US3197171A

US3197171A - Combined concrete wall form spreaders and reinforcing rod spacer devices

Info

Publication number: US3197171A
Application number: US333581A
Authority: US
Inventors: Michalak Hillard
Original assignee: Superior Concrete Accessories Inc
Current assignee: Superior Concrete Accessories Inc
Priority date: 1963-12-26
Filing date: 1963-12-26
Publication date: 1965-07-27
Anticipated expiration: 1982-07-27

Description

July 27, 1965 H. MICHALAK 3,197,171

COMBINED CONCRETE WALL FORM SPREADERS AND REINFORCING ROD SPACER DEVICES Filed Dec. 26, 1963 2 Sheets-Sheet l Us n! so 4:842 50 g i FIG. 2

3 50 344 7 250 FIG. 7 INVENTOR. 1% *7 HILLARD MICHALAK July 27, 1965 H. MICHALAK 3,197,171

COMBINED CONCRETE WALL FORM SPREADERS AND REINFORCING ROD SPACER DEVICES Filed Dec. 26, 1963 2 Sheets-Sheet 2 INVENTOR.

HILLARD MKIH AK BY M United States Patent Delaware- Filed Dec. 26, 1963, Ser. No. 333,581 5 Claims. (Cl. 249-40) The present invention relates to concrete wall form hardware and has particular reference toa novel combined concrete wall form spreader and reinforcing rod spacer device which, when operatively positioned in a standard or conventional concrete wall form installation, serves the triple function of first, maintaining the opposed wall form sides accurately spaced from each other and against inward bulging or sagging; secondly, maintaining the usual two opposed, spaced apart reinforcing rod frames properly spaced from each other and in their proper erect positions between the wall form sides; and thirdly, maintaining uniform spacing between the two reinforcing rod frames and their respective adjacent wall form sides.

The problem of inward bulging or leaning of the opposed, spaced apart sides of a concrete wall form is one that arises during erection of the form and before the wet concrete is poured between the form sides. To obviate this problem, it has been the practice to employ horizontal tie rod assemblies which have incorporated therewith spacer cones and similar devices to occomplish the necessary spreading function. The spreading function of the present invention eliminates the need for employing such cone-equipped tie rod assemblies and makes possible the use of tie rod assemblies which make no provision for compressional forces but function in tension only.

Fire underwriter and other specifications for the placement of the reinforcing rod frames in the space between the opposed, spaced apart sides of a concrete wall form are based upon the length of the time that heat will penetrate a given concrete wall structure and reach the embedded reinforcing rods of the frames. Therefore, these specifications specify the minimum distance which shall exist between the side surfaces of the formed concrete wall and the reinforcing rod frames. According to the present invention, the improved combined concrete wall form spreader and reinforcing rod spacer device maintains a uniform distance between each reinforcing rod frame and the adjacent side of the form wall so that, after the concrete has been poured and become hardened, the entire reinforcing rod installation, i.e., both reinforcing rod frames, will be positionedwithin the wall at precisely the minimum allowable distance from the side surfaces of the formed concrete wall.

While the compressional characteristics of concrete are admirable, the tensional characteristics thereof are extremely poor. It is mainly for this reason that reinforcing bar frames are provided in the first place. These frames are positioned within the wall form as close to the inner faces of the wall form sides as fireproofing specifications will permit in order to lend tensional characteristics to the finished wall near the side surfaces thereof. In the event that there is any tendency for wall buckling arising, for example, due to' foundation settling or uneven expansion or contraction of adjoining building walls, or from any other reason whatsoever, one side of a given concrete wall will be placed under compression while the other side thereof will be placed under tension. It follows, therefore, that the reinforcing rod frames which are embedded in the concrete wall structure must be substantially linearly straight in the ice longitudinal direction of the wall. Since it is geometrically axiomatic that a line parallel to a straight line is itself, straight, the fact that the combined concrete wall form spreader and reinforcing rod spacer device of the present invention maintains the reinforcing rod frames at a fixed distance from the linearly straight sides of the associated form wall, it follows, therefore, that the reinforcing rod frames are, themselves, maintained linearly straight so that they will absorb tensional forces at the slightest tendency for the completed concrete wall to buckle.

The fact that the particular device which comprises the present invention serves to maintain'the reinforcing rod frames uniformly spaced from the adjacent sides of the concrete wall form precludes outward bulging of the frames but does not preclude inward bulging of the frames because the portions of, the device which perform this function operate under compression only and receive their reaction force by direct contact with the sides of the associated concrete wall form. Therefore, in order to prevent inward bulging of the reinforcing rod frames, i.e., toward each other, the device spans the two frames and operate under compression to maintain the frames spread or spaced apart.

