US3457687A - Means of depressing and/or holding-down pre-tensioning tendons in pretensioned concrete members employing draped,harped or depressed tendons - Google Patents

Description

July 29, 1969 A. L.. JAcoBUs 3,457,687

MEANS 0F DEPRESSING AND/OR HOLDING-DOWN PRETENSIONING TENDONS IN PRETENSIONED CONCRETE MEMBERS EMPLOYING DRAPED, HARPED OR DEPRESSED TENDONS File d April 3, 1968 5 Sheets-Sheet 1 miv",

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/L-/G 4 mi ALEXANDER Lmcoeus July 29, 1969 3,457,687 TENS 10N ma A. L.. JACOBUS MEANSOF DEPRESSING AND/OR HOLDING-DOWN PRE TENDONS IN PRE-TENSIONEI) CONCRETE MEMBERS l".MPI..OYTN(`| DRAPED, HARPED OR DEPRESSED TENDONS Filed April 3. 1968 July 29, 1969 A. L. JAcoBUs 3,457,687

MEANS OF DEPRESSING AND/OR HOLDING-DOWN PRETENSIONING TENDONS IN PARE-TENSIONE@ CONCRETE MEMBERS EMPLOYING' DRAPED, HARED OR DEPRESSED TENONS Filed April 5, 1968 3 Sheets-Sheet 3 5 llllih` 7 13 INVENTUM WM ALEXANDER L JAcoaus HY F/. /2 zm.`

ff ,11g/gif J ATfoRNEY v United States Patent O 3,457,687 MEANS OF DEPRESSING AND/ OR HOLDING- DOWN PRE-TENSIONING TENDONS IN PRE- TENSIONED CONCRETE MEMBERS EMPLOY- ING DRAPED, HARPED OR DEPRESSED TENDONS Alexander L. Jacobus, Jacobus Engineering Co., 2520 Highland, Salina, Kans. 67401 Filed Apr. 3, 1968, Ser. No. 718,425 Int. Cl. E04c 5/08 U.S. Cl. 52-226 10 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a means of manufacturing reinforced concrete support structures and, more particularly, to means for construction of concrete girders provided with pre-tensioned reinforcing members therein. Still, more specifically, this invention relates to means for depressing or holding-down elongated tendons or cable members within a form means to produce elongated concrete I-beams, girders, and the like; the means including structure for grasping the cable members and pre-tensioning the same in a spaced, pre-determined manner requir ing a minimum amount of space within the concrete members with a minimum cost of the elements left therein.

The construction industry has long recognized the advantages of forming concrete girders, beams, and the like in the pre-stressed condition. The desirability of pre-stressing by depressing elongated tensioned reinforcement has been recognized particularly as applied to relatively long concrete support structures. The use of long beams having pre-tensioned cables or strands therein has been long recognized and such structures have been produced but the cost making the same has been excessive and the equipment employed has been elaborate and expensive to install and operate. The use of pre-tensioned reinforced strands or cables has been used normally in top push-down or bottom hold-dowr1 methods. However, in the prior art, it has been found that elaborate equipment has been necessary and substantial equipment is normally left within the concrete structure being produced or if not, a large opening in which the equipment for depressing the cable member has been placed, must be lled which is undesirable as producing a weakened portion of the structure plus being an additional manufacturing step adding to overall costs.

