US3840054A

US3840054A - Stirrup fabric pipe reinforcement

Info

Publication number: US3840054A
Application number: US00300114A
Authority: US
Inventors: W Tolliver
Original assignee: New York Wire Mills Corp
Current assignee: New York Wire Mills Corp
Priority date: 1972-10-16
Filing date: 1972-10-16
Publication date: 1974-10-08
Anticipated expiration: 1991-10-08
Also published as: FR2203312A5; DE2343172A1; AT328691B; ATA762773A; CA1002774A

Abstract

Concrete pipe reinforcing fabric including elongated stirrup members hingedly mounted to the fabric. Alternative embodiments include elongated sinusoidal stirrup members joined to a tie rod which, in turn, is hinged to a longitudinal defining strand of the fabric or to an elongated hinge rod which is joined to the fabric parallel to the longitudinal defining strands, sinusoidal stirrup members hinged directly to the longitudinal defining strands, and individual stirrup rods joined to a tie rod which is hingedly mounted to the fabric. The hinges are shaped to receive and conform to a portion of the stirrup member of irregular cross section so that when the stirrup is erected, it is held firmly in place in an erected position. In the alternative, bayonet-type clips are employed as hinges. Hinged stirrup members are arranged either in groups which are spaced along the length of the fabric so that the fabric can be cut and formed into a cage with groups of hinged stirrups at the crown and invert thereof, or are spaced at regular intervals along the length of the fabric so that the fabric can be cut into mats and joined to a separately formed cage at the crown and invert portions thereof.

Description

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Primary Examiner-Jerry W. Myracle Attorney, Agent, or Firm-Price, Heneveld, Huizenga & Cooper [57] ABSTRACT Concrete pipe reinforcing fabric including elongated 40 Claims, 19 Drawing Figures 3.840.054 SHEET 10F 5 PATENTED 31974 nets FIG.2

m n mum 81974 MUMPS 3.8403354 v PAIENIEUBET 8m sHwuoF 5 3,840,054

PAIENTEDBBI 8I974 3.840.054 SHEET 50F 5 STIRRUP FABRIC PIPE REINFORCEMENT BACKGROUND OF THE INVENTION This invention relates to fabric for reinforcing concrete pipe or the like. In the production of concrete pipe, wire fabric cages are formed and concrete is cast around the cages. The wire fabric conventionally comprises a plurality of crisscrossed strands, those strands running one way defining the longitudinal strands of a formed cage and those strands running the other way defining the circumferential strands of the cage. Typically, cages are formed by passing th fabric through forming rollers.

It is common to further reinforce concrete pipe at the crown and invert regions thereof by welding stirrup members to these portions of the cage. Such stirrup members project radially outwardly from the cage. They may be rigidly connected both to an inner cage and to an outer cage. The stirrups may be individual stirrups which are welded to either an inner or outer cage, or both, or they may comprise a continuous sinusoidal-shaped strand of wire.

Present industry practice involves first taking a flat sheet of fabric and passing it through rollers to form a generally circular or elliptical cage. The ends of the rolled cage are welded together. Stirrup members are then welded to the cage, or fastened between inner and outer cages, as described above.

'While the employment of stirrups renders the ultimate concrete pipe considerably stronger and more reliable, it is both cumbersome and costly for the concrete pipe fabricator to assemble the stirrups to the rolled cages.

SUMMARY OF THE INVENTION The present invention comprises a reinforcing fabric in which a plurality of elongated stirrup members, each defining a plurality of stirrup projections, are hingedly joined to the fabric, generally parallel to the longitudinal defining wires of the fabric. This enables one to collapse the stirrup members during shipment of the fabric so that they are generally coextensive with the fabric.

Fabric employing such hinged stirrups can either be shipped on rolls, as in conventional, or can be shipped flat. Further, circular or elliptical cages can be formed or rolled with the stirrup members in their collapsed condition. Once the cages are formed, the stirrup members can be erected simply by rotating them with respect to the surface of the fabric so that the stirrup projections project away from the fabric surface.

Fabric of this nature can either be used for forming cages per se, or for integral reinforcing mats used as components in an overall cage assembly or used in other reinforcing applications. By securing the hinged stirrups to the fabric in spaced groups, one has a fabric which can be cut and formed into a cage with one group of hinged stirrups located at the crown of the cage and another group located at the invert of the cage. The concrete pipe manufacturer has then merely to erect the various stirrup members at the crown and invert and pour concrete around the cage. In the alternative, the stirrup members can be arranged at regular intervals along the length of the fabric and the fabric can be cut into mats. Once a cage is cut and formed from conventional fabric, one stirrup mat can be joined to the cage at the crown thereof and the other can be joined to the cage at the invert thereof. Either method of employing the fabric effects a substantial savings in cost to the concrete pipe manufacturer.

