in an axially ex-tending steel anchor grip for anchoring tension elements in a prestressed concrete structure, said wedge sections being formed from an axially extending steel wedge blank which has a generally cylindrical inside surface and a frusto-conical outside surface; said method comprising:
i) cutting teeth into the inside surface of the wedge blank in the form of a thread, said teeth encircling the axis of the wedge blank and being spaced apart in the axial direction thereof;
ii) cutting the steel blank along planes extending radially and axially relative to the axis of the wedge blank to form a plurality of axially extending wedge sections;
iii) subjecting the individual wedge section to a tumbling operation along with loose abrasive bodies with bent or curved surfaces; said bent or curved surfaces having a radius less than the radius of the inside surface of the wedge blank.
The invention also provides an axially extending steel anchor grip for anchoring tension elements in a prestres-sed concrete structure formed from a plurality of steel wedge sections adapted to be arranged in a conical borehole of an anchor member located in said prestressed concrete structure;
said wedge sections being separated from each other along planes extending radially and axially relative to the axis of the anchor grip, and said wedge sections having an axially extending inside surface and outside surface, said inside sur-face being formed with teeth extending circumferentially relative to the axis of the anchor grip and spaced apart in the axial direction of the anchor grip; each said tooth having a pair of flanks converging to a radially inwardly directed tip, and said flanks, only at said tips being rounded off and with-out otherwise deforming said flanks, so that said teeth only press into the surface to the tension element and do not cut into the surface, said anchor grip having an outside surface having a generally frusto-conical shape and an inside surface having a generally cylindrical shape.
.~
~276777 The invention is based on the method, known per se, of removing imperfections from the surface of cast parts or the like, such as removing burrs, fins and similar imperfections by tumbling these parts in a drum with loose abrasive bodies usually formed of ceramic material. The wedge sections move along with the loose abrasive members during the rotation of the drum so that they rub against one another with the surfaces of the case parts being smoothed by the grinding action of the abrasive members. This type of surface processing is character-ized as tumbling or slide grinding.
The invention is based on the surprising discovery that when the wedge sections, formed by cutting the wedge blank after a thread is cut in its inside surface, are tumbled along with abrasive bodies in a drum, the thread teeth in the indivi-dual wedge sections are not destroyed, rather only the tips of the teeth are rounded off. This tumbling action is preferably ,.,~ i performed after hardening or case hardening the wedge sections so that the thread teeth are not ground excessively, however, the grinding operation can also be carried out before hardening under certain circumstances in order to save time.
The abrasive bodies are preferably formed of ceramic material, such as glass powder, alumina, or the like with the possible addition of corundums,metallic oxides or the like.
., , There is the advantage according to the invention that the thread teeth in the wedge sections no longer cut into the tension element in a manner that damages the surface of the element, rather the teeth only press into the tension element surface. Accordingly, the surface of the tension element is not cut or notched, instead it is only deflected or depressed so that a local increase in strength occurs which is approximately comparable to the cold coiling of a thread. With wedges processed in this manner, an increase in the fatigue strength and the static tensile strength of the anchor of up to 100~ of the actual strength of the tension element is attained in the region of the free length of the element without any additional steps.
~6~ 21182-264 In the accompanying drawings which illustrate an exemplary embodiment of the invention, Figure 1 is an axially extending view, partly in section, of an anchor grip for a strand or tension element using an annular wedge made up of a number of wedge sections;
Figure 2 is a perspective view of the anchor grip shown in Figure l;
Figure 3 is an end view of the larger end of the anchor grip shown in Figure 2;
Figure 4 is a sectional view of the anchor grip taken along the line IV-IV in Figure 3; and Figure 5 is an enlarged view of the detail V in Figure 4.
In the anchor grip shown in axially extending section in Figure 1, a steel wire strand 1 is secured in a conical ~orehole 3 in an anchor member 4 by means of an anchor grip 2 made up of a number of wedge sections. The anchor member 4 is supported in a known manner with its con-tact surface 5 bearing against an abutment plate, not shown, for transmitting the tensile force.