In preferred specific embodiments of this invention, a pre-tensioning means is provided including cable connector means adapted to be connected to a plurality of elongated cable members or tendons in a pre-tensioned concrete member and having anchoring means connected thereto to hold the inter-connected cable members in a tensioned or depressing condition. The cable connector means is provided with a number of different embodiments including a multiple strand, horizontal and vertically spaced attachment assembly; a multiple strand vertically adjacent, horizontally spaced attachment assembly; a multiple strand vertically aligned and spaced attachment assembly; a multiple strand vertically aligned and adjacent attachment assembly; and each of these various assemblies constructed of a plurality of elements arranged in a predetermined order to change from one assembly to the other. More specifically, the elements include elongated banding straps operably connected to horizontal spacing clips, vertical spacing struts, and strap spacing clips in a pre-determined manner. The banding strap is preferably of a high-strength steel construction adapted to be `bent about the tendons or cable members and inter-connected to the vertical spacing struts and horizontal spacing clips ice for connection to the anchor means. The horizontal spacing clips are provided with main bodies having downwardly depending abutment sections and outer end sections each formed with elongated slots adapted to receive the banding strap therethrough. The vertical spacing strips are provided with parallel end sections having elongated slots interconnected by a vertical box-like main body. The strap spacing clips are of a flat plate construction having two parallel elongated slots therein adapted to receive the banding strap therethrough. The aforementioned various elements are readily used in a pre-determined manner in order to provide various horizontal and vertical spacing of the cable members so as to positively maintain the spacing in order to provide a more desirable structure. On assembly of the selected connector means, the banding strap is extended through a lower support bed or soft and connected to the anchor means. The anchor means used may be one of three different embodiments, namely, a single slot, wedge-type anchoring assembly; a double slot, wedge-type anchoring assembly; or a winch-type anchoring assembly. In the single slot anchoring assembly, the 4banding strap is interconnected by a banding clamp about a single strip anchor pad having a pair of channel members and split wedges mounted between the same and the lower surface of the working bed. The split wedges are operable to move the single strip anchor pad and the inter-connected banding strap downwardly to pre-tension the cable members through the connector means. The double slotted, wedge-type anchoring assembly is provided with a pair of plain tapered Wedges and an I-beam spacing member mounted under the lower surface of the sot and connected to a double strip anchor pad. In this embodiment, the banding strap is extended through spaced parallel slots in the soft and trained about the lower surface of the double strip anchoring pad and inter-connected as by banding clamp. The tapered wedges are additionally movable relative to each other to regulate the amount of down-pull on the banding strap and inter-connected cable members. In the third embodiment of the anchor means, a special depressor or hold-down frame is provided mountable against `a plurality of elongated `beam members which, in turn, are adjacent the soflit. The depressor frame is provided with one or more roller sheaves adapted to receive the banding strap thereabout for connection to a slotted vshaft which, in turn, is rotatable by a tool to pull the interconnected banding strap and cable members downwardly.

Accordingly, one object of this invention is to provide a new and novel means for holding-down pre-tensioning cables or tendons overcoming the above-mentioned disadvantages of the prior devices.

A further object of this invention is to provide a depressing means operable against the lower surface of a supporting working bed or soit of a concrete form box to depress a plurality of longitudinally extended tendons or cables mounted within the form box.

One further object of this invention is to provide a pretensioning means connectable to a plurality of elongated cable members to be embodied within a concrete structure; the pre-tensioning means including connector means having horizontal and vertical spacer members engageable with the cable members for holding in a pre-determined pattern by a banding strap which is anchored to a support bed as by various anchor means to provide tensioning to the cable members.

One other object of this invention is to provide a pretensioning means readily attachale to a plurality of substantially parallel cable members so as to deform the same as desired in adjacent, or vertical and horizontally spaced positions in construction of a concrete structure and having means for connecting to the cable members which are inexpensive to manufacture and readily eX- pendable on -soliditication of the concrete material thereabout.

A still further object of this invention is to provide a pre-tensioning means engageable with a plurality of cable members to apply a desired downward or depressed force that is economical to manufacture, easy to assemble in a pre-determined desired pattern, using a minimum amount of deformity in the concrete structure to be produced, and economical in having a minimum amount of cost in material retained in the finished product.

Various other objects, advantages and features of the invention will become apparent to those skilled in the art in light of the following discussion, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a side elevational View `of a pre-tensioned concrete member within a form for the same having a portion broken away for clarity to reveal the pre-tensioning means of this invention;

FIG. 2 is an enlarged fragmentary perspective view of one pre-tensioning means of this invention mounted within a form and secured to cable members;

FIG. 3 is a fragmentary sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a view similar to FIG. 3 illustrating a second embodiment of an anchor means of this invention;

FIG. 5 is a view similar to FIG. 3 showing a third embodiment of the anchor means of this invention;

FIG. 6 is an exploded perspective view of one embodiment of the pre-tensioning means of this invention having a banding strap shown in dotted lines for clarity;

