05/232072

01/15/1974

03/06/1972

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Symons Corporation (Des Plaines, NY)

249/214

249/217

E04G17/06; E04G17/06

249/217,214,41,43

3653628

TIE ROD AND CONE ASSEMBLY FOR A CONCRETE WALL FORM

April 1972

Shoemaker

Baldwin, Robert D.

Mcquade, John

Gerlach, Norman H.

Having thus described the invention what I claim as new and desire to secure by letters patent is

1. As a new article of manufacture, a tie rod assembly adapted for use in connection with a concrete wall form and comprising a tie rod in the form of a length of cylindrical rod stock, said tie rod having a loop portion at one end thereof whereby the tie rod may be attached to one side of the form, and also having a breakback disposed inwardly from said loop portion, and an integral one-piece spacer member telescopically disposed on and completely encircling said tie rod and interposed between said loop portion and the break-back, said spacer member being formed of a rigid molded plastic material and embodying an open-ended frusto-conical shell having its small rim effectively bearing against said breakback, said loop portion of the tie rod being disposed partially within the confines of the shell and projecting outwardly therefrom through the large rim of the shell, and an internal rib formed on and disposed within the confines of the shell and effective between said loop portion and shell, whereby upon rotation of the loop portion in either direction, the rib will engage an eccentric portion of the loop and the spacer member will be constrained to rotate bodily with the loop and break the bond existing therebetween and the concrete of the wall that is produced by the form.

2. A tie rod assembly as set forth in claim 1 and wherein a plurality of circumferentially spaced radially disposed internal ribs are formed on said shell and have the inner edges thereof disposed in the rotational path of movement of said loop portion.

3. A tie rod assembly as set forth in claim 2 and wherein four ribs are provided and the inner edges of one pair of adjacent internal ribs straddle the cylindrical rod stock of said loop portion in close proximity thereto whereby, upon rotation of said loop portion in either direction, said spacer member will be constrained to rotate bodily therewith.

4. A tie rod assembly as set forth in claim 3 and wherein said loop portion embodies a reentrant section which is secured in tangential fashion to the rod at the base of the loop portion by a weld, the inner edges of the internal ribs lie closely alongside the rod in centering relationship and overlap said reentrant section, and the outer edge regions of the ribs are relieved and afford a clearance for the reentrant section whereby the inner end of the latter and the weld directly oppose each other so as to confine the spacer member between the breakback and weld against appreciable longitudinal shifting on the rod.

The present invention relates generally to a concrete wall form tie rod assembly and has particular reference to a novel spacer member which is installed upon the tie rod of the assembly and functions in the manner of a conventional spacer cone to assimilate any inward thrust that may be exerted thereon by the adjacent wall form panel and also to exclude the flow of wet concrete into the hole or opening where the tie rod passes into the confines of the adjacent panel-formed side of the associated concrete wall form, but which is more easily extracted from its position of embedment in the surface region of the hardened concrete wall after the various wall form panels constituting the two opposed and spaced apart sides of the form have been stripped from the finished or completed wall. The invention is specifically concerned with a tie rod assembly of the type in which the tie rod proper is formed from cylindrical wire or rod stock and has reentrant looped ends which constitute fastening means for tie rod anchoring purposes so that the tie rod may be connected at its ends to the opposed and spaced apart sides of the associated concrete wall form, the assembly including on the tie rod rigid spacer members which are of frusto-conical design and are telescopically received over the tie rod in the vicinity of the latter's looped ends. In the erected concrete wall form, these frusto-conical spacer members assume positions close to or in contact with the inner concrete-receiving faces of the opposed and spaced apart sides of the associated concrete wall form so that, after the concrete is poured into the space between the sides of the form and has become hardened, they remain embedded in the resultant side surfaces of the wall while the looped ends of the tie rod project forwardly of the spacer members through the adjacent form sides and are thus exposed for twist-off purposes. The tie rod is usually weakened near the inner ends or small bases of the two frusto-conical spacer members in order to enable the projecting looped ends of the tie rod to be twisted and thus severed from the concrete-embedded medial or intermediate region of the tie rod, thus leaving the spacer members countersunk within comparatively deep sockets in the side surfaces of the finished or completed concrete wall. In order to facilitate extraction of these spacer members from the sockets in which they are embedded, the members usually are of frusto-conical configuration as previously pointed out, thus giving rise to the name "spacer cone" or "spreader cone" which has long been applied to such spacer members regardless of whether they are truly frusto-conical, cylindrical, or some other configuration. Such rigid spacer members or cones are frequently extremely difficult to extract after use and, if the application of twisting force to them is not sufficient to dislodge them from their bonded relationship within their respective sockets in the side surfaces of the hardened and finished concrete wall, they must be intentionally fractured and then removed from the sockets in piecemeal fashion.