~, i,.
l.~76m In Figure 2 the anchor grip 2 is shown in perspec-tive. The anchor grip 2 is made up of three axially extending wedge sections 2a, 2b and 2c each of which extends for approximately 120 around the axis of the wedge. In combina-tion, the three wedge sections 2a, 2b and 2c form a closed annular cross-section separated by narrow wedge joints 6, each extending in the axial direction of the wedge, note Figure 3.
While the inside surface of the anchor grip generally is cylindrical in shape its outside surface is frusto-conically shaped with the smaller diameter end shown at the right in Figure 1 and with the larger diameter or thicker end 7 shown at the left. Each wedge section may have a groove 8 so that in combination an annular groove is formed around the outside surface of the wedge. A spring ring 9 may be inserted into the annular groove 8 to hold the wedge sections together for easier assembly.
As shown, particularly in Figure 4, each individual wedge section 2a, 2b and 2c has a profiled or shaped surface 11 defining the inside surface 10 of the wedge. The shaped surface 11 is formed as a thread with teeth 12 extending cir-cumferentially around the inside surface of the axial bore through the frusto-conically shaped wedge blank before it is cut into the individual wedge sections 2a, 2b and 2c.
In accordance with the invention, the wedge sections 2a, 2b and 2c are preferably placed in a grinding or tumbling drum after they are case hardened. Loose abrasive members formed 1~767 77 .. . .
of a ceramic material, such as glass powder, alumina or the like, are mixed with the wedge sections within the drum and the drum is rotated so that a continuous circular motion is developed with the abrasive bodies moving relative to the wedge sections.
Basically, the abrasive bodies can have any desired shape. It is important that the surfaces of the abrasive bodies, at least in a partial region of their surfaces, are provided with bent or curved surfaces having a radius less than the radius of the threaded opening through the annular wedge so that the abrasive bodies can provide a grinding effect on the thread teeth 12. The tumbling of the wedge sections and the abrasive bodies need only be carried out until the sharp edges of the thread tee-th 12 formed when the thread is cut, are rounded off so that they no longer cut into the surface of the tension element, note Fig. 5. The rounding off action also takes place where the thread teeth 12 end along the wedge joints 6 so that at this location the thread teeth do not cut into the surface of the tension element 1 and cause it damage.
lZ767~ 21182-264 For the sake of simplicity, the shaping of the inside surface is formed as a thread cut into an axial borehole in a frusto-conically shaped wedge blank before it is cut into the in-dividual wedge sections, Great Britain patent 869 923.
Known wedge anchor grips for high-strength smooth wires and strands are sensitive with respect to fatigue strength. In practice, it has been found that the wires and strands always break in the front region of the anchor, that is, at the smaller diameter end of the anchor grips. Such failures are caused substantially by high transverse compression in the region of the introduction of force and by notches, particular-ly formed at the commencement of the anchoring operation and caused by the sharp edges of the thread teeth. Since the diameter of the individual wedge sections is somewhat smaller than the outside diameter of the tension element, the sharp edges on the thread teeth at the axially extending edges of the wedge sections, that is, where the thread teeth end along the elongated edges of the wedge sections, cut into the surface of the tension element.
The present invention provides, in the most economi-cal manner possible, for the improved fatigue strength of a wedge anchor of the aforesaid type.
In particular, the present invention provides method for producing wedge sections for use in an axially ex-tending steel anchor grip for anchoring tension elements in a prestressed concrete structure, said wedge sections being formed from an axially extending steel wedge blank which has a generally cylindrical inside surface and a frusto-conical outside surface; said method comprising:
i) cutting teeth into the inside surface of the wedge blank in the form of a thread, said teeth encircling the axis of the wedge blank and being spaced apart in the axial direction thereof;
ii) cutting the steel blank along planes extending radially and axially relative to the axis of the wedge blank to form a plurality of axially extending wedge sections;
iii) subjecting the individual wedge section to a tumbling operation along with loose abrasive bodies with bent or curved surfaces; said bent or curved surfaces having a radius less than the radius of the inside surface of the wedge blank.