FIG. 7 is an exploded fragmentary perspective view similar to FIG. 6 except having another embodiment of the anchor means of this invention connected thereto;

FIG. 8 is a fragmentary elevational view of an anchor pad of one embodiment of the anchor means of this invention;

FIG. 9 is a fragmentary elevational view of another embodiment of the connector means of the pre-tensioning means of this invention;

FIG. 10 is a perspective view of an anchor pad used in another embodiment of the anchor means of this invention;

FIG. 11 is a fragmetnary elevational view of another embodiment of the connector means of the pre-tensioning means of this invention;

FIG. 12 is a fragmentary elevational view of still another embodiment of the connector means of the pretensioning means of this invention;

FIG. 13 is a fragmentary sectional view taken along line 13-13 in FIG. 12; and

FIG. 14 is a perspective view of a strap Spacing clip of the connector means of this invention.

The following is a discussion and ldescription of preferred specific embodiments of the new means of depressing and/or holding down pre-tensioning tendons or cables of pre-tensioned concrete members of this invention, such being made with reference to the drawings, whereupon the same reference numerals are used to indicate the same or similar parts and/ or structure.

Referring to the vdrawings in detail and in particular to FIG. 1, a concrete beam o-r girder 18 is illustrated having a plurality `of longitudinally extended tendons or cable members 20 held in a downward or `depressed position as by the pre-tensioning means 22 of this invention. In construction of the girder 18, a form box 23 is provided of the desired width and height which is placed on an elongated working bed or soit 25 elevated above a support surface 26 as by I-beams 2S.

The form box 23 is of a generally rectangular shape having end bulkheads 30 adapted to receive the cable members 20 therethrough to position the same at the right height and separation. The end bulkheads 30 are releasably secured to the soiiit 25 as by bolt members 32 and various types thereof may be used depending on the desired number and positioning of the cable members 26 in the form box 23 as will be explained. It is obvious that a plurality of the form boxes 23 can be positioned on the sot 25 with common cable members 20 extended transversely through adjacent ones whereby numerous pre-tensioned girders 18 could be formed at the same time.

The pre-tensioning means 22 includes connector means 33 attachable to the cable members 20 in combination with anchor means 35 engageable with the soit 25 to apply the idesired pressure to cable members 20. The connector means 33 includes various structures using similar elements arranged dilerently depending on pattern of the cable members 20 within the girder 18 to be formed. Therefore, the connector means 33 includes the embodiments of (1) a muliple strand, horizontally and vertically spaced attachment assembly 38 (FIGS. 2 and 6); (2) a multiple strand vertically adjacent, horizontally spaced, attachment assembly 40 (FIG. 9); (3) a multiple strand vertically aligned and spaced attachment assembly 42 (FIG. 11); and (4) a vertically aligned and adjacent attachment assembly 44 (FIGS. 12 and 13). Each of these embodiments are constructed from assembly of various ones of the elements of the connector means 33, being horizontal spacing clips 46, vertical spacing struts 48, strap spacing clips 50, and an elongated exible banding strap 52 used with each given embodiment for anchoring purposes to be explained.

More specifically, the horizontal spacing clips 46 are preferably of a bent-sheet construction having a main body 53 provided with facing leg sections 54 reversely bent so as to extend the same direction laterally of the main body 53 to function as spacers as will be explained. The main body S3 is formed with end sections 56 on opposite sides of the leg sections 54 formed with parallel elongated slots 58 of a suicient width and length so as to receive the banding strap 52'as will be explained. Additionally, the outer end portion of the leg sections 54 are formed with inwardly extendedflange portions 59 positioned in a common plane to provide positive spacing and support as will be explained.

The vertical spacing struts 48 are of a box-like structure having a main spacer body 61 provided with a base wall 62 integral with two sidewalls 64 and having two er1- larged end walls 66 extended laterally of the sidewalls 64. The inner edges of the sidewalls 64 are turned inwardly to form iianges 67. The endwalls 66 are of the generally rectangular shape each having an elongated slot 69 aligned with the slot 69 in the other endwall 66 extended adjacent and outwardly from the ange 67 on the sidewalls 64 for reasons to become obvious.