The very concept of employing mats, having stirrup projections projecting therefrom, for reinforcing pipe cages appears to be revolutionary to the industry. While it is preferable that the stirrups be hinged, this aspect of the invention appears new whether the projections are hinged or not.

Preferably, the hinge means and the stirrups include meansv cooperating to firmly hold the stirrups in their erected posiition once erected. This provides insurance against the stirrups collapsing when concrete is poured around the cages. This aspect of the invention is applicable either to the employment of an elongated stirrup member hinged to the fabric, or to a plurality of individusl stirrup rods each individually hinged to the fabric.

Preferably, the elongated stirrup members comprise a plurality of projections joined to and projecting from a tie rod, the tie rod being hingedly joined to the fabric generally parallel to the longitudinal defining members thereof. While these projections may be defined by a continuous, sinusoidal segment joined to the tie rod, it is preferable that the projections comprise individual rods individually joined to the tie rod.

These and other features, objects and advantages of the invention will be more fully appreciated by reference to the written specification and appended drawmgs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of a portion of a first embodiment hinged stirrup fabric made in accordance with the present invention;

FIG. 2 is a cross-sectional view taken along plane IIII of FIG. 1;

FIG. 3 is a fragmentary cross-sectional view taken generally along planes III-III of FIG. 1;

FIG. 4 is a fragmentary top plan view of the fabric shown in FIG. 1;

FIG. 5 is a perspective view of a second alternative embodiment fabric embodying the present invention;

FIG. 6 is a perspective view of a third alternative embodiment fabric embodying the present invention;

FIG. 7 is a cross-sectional view taken generally along plane VII-VII of FIG. 6;

FIG. 8 is a fragmentary cross-sectional view taken generally along plane VIII-VIII of FIG. 6;

FIG. 9 is a fragmentary perspective view of a first type of bayonet clip hinge;

FIG. 10 is a fragmentary perspective view of a second type of bayonet clip hinge;

FIG. 11 is a perspective view of a third type of bayonet clip hinge;

FIG. 12 is a perspective view of a portion of a fourth alternative embodiment fabric embodying the present invention;

FIG. 13 is a perspective view of a portion of a fifth alternative embodiment fabric embodying the present invention;

FIG. 14 is an enlarged view of the tie rod of the hinged stirrup member of the fabric shown in FIG. 13 showing the crimped portion of the tie rod member;

FIG. 15 is a fragmentary cross-sectional view taken along plane XV-XV of FIG. 13;

FIG. 16 is a fragmentary cross-sectional view taken along plane XVI-XVI of FIG. 13;

FIG. 17 is a schematic cross-sectional view of a concrete pipe reinforced with fabric of the present invention;

FIG. 18 is a schematic cross-sectional view of the concrete pipe reinforced with the fabric of the present invention; and

FIG.. 19 is a schematic cross-sectional view of concrete pipe reinforced with fabric of the present invention;

DESCRIPTION OF THE PREFERRED EMBODIMENT In all of the alternative embodiments disclosed herein, the fabric 1 comprises a plurality of elongated stirrup members 10, each defining a plurality of stirrup projections 11, hingedly joined to the fabric 1 by hinges 20 (FIGS. 1, 5, 6, l2 and 13). The elongated stirrup members 10 can be collapsed so as to lie generally coextensive with fabric l, or they can be erected to a position with their projections 11 projecting outwardly from the surface of fabric 1. Fabric 1 can be cut into mats 5 for positioning at the crown and invert of a conventional elliptical cage body 4 as shown in FIG. 17, or for positioning at the crown and invert of an inner cage 6 and at the sides of an outer cage 7 as shown in FIG. 19. In the alternative, elongated stirrup members 10 can be joined to fabric 1 in groups, the groups being spaced from one another so that the fabric can be cut to width and formed into a cage with the stirrups collapsed. One group of stirrups 10 will be positioned at the crown and the other at the invert (FIG. 18). Once the cage is formed, stirrups 10 are erected and concrete is cast around the cage.

