US3618887A

US3618887A - Concrete wall form and particular elastomeric tie rod bushing therefor

Info

Publication number: US3618887A
Application number: US818515A
Authority: US
Inventors: George J Eriksson
Original assignee: Superior Concrete Accessories Inc
Current assignee: Superior Concrete Accessories Inc
Priority date: 1969-04-23
Filing date: 1969-04-23
Publication date: 1971-11-09
Anticipated expiration: 1988-11-09

Abstract

A tie rod bushing which is pressed into a hole in a plywood panel of a concrete wall form and has a flexible lip which enables the tie rod to be projected through the bushing during form erection and prevents poured concrete from seeping past the bushing. In one form of bushing, the inner end face thereof lies flush with the inner side or face of the panel so that when the panel and bushing are removed, the wall surface is substantially continuous. In another form of bushing, the bushing projects into the concrete and leaves a socket in the latter when the panel and bushing are removed.

Description

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Primary Examiner-J. Spencer Overholser Assislan! Examiner-B. D. Tobor AnarneyNorman H. Gerlach ABSTRACT: A tie rod bushing which is pressed into a hole in a plywood panel of a concrete wall form and has a flexible lip which enables the tieirod to be projected through the bushi during form erection and prevents poured concrete from see ing past the bushing. In one form of bushin face thereof lies flush panel so that when the pa face is substantiall the bushing projec the latter when the EREFOR E043 17/08 249/38,40, 214, 217, 96, 97, 42, 46, 213, 216,215, 218,40-47; 25/131 T; 277/212, 212 C [54] CONCRETE WALL FORM AND PARTICULAR ELASTOMERIC TIE ROD BUSHING TH 8 Claims, 8 Drawing Figs.

[50] Field of 41,43,190, 191,

[56] References Cited UNITED STATES PATENTS 3,327,986 6/1967 Ou 1,350,603 8/1920 Gerritson 1,723,631 8/1929 Pollock CONCRETE WALL FORM AND PARTICULAR ELASTOMERIC TIE ROD BUSHING THEREFOR The present invention relates generally to concrete wall forms and has particular reference to a tie rod bushing for use in a concrete wall form of the type which includes on one side of the form a waler-reinforced panel and in which aligned holes are provided in the waler and the panel for reception therethrough of one end of a conventional tie rod.

In the use of horizontally disposed tie rods in connection with the formation of a concrete wall by way of a form of the type which comprises a pair of opposed spaced apart upstanding sides of which embodies a series of edge-to-edge walerreinforced plywood panels, it has long been the practice to string or mount upon the tie rods adjacent to the inner faces of the sides of the concrete wall form, short cones or other forms or kinds of inserts which serve as spacers or abutments for the sides of the concrete wall form and are temporarily embedded in the side faces of the concrete wall. Such cones or inserts and the end portions of the tie rods are subsequently removed from the side faces of the hardened concrete wall leaving cavities which must be pointed or filled with concrete, grout, or other material in order permanently to seal such cavities as well as to cause the side faces of the'wall to be smooth or unbroken. The removable cones or other inserts are usually formed of cast metal, wood or plastic material and the breaking points (breakbacks) of the tie rods (usually referred to as (snap ties") are either substantially coincident with or slightly offset with respect to the inner ends of the cones or inserts. The breakage and subsequent removal of the end portions of the tie rods from the tie rod metal portions at the breakbacks leave the ,cones or inserts firmly embedded in the side faces of the hardened concrete wall. Removal of such embedded cones or inserts not only is a time-consuming operation even when a special cone-extracting tool is employed, but the presence of the concrete embedded cones or inserts in closely surrounding relationship with the inner extremities of the end portions of the tierods inhibits freedom of working the end portions of the tie rods back and forth in connection with cleavage or severance thereof from the tie rod medial portions at the breakbacks.