The strap spacing clips 50 are merely of a rectangular plate structure having a pair of spaced, parallel, elongated slots 71 extended along parallel sides 72 and having a distance between the adjacent sides of the elongated slots 71 equal to or slightly greater than the diameter of the cable members 20 for reasons to become obvious. The slots 71 are of a suflicient size to receive the banding strap 52 therein for reasons to be explained.

The banding strap 52 is preferably constructed of a high strength, flexible, steel material similar to a conventional narrow belt structure and, in the assembled condition, the banding strap 52 is held together by a clamp 74. It is obvious that the banding strap 52 has to be of a sufcient high strength to withstand the tension and stresses to be placed on the cable members 20 in the assembled condition as will be explained.

As shown in FIGS. 3, 4, and 5, the anchor means 35 also includes various structures using somewhat similar elements depending on the pattern of the cable members 20 to be formed within the girder 18, The anchor means 35 includes the embodiments of (1) a single slot, wedgetype anchor assembly 76 (FIG. 3); (2) a double slot, wedge-type anchor assembly 78 (FIG. 4); and a Winchtype anchor assembly 80 (FIG. 5). All of the aforementioned anchor assemblies 35 are operable in a similar manner, namely, to grasp onto the banding strap 52 for providing a downward pull on the cable members 20 secured to respective ones of the embodiments of the c011- nector means 33.

The single slot anchor assembly 76, as shown in FIGS. 2 and 3, includes a pair of elongated channel members 83 placed on opposite sides of a slot 84 in the sofiit 25 adapted to receive the banding strap 52 therethrough; a pair of split Wedges 86; and a single strap anchor pad 87. The split wedges 86 are of a generally U-shape having parallel sloping legs 89 dening an open slot 91 therebetween. The anchor pad 87 is constructed of a pair of parallel bar members 92 inter-connected by a cylindrical shaft section 93. The use and function of these various elements will be fully explained in the respective completed assembly.

The double slot anchor assembly 78, as shown in FIGS. 4 and 7, includes a pair of tapered wedges 94 and 96 mounted between an elongated I-beam 98 and a double strip anchor pad 99 as will be explained. The anchor pad 99 is of a substantially rectangular block shape having the undersurface 101 formed with an arcuate surface 103 adapted to receive the banding strap 52 thereabout as will be explained.

The winch-type anchor assembly 80 includes a plurality of the elongated channel members 83 and a Winch device 105. More specifically, the winch device 105 is provided with a U-shaped depressor frame 107 having parallel legs 108 joined -by a base section 109. The legs 108 are adapted to receive roller sheaves 111 and 112 rotatably mounted therein and the banding strap 52 thereabout as will be explained. Additionally, a slotted shaft 114 is mounted parallel to the roller sheaves 111 and 112 spaced therefrom and being rotatably mounted in the leg members 108. One end of the shaft 114 is extended laterally of the legs 108 so as to be rotatable by a pull-down wrench (not shown) or the like point it is obvious that the laterally extended end of the slotted shaft 114 may be provided with a ratchet assembly (not shown) rotatable in one direction only for reasons to become obvious.

In the use and operation of the pre-tensioning means 22 of this invention, the cable members 20, as shown in FIG. l, are extended through the form box 23 at the desired height and the multiple strand horizontally and vertically spaced attachment assembly 38 is used with six of the cable members 20. The horizontal spacing clips 46 are first placed upon pairs of the cable members 20 extended in common horizontal planes With the leg sections 54 extended downwardly as clearly shown in FIG. 6. Next, the vertical spacing struts 48 are placed between adjacent pairs of the cable members 20 having their end- Walls 66 extended in horizontal planes in contact with the cable members 20. The banding strap 52 is thereupon placed through the vertically aligned slots 69 and 58 in the vertical spacing struts 48 and the horizontal spacing clips 46 in order to group the cable members 20 in a compact package. It is noted that in this assembled condition of the attachment assembly 38, the banding strap 52 prevents outward lateral movement of the cable members 20 While the leg sections 54 of the horizontal spacing clips 46 prevent inward movement of the cable members 20. Additionally, the cable members 20 are clamped between adjacent ones of the vertical spacing struts 48 and the horizontal spacing clips 46 in order to restrict vertical movement therefrom. It is seen, therefore, that the cable members 20 are positively held in a given horizontal and vertical spaced relationship by the attachment assembly 38 of this embodiment. The banding strap 52 can thereupon be pulled together as shown in FIG. 6 and trained through the slot 84 in the soft 25 to be attached to the single slot anchor assembly 76.

