US2965356A - Cable pulling and anchoring means - Google Patents

Description

Dec. 20, 1960 1:. B. CHESKIN CABLE PULLING AND ANCHORING MEANS 2 Sheets-Sheet 1 Filed May 13, 1959 F igu re //V VE/V 701?: David B. Ghes/rin y 1 l Q,

A TTOR/VEY Figure 2 .Intu L Dec. 20, 1960 D. B. CHESKIN CABLE PULLING AND ANCHORING MEANS 2 Sheets-Sheet 2 Filed May 13, 1959 //V VE/V TOR- David B. Chas/rm A TTOR/VEY United States Patent 9 CABLE PULLI NG AND AN CHORING MEANS David B. Cheskin, 407 S. Dearborn St., Chicago 5, Ill.

Filed May 13, 1959, Ser. No. 812,950

Claims. (Cl. 25429) This invention relates to an improved and simplified type of apparatus for anchoring wires or cables. The apparatus is particularly suitable for tensioning a plurality of cables and subsequently or substantially simultaneously eflecting their anchorage.

The anchoring means of this invention may be used in connection with the tensioning or stressing of all types of structural members, whether of steel or concrete, but generally finds its widest use with concrete sections, such as reinforced concrete beams, columns, concrete piles and the like.

Cable pulling and anchoring devices of various types are used in connection with pre-stressed or pre-tensioned reinforced concrete members, where the reinforcing steel is tensioned prior to the pouring and setting of the surrounding concrete. Similar cable pulling and anchoring means is used in connection with post-stressed or post-tensioned structures, where the cables or Wires are passed through holes which are left in the concrete structure and are subsequently filled with the cement so that the cables are bonded in place while under tension from a pulling force. .In either case, the tensioned members exert a compressive action on all or part of the resulting structural member when the tensioning force is removed from the ends of the wire or cables. By the use of the present invention, simplified pulling and anchoring means is provided for structural members of all kinds, and either pre-tensioning or post-tensioning may be accomplished in such members.

Each device or apparatus may be utilized to pull a plurality of wires or cables and a plurality of the devices may, in turn, be utilized at spaced points in connection with a large structural member to provide for the pulling of a larger number of cables. The present apparatus may be used as a permanent anchor in a permanent location; or, alternatively, each device may be used as a stressing apparatus, which is normally removed and reused in another location for the tensioning of cables or wires in the construction of post-stressed or pre-stressed members.

Briefly, the anchoring device of the present invention comprises in combination, a central draw member having an elongated shaft-portion and an enlarged diameter spreader section, the shaft portion having means for attaching a pulling force while the spreader section is constructed to have a plurality of spaced passageways for accommodating the passage of a plurality of separate cables or holding members, said spreader section also having external threading adapted to match and fit into an enlarged final adjustment nut, a flanged collar member is slidably positioned over the shaft portion of the draw member and perforations in the flanged portion of said collar member are adapted to accommodate the passage of the holding members which, in turn, pass through the spreader portion of the draw member, said collar member also having a short external threaded sleeve section proiecting away from the flanged portion thereof and away from the spreader section of the central draw member, and an internally threaded nut sized to fit over said draw 2,965,355 Patented Dec. 20, 1966 member and engage with said externally threaded sleeve section of said collar member and provide means for the initial wedging and holding of the ends of all holding members passing through the spreader sections and said flanged portion of the collar member.

In connection with each anchoring device, the large adjustment nut which passes around the spreader section of the apparatus is adapted to bear against a plate or other bearing surface at the end of each member having cables or other holding members that pass therethrough.

The design and operation of the improved anchoring means of this invention may be better described and understood by referring to the accompanying drawing and the following description thereof:

Figure 1 of the drawing is a sectionalview through one embodiment of the holding apparatus showing its attachment to a plurality of cable members.

Figure 2 shows an elevational view of one end of the holding apparatus taken along line 2-2 in Figure 1, indicating how a plurality of cables or holding members are spaced and passed through the end of the apparatus.