The invention also provides an axially extending steel anchor grip for anchoring tension elements in a prestres-sed concrete structure formed from a plurality of steel wedge sections adapted to be arranged in a conical borehole of an anchor member located in said prestressed concrete structure;
said wedge sections being separated from each other along planes extending radially and axially relative to the axis of the anchor grip, and said wedge sections having an axially extending inside surface and outside surface, said inside sur-face being formed with teeth extending circumferentially relative to the axis of the anchor grip and spaced apart in the axial direction of the anchor grip; each said tooth having a pair of flanks converging to a radially inwardly directed tip, and said flanks, only at said tips being rounded off and with-out otherwise deforming said flanks, so that said teeth only press into the surface to the tension element and do not cut into the surface, said anchor grip having an outside surface having a generally frusto-conical shape and an inside surface having a generally cylindrical shape.
.~
~276777 The invention is based on the method, known per se, of removing imperfections from the surface of cast parts or the like, such as removing burrs, fins and similar imperfections by tumbling these parts in a drum with loose abrasive bodies usually formed of ceramic material. The wedge sections move along with the loose abrasive members during the rotation of the drum so that they rub against one another with the surfaces of the case parts being smoothed by the grinding action of the abrasive members. This type of surface processing is character-ized as tumbling or slide grinding.
The invention is based on the surprising discovery that when the wedge sections, formed by cutting the wedge blank after a thread is cut in its inside surface, are tumbled along with abrasive bodies in a drum, the thread teeth in the indivi-dual wedge sections are not destroyed, rather only the tips of the teeth are rounded off. This tumbling action is preferably ,.,~ i performed after hardening or case hardening the wedge sections so that the thread teeth are not ground excessively, however, the grinding operation can also be carried out before hardening under certain circumstances in order to save time.
The abrasive bodies are preferably formed of ceramic material, such as glass powder, alumina, or the like with the possible addition of corundums,metallic oxides or the like.
., , There is the advantage according to the invention that the thread teeth in the wedge sections no longer cut into the tension element in a manner that damages the surface of the element, rather the teeth only press into the tension element surface. Accordingly, the surface of the tension element is not cut or notched, instead it is only deflected or depressed so that a local increase in strength occurs which is approximately comparable to the cold coiling of a thread. With wedges processed in this manner, an increase in the fatigue strength and the static tensile strength of the anchor of up to 100~ of the actual strength of the tension element is attained in the region of the free length of the element without any additional steps.
~6~ 21182-264 In the accompanying drawings which illustrate an exemplary embodiment of the invention, Figure 1 is an axially extending view, partly in section, of an anchor grip for a strand or tension element using an annular wedge made up of a number of wedge sections;
Figure 2 is a perspective view of the anchor grip shown in Figure l;
Figure 3 is an end view of the larger end of the anchor grip shown in Figure 2;
Figure 4 is a sectional view of the anchor grip taken along the line IV-IV in Figure 3; and Figure 5 is an enlarged view of the detail V in Figure 4.
In the anchor grip shown in axially extending section in Figure 1, a steel wire strand 1 is secured in a conical ~orehole 3 in an anchor member 4 by means of an anchor grip 2 made up of a number of wedge sections. The anchor member 4 is supported in a known manner with its con-tact surface 5 bearing against an abutment plate, not shown, for transmitting the tensile force.
~, i,.
l.~76m In Figure 2 the anchor grip 2 is shown in perspec-tive. The anchor grip 2 is made up of three axially extending wedge sections 2a, 2b and 2c each of which extends for approximately 120 around the axis of the wedge. In combina-tion, the three wedge sections 2a, 2b and 2c form a closed annular cross-section separated by narrow wedge joints 6, each extending in the axial direction of the wedge, note Figure 3.