More specifically, as shown in FIG. 3, the strap 52 is trained about the shaft section 93 of the anchor pad 87 with free ends of the banding strap 52 inter-connected by the ybanding clamp 74. The pair of the channels 83 are mounted in a facing relationship on opposite sides of the bandin g strap 52 whereupon the split wedges 86 are placed about the strap 52 and between the anchor pad 87 and lowermost wedge 86. Movement of the wedges 86 toward each other acts to move the anchor pad 87 downwardly to increase a downward pull upon the banding strap 52 and inter-connected attachment assembly 38. It is obvious that relative sizes of the split wedges 86 can be varied and the length of the banding strap 52 controlled in order to achieve a desired downward pull on the cable members 20 in the assembled condition.

The same horizontal and vertical attachment assembly 38 may be used with the double slot anchor assembly 78 as shown in FIG. 7. The main difference is that two parallel slots 117 are formed in the soft 25 in order to receive the banding strap 52 whereupon the strap 52 is placed on opposite sides of the tapered wedges 94 and 96 and trained about the double strip anchor pad 99 on the arcuate surface 103. The I-beam 98 is placed between the soit 25 and the uppermost tapered wedge 94 whereupon the wedges 94, 96 can be moved relative to each other to regulate the downward movement of the anchor pad 99 to achieve a desired downward pull on the cable members 20.

Additionally, the winch anchor assembly can be used with either an adjacent single, or a spaced double position of the banding strap 52. In the instance of an adjacent banding strap 52, the same is trained about the lower section of the rst roller sheave 111 and the elongated channels 83 are placed on opposite sides between the lower surface of the sofiit 25 and the depressor frame 105. The free ends of the banding strap 52 are placed within the slot on the shaft 114 and the shaft 114 is rotated in a conventional manner to cause a downward movement of the banding strap 52 and connector means 33. It is obvious, that in this embodiment of the anchor means 35, the downward movement of the connector means 33 and inter-connected banding strap 52 is unlimited as it is not controlled by the various thicknesses of any wedges. It is seen that the second roller sheave 112 may be used when the banding strap 52 is extended through the parallel slots 117 in the soit 25 similar to usage of the double slot anchor assembly 78.

In the multiple strand, vertically adjacent and horizontally spaced attachment assembly 40 as shown in FIG. 9, it is seen that three of the horizontal spacing clips 46 are used in an assembly of six of the cable members 20 inter-connected by the banding strap 52 through the aligned slots 58 therein. As shown in FIG. 9, the banding strap 52 is trained through a single slot in the sofht 25 but may be extended downwardly in parallel relationship through the sot 25 depending on whether using the anchor assembly 76, 78, or 80.

The third embodiment of the connector means 33 is shown with the vertically aligned, spaced attachment assembly 42 of FIG. ll whereupon the strap spacing clips 50 are placed on top of each of the cable members 52 and maintained in a spaced relationship by vertical spacing struts 48 placed therebetween. The vertically aligned slots 69 and 71 are adapted to receive the banding strap 52 therethrough. In this embodiment, it is obvious due to the narrow relationship of the banding strap 52 they are preferably trained through a single slot 84 in the sot 25 and may be anchored to the winch-type anchor assembly 80 or the single slot anchor assembly 76 as desired to provide a downward pull thereon.