In all embodiments, fabric 1 includes a plurality of longitudinal defining steel wires 2 welded to a plurality circumferential defining wires 3 at right angles. When a cage is formed, wires 2 will run the length thereof and wires 3 will define the circumference thereof.

In the embodiment shown in FIG. 1, each elongated stirrup member 10 comprises a segment of sinusoidally formed wire 40 joined to a tie rod 30 (FIG. 1). Sinusoidal wire 40 and tie rod 30 are both made of steel wire. Various ones of the bottom nodes 41 of sinusoidal wire 40 are joined to tie rod 30 by means of welding or the like. It is not absolutely esential that all of the bottom nodes 41 be rigidly secured to tie rods 30. Bottom nodes 41 hook under circumferential defining wires 3 of fabric 1 and lie generally in a plan parallel to the longitudinal defining strands 2 of fabric 1. It is not essential that the spacing of bottom nodes 41 be identical to the spacing of circumferential defining strands 3, it being conceivable that certain ones of bottom nodes 41 might not have to pass beneath a given circumferential defining strand 3.

Tie rod 30 is hingedly mounted to a hinge rod 23 by means of hinges 20. Hinge rod 23, in turn, is welded to at least two circumferential defining strands 3 of fabric 1. Each hinge 20 comprises a hinge channel 21 joined to an attachment channel 22 (FIGS. 2 and 3). Attachment channel 22 is secured to hinge rod 23, hinge rod 23 having a square cross section and attachment channel 22 having a matching configuration. Preferably, attachment channel 22 is welded to hinge rod 23. Hinge channel 21 is adapted to receive tie rod 30.

Tie rod 30 is generally square in cross section. Hinge channel 21 of hinge 20 has a similar configuration, the opposite vertical walls of hinge channel 21 being generally fiat. As a result of this construction, stirrup member 10 is firmly held in either its erected or collapsed positions. Hinge 20 is made of a material sufficiently flexible that as stirrup member 10 is rotated between its collapsed and erected positions, the opposite vertical walls of hinge channel 21 are free to flex outwardly slightly and to close back into their normal position as stirrup member 10 reaches its erected or collapsed position.

Tie rod 30 includes a deviation 31 therein for each hinge 20 (FIGS. 2, 3 and 4). Deviation 31 is received within hinge channel 21 of hinge 20. Deviation 31 deviates from the axis of tie rod 30 a distance approximately equal to the thickness of sinusoidal strand 40. The deviation 31 makes it possible for all of hinge 20, including-hinge channel 21, to lie generally in the plane of the longitudinal defining strands of fabric 1. Because of deviation 31, stirrup member 10 can be opened to its erected position with bottom nodes 41 of sinusoidal strand 40 being positioned generally in the plane of Iongitudinal defining strands 2, and tie rod 30 being positioned below bottom nodes 41 exceot for the upwardly deviating deviations 31 which lie in hinge channels 21. Yet, when stirrup member 10 is collapsed, all of tie rods 30 and the bottom portions of sinusoidal strand 40 lie generally in the same plane as longitudinal defining strands 2.

The upper portions of projections 11 of sinusoidal strand 40 must lie outside of the plane of longitudinal defining strands 2 when stirrup member 10 is collapsed since they are sufficiently tall that they must lie on top of one or more adjacent longitudinal defining strands 2. Accordingly, each prjojection 11 includes a deviating portion 42 therein which causes the upper portions of projections 11 to lie generally in the same plane as the circumferential defining strands 3 of fabric 1 when stirrup members 10 are collapsed (compare FIGS. 2 and 3). In this manner, the entire stirrup member 10 and its attendant hinges 20 are generally coextensive with fabric 1 when collapsed. This makes it possible to pass fabric 1, including stirrup members 10, through a set of forming rollers without causing damage to or hang-ups in the forming rollers as a result of projections from the surface of fabric 1.

The alternative embodiment fabric shown in FIG. 5 is identical to that shown in FIG. 1, except for the fact that the hinge rods 23 have been eliminated. Instead, attachment channels 22 of hinges 20 are secured directly to a longitudinal defining strand 2 of fabric 1. In all other respects, the construction of the two alternative fabrics is identical.

In the alternative embodiment fabric shown in FIG. 6, a sinusoidal wire 50 having a generally square cross section is substituted for sinusoidal wire 40. Both tie rod 30 and hinge rod 23 is eliminated. Instead, a bottom node 51, of sinusoidal strand 50 is carried in hinge channel 21 of binge 20. Attachment channel 22 is attached directly to a longitudinal defining strand 2. Because sinusoidal strand 50 is generally square in cross section, it is firmly held in either its erected or collapsed position by its interaction with the similarly shaped hinge channel 21. Rotating sinusoidal strand 50 between its two positions tends to spread the opposite walls of hinge channel 21 slightly apart and allows them to close back together when sinusoidal strand 50 reaches its collapsed or erected position.