The provision of a combined concrete wall form spreader and reinforcing rod spacer device which is of the character briefly outlined above and will perform the aforementioned triple functions being among the principal object of the invention, it is another and important object of the invention to provide such a device which is capable of extreme case of installation and, for this purpose, does not require the use of special tools or skills.

Another object of the invention is to provide in a device of the character under consideration, novel protective means for certain protruding or exposed ends which engage the sides of the associated concrete wall form after installation of the device, such means serving not only to protect the panel facings of the wall form side from rust spots, as well as from being gouged, scratched or otherwise damaged but also to facilitate handling of the device during packing, shipping and installation.

A similar and related object of the invention is to provide a combined concrete wall form spreader and reinforcing rod spacer device of the last mentioned character in which the protective means for the protruding ends of the device assume the form of protective cover caps or tips and have associated therewith novel means for preventing inadvertent removal of the cover caps during handling or shipment of the device,

The provision of a concrete Wall form spreader and reinforcing rod spacer device which is comprised of a relatively few, separately manufactured parts and which, when these parts are assembled, form an integral unit or device; one which, in the several forms which it is capable of assuming, is comprised entirely of rod stock; one which is rugged and durable and, therefore, will withstand rough usage; one which contains no relatively moving parts and, therefore, is unlikely to get out of order; and one which otherwise is well adapted to perform the services required of it, are further desirable features which have been borne in mind in the production and development of the present invention.

Numerous other objects and advantages of the invention, notat this time enumerated, will readily suggest themselves as the following description ensues.

In the accompanying two sheets of drawings forming a part of this specification, several illustrative embodiments of the invention have been shown.

In these drawings:

FIG. 1 is a fragmentary perspective view of a concrete wall form installation embodying several of the combined concrete wall form spreader and reinforcing rod spacer devices of the present invention;

FIG. 2 is a side elevational view of a combined concrete wall form spreader and reinforcing rod spacer device showing one form or embodiment of the invention;

FIG. 3 is a plan view of the device that is shown in FIG. 2;

FIG. 4 is a side elevational view similar to FIG. 2 but showing a modified form of the improved device, this form being susceptible to adjustment as'to overall length on specification and at the time of manufacture;

FIG. 5 V is a side elevational view similar to FIG. 4 but showing another modified form of adjustable device;

FIG. 6 is an enlarged sectional view taken on the line 6-6 of FIG. 3;

FIG. 7 is an enlarged sectional view taken on'theline 7-7 of FIG. 9;

FIG. 8 is an enlarged sectional view taken on the line 8-8 of FIG. 1 and in the direction indicated by the ar- 7 rows;

FIG. 9 is a sectional view similar to FIG. 8 but showing an installation embodying a further modified form of the invention;

FIG. 10 is a sectional view similar to FIG. 8 but showing an installation employingthe device of FIG. 4; and

FIG. 11 is a sectional view similar to FIG. 8 but showing an installation embodying a further modified form of the device which differs slightly from the device of FIG. 5.

Referring now to the drawings in detail and in particular to FIG. 1, a fragmentary portion of both sides of a composite concrete wall form has been illustrated herein and designed in its entirety by the reference numeral 10. The wall form 10 is made up of

opposed form sides

12 and 14, each side presenting plywood or other suitable panel facings 16 which are supported by vertical members 18. Walers 20 extend horizontally along the vertical members 18, bridge. the distance between adjacent members, and serve to reinforce the concrete wall form installation and also to maintain the vertical members 18 in alignmentin the usual manner of operation of such walers. Conventional tie rods 22 extend transversely across. the form 10 and pass through the opposedpanel facings 16 and the walers 20. The ends 24 of the tie rods are threaded and receive thereon threaded clamps 26.

Conventional reinforcing rod frames 2'7 and 28 are disposed inwards of the sides of the wall form 10 and are spaced inwardly from the panel facings 16-a predetermined minimum distance, such distance being specified under existing fireprooting specifications as heretofore set forth. The two frames 27 and28 are substantially identical in construction and, therefore, a description of one of them will suffice for the other. The frame 27 is in the form of an open lattice structure which has wide rectangular openings and consists: of vertical framerods 30 and horizontal frame rods 32. The

rods

30 and 32 are wired together at selected regions of crossing as shown at 34 so that each frame is a self-contained unit. The usual frame-supporting membersor elements whereby the two

frames

27 and 28 are supported in the installation have been omitted from the herein illustrated concrete wall form installation inasmuch as the combined wall form spreader and reinforcing rod spacer device of the present invention serves the function of such members or elements as will become clear presently.