The fourth embodiment of the connector means 33 is illustrated in FIGS. l2 and 13 being the vertically aligned and adjacent attachment assembly 44. More particularly, the attachment assembly 44 is provided with the strap spacing clips 50 placed on the upper surface of the three adjacent ones of the cable members 20 and interconnected as by the banding strap 52 which is extended through the common slot 84 in the soit 25 for attachment to the anchor assembly 76 or 80 as desired. It is noted that the various dimensional relationships of the vertical spacing struts 48, the horizontal spacing clips 46, and the clips 50 are regulated so that the cable members 20 are always maintained in a compact restrictive relationship preventing horizontal and vertical movement. The banding strap 52 operates to provide a lateral restriction of the cable members and, because there is always an upward force thereupon, even the lowermost cable members 20 are restricted in all directions against movement.

Although the numerous embodiments have been discussed have wedge members to apply a downward force on the banding strap 52, the various connector means 33 could be first attached to the cable members 20 when they are in a slacked condition. The banding strap 52 used in the connector means 33 would be constructed to a predetermined length in an attached loop with the lower end extended through a slot on the sot 25. Next, a bolt or connector shaft would be extended through the lowermost looped end of the banding strap 52 and anchored to adjoining channel member 83 or the like. Such a structure would resemble FIG. 3 without the wedges 86 and having the shaft section 93 removable so as to be placed in the banding strap 52. Conventional cable tightening mechanisms could then be used to raise the cable members 2) to achieve the desired pre-tensioning thereto. This is very desirable as the banding strap 52 could be constructed to uniform length to eliminate the necessity for skilled labor as may be needed on use of the wedges.

This invention has been primarily concerned with depressing or holding-down cable members; however, it is obvious that the same could be used to pull up the cable members by attachment to the upper surface of the form box. In fact, the cable members could be alternately depressed and raised in a wave type form with the final product being sawed into predetermined lengths to achieve a plurality of concrete beams `from one pouring in an elongated form box.

It is seen that the pre-tensioning means of this invention provides a new and novel means for depressing or pulling upwardly elongated cable members to be formed in concrete beams, girders and the like whereupon various patterns of the cable members can be readily achieved. Additionally, the connector means of this invention are readily constructed with the numerous elements that are substantially inexpensive to manufacture whereby on completion of the concrete girder or the like the banding strap may be severed whereupon a minimum amount of material and expense is left with the completed product. Additionally, in using the pre-tensioning means of this invention a minimum opening is left within the completed concrete product which is extremely desirable in that filling with concrete or repair material is not necessary to achieve a uniform attractive end product.

As will be apparent from the foregoing description of the applicants new and novel pre-tensioning means, relatively inexpensive means have been provided which are readily assembled to a plurality of longitudinally extended cable members to provide a pre-determined downward pull or tension thereto. This is extremely desirable in the formation of concrete support members because concrete by itself is known to have a great compression but low tension strength. Because of the varying bending or flexural forces exerted on a concrete support member, the positioning of the cable members therein may be regulated as desired depending on whether the member is to be supported in the middle, at opposite ends, etc. The location of the pre-tensioning cables within a prestressed concrete member is commonly referred to as draping, depressing or harping the cable members to achieve the desired end product.

I claim:

1. A pre-tensioning means operable for holding-down or depressing cable members to be formed in concrete structural members produced in form boxes placed upon a support solit, comprising:

(a) connector means mounted within the form box connected to the cable means, said connector means having a band member extended about the cable members and extended laterally of the respective form box; and

(b) anchor means connected to said band member positioned below and against the form box, said anchor means having extension means to move said band member relative the form box to regulate pull on the cable members.

2. A pre-tensioning means as described in claim 1,

wherein:

(a) said connector means including a vertical and horizontally spaced attachment assembly having a pl-urality of vertical spacing struts and horizontal spacing clips connected to said band member and the cable members;

(b) said vertical spacing struts engaged with upper and lower surfaces of the cable members to maintain the same in a given vertical position and having slot sections adapted to receive the band member therethrough;

(c) said horizontal spacing clips mounted between adjacent ones of said vertical spacing struts and having downwardly depending leg sections engageable with inner vertical sides of the cable members to maintain the same in a given spaced relationship; and

(d) said horizontal spacing clips having outward slot portions aligned with said slot sections of said vertical spacing struts and having said -band member extended through said slot portions to hold the cable members against outward lateral movement.