The tie rod assembly of the present invention is designed to overcome the above-noted difficulty which is encountered in the extraction of conventional spacer members or cones from their positions of embedment in the side surfaces of a concrete wall and, toward this end, the invention contemplates the provision of a tie rod assembly in which the spacer members that are associated therewith are formed of a relatively hard, rigid plastic material, present smooth outer surfaces for inhibiting binding of the members to the hardened concrete, and are interlocked with the looped ends of the tie rod so that, after the panels of the concrete wall form have been stripped from the completed hardened concrete wall, the usual rotational twisting of the looped ends will apply torque to the spacer members, first, to break the bond between the outer surfaces of the members and the concrete and, secondly, to pull the spacer members from their respective sockets in the side surfaces of the completed concrete wall.

Apart from the application of rotational torque to the frusto-conical spacer members for ease of removal of the spacer members, an additional advantage of the invention resides in the fact that the plastic spacer members are reuseable since they are not damaged, deformed, or destroyed in the process of extracting them from their respective sockets in the side surfaces of the finished concrete wall.

The provision of a tie rod assembly embodying plastic frusto-conical spacer members such as have briefly been outlined above constitutes the principal object of the present invention. Other objects and advantages of the invention, not at this time enumerated, will become readily apparent as the nature of the invention is better understood from a consideration of the following detailed description.

The invention consists in the several novel features which are hereinafter set forth and are more particularly defined by the claims at the conclusion hereof.

In the accompanying single sheet of drawings forming a part of this specification, one illustrative embodiment of the invention is shown.

In these drawings:

FIG. 1 is a fragmentary top perspective view of a concrete wall form employing a plurality of tie rod assemblies embodying the principles of the present invention;

FIG. 2 is a fragmentary top perspective view of a portion of a finished or completed concrete wall from which the wall form panels have been removed, the view showing one looped end of the tie rod of one of the assemblies preparatory to fracture and removal of said tie rod end and subsequent removal of the associated plastic frustoconical spacer member from its encompassing socket in the adjacent side surface of the wall;

FIG. 3 is an enlarged fragmentary sectional view taken substantially on the vertical plane indicated by the line 3--3 of FIG. 2 and in the direction of the arrows;

FIG. 4 is a vertical transverse sectional view taken on the line 4--4 of FIG. 3; and

FIG. 5 is a sectional view similar to FIG. 2 but showing the looped tie rod end and its associated spacer member wrested from the socket in the adjacent side surface of the concrete wall.

Referring now to the drawings in detail and in particular to FIG. 1, a typical concrete wall form employing tie rod assemblies embodying and constructed according to the present invention is designated in its entirety by the reference numeral 10, while the improved tie rod assemblies which are employed in connection with the wall form are each designated by the reference numeral 12. These tie rod assemblies 12 are capable of use with a wide variety of concrete wall forms, as, for example, concrete wall forms employing panels having either wooden or metal reinforcing studding for the usual rectangular plywood facings or having no reinforcing studding whatsoever. Furthermore, the tie rods of the assemblies 12 may extend across the concrete wall form 10, either at the juncture region between adjacent panels or they may bridge the form by extending through centrally dispoed regions of the opposed and spaced apart individual panels. However, for exemplary purposes herein, the tie rod assemblies 12 are shown as being associated with a concrete wall form eploying steel-studded prefabricated panels 14 of the type which is commonly known in the concrete forming industry as "Steel-Ply" panels. Such panels are manufactured and sold by Symons Corporation of Des Plaines, Ill. and are widely known and used in the concrete construction industry. Although only the fragmentary edge regions of abutting pairs of panels are disclosed in FIG. 1 of the drawings herein, it will be understood that each panel is of shallow, open, tray-like design and includes a rectangular plywood facing 16 and a marginal reinforcing frame including vertical frame members 18 and horizontal frame members (not shown). At appropriate levels, intermediate horizontal steel crossbars 20 extend between and are welded to the opposed vertical frame members 18. Both the vertical and horizontal frame members are in the form of structural steel bars which are of shallow channel shape in cross section, and each bar includes inner and outer outwardly extending marginal ribs 22 and 24, and a connecting web portion 26. On the side of each web portion that is opposite to the ribs 22 and 24 is a lateral inwardly extending flange 28 on which the adjacent marginal portion of the associated plywood facing 16 seats. At vertically spaced regions along the outwardly extending ribs 22 and 24 of the vertical frame members 18 of the panels 14, pairs of transversely-registering notches 30 are formed, and these notches, when said vertical frame members 18 are in contiguity, define therebetween horizontal channel-like voids 32 which are adapted to receive therethrough the adjacent looped ends of the tie rods of the tie rod assemblies 12 as will be described in detail presently. A rectangular slot 34 is formed in the web portion 26 of each vertical frame member at the level of each pair of notches 30, and such slot is adapted to receive therethrough the shank portion of a horizontal T-bolt 36. A vertical wedge 38, which is driven through a longitudinal slot in the shank of the T-bolt 36, serves to place the T-bolt under tension and this draws adjacent or contiguous vertical frame members 18, as well as their associated panels 14, tightly together.