Figure 3 is a sectional view through another form of tensioning and anchoring apparatus, the design providing somewhat modified means for effecting the initial anchoring of the cable members.

Figure 4 of the drawing is another elevational View showing still another variation in the form and design of the spreader member and of the collar member.

Referring now to Figures 1 and 2 of the drawing, there is shown a bearing plate 1 which is positioned at the end of a structural member, which in the present instance is indicated as the end of a concrete structural member 2 having an opening or passageway 3. A plurality of cables 4 are indicated as passing through the opening 3 and structural member 2 and the opening in the bearing plate i. After proper pulling and tensioning by the pulling apparatus, as provided by this invention, the cables 4 may be embedded in concrete grout (not shown) which is subsequently forced into the opening 3 and allowed to set around the cables and fix them in place within the beam 2 while under tension. In a construction indicated, with the grouting of cables after tensioning, there is provided a resultingpost-tensioned construction; however, as previously indicated, the apparatus of this invention may be utilized for tensioning a plurality of cables which are subsequently embedded in concrete to provide a resulting reinforced concrete beam or girder which, in turn, provides a pretensioned structural member.

The apparatus of the embodiment of Figure 1 has a central draw member 5 which, in turn, has an enlarged head or spreader section 6 having external threading 7 and a plurality of notches or groooves 8. The grooves 8 are spaced symmetrically around the periphery of the spreader section 6 so as to provide notches or passage ways for tensioned holding members, such as wires or cables 4. Where the apparatus is of a fairly large scale, adaptable for use in connection with large reinforced concrete sections, the spreader section 6 will. be of a fairly large diameter and will have a large number of passageways 8. It is not intended to limit the present invention to any predetermined number of passageways in order to accommodate any set number of reinforcing cables or wires 4. A flanged collar member 9 is designed to slidably fit on the shank portion 5 of the central draw memher and the flanged portion 9 is, in turn, provided with a plurality of holes or openings 10 which are spaced circumferentially around the flange to, in turn, accommodate the passage of the plurality of cables 4. A separate internally threaded nut 11 is sized and designed to pass over and engage with an externally threaded short sleeve section 12 of the collar member 9. The nut 11 has a tapered end portion 13 which may, if desired, be slightly roughened or knurled so as to provide a good frictional engagement with the ends of the cables 4. As may be seen in the drawing, the tightening of the nut 1 1 onto the threaded sleeve 12 of the cbllar' in'erriber provides for the squeezing of the ends of cables 4 against the flange portion of the" collar member 9 and a resulting initial anchoring of the cables 4. v

In using the apparatus to tensionthe cables passing through a beam section, each of the cables 4 are threaded through the respective notches or grooves 8 in a suitably spaced relationship around the periphery of spreader section 6 and then through the passageway of the collar member 9. After the threading operation, each cable member 4 may be pulled to take out the slack within the hole or passageway 3 and the nut 11 tightened on the collar member 9 to effect an initial anchoring and holding of all of the ends of the cables 4. A pulling force on the end of shan'kS of the central draw member may then be utilized to effect the tensioning of all of the plurality of cables 4. In the present embodiment, a hole or slot 14 is provided in the shank 5 to permit the attachment of a jack or other pulling means on the apparatus. The pulling operation effects the wedging of the inside face of the spreader section 6 against the flange of collar member 9 and the clamping and wedging of cables 4 therebetween to result in their final anchoring as they are being tensioned in beam 2. Surrounding the spreader section 6 of the central draw member is an enlarged internally threaded nut which provides for the final adjustment and tensioning of all cables passing through the apparatus and through the structural member 2. The face of the nut 15 also provides a bearing surface to, in turn, come in contact with and bear on the bearing plate 1.