According to the present invention, and in a preferred form thereof, the use of tie rod cones or other inserts which temporarily remain in the side faces of the hardened concrete wall after removal of the plywood panels therefrom is eliminated altogether so that the problem of cone extraction is no longer present. Furthermore, in this form of the invention, by the use of a novel resilient and deformable tie rod bushing which surrounds the adjacent end portion of the associated tie rod and seals the annular space at the point of entry of said tie rod end portion through the tie rod-receiving hole in the associated form panel, after the form panel has been stripped from the concrete wall and said tie rod end portion removed from the tie rod medial portion by twisting or wiggling, only a small bumplike protuberance remains on the adjacent side face of the concrete wall and this can be readily removed by a small amount of abrasion, conveniently using a handy brick or brick fragment for the purpose.

In another modified form of resilient and deformable tie rod bushing which similarly seals the annular space at the point of entry of the adjacent end portion of the associated tie rod through the hole in the associated form panel, a cone-shaped extension of the bushing projects inwardly of the panel and constitutes a pattern which leaves the usual cone-shaped socket in the adjacent side face of the hardened concrete wall after the panel and the bushing have been removed as a unit.

In each form of the invention, the resilient and deformable bushing is in the form of a panel insert which remains permanently installed in the associated panel so that when the panel is stripped from the adjacent side face of the hardened concrete wall. the bushing remains with the panel and is automatically withdrawn from the wall. Thus, whether the adjacent side face of the wall is left intact or whether it is left with a conical socket therein, the problem of cone extraction is obviated.

The invention finds particular use in connection with a gang-type concrete wall form (a rectilinear series of edge-toedge plywood panels) although it is by no means limited to such use. In carrying out the invention, in the preferred form thereof, the aforementioned resilient and deformable tie rod bushing is in the form of a cylindrical sleeve having an outturned radial flange on its outer end and an inturned radial flange on its inner end. In assembling the bushing with respect to its associated wall form panel, the bushing is pressed into the tie rod-receiving hole in the panel so that the inturned flange constitutes an inwardly extending sealing lip which lies flush with the inner side or face of the panel while the outturned flange lies flatly against the outer side or face of the panel where it is mashed flat and thus captured by the waler or other panel-reinforcing member which is permanently clamped or attached to the outer side of the panel in the case of a gang-type concrete wall form. In the case of a single panel, the outturned flange at the outer end of the bushing is clamped against the outer side of the panel by tierod tension if the associated waler or other reinforcing member is removable from the panel. The inturned flange constitutes a flexible sealing lip which bears snugly against the adjacent end portion of the associated tie rod and prevents seepage of concrete outwardly through the tie rodreceiving hole in the associated panel, and, due to the resiliency of the bushing as a whole, it also is capable of displacement upon initial projection of the tie rod through the panel hole during erection of the form despite the fact that the tie rod may have one or more enlargements at its end portions as is the case with a so-called button-head" tie rod. In the modified form of the invention, the radial out-turned flange remains captured between the waler and panel but the sealing lip, instead of lying flush with the inner side face of the associated panel, is disposed at the inner end of a tapered pattern extension of the bushing, this pattern extension becoming embedded in the poured concrete and leaving a conical socket in the adjacent side face of the hardened concrete wall as heretofore stated.

The provision of a tie rod bushing such as has been briefly described above and possessing the stated advantages constitutes the principal object of the present invention. Other objects and advantages, not at this time enumerated, will readily suggest themselves as the following description ensues.

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 two sheets of drawings forming a part of this description or specification, two illustrative forms or embodiments of the invention are shown.

In the drawings:

FIG. 1 is a fragmentary sectional view taken vertically and transversely through a concrete wall form and illustrating schematically the manner of installation of a tie rod and bushing assembly embodying the principles of the present invention;

FIG. 2 is a fragmentary sectional view similar to FIG. I but showing the tie rod and bushing assembly in its installed position with concrete poured between the opposed, spaced apart sides of the wall form;

FIG. 3 is an inside end view of the tie rod bushing of the assembly of FIGS. 1 and 2;

FIG. 4 is an inside perspective view of said bushing;

FIG. 5 is a fragmentary sectional view taken vertically through a portion of the hardened concrete wall showing the expendable medial portion of the tie rod of the assembly of FIGS. 1 and 2 embedded in the concrete and with the end portions of the tie rod removed;

FIG. 6 is a sectional view taken centrally and longitudinally through a modified form of tie rod bushing embodying the invention;

FIG. 7 is a fragmentary sectional view similar to FIG. 2 but showing the tie rod bushing of FIG. 6 operatively installed in a concrete wall form; and

FIG. 8 is a sectional view similar to FIG. 5 but showing the socketed concrete wall after the panel and pattern-type tie rod bushing of FIG. 7 have been removed from the wall.