While the inside surface of the anchor grip generally is cylindrical in shape its outside surface is frusto-conically shaped with the smaller diameter end shown at the right in Figure 1 and with the larger diameter or thicker end 7 shown at the left. Each wedge section may have a groove 8 so that in combination an annular groove is formed around the outside surface of the wedge. A spring ring 9 may be inserted into the annular groove 8 to hold the wedge sections together for easier assembly.
As shown, particularly in Figure 4, each individual wedge section 2a, 2b and 2c has a profiled or shaped surface 11 defining the inside surface 10 of the wedge. The shaped surface 11 is formed as a thread with teeth 12 extending cir-cumferentially around the inside surface of the axial bore through the frusto-conically shaped wedge blank before it is cut into the individual wedge sections 2a, 2b and 2c.
In accordance with the invention, the wedge sections 2a, 2b and 2c are preferably placed in a grinding or tumbling drum after they are case hardened. Loose abrasive members formed 1~767 77 .. . .
of a ceramic material, such as glass powder, alumina or the like, are mixed with the wedge sections within the drum and the drum is rotated so that a continuous circular motion is developed with the abrasive bodies moving relative to the wedge sections.
Basically, the abrasive bodies can have any desired shape. It is important that the surfaces of the abrasive bodies, at least in a partial region of their surfaces, are provided with bent or curved surfaces having a radius less than the radius of the threaded opening through the annular wedge so that the abrasive bodies can provide a grinding effect on the thread teeth 12. The tumbling of the wedge sections and the abrasive bodies need only be carried out until the sharp edges of the thread tee-th 12 formed when the thread is cut, are rounded off so that they no longer cut into the surface of the tension element, note Fig. 5. The rounding off action also takes place where the thread teeth 12 end along the wedge joints 6 so that at this location the thread teeth do not cut into the surface of the tension element 1 and cause it damage.
Claims (8)
1. Method for producing wedge sections for use in an axially extending steel anchor grip for anchoring tension elements in a prestressed concrete structure, said wedge sections being formed from an axially extending steel wedge blank which has a generally cylindrical inside surface and a frusto-conical outside surface; said method comprising:
i) cutting teeth into the inside surface of the wedge blank in the form of a thread, said teeth encircling the axis of the wedge blank and being spaced apart in the axial direction thereof;
ii) cutting the steel blank along planes extending radially and axially relative to the axis of the wedge blank to form a plurality of axially extending wedge sections;
iii) subjecting the individual wedge sections to a tumbling operation along with loose abrasive bodies with bent or curved surfaces; said bent or curved surfaces having a radius less than the radius of the inside surface of the wedge blank.
i) cutting teeth into the inside surface of the wedge blank in the form of a thread, said teeth encircling the axis of the wedge blank and being spaced apart in the axial direction thereof;
ii) cutting the steel blank along planes extending radially and axially relative to the axis of the wedge blank to form a plurality of axially extending wedge sections;
iii) subjecting the individual wedge sections to a tumbling operation along with loose abrasive bodies with bent or curved surfaces; said bent or curved surfaces having a radius less than the radius of the inside surface of the wedge blank.
2. Method, as set forth in claim 1, including the step of hardening the wedge section and tumbling the wedge sections with the abrasive bodies subsequent to the hardening step.
3. Method, as set forth in claim 1, wherein the loose abrasive bodies are formed of a ceramic material, such as glasspowder or alumina.
4. Method, as set forth in claim 3, including the step of adding at least one of corundum and metal oxides to the abrasive bodies.