3. A pre-tensioning means as described in claim 2,

wherein:

(a) said vertical spacing struts provided with a main body having outward end sections provided with slots being in alignment; and

(b) said horizontal spacing clips having outwardly extending end sections from said leg sections with said slot portions spaced a distance for maintaining the cable members in horizontally spaced positions.

4. A pre-tensioning `means as described in claim 1,

wherein:

(a) said anchor means including a single slot, wedgetype anchor assembly having a plurality of split wedge members, an anchor pad, and elongated channel members;

(-b) said split wedges of generally U-shape adapted to receive said banding strap therebetween engageable with said anchor pad and said channel members;

(c) said channel members engageable with one of said wedges and the lower surface of the soi-lit; and

(d) said band member mounted about said anchor pad whereby said wedge members are movable relative to each other to cause a desired increase and decrease in the overall effective length of said band member to cause a downward pull on said connector means and inter-connected cable members for pre-tensioning the same.

5. A pre-tensioning means as described in claim 1,

wherein:

(a) said anchor means including a double slot wedgetype assembly having a beam member engaged with the lower surface of the soft, la plurality of tapered wedges having one thereof engaged with said beam member, and an anchor pad mounted against the other one of said tapered wedges;

(b) said band member extended through a pair of spaced openings in the soft and trained about opposite sides of said tapered wedges and the lower surface of said anchor pad and inter-connected to form a continuous endless -band structure; and

(c) said tapered wedges movable relative each other to move said anchor pad to adjust the overall effective length of said band member to cause a desired downward pull on said cable members for pre-tensioning the same.

6. A pre-tensioning means as described in claim 1,

wherein:

(a) said anchor means including a winch-type anchor assembly having a depressor frame separated from the lower surface of the soit by elongated channel members;

(b) said depressor frame having spaced, parallel roller sheave members and `a third parallel slotted, pulldown shaft;

(c) said band member extended transversely of the soft and mounted about said roller sheaves and attached to said slotted shaft; and

(d) said depressor frame having winch means connected to said slotted shaft whereby the same may be rotated as desired to wrap said band member about said shaft to regulate the effective length of said band strap causing a downward force on the cable members for the pre-tensioning thereof.

7. A pre-tensioning means as described in claim 6,

wherein:

(a) said band member extended through parallel openings in the sot with each portion mounted about a respective one of said roller sheaves and connected to said slotted shaft; and

(b) said slotted shaft rotatable to decrease the effective length of the said band member to cause a pulldown and pre-tensioning of the cable members.

8. A pre-tensioning means as described in claim 1,

wherein:

(a) said connector means including a vertically aligned and spaced attachment assembly including a plurality of horizontal spacing clip members engageable with the upper and inner facing surfaces of the cable members;

(b) said horizontal spacing clips each having a main body with an inte-gral laterally extending leg section and outward end sections having elongated parallel slots therein; and

(c) said band members extended through said slots about the cable members to prevent outward, lateral movement whereby the cable members are positively held in the given spaced horizontal relationship.

9. A pre-tensioning means as described in claim 1,

wherein:

(a) said connector means including an aligned and spaced attachment assembly having a plurality of vertical spacing struts and clip members;

(b) said vertical spacing struts having laterally extended end portions with aligned slots therein to receive said band members therethrough; and

(c) said spacing clips of a plate shape having spaced,

parallel slot openings placed adjacent the upper surface of the cable members with said banding strap extended through said slot openings and said slots of said spacing clips and said vertical spacing struts, respectively, to positively hold the cable members in a given vertical spacing and aligned position.

10. A pre-tensioning means as described in claim 1,

wherein:

(a) said connector means including a vertically aligned and adjacent attachment assembly having a plurality of spacing clips placed on opposite surfaces of the cable members and having parallel spaced slots therein to receive said band member therethrough to hold the cable members.

References Cited UNITED STATES PATENTS 1,523,438 1/1925 McMillan 24-25 2,123,484 7/1938 Matera 254-104 2,780,429 2/1957 Vanier 248-60 X 3,003,217 10/1961 Gerwick 52--225 X 3,286,419 ll/l966 Eriksson 52--225 FOREIGN PATENTS 561,555 4/1957 Italy.

ALFRED C. PERHAM, Primary Examiner

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