Referring now to the drawings in detail and in particular to FIG. 2, a fragmentary portion of a composite concrete wall form of conventional construction is designated in its entirety by the reference numeral and comprises two opposed, spaced apart,

upstanding sides

12 and 14, each side including a rectilinear series of rectangular plywood panels 16 which are arranged in a vertically disposed edge-to-edge relationship, only one panel 16 in each of the two series being shown. The panels 16 of the two series that constitute the

sides

12 and 14 of the concrete wall form R0 are held against outward spreading by means of a plurality of horizontally disposed tie rod and bushing assemblies 18 embodying the present invention, only a single assembly being illustrated in the drawings hereof.

The tie rod and bushing assembly which is illustrated in the drawings consists of a tie rod proper 20 (hereinafter referred to simply as the tie rod) and a pair of elastomeric bushings 22. The tie rod 20 projects through circular openings 24 in the panels 16 and aligned circular openings 26 in a pair of walers 28 on opposite sides of the concrete wall form 10, and the opposite end portions of the tie rod extend outwardly beyond the walers and are provided at their free end extremities with enlarged heads 30. The walers 28 extend horizontally and are disposed adjacent to the outer sides or faces of the plywood panels 16. The heads 30 are engaged by conventional-type wedge tie holders 32 which are longitudinally slotted and straddle the tie rod end portions intermediate the heads 32 and the walers 28 so as to exert a spreading action thereon when the wedges are driven to their home position. Overhanging arms 33 on the holders 32 bear against the outer ends of the heads 30 in order that the heads are captured between the arms and the tie holders when the latter are in their operative position. The tie rod, thus connected with the concrete

wall form sides

12 and 14, resists in tension any tendency for said sides to separate under the outward thrust of wet concrete poured between the two series of plywood panels 16. The overhanging arms 33 maintain the

sides

12 and 14 against inward movement.

Where a gang-type concrete wall form is concerned, vertical studs 34 are clamped against the walers 38 by horizontal ties 35 which also pass through the panels 16 so that comparatively large numbers of panels, walers and studs may be permanently assembled together to form gang form sections as is customary with a gang-type concrete wall form.

Intermediate the panels 16, and preferably near the inside faces of the latter, the tie rod 20 is provided with weakened portions 36 which are commonly known as breakbacks" and divide the tie rod into a medial portion 37 which remains embedded in the concrete wall W resulting from pouring of wet concrete between the concrete

wall form sides

12 and 14 as shown in FIG. 2, and end portions 38 which are wrested from the embedded medial portion by a twisting operation either before or after the panels of the concrete wall form sides have been stripped from the hardened concrete wall W (see FIG. 5).

The elastomeric tie rod bushings 22'constitute the principle feature of the present invention, each bushing being in the form of a resilient, one-piece, cup-shaped member and consisting of a cylindrical sidewall 40 which constitutes the body portion of the bushing, an annular, out-turned, radial rim flange 42 at the outer end of the cylindrical wall 40, and an inturned radial flange or lip 44 at the inner end of said cylindrical wall, the lip being provided with a series of equidistantly spaced radial sits 45 and defining a small diameter circular hole 46 of smaller proportions than the normal cross-sectional thickness of the tie rod 20. Each bushing is pressed in the opening 24 in the associated plywood panel 16 and has its outturned rim flange 42 tightly compressed between the outer side or face of the panel and the opposed inside face of the adjacent waler 28. In the case ofa gang-type concrete wall form, since the waler 28 is permanently secured by the ties 35 to the panel 16 so that the bushing 22 at all times remains intact within the opening 24 in the panel, the bushing is withdrawn bodily with the panel when the associated gang from section is stripped from the adjacent side face of the hardened concrete wall W and remains effective for use with a fresh tie rod in a succeeding use of the concrete wall form 10. In a non-gangtype concrete wall form where the panels 16 and the walers 28 are not in the form of a gang form section, the tensioning of the tie rod 18 by the wedge-type tie holders 32 forces the walers 28 against the outturned radial flanges 42 of the bushings 22, thus serving securely to capture said outturned flanges for at least the duration of concrete wall form erection and use.