5. An axially extending steel anchor grip for anchoring tension elements in a prestressed concrete structure formed from a plurality of steel wedge sections adapted to be arranged in a conical borehole of an anchor member located in said prestressed concrete structure; said wedge sections being separated from each other along planes extending radially and axially relative to the axis of the anchor grip, and said wedge sections having an axially extending inside surface and outside surface, said inside surface being formed with teeth extending circumferentially relative to the axis of the anchor grip and spaced apart in the axial direction of the anchor grip; each said tooth having a pair of flanks converging to a radially inwardly directed tip, and said flanks, only at said tips being rounded off and without otherwise deforming said flanks, so that said teeth only press into the surface to the tension element and do not cut into the surface, said anchor grip having an outside surface having a generally frusto-conical shape and an inside surface having a generally cylindrical shape.
6. An axially extending anchor grip as set forth in claim 5 wherein said teeth are formed by a continuous thread cut in the inside surface of said wedge sections.
7. An axially extending anchor grip as set forth in claim 5 including means laterally encircling the outside surface of said wedge sections for holding the wedge sections together.
8. An axially extending anchor grip as set forth in claim 5 wherein said rounded off teeth are hardened.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19843427901 DE3427901A1 (en) | 1984-07-28 | 1984-07-28 | Method for manufacturing a multipart ring wedge of a wedge anchoring for a prestressing element in a concrete structural part |
DEP3427901.6 | 1984-07-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1276777C true CA1276777C (en) | 1990-11-27 |
Family
ID=6241823
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000487360A Expired - Lifetime CA1276777C (en) | 1984-07-28 | 1985-07-24 | Method of producing an annular steel wedge formed of a plurality of parts and used for anchoring a tension element in prestressed concrete |
Country Status (9)
Country | Link |
---|---|
JP (1) | JPS6138826A (en) |
AT (1) | AT396167B (en) |
CA (1) | CA1276777C (en) |
CH (1) | CH669630A5 (en) |
DE (1) | DE3427901A1 (en) |
ES (1) | ES8703564A1 (en) |
GB (1) | GB2162449B (en) |
IT (1) | IT1182546B (en) |
NO (1) | NO163873C (en) |
Families Citing this family (15)
Publication number | Priority date | Publication date | Assignee | Title |
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JPS63219747A (en) * | 1987-03-06 | 1988-09-13 | 小林 一輔 | Tensioning anchor apparatus of plastic rod |
FR2625241B1 (en) * | 1987-12-23 | 1991-09-27 | Chaize Alain | LOCKING DEVICE FOR LENGTHENED REINFORCEMENT UNDER VOLTAGE |
JPH0668195B2 (en) * | 1988-10-24 | 1994-08-31 | 三井建設株式会社 | Fiber rod structural material fixture |
JPH04286744A (en) * | 1991-03-18 | 1992-10-12 | Fujitsu Ltd | High frequency superimposing circuit of magneto-optical disk device |
JP2768032B2 (en) * | 1991-03-26 | 1998-06-25 | アンダーソンテクノロジー株式会社 | PC steel stranded wire connector and connection method |
JPH055938U (en) * | 1991-07-09 | 1993-01-29 | 住友電気工業株式会社 | Wedge stopper for pretensioning grip |
DE19818739A1 (en) * | 1998-04-27 | 1999-10-28 | Fischer Artur Werke Gmbh | Fastening element for subsequent reinforcement connection, especially for earthquake protection |
DE19833332C1 (en) * | 1998-07-24 | 1999-12-16 | Dyckerhoff & Widmann Ag | Corrosion protected tension cable for building |