The arrangement of parts thus far described is con ventional and no claim is made herein to any novelty as sociated with it. Other types of concrete wall form in- ;tallations are adaptable for use in connection with the Jresent invention which consists of the novel construc- Lions, combinations and arrangement of parts of the sev- :ral forms of the device now to be described in detail.

:2. Still referring to FIG. I and, additionally, to FIGS. 2,

invention is illustrated in detail, the device 40 which constitutes this embodiment consists of three principal parts, namely, an elongated rod 42 and two inverted generally U-shaped

clips

44 and 46. The rod 42 is in the form of a straight length of commercial steel rod stock. The ends of the rod 42 are turned laterally at an angle slightly in excess of to provide slightly reentrant ends 48 which lie in the same vertical plane. The two laterally turned ends 43 are covered by elastomeric tips 50 within which the rod ends 48, as well as short adjacent portions of the rod, are embedded.

The two U-shaped clips 44'and 46 of the device 40 are spaced inwardly from the ends of the rod 42 a slight distance and each clip is in the form of a short length of spring rod stock bent into its U-shaped form and having one leg 52 thereof welded as at 53 to the rod and having the other leg 54 free so that it is capable of limited lateral movement toward and away from the leg 52, during which movement the bight portion 56 of the clip will flex inone direction or the other. The

legs

52 and 54 are inclined downwardly and inwardly toward each other and the leg 52 and the rod are welded together at a point near the distal end. of the former with the clip so disposed with respect to the rod that the end regions of the

legs

52 and 54,.together with a limited extent of the rod, define a small generally triangular snap-in pocket for reception therein of one of the horizontal reinforcing rods 32 whenthe device 40 is installed in the concrete wall form installation 10. The major portion of each clip projects upwardly above the level of the rod .42. The extreme distal end regions of

thelegs

52 and 54 of each clip are bowed outwardly to facilitate pushing of the clip into position over the associated rod 32.

The previously mentioned elastomeric tips 59 are preferably applied to the laterally turned ends 48 of the rod 42 by a clipping operation to insure good adhesion of the tips and to prevent looseness and consequent internal frictional wear of the tips. Such a clipping operation also facilitates application of the tips to the rods inasmuch as the application of a preformed tip to an obtuse angle bend would otherwise involve installation difficulties and possible deformation of the tip beyond its elastic limit. Alternatively, the tips may be applied to the laterally turned ends of the rod 42 by a molding operation, followed by a vulcanization process. If desired, the tips 50 may be formed of a suitable plastic material which may be molded about the ends of the rod 42 and, subsequently,

polymerized. Certain plastic materials are adaptable to dipping operations and these include many of the phenolformaldehyde resins, as well as certain epoxy adhesives. Irrespective of the particular material of which the tips 59 may be formed, the essential features of the invention are at all times preserved.

In the installation and operation of the above described preferred form of combined concrete wall form spreader and reinforcing rod spacer device 40, after the form wall sides 12 and 14 have been erected and the two reinforcing rod frames 27 and 28 properly positioned between them, the device 40 of the present invention, and like or similar devices, are successively applied to the horizontal reinforcing rods 32 with one of the clips 44 of each device engaging a rod 32 of one

frame

27 or 28, as the case may be, with the other clip 46 engaging a rod 32 of the other frame, and with the rod 42 extending horizontally and transversely across the form 10. Thereafter, the form sides 12, and 14 may be effectively tightened against the covered or tipped laterally turned ends 48 of the rods 42 of the device by tightening the clamp 26 on the ends of the tie rods 22 in the usual manner of tie rod installation. After such tie rodtightening operations are complete, the form 10 is ready for concrete pouring operations.