In effecting tensioning of cable members with the use of the improved present apparatus, a pulling force, which is attached thereto at'the end of the draw member 5, of course causes the pulling away from the bearing plate 1 of the entire apparatus, including the adjustment nut 15. After proper tensioning of cables 4, the pulling force is discontinued and held in a static position while the adjustment nut 15 is turned on section 6 and brought to bear against the bearing plate 1. In Figure l of the drawing the dotted lines are shown to represent diagrammatically the movement of adjustment nut 15 away from the hearing plate 1, while the cross-hatched full line indication of the adjustment nut 15 shows the latter in position against the bearing plate 1 against the structural member. Further turning of adjustment nut 15, after disconnection of the pulling force from hole 14 at the end of the central draw member, will of course permit further and final adjustment of tensioning in the cable members 4. Additional tightening of nut 15 will provide still further tensioning of the cables 4, while a loosening of nut 15 will effect a decreased tension in the cable members 4.

Referring now to Figure 3 of the drawing, there is shown a modification of the design set forth in Figures 1 and 2, however, it is to be noticed that similar provisions are provided for the spreading and placement of a plurality of cables 4' in a manner similar to the embodiment of Figure 1. A separate long threaded bolt 16 is positioned centrally within the apparatus and has adjacent its head 18 a separate enlarged externally threaded spreader section 17. The latter has a central opening or hole which permits its passage over the threaded shank portion of the bolt 16 whereby it may come to rest against the head 18 of the center bolt 11%. The spreader 17 may be assembled loose on the bolt 16 or alternatively, welded or otherwise attached to the bolt shaft or to the bolt head 18. Spreader section 17 has a plurality of external notches or grooves 8' adapted to permit the passageway of cables 4 and a slanting frusto-conically shaped face or a rounding face portion 19 which extends away from the bearing plate 1' of thestructural member 2'. A flanged collar" member 9', having a' sleeve portion 12, is provided to slidably pass over the bolt section 16.- There is further provided through the flange and sleeve sections of the collar member 9 a plurality of holes 10' which accommodate the passage of cables 4'. An internally threaded nut 11' is provided to fit onto and engage with sleeve portion 12 of the collar member. In the present embodiment; the cables 4' are permitted to pass through holesli) in collar 9 and on through elongated grooves in the face of the threading-on-the sleeve portion 12', whereby the tightening of nut 11 efiects a friction engagement around the cables 4' and their initial anchoring.

As described in connection with Figure 1, after the slack in each of the cables 4' is pulled out, there should be effected the initial tightening of nut 11 on sleeve 12" and the initial anchoring accomplished. Subsequently, a pulling force may be attached to the shank section 16 of the central draw member such that the entire apparatus may be pulled with cables 4 to effect a tensioning in the latter. In the embodiment of Figure 3, there is shown means 20 threadably engaging with bolt 16 whereby a pulling force may be connected therewith. An internally threaded large anchoring nut 15' is provided around the periphery of spreader section 17 and as set forth in connection with Figure 1, means is provided for effecting the final adjustment of the tensioning incables 4' by either tightening or loosening the nut 15' with respect to its bearing against plate 1'. Final anchoring of cables 4' is effected between the sloping face 19 of section 17 and the depressed face of collar member 9 as the pulling force is applied to bolt 16.

One of the principal differences between the embodiments of Figures 1 and 3 is in the design utilizing a standard type of threaded bolt, such as 16, as a central draw member in lieu of utilizing a one-piece central draw member, such as the one having elongated shaft portion 5 and an integral enlarged section 6. Various types of means may be utilized to connect a pulling force to the central draw member and it is not intended to limit the invention to the use of a hole such as 14' in shaft section 5 of Figure 1; nor, to external threading on bolt-like section 16 of Figure 3, inasmuch as hooks, pins or other arrangements may be utilized at the end of the shaft portion to accommodate attachment of a pulling force. 7