As with sinusoidal strand 40 described above, sinusoidal strand 50 includes a deviating portion 52 to allow the upper portions of projections 11 to lie on top of adjacent longitudinal defining strands 2, in a plane generally parallel to circumferential defining strands 3. The bottom portions and bottom nodes 51, on the ther hand, lie generally in the plane of longitudinal defining strands 2 when sinusoidal strand 50 is collapsed (compare FIGS. 7 and 8).

The alternative embodiment shown in FIG. 6 could be modified by employing sinusoidal strand 40, having a generally circular cross section, in place of sinusoidal strand 40, having a generally square cross section, but in conjunction with a bayonet-type hinge rather than in conjunction with the particular hinge 20 disclosed in FIG. 6. Three such bayonet-type hinges 90, 100 and 110 are shown in FIGS. 9, 10 and 11, respectively. Bayonet hinge 90 comprises a channel 91 with a mounting flange 92 projecting at least from one side thereof. Mounting flange 92 is welded to a longitudinal defining strand 2. There may also be a mounting flange 92a on the opposite side of channel 91 positioned generally beneath a circumferential defining strand 3. The bottom node 41 of sinsuoidal strand 40 passes beneath circumferential strand 3 and is positioned within channel 91.

Bottom node 41 is sufficiently long in arc that sinusoidal strand 40 can be slid back and forth either in the direction of arrow A or arrow B. Bayonet hinge 90 includes a stop flange 93 extending upwardly from that wall of channel 91 which is opposite mounting flange 92. When sinusoidal strand 40 is in its erected position as shown in FIG. 9, stop flange 93 prevents sinusoidal strand 40 from being rotated downwardly to its collapsed position. In order to collapsesinusoidal strand 40, it is first slid in the direction of arrow B such that it is out of the way of stop flange 93 and is then rotated downwardly to its collapsed position.

Bayonet hinge 100 is similar in construction, (FIG. 10), including a channel 101, a mounting flange 102 and a stop flange 103, all of which operate the same as channel 91, mounting flange 92 and stop flange 93 of bayonet hinge 90. In addition, bayonet hinge 100 includesa lock flange 104 projecting upwardly from the bottom of channel 101. In order to erect sinusoidal strand 40, it is rotated upwardly and slid in the direction of arrow A. Then it is slid in the direction of arrow C, into position behind lock flange 104. In this position, it is not possible to slide sinusoidal strand 40 back in the direction of arrow B. To collapse sinusoidal strand 40, it must first be slid in the direction of arrow D, then slid in the direction of arrow B and then rotated downwardly to its collapsed position.

Bayonet hinge 110 (FIG. 11) is very similar to bayonet hinge 100. It includes a channel 101, a mounting flange 102, a stop flange 103, and a lock flange 104. The only difference in construction from bayonet hinge 100 is that lock flange 104 extends outwardly from the sidewall of channel 101 which is adjacent mounting flange 102. The manner in which sinusoidal strand 40 is erected and collapsed in bayonet hinge 110 is identical to the manner in which it is erected and collapsed in bayonet hinge 100.

The alternative embodiment fabric shown in FIG. 12 is quite similar to that shown in FIG. 5, with the esxception of the fact that individual Z-shaped projection rods 60 are substituted for a continuous, sinusoidal strand 40. Each upwardly projecting Z-shaped rod 60 is welded to tie rod 30. Tie rod 30 in turn is mounted in hinge channel 21 of hinge 20 and hinge 20 is in turn attached to an adjacent longitudinal defining strand 2. Each Z-shaped projection rod 60 includes a hook 61 at the top thereof to provide an additional anchor when a cage made from fabric 1 is embedded in concrete. The bottom of each rod 60 hooks under a circumferential defining strand 3 at 62 in order to provide a firm anchor for each circumferential defining strand 3.