In a slightly modified form of the invention illustrated in FIG. 9, instead of causing the end regions of the rod .1 and 8 wherein a preferred embodiment of the present 142 of the device 140 to be bent downwardly and inwardly laterally as shown in FIG. 6, and as is the case in connection with the form of the invention shown in FIGS. 1, 2 and 8, the ends may remain straight as shown in FIG. 7 and indicated at 148. Except for the difference in the end regions 148 of the rod 142 shown in FIG. 9, the device 140 remains the same as the device 40 and, therefore, to avoid needless repetition of description, similar reference numerals but of a higher order have been applied to the corresponding parts as between the disclosures of FIGS. 2 and 9. In order to retain the elastomeric or other close-fitting cup-shaped tips 150 over the end regions 148 of the rod 142, an annular groove 149 is formed in each end region and the elastomeric material of the tips flows into these grooves during the dipping or molding operation as the case may be. It has been found that, in the absence of such grooves, even the intimacy of bond that is afforded by the dipping or molding operation is insuflicient to retain the tips securely in position against dislodgment.

In the form of the invention shown in FIGS. 4 and 10, another modified form of the invention has been illustrated and, again, to avoid needless repetition of description, similar reference numerals of a still higher order have been applied to the corresponding parts as between the disclosures of FIGS. 2 and 4. In this latter form, the clip-supporting rod is formed in two

sections

242a and 242b, the adjacent or inner end regions of the rod sections being reversely turned or bent laterally as indicated at 243 and 245, respectively, the end 243 being turned upwardly and the end 245 being turned downwardly (in excess of 90). The thus laterally turned ends are welded to the opposed rod sections as indicated at 255 to form a central quadrilateral parallelogram structure in which the rod sections extend in parallelism in different horizontal planes. This will result in a slight inclination of the rod sections when the device is applied to the horizontal reinforcing rods 232 of the two opposed reinforcing flames. Otherwise, the details of the device 240 remain substantially the same as those of the previously described device 40. This modified form of device offers the advantage that by selecting difi'erent weld points 255, the effective length of the device may be varied to accommodate dilferent spacings of the reinforcing rod frames.

In the form of the invention shown in FIG. 5, still another modified form of the invention is shown. Utilizing reference numerals of the next higher order to distinguish the device 340 from the previously described device of FIG. 2 the composite clip-supporting rod 342 is formed in three sections including two substantially

identical sections

342a and 342b, and an interconnecting section 3420. The

sections

342a and 342b have laterally turned ends 345 which extend downwardly and are welded as at 355 to the interconnecting section 3400, this latter section being in the form of a short length of straight rod stock. Otherwise, the device 340 remains substantially the same as the device of FIG. 2. As is the case in connection with the form of the invention shown in FIG. 4, by selecting different weld points 355, the effective length of the composite rod of the device 340 may be varied.

In FIG. 11, a further modified form of device 440 is shown, this device differing from the previously described device 340 of FIG. 5 only in the manner in which the end regions of the composite rod 442 are formed. In this latter form of the invention, the rod sections 442a and 4421;, instead of having downwardly and inwardly turned end regions, are provided with straight end regions of the type illustrated in FIG. 6. Otherwise, the device 449 remains substantially the same as the device 340 of FIG. 5.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of the construction may be resorted to without departing from the spirit or scope of the invention. For

example, the few modifications which have been illustrated herein suggest other modifications which have not been illustrated. For instance, if desired, the modified form of the invention shown in FIGS. 2 and 10 which employ laterally turned ends of the type shown in FIG. 6 may, if desired, dispense with such ends'and employ linearly straight ends of the type shown in FIG. 7. Still further, while the

various clips

244 and 250 are shown and described herein as having their

legs

52, 152, 252, 352 or 452, as the case may be, welded to the adjacent supporting rod, it is within the purview of the invention that either leg of either clip may be so welded to the rod to the exclusion of the other leg. Therefore, only insofar as the invention has particularly been pointed out in the accompanying claims is the same to be limited.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. In a concrete wall form installation, the combination with a pair of spaced parallel vertically disposed form sides presenting opposed planar panel facings between which wet concrete is adapted to be poured for wall-forming purposes, and a pair of reinforcing rod frames positioned within the confines of the form installation in spaced parallel relationship, each reinforcing rod frame being spaced from an adjacent panel facing by a predetermined fixed distance and including vertical and horizontal frame rods, of a combined form spreader and reinforcing rod spacer device for preventing inward movement of the form sides and for maintaining the frames accurately spaced from the adjacent panel facings, said device comprising a substantially straight length of rod stock disposed within the confines of the form installation, extending transversely and horizontally thereacross, spanning the distance between the opposed panel facings, said straight length of rod stock being provided with laterally turned end regions which are joined to the intervening portion of the length of rod stock by reentrant bends slightly in excess of elastomeric tips completely covering said laterally turned end regions and reentrant bends, the portions of said elastomeric tips in the vicinity of the reverse bends bearing against the inside surfaces of the panel facings and serving to place the intervening portion of the length of rod stock under compression, said intervening portion extending across, resting upon, and supported by corresponding horizontal frame rods of the two reinforcing rod frames, and a pair of spring clips fixedly secured to said length of rod stock at its regions of contact with the horizontal frame rods and serving releasably to maintain the length of rod stock in contact with said horizontal frame rods, each of said spring clips being in the form of a short length of resilient steel rod stock bent to U-shape configuration and presenting converging side legs and a connecting bight portion, one of said side legs being welded to the straight length of rod stock and the other side leg being free for movement toward and away from said one side leg under the yielding influence of flexing of said bight portion, said side legs crossing said straight length of rod stock at spaced points and the distal end regions thereof, in combination with the intervening portion of the rod stock between said spaced points, defining a snap-in pocket for releasably confining said adjacent horizontal reinforcing rod.