JP2003056299A (en) * | 2001-08-17 | 2003-02-26 | Furukawa Co Ltd | Fixture for wire rope and steel stranded wire |
CH696767A5 (en) * | 2003-07-23 | 2007-11-30 | Sacac Schleuderbetonwerk Ag | Clamping and tension mount for temporary use of CFRP reinforcing bars with a circular cross section and associated CFRP reinforcing bars. |
CN102979253A (en) * | 2012-12-13 | 2013-03-20 | 大连民族学院 | Anchor system for fixing steel strand in pre-stressed structure |
ES2642193T3 (en) | 2012-12-18 | 2017-11-15 | Wobben Properties Gmbh | Anchoring, tensioning device, wind power installation and procedure for tensile tension of traction cables in an anchor |
CN103741672B (en) * | 2014-01-24 | 2016-01-13 | 俞向阳 | A kind of pre-tensioning system centrifugal concrete pile and manufacture method with steel strand |
EP3149256A4 (en) * | 2015-07-17 | 2018-06-20 | Felix L. Sorkin | Compact anchor for post-tensioned concrete segment |
CN108035490A (en) * | 2017-12-08 | 2018-05-15 | 卡本复合材料(天津)有限公司 | A kind of dentation pre-stressed carbon fiber beaverboard anchorage |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1495258A (en) * | 1923-04-11 | 1924-05-27 | Harry V Duty | Wire-line clamp |
GB365280A (en) * | 1930-12-20 | 1932-01-21 | Steel Wing Company Ltd | Improvements in or connected with sheet metal spars particularly adapted for use in aircraft structures |
GB869923A (en) * | 1957-06-29 | 1961-06-07 | Cable Covers Ltd | Improvements relating to anchor grips for tensioning wires, rods and the like |
DE1255274B (en) * | 1962-08-06 | 1967-11-30 | Rudolf Buehrer Dipl Ing | Anchoring for profiled reinforcement bars in reinforced concrete or prestressed concrete structures |
US3344485A (en) * | 1965-07-12 | 1967-10-03 | Alan J Lommen | Rope clamp and clevis |
CH456906A (en) * | 1965-09-16 | 1968-05-31 | Losinger Ag | Device for tensioning and anchoring several tendons that together form a tensioning cable |
AT354029B (en) * | 1974-10-31 | 1979-12-10 | Vorspann Technik Gmbh | PROCEDURE FOR PRELOAGING TENDON STRUCTURES IN ANCHOR |
DD201396A1 (en) * | 1979-12-11 | 1983-07-20 | Arnulf Dehoff | METHOD AND DEVICE FOR THE ABRASIVE FINE GRADING OF WORKPIECES |
DE3470394D1 (en) * | 1983-06-09 | 1988-05-19 | Walther Carl Kurt Gmbh | Finishing with a dragging movement, and device for carrying it out |
-
1984
- 1984-07-28 DE DE19843427901 patent/DE3427901A1/en active Granted
-
1985
- 1985-07-17 NO NO852858A patent/NO163873C/en unknown
- 1985-07-18 GB GB08518109A patent/GB2162449B/en not_active Expired
- 1985-07-24 CA CA000487360A patent/CA1276777C/en not_active Expired - Lifetime
- 1985-07-24 CH CH3203/85A patent/CH669630A5/de not_active IP Right Cessation
- 1985-07-26 JP JP16420385A patent/JPS6138826A/en active Granted
- 1985-07-26 AT AT0222085A patent/AT396167B/en not_active IP Right Cessation
- 1985-07-26 ES ES545582A patent/ES8703564A1/en not_active Expired
- 1985-07-26 IT IT67694/85A patent/IT1182546B/en active
Also Published As
Publication number | Publication date |
---|---|
NO163873B (en) | 1990-04-23 |
DE3427901A1 (en) | 1986-02-06 |
IT1182546B (en) | 1987-10-05 |
AT396167B (en) | 1993-06-25 |
IT8567694A0 (en) | 1985-07-26 |
JPS6138826A (en) | 1986-02-24 |
CH669630A5 (en) | 1989-03-31 |
ATA222085A (en) | 1992-10-15 |
DE3427901C2 (en) | 1990-01-04 |
GB2162449B (en) | 1987-09-16 |
NO852858L (en) | 1986-01-29 |
JPH0513770B2 (en) | 1993-02-23 |
GB8518109D0 (en) | 1985-08-21 |
NO163873C (en) | 1990-08-01 |
GB2162449A (en) | 1986-02-05 |
ES8703564A1 (en) | 1987-02-16 |
ES545582A0 (en) | 1987-02-16 |
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