In the alternative embodiment shown in FIG. 13, each stirrup member 10 comprises a straight, elongated tie rod to which are welded a plurality of straight projection rods 80. Because projection rods do not hook beneath any circumferential defining strands 3, tie rods 70 can lie directly beneath circumferential defining strands 3 and entirely within the plane of longitudinal defining strands 2 without any deviations therein. Projection rods 80 are welded to one side of tie rod 70, specifically to the side opposite the direction in which stirrup member 10 is rotated in order to collapse it. Because of this connection, tie rods 70 lie directly on top of any adjacent longitudinal defining strands 2 and still lie in the same plane as circumferential defining strands 3 when stirrup member 10 is collapsed (compare FIGS. 15 and 16).

Because tie rod 70 is generally round in crosssectional configuration, it is crimped at those points along its length which correspond to the location of hinges 20. This crimping creates a pair of flat surfaces 71 in tie rod 70 (FIG. 14). When stirrup member 10 is erected (FIG. 15) flats 71 cooperate with the flat bottom and flat side of hinge channel 21 to firmly hold stirrup member 10 in its erected position. When stirrup member 10 is collapsed (FIG. 16) flats 71 cooperate with the bottom wall and opposite sidewall of hinge channel 21 to firmly hold stirrup member 10 in its collapsed position.

In FIG. 17, a concrete pipe has been constructed employing an elliptical cage 4 made of conventional fabric in conjunction with a pair of stirrup mats cut from fabric made in accordance with the present invention. In constructing elliptical cage 4, conventional fabric is first cut, formed and welded at its free ends. Then, the hinged stirrup members 10 of stirrup mats 5 (stirrup mats 5 being cut from fabric 1) are rotated to their erected position, and are inserted through the openings in cage 4. Stirrup mats 5 are positively secured to cage 4 by means of welding at a few points, or by some other fastening means. The resulting cage assembly is placed in a pipe manufacturing machine and concrete is cast therearound.

FIG. 18 shows a concrete pipe in which stirrup members 10 have been hingedly joined to fabric 1 in groups, each group being spaced from the other a predetermined distance. The fabric 1 is then cut, formed into a cage 8 and welded as would be conventional. One group of hinged stirrup members 10 are located at the crown of the pipe and a second group of hinged stirrup members 10 are located at the invert of the pipe. A workman merely erects the various hinged stirrup members 10, places cage 8 in a pipe making machine, and casts concrete therearound. Naturally, the distance between adjacent groups of hinged stirrup members 10 varies in accordance with the diameter of configuration which cage 8 is to have.

FIG. 19 shows yet another pipe made in accordance with the present invention in which a conventional inner cage 6 and outer cage 7 are first formed. A stirrup mat is positioned at the crown and invert of inner cage 6 in the same manner as described in conjunction with cage 4 shown in FIG. 17. a stirrup mat 5 is positioned at each side of outer cage 7 with the projections 11 of individual stirrup members projecting through outer cage 7 from the outside to the inside. The two cages 6 and 7 are arranged in concentric fashion within a pipe making machine and concrete is cast therearound.

As a result of the above invention, the laborious onthe-job securing of individual stirrup members or of individual sinusoidal stirrup segments to a formed pipe reinforcing cage is eliminated. When stirrup mats 5 are used, an entire group of stirrups are secured to the crown or invert of a cage in a single operation. Surprisingly, fabric 1 made in accordance with the present invention can be formed in conventional forming rollers. Fabric 1 will readily roll through and form in such rollers with stirrup members 10 in their collapsed positions.

Accordingly, the present invention represents a significant time and laborsaving contribution to the art. Of course, it is understood that the above are merely preferred alternative embodiments of the invention, and that various modifications and alterations can be made of these embodiments without departing from the spirit and broader aspects of the invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a fabric for reinforcing concrete pipe or the like, said fabric having a plurality of longitudinal and circumferential cage defining strands, the improvement comprising: a plurality of elongated stirrup members, each defining a plurality of stirrup projections; hinge means hingedly joining said stirrup members to said fabric with said stirrup members generally parallel to said longitudinal defining strands, whereby said fabric can be shipped and formed with said stirrup members and said projections lying generally coextensive with said fabric and whereby said stirrup members can be erected after a cage is formed so that said stirrup projections project from the surface of said fabric.

2. The fabric of claim I in which each of said stirrup members comprise a tie rod extending generally the length thereof, said projections being joined to said tie rod; said tie rod being hingedly joined to said fabric.

3. The fabric of claim 2 in which each of said projections comprises a separate stirrup rod joined to said tie rod at an angle thereto so as to project away from said tie rod.

4. The fabric of claim 2 in which said plurality of projections for each of said stirrup members comprises a continuous sinusoidal-shaped strand joined to said tie rod.