2. In a concrete wall form installation, the combination with a pair of spaced parallel vertically disposed form sides presenting opposed planar panel facings be tween which wet concrete is adapted to be poured for Wall-forming purposes, and a pair of reinforcing rod frames positioned within the confines of the form installation in spaced parallel relationship, each reinforcing rod frame being spaced from an adjacent panel facing by a predetermined fixed distance and including vertical and horizontal frame rods, of a combined form spreader and reinforcing rod spacer device for preventing inward movement of the form sides and for maintaining the against the inside surfaces of said panel facings respectively, and having its medial region extending across and contacting corresponding horizontal frame rodsof the two reinforcing rod frames, elastomeric tips completely covering the end regions of said elongated member and hearing against the inside surfaces of the panelfacings and serving the place the length of rod stock under compression, and a pair of spring clips fixedly secured to said member at its region of contact with the horizontal frame rods and serving releasably to maintain the member in contact with said horizontal frame rods, each of said said spring clips being in the form of a short length of resilient steel rod stock bent to U-shape configuration and presenting converging side,legs and 'a connection bight portion, one of said side legs being welded to the straight length of rod stock and the other side leg being free for movement toward and away from said one side leg under the yielding influence of flexing of said bight portion, said side legs crossing said straight length of rod stock at spaced points and the distal end regions; thereof, in combination with the intervening portion ofthe rod stock between said spaced points, defining a' snap-in pocket for releasably confining said adjacent horizontal reinforcing rod.

3. In a concrete wall form installation, the combination with a pair of spaced parallel yertically disposed form sides presenting opposed planar panel facings between which wet concrete is adapted to be poured for wall-forming purposes, and a pair of reinforcing rod frames positioned within the confines of the form installation in spaced parallel relationship, each reinforcing rod frame being spaced from an adjacent panel facing by a predetermined fixed distance and including vertical and horizontal frame rods, of'a combined form spreader and reinforcing rod spacer device for preventing inward movement of the form sides and for maintaining the frames accurately spaced from, the adjacent panel facings, said devices comprising a substantially straight length of rod stock disposed within the confines of the form installation, extending transversely and horizontally thereacross, spanning the distance between the opposed panel facings, said device comprising a two-piece sectional elongated member formed of rod stock and ineluding two parallel rod stock sections, each section havr ing its inner end turned laterally, crossing the other rod itock section and welded thereto at its point of crossing,

;o as to define a parallelogram structure in the medial 'egion of the member, the remote outer ends of said sec- I gions effectively bearing against the inside surfaces of aid panel facings respectively, the medial regions of said iections extending across, resting upon and contactingcorresponding horizontal frame rods of the two reinforcing rod frames, and a pair of spring clips fixedly secured to each section of said member atits region of contact with the horizontal frame rods and serving releasably to maintain the section in contact with its respective hori wall-forming purposes, and a pair of reinforcing rod frames positioned within the confines of the form installation in spaced parallel relationship, each reinforcing rod frame beingspaced from an adjacent panel facing by a predetermined fixed distance and including vertical and horizontal frame rods, of a combined form spreader and reinforcing rod spacer device for preventing inward movement of the form sides and for maintaining the frames; accurately spaced from the adjacent panel facings, said device comprising a substantially straight length of rod stock disposedwithin the. confines of the form installation, extending transversely and horizontally thereacross, spanning the distance between the opposed panel facings, said device comprising a three-piece sec,- tional elongated member formed of rod stock and including two coaxial rod stock sections shaving adjacent tively bearing against the inside surfaces of said panel facings respectively, the medial regions of said sections extending across, resting upon and contacting corresponding horizontal frame rods of the two reinforcing rod frames and a pair of spring clips fixedly secured to each section of said member at its region of contact with the horizontal frame rods and serving releasably to maintain the section in contact with its respective horizontal frame rod. Y 7