The arrangement of parts thus far described is purely conventional and no claim is made herein to any novelty that may be associated with the same, the novelty of the present invention residing rather in the particular novel construction, combination, and arrangement of parts of the tie rod assemblies 12. Such assemblies will now be described in detail. Since all of the tie rod assemblies 12 are identical, a description of one of them will suffice for them all.

Still referring to FIG. 1, the illustrated form of tie rod assembly 12 involves in its general organization a normally horizontal tie rod 40 which is in the form of a length of cylindrical wire or rod stock and has integral looped ends 42. The latter are adapted to encircle the shanks of the associated T-bolts 36 or otherwise be attached to the opposite panel form sides of the concrete wall form 10. As best shown in FIG. 3 of the drawings, the looped ends 42 of the tie rod 40 are neither circular nor symmetrical, each such end consisting of a laterally offset curved spiral section 44 which merges gradually into a linearly straight section 46, the distal end of which extends tangentially alongside the main body of the tie rod and is connected thereto by a weld 48 as best shown in FIG. 3.

At regions spaced inwardly from the looped ends 42, the metal of the tie rod is flattened in order to provide weakened portions 49 which are commonly known in the art as "breakbacks" and by means of which the looped ends 42 of the tie rod 40 may be readily severed from the concrete-embedded medial region of the tie rod by twisting them after hardening of the concrete wall and removal or stripping of the panels 14 from the wall.

Mounted on the tie rod 40 and interposed between each breakback 44 and its adjacent looped end 42 is a spacer member 50 of novel design, such member constituting the principal feature of the present invention. A flat washer 52 is interposed between each spacer member 50 and the adjacent breakback 44.

Each spacer member of the tie rod assembly 12 is formed of a relatively rigid, unyielding plastic material which may be a high density styrene, the member being formed by a suitable molding operation and embodying an open-ended tubular frusto-conical shell 54, the large and small bases of which present respective circular rims 56 and 58. On the interior of the shell 54 there is provided a series of four quadrilaterally arranged radial ribs 60 which are tapered in the direction of the small base of the frusto-conical shell and terminate thereat. These ribs are formed integrally with and extend radially inwards from the inner surface of periphery of the frusto-conical shell 54 and terminate near the large base of said shell. The inner edges 62 of the ribs 60 extend in parallelism as clearly shown in FIG. 3, but are relieved on a curved bias as indicated at 64 in the vicinity of the rim 56 of the large base of the shell. These relief areas of the ribs directly oppose the weld 48 and allow partial nesting of the looped ends 42 within the confines of the shell, while at the same time confining the spacer member 50 against appreciable outward shifting movement away from the breakback 49.

The spacer member 50 at each end of the tie rod 40 is telescopically received over the tie rod so that the inner edges 62 of the ribs 60 lie closely alongside the rod and center the latter axially in the member 50. The spacer member 50 is captured on the tie rod by means of the associated washer 52 which bears against the rim 58 of the small base of the shell of the spacer member and prevents inward shifting of said spacer member 50 on the rod, as well as by the weld 48 which contacts the inner edges 62 of the ribs 60 and prevents the member 50 from shifting outwardly of the tie rod. A small amount of longitudinal play in a longitudinal or axial direction is preferably but not necessarily provided for. The main body of the looped tie rod end 42 projects outwardly beyond the large rim 56 of the shell 54 of the spacer member 50. As clearly shown in FIGS. 3 and 4 of the drawings, the straight section 46 of the looped end 42 of the tie rod 40 is eccentrically disposed with respect to the axis of the tie rod so that it interlocks between two adjacent ribs 60 within the confines of the frusto-conical shell 54 of the spacer member 50 and prevents rotational movement of the tie rod end with respect to the spacer member. This interlock constitutes a driving connection between the looped tie rod end and the spacer member 50 during the twist-off operation as will be described presently.