5. The fabric of claim 4 in which said hinge means comprises: a channel and attachment means integral therewith; said attachment means being joined to said fabric such that said channel lies in generally the plane of said longitudinal defining strands; at least some of the nodes of each said sinusoidal strand lying under at least some of said circumferential defining strands and lying generally in the plane of said longitudinal defining strands; said tie rod passing underneath said some nodes and including an upward deviation therein at each said channels; said deviation lying in said channel whereby when said stirrup members are collapsed, said tie rod lies entirely in the plane of said longitudinal strands, but when erected, said tie rod lies below the plane of said longitudinal strands to allow said some nodes to lie in the plane of said longitudinal strands.

6. The fabric of claim 5 in which each projection of said sinusoidal strand includes a deviation therein whereby when said strand is collapsed, said some nodes and said lower portions of said projections lie in the plane of said longitudinal strands, but the upper portions of said projections lie in the plane of said circumferential defining strands and thereby lie on top of adjacent longitudinal strands.

7. The fabric of claim 5 in which the spaced vertical walls of each of said channels are generally planar; each of said tie rods being generally square in cross section whereby said tie rods are firmly held in position between said spaced channels walls in either an erected or collapsed condition.

8. The fabric of claim 2 in which said hinge means join each said tie rod to an adjacent longitudinal defining strand.

9. The fabric of claim 2 in which said hinge means comprises a hinged rod for each of said stirrup membrs extending generally the length thereof and means hingedly joining each said stirrup member to each said hinge rod, said hinge rod being joined to said fabric generally parallel to said longitudinal defining strands.

10. The fabric of claim 2 in which said hinge means comprises at least one channel-shaped member for each of said stirrup members; said tie rod for each said stirrup member lying in said channel member; said tie rod having an irregular cross section and said channel member having a similar configuration to said irregular cross section whereby said stirrup member is firmly held in a generally upright position by the interaction of said tie rod and said channel member when said stirrup member is opened.

11. The fabric of claim 2 in which said hinge means comprises at least one channel-shaped member for each of said stirrup members; said tie rod for each said stirrup member lying in said channel member; each said tie rod including a crimped portion therein for each said channel member; said crimped portion lying in said channel member and said channel member including at least one generally flat surface for cooperating with said crimped portion to firmly hold said stirrup member in its erected position.

12. The fabric of claim 1 in which said stirrup member comprises: a sinusoidal strand.

13. The fabric of claim 12 in which said hinge means joins said sinusoidal strand to an adjacent longitudinal defining strand of said fabric.

14. The fabric of claim 13 in which at least some of the nodes of said sinusoidal strand lie immediately under said circumferential defining strands of said fabric, generally in the plane of said longitudinal defining strands; each projection of said sinusoidal strand including a deviation therein whereby when said strand is collapsed, said nodes and lower portions of said projections lie generally in the plane of said longitudinal defining strands but the upper portions of said projections lie in the plane of said circumferential defining strands and thereby lie on top of adjacent longitudinal defining strands.

15. The fabric of claim 12 in which at least some of the nodes of said sinusoidal strand lie immediately under said circumferential defining strands of said fab? ric, generally in the plane of said longitudinal defining strands; each projection of said sinusoidal strand including a deviation therein whereby when said strand is collapsed, said nodes and lower portions of said projections lie generally in the plane of said longitudinal defining strands but the upper portions of said projections lie in the plane of said circumferential defining strands and thereby lie on top of adjacent longitudinal defining strands.

16. The fabric of claim 12 in which said hinge means comprises at least one channel-shaped member for each said stirrup member, said channel-shaped member'being joined to said fabric; at least some of the nodes of said sinusoidal strand lying in said channelshaped member; said sinusoidal strand having an irregular cross-sectional configuration and said channelshaped member having a similar irregular configuration whereby said sinusoidal strand is firmly held in its erected position when erected.

17. The fabric of claim 12 in which said hinge means comprises at least one bayonet clip for each said sinusoidal strand; said bayonet clip being secured to said fabric and said sinusoidal strand being received by said bayonet clip whereby when said sinusoidal strand is erected, it can be firmly held in an erected position by its cooperation with said bayonet clip.

18. The fabric of claim 1 in which said hinge means and each said stirrup member includes means cooperating to firmly hold said stirrup member in its erected position when erected.