, 5,111 a concrete wall form installation, the combination set forth in claim 4 and wherein said remote outer ends of the sections are provided with short laterally extending endregions joined to the remainder of the sections by reentrant reverse bends slightly in excess of bpnds effectively bearing against the opposed panel facings and serving toplacethe three-piece sectional elongated member under compression.

References Cited by the Examiner UNITED STATES PATENTS MICHAEL v. namnrsr, Primary Examiner.

Claims

2. IN A CONCRETE WALL FORM INSTALLATION, THE COMBINATION WITH A PAIR OF SPACED PARALLEL VERTICALLY DISPOSED FORMS SIDES PRESENTING OPPOSED PLANAR PANEL FACINGS BETWEEN WHICH WET CONCRETE IS ADAPTED TO BE POURED FOR WALL-FORMING PURPOSES, AND A PAIR OF REINFORCING ROD FRAMES POSITIONED WITHIN THE CONFINES OF THE FORM INSTALLATION IN SPACED PARALLEL RELATIONSHIP, EACH REINFORCING ROD FRAME BEING SPACED FROM AN ADJACENT PANEL FACING BY A PREDETERMINED FIXED DISTANCE AND INCLUDING VERTICAL AND HORIZONTAL FRAME RODS, OF A COMBINED FORM SPREADER AND REINFORCING ROD SPACER DEVICE FOR PREVENTING INWARD MOVEMENT OF THE FORM SIDES AND FOR MAINTAINING THE FRAMES ACCURATELY SPACED FROM THE ADJACENT PANEL FACINGS, SAID DEVICE COMPRISING AN ELONGATED MEMBER FORMED OF ROD STOCK DISPOSED WITHIN THE CONFINES OF THE FORM INSTALLATION, EXTENDING TRANSVERSELY AND HORIZONTALLY THEREACROSS, SPANNING THE DISTANCE BETWEEN THE OPPOSED PANEL FACINGS, HAVING ITS OPPOSITE ENDS EFFECTIVELY BEARING AGAINST THE INSIDE SURFACES OF SAID PANEL FACINGS RESPECTIVELY, AND HAVING ITS MEDIAL REGION EXTENDING ACROSS AND CONTACTING CORRESPONDING HORIZONTAL FRAME RODS OF THE TWO REINFORCING ROD FRAMES, ELASTOMERIC TIPS COMPLETELY COVERING THE END REGIONS OF SAID ELONGATED MEMBER AND BEARING AGAINST THE INSIDE SURFACES OF THE PANEL FACINGS AND SERVING THE PLACE THE LENGTH OF ROD STOCK UNDER COMPRESSION, AND A PAIR OF SPRING CLIPS FIXEDLY SECURED TO SAID MEMBER AT ITS REGION OF CONTACT WITH THE HORIZONTAL FRAME RODS AND SERVING RELEASABLY TO MAINTAIN THE MEMBER IN CONTACT WITH SAID HORIZONTAL FRAME RODS, EACH OF SAID SAID SPRING CLIPS BEING IN THE FORM OF A SHORT LENGTH IN RESILIENT STEEL ROD STOCK BENT TO U-SHAPED CONFIGURATION AND PRESENTING CONVERGING SIDE LEGS AND A CONNECTION BIGHT PORTION, ONE OF SAID SIDE LEGS BEING WELDED TO THE STRAIGHT LENGTH OF ROD STOCK AND THE OTHER SIDE LEG BEING FREE FOR MOVEMENT TOWARD AND AWAY FROM SAID ONE SIDE LEG UNDER THE YIELDING INFLUENCE OF FLEXING OF SAID BIGHT PORTION, SAID SIDE LEGS CROSSING SAID STRAIGHT LENGTH OF ROD STOCK AT SPACED POINTS AND THE DISTAN END REGIONS THEREOF, IN COMBINATION WITH THE INTERVENING PORTION OF THE ROD STOCK BETWEEN SAID SPACED POINTS, DEFINING A SNAP-IN POCKET FOR RELEASABLY CONFINING SAID ADJACENT HORIZONTAL REINFORCING ROD.