The herein described tie rod assembly 12 is adapted for use in connection with a concrete wall form such as the form which is fragmentarily shown in FIG. 1 in substantially the same manner as a conventional or standard tie rod assembly, the looped ends 42 of the tie rod 40 being arranged in encircling relation with the shanks of the T-bolts 36 as heretofore set forth and the tie rod being arranged so that the portions thereof that are immediately inwards of the looped ends 42 project through the channel-like voids 32 between the inner and outer outwardly extending marginal ribs 22 and 24 of adjacent vertical frame members 18. The rims of the large bases of the frusto-conical shells 54 of the spacer members 50 assume positions of contiguity or abutment with the inner side faces of the inner ribs 22 so that they serve to seal the adjacent channel-like voids 32 against seepage of wet concrete out of the space between the sides of the concrete wall form 10. The washers 52 which bear inwardly against the breakbacks 44 of the tie rod 40 and abut against the rims 58 of the small bases of the shells 54 of the spacer members 50 and hold said spacer members tightly against the form sides.

After the concrete has been poured between the two sides of the concrete form 10 and has become set or hardened, the wedges 38 are driven out of their connected relation with the slotted shanks of the associated T-bolts 36 in order to release the panels 14 so that they may be stripped from the resulting concrete wall W (see FIGS. 2 and 5). The medial region of the tie rod 40, together with the spacer members 50 and their associated washers 52, remain embedded within the concrete with the rims 56 of the large bases of the shells 54 of the spacer members being exposed and flush with the side surfaces of the concrete wall W as shown in FIG. 2 of the drawings. The projecting end portions of the tie rod 40 including the looped ends 42 are then worked back and forth to the extent permitted by any looseness thereof within the spacer members 50 and, at the same time, twisted until such time as they break loose from the embedded medial portion of the tie rod 40 in the vicinity of the breakbacks 49. During this twisting operation, the laterally offset and eccentrically disposed, linearly straight sections 46 of the tie rod 40 establish driving connections between the looped tie rod ends 42 and the spacer member 50 and cause rotation of the latter, thus breaking the bond between the concrete and the spacer members so that, when the looped ends are pulled outwardly and away from the side surfaces of the concrete wall W, the thus loosened spacer members will either fall from the wall or they will adhere to the removed tie rod ends 42 due to the presence of any burrs or offset portions of the metal of the tie rod which may be present as a result of the uneven lines of cleavage at the break-off points. As is the case with conventional frusto-conical spacer members, such removal of the spacer members 50 from the completed concrete wall W will result in the provision of frusto-conical sockets such as is indicated at 70 in FIG. 5, the spacer members functioning in the manner of patterns for the production of such sockets.

In the unlikely event that the looped ends 42 of the tie rod 40 of the tie rod assembly 12 should pull from the spacer members 50, thus leaving the latter still present in the frusto-conical sockets 70, the fact that the bond between the spacer members and the sockets has been broken by rotation of the spacer members within the sockets will facilitate subsequent easy finger-removal of the spacer members.

During removal of the spacer members 50 and the looped tie rod ends 42 from the concrete wall W, the associated washers 52 may or may not, depending on chance, remain within the sockets 70. In either event, the sockets may be filled with a suitable patching material (grout) as is customary in the art. Inasmuch as during concrete pouring and hardening operations, the washers substantially close the inner ends of the spacer members 50, concrete will not flow outwardly and into the interior of the spacer members. These members thus remain in condition for subsequent reuse with little or no cleaning operations being required.

In manufacturing the tie rod assembly 12 of the present invention at the factory, a straight or unbent length of wire or rod stock is first cut to the desired or specified length. Thereafter, the washers 52 and the frusto-conical spacing members 50 are mounted on the end portions of the straight piece of stock and then slid inwards onto the intermediate or medial portion of the straight piece of stock. After these two operations, the ends of the piece of wire stock are bent into loop form and subsequently welded in place in order to form the tie rod 40 of the assembly 12. Directly following the bending and welding operations, the spacing members 50 and the washers 52 are slid outwards in order to bring the large bases of the spacing members into interlocked relation with the welded extremities of the looped ends 42 of the tie rod 40. The final step in the manufacture of the tie rod assembly 12 is the formation of the flat "breakback" portions 49. After formation of such portions, the outer ends thereof abut against the washers 52 and serve to hold the washers and the frusto-conical spacer members in their proper position on the tie rod 40.

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 construction may be resorted to without departing from the spirit or scope of the invention. Therefore, only insofar as the invention is particularly pointed out in the accompanying claims is the same to be limited.