19. The fabric of claim 18 in which said hinge means comprises at least one channel-shaped member for each of said stirrup members; said tie rod for each said stirrup member lying in said channel member; said tie rod having an irregular cross section and said channel member having a similar configuration to said irregular cross section whereby said stirrup member is firmly held in a generally upright position by the interaction of said tie rod and said channel member when said stirrup member is opened.

20. The fabric of claim 18 in which said hinge means comprises at least one channel-shaped member for each of said stirrup members; said tie rod for each said stirrup member lying in said channel member; each said tie rod including a crimped portion thereon for each said channel member; said crimped portion lying in said channel member and said channel member including at least one generally flat surface for cooperating with said crimped portion to firmly hold said stirrup member in its erected position.

21. The fabric of claim 18 in which each said stirrup member comprises a sinusoidal strand; said hinge means comprising at least one channel-shaped member for each said stirrup member, said channel-shaped member being joined to said fabric; at least some of the nodes of said sinusoidal strand lying in said channelshaped member; said sinusoidal strand having an irregular cross-sectional configuration and said channelshaped member having a similar, irregular configuration whereby said sinusoidal strand is firmly held in its erected position when erected.

22. The fabric of claim 18 in which each said stirrup member comprises a sinusoidal strand; at least one bayonet clip being secured to said fabric for each said sinusoidal strand and said sinusoidal strand being received by said bayonet clip whereby when said sinusoidal strand is erected, it is firmly held in an erected position by its cooperation with said bayonet clip.

23. The fabric of claim '1 in which said plurality of stirrup members are joined to said fabric in groups, said groups being separated by spaced intervals along the length of said fabric, whereby said fabric can be cut at appropriate lengths and formed into a complete cage with said groups of stirrups being located at least at the crown and invert portions of said cage.

24. In a fabric for reinforcing concrete pipe or the like, the improvement comprising: a plurality of stirrup projections; hinge means hingedly joining said stirrup projections to said fabric whereby said stirrup projections can be rotated to a collapsed position generally coextensive with said fabric or can be rotated to an erected position projecting away from the surface of said fabric; said hinge means and said stirrup projections including means cooperating to firmly hold said stirrup projections in said erected positions.

25. A cage assembly for reinforcing concrete pipe, said cage assembly comprising: a cage body having a plurality of longitudinal and circumferential strands; a fabric mat having a first set of strands running generally parallel to said longitudinal strands and a second set of strands running generally parallel to said circumferential strands; a plurality of elongated stirrup members, each defining a plurality of stirrup projections; hinge means hingedly joining said stirrup members to said fabric mat, generally parallel to said first set strands, whereby said fabric mat can be shipped and formed with said stirrup members and said projections lying generally coextensive with said fabric mat and whereby said stirrup members can be rotated to an erected position with respect to said fabric mat so as to project away from the surface thereof; at least one of said fabric mats being operably connected to said cage body at the crown and at the invert thereof with said elongated stirrups projecting away from the surface of said cage body.

26. The cage assembly of claim 25 in which said fabric mats are arranged on one side of said cage body with said projections of said stirrup members projecting through said cage body and out the opposite side.

27. In a fabric for reinforcing concrete pipe or the like, said fabric having a plurality of longitudinal and circumferential cage-defining strands, the improvement comprising: a plurality of elongated stirrup members, each defining a plurality of stirrup projections; hinge means hingedly joining said stirrup members to said fabric with said stirrup members generally parallel to said longitudinal defining strands, whereby said fabric can be shipped and formed with said stirrup members and said projections lying generally coextensive with said fabric and whereby said stirrup members can be erected after a cage is formed so that said stirrup projections project away from the surface of said fabric; each of said stirrup members comprising a tie rod extending generally the length thereof, said tie rod being hingedly joined to said fabric and being positioned generally in the same plane as said longitudinal defining strands; said projections comprising projection members joined to said tie rod on a common side thereof; each of said projection members lying entirely out from underneath any circumferential defining strands; said stirrup members being hingedly rotatable in a direction which will carry said common side of said tie rod to the top thereof whereby said projection members will lie generally in the plane of said circumferential defining strands.

28. The fabric of claim 27 in which said projection members comprise a plurality of individual stirrup rods joined to said tie rod.

29. The fabric of claim 28 in which said hinge means and each said tie rod includes means cooperating to firmly hold said stirrup member in its erected position when erected.

30. The fabric of claim 29 in which said hinge means comprises at least one channel-shaped member for each of said stirrup members; said tie rod for each said stirrup member lying in said channel member; said tie rod having an irregular cross section and said channel member having a similar configuration to said irregular cross section whereby said stirrup member is firmly held in a generally upright position by the interaction of said tie rod and said channel member when said stirrup member is opened.