Referring now to Figure 4 of the drawing, there is shown still another embodiment of the invention with modified design aspects, particularly with respect to a central spreader section 17 and collar member 16'. A construction similar to that in Figure 3, with a large bolt member having a shank portion 16 and head portion 18", is utilized to provide a central draw member. Sliding over the bolt or shank portion 16 is an externally threaded spreader section 17 which has a plurality of passageways 21 to accommodate the plurality of cables 4". The present embodiment, however, indicates that the passageways 21 may be placed away from the periphery of the spreader section and constructed as holes rather than notches such as 8 and 8' which have been indicated in the afore-described embodiments. The inner face of the spreader section 17 is indicated to have a concave contour while the collar member 9", which passes over the shank portion 16' of the central draw member, in turn, has adjacent thereto a separate washer like section 22 with a convex face adapted to fit into the concave face of the spreader section. The flanged portion of the collar member 9 has a plurality of spaced holes 10" which again are peripherally spaced to substantially align radially with the passageways 21 in section 17' whereby the cables 4" may be passed through both members. The internally threaded'nut 11" engages with the sleeve section of the collar member and again'provides' means for effecting the squeezingor compression of the (Sable members against the" flanged portion 9"" of the collar member and the resulting initial anchoring of the cables. After the initial anchoring and after the attachment of the pulling force to the shank portion 16' of the central draw member, there is effected the resulting of pre-tensioning of cables 4" and their final squeezing and anchoring between the concave face of the spreader section 17 and the convex face of the washer member 22.

The present drawing shows a spacing between the spreader section and the collar section, however, upon the tensioning and pulling of the bolt 16 there will be effected a close proximity to the aforementioned concave and convex faces and, respectively, the spreader section 17 and the collar member whereby there is a squeezing final anchoring of all the cable members 4". The final adjustment also of the external nut 15 against the bearing place 1" will obtain the desired tensioning in the cables prior to their being grouted into place within the beam 2".

As has been illustrated, minor variations, shapes and designs may be provided for the principal elemental portions comprising the pulling and anchoring device of this invention and it is not intended to limit any one design to any one particular form or shape. Further, it is not intended to limit the improved design to any particular size, or its adaptability to any pre-determined number of cable members which may be tensioned and anchored by the apparatus.

I claim as my invention:

1. Apparatus for stressing longitudinal holding members in construction work, which comprises in combination, a central draw member having an elongated shaft portion and an enlarged diameter spreader section connecting therewith, said shaft portion having means for attaching a pulling force and said spreader section having a plurality of spaced passageways for accommodating the passage of the holding members, said spreader section further having external threading matching and fitting into an enlarged internally threaded final adjustment nut, a flanged collar member slidably positioned over the shaft portion of said draw member and perforations through a flange of said collar member adapted to accommodate the passage of the holding members which in turn pass through said spreader portion of the draw member, said collar member also having a short externally threaded sleeve section projecting away from the flange thereof and away from said spreader section of said central draw member, and an internally threaded nut fitting over and engaging with said sleeve of said collar member and providing means for the initial wedging and holding of the ends of all holding members passing through said spreader section and said flange of said collar member.

2. The apparatus of claim 1 further characterized in that said central draw member has external threading on the shaft portion thereof providing means for attaching a pulling force, and said enlarged adjustment nut has a flat surface on the face thereof which is adapted to rest against a bearing surface, whereby after effecting initial positioning and pulling of reinforcing members a further turning of said adjustment nut provides additional tension and pulling of said holding members.

3. The apparatus of claim 1 further characterized in that said spreader section has a concave shaped face facing a face on said collar member whereby said sections substantially mesh with one another for clamping said holding members.

4. The apparatus of claim 1 further characterized in that said central draw member has a shaft portion and a spreader section separate from one another, with the spreader section slidably engaging with an end of said shaft portion whereby the pulling of the latter pulls said spreader section against said collar member.

5. The apparatus of claim 1 further characterized in that said spreader section has a plurality of notches-extending across the thickness thereof and are equally spaced around its periphery.

References Cited in the file of this patent UNITED STATES PATENTS 2,264,794 Gunderson Dec. 2, 1941 2,332,032 Troiel Oct. 19, 1943 2,768,810 Boury et al Oct. 30, 1956

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