31. The fabric of claim 29 in which said hinge means comprises at least one channel-shaped member for each of said stirrup members; said tie rod for each said stirrup member lying in said channel member; each said tie rod including a crimped portion therein for each said channel member; said crimped portion lying in said channel member and said channel member including at least one generally flat surface for cooperating with said crimped portion to firmly hold said stirrup member in its erected position.

32. The fabric of claim 29 in which each said projection comprises a straight stirrup rod.

33. The fabric of claim 29 in which each said projection comprises a generally straight stirrup rod with a hook at the top thereof.

34. A cage assembly for reinforcing concrete pipe,

said cage assembly comprising: a cage body having a plurality of longitudinal and circumferential strands; a pair of mats, each formed of fabric comprising a network of a plurality of interconnected strands; one of said mats located generally at the crown and the other located generally at the invert of said cage body; each of said mats including a plurality of stirrup projections projecting from the surface thereof and projecting outwardly from the surface of said cage body.

35. The cage assembly of claim 34 in which said fabric mats are arranged on one side of said cage body with said projections of said stirrup members projecting through said cage body and out the opposite side.

36. The cage assembly of claim 35 in which said mats are located on the inside of said cage body, said stirrup projections projecting through said cage body and outwardly therefrom.

37. A fabric mat for reinforcing concrete pipe of the like comprising: a mat of fabric comprising a network of a plurality of interconnected strands; a plurality of elongated stirrup members each defining a plurality of stirrup projections; joining means joining said stirrup members to said mat of fabric at spaced intervals, said stirrup members being generally parallel to one another.

38. The fabric mat of claim 37 in which said joining means comprise a plurality of strands extending generally laterally of said stirrup members.

39. A fabric mat for reinforcing concrete pipe or the like comprising: a plurality of elongated stirrup members each defining a plurality of stirrup projections; joining means joining said stirrup members at spaced intervals, said stirrup members being generally parallel to one another; hinge means hingedly joining each of said stirrup members to said joining means.

40. The fabric mat of claim 39 in which said joining means comprise a plurality of strands extending generally laterally of said stirrup members.

Claims

2. The fabric of claim 1 in which each of said stirrup members comprise a tie rod extending generally the length thereof, said projections being joined to said tie rod; said tie rod being hingedly joined to said fabric.

15. The fabric of claim 12 in which at least some of the nodes of said sinusoidal strand lie immediately under said circumferential defining strands of said fabric, generally in the plane of said longitudinal defining strands; each projection of said sinusoidal strand including a deviation therein whereby when said strand is collapsed, said nodes and lower portions of said projections lie generally in the plane of said longitudinal defining strands but the upper portions of said projections lie in the plane of said circumferential defining strands and thereby lie on top of adjacent longitudinal defining strands.

16. The fabric of claim 12 in which said hinge means comprises at least one channel-shaped member for each said stirrup member, said channel-shaped member being joined to said fabric; at least some of the nodes of said sinusoidal strand lying in said channel-shaped member; said sinusoidal strand having an irregular cross-sectional configuration and said channel-shaped member having a similar irregular configuration whereby said sinusoidal strand is firmly held in its erected position when erected.

21. The fabric of claim 18 in which each said stirrup member comprises a sinusoidal strand; said hinge means comprising at least one channel-shaped member for each said stirrup member, said channel-shaped member being joined to said fabric; at least some of the nodes of said sinusoidal strand lying in said channel-shaped member; said sinusoidal strand having an irregular cross-sectional configuration and said channel-shaped member having a similar irregular configuration whereby said sinusoidal strand is firmly held in its erected position when erected.

23. The fabric of claim 1 in which said plurality of stirrup members are joined to said fabric in groups, said groups being separated by spaced intervals along the length of said fabric, whereby said fabric can be cut at appropriate lengths and formed into a complete cage with said groups of stirrups being located at least at the crown and invert portions of said cage.

34. A cage assembly for reinforcing concrete pipe, said cage assembly comprising: a cage body having a plurality of longitudinal and circumferential strands; a pair of mats, each formed of fabric comprising a network of a plurality of interconnected strands; one of said mats located generally at the crown and the other located generally at the invert of said cage body; each of said mats including a plurality of stirrup projections projecting from the surface thereof and projecting outwardly from the surface of said cage body.