In erecting the concrete wall form 10, regardless of whether or not it is of the aforementioned gang type, a pair of the elastomeric bushings 22 will be initially pressed into the openings 24 in the panels 16 (see FIG. 1) so that the cylindrical sidewalls 40 thereof line or fit snugly against openingdefining portions of the panels 16 while the outturned flanges 42 bear flat against the outer sides or faces of the panels and the inturned flanges or lips 44 lie substantially in the planes of the inner sides or faces of the panels. If gang form sections are used in connection with the concrete wall form 10, the walers 28 will be clamped in place over the outturned flanges 42 as previously described. Otherwise the walers will be put in place manually at the time of form erection. With the bushings 22 thus in place, the tie rod 20 may be projected successively and endwise through the two bushings as shown in FIG. 1, the inturned flanges or lips 44 yielding due to their flexibility, as enhanced by the slits 45 therein, to allow the enlarged heads 30 of the tie rod to pass through the small holes 46 within the lips. If the walers 28 have not been previously nailed in place as in the case of gang form sections, their application to the panels and the tightening of the wedge-type tie holders 32 will compress the elastomeric flanges 42 and thus capture the bushings 22 as heretofore described.

After the concrete has been poured and allowed to set or harden, the tie holders 32 have been removed, and the protruding end portions 38 of the tie rod 20 have been twisted or otherwise worked loose from the embedded medial tie rod portion 36 as shown in FIG. 5, small outward bulges or protuberances 50 will remain on the side faces of the hardened wall W, together with short bores or sockets 52 which are left by removal of the tie rod end portions 38. These bulges 50 exist or occur by reason of the fact that the thinness of the flexible inturned flanges or lips 44 is such that the outward pressure of the wet concrete bearing against said flanges or lips 44 bulges the latter outwards to a small extent as shown in FIG. 2 of the drawings. The concrete is unable to flow past the lips 44 which are in sealing engagement with the tie rod end portions 38 but is does flex the lips slightly outwards and the concrete hardens while the lips remain in such displaced condition. Thus, when the panels 16 are stripped from the sides of the hardened concrete wall W, the bulges 50 remain. Subsequent removal of the bulges 50 may readily be made by abrasion, utilizing any suitable abrasive media such as a handy brick or brick frag ment.

There are occasions in the concrete wall construction industry where a contractor will specify that a given concrete wall be provided in its side faces with conical sockets, either for decorative or functional purposes. Accordingly, in the modified form of the invention as illustrated in FIGS. 6, 7 and 8, the small illustrated elastomeric bushing 122, which is capable of substitution for one of the bushings 22 of the tie rod and bushing assembly 18 of FIGS. 1 and 2, is provided with an inwardly extending frustoconical pattern extension 145 which leaves a frustoconical socket such as the socket 152 in the concrete wall W when the form section including the panel 116, the waler 128 and the stud 134 has been stripped from the adjacent side face of the wall. Due to the similarity between the disclosures of FIGS. 6, 7 and 8 and those of FIGS. 4, 2 and 5, corresponding reference numerals but of a higher order, have been applied to the corresponding parts as between these two groups of disclosures. It is, of course, to be understood that in the modified form of the invention, the tie rod and bushing assembly will comprise one tie rod and two of the bushings 122. However, since only one bushing 122 is illustrated in FIGS. 6 and 7, only one bushing will be referred to hereafter.

Except for the pattern extension 145, the bushing 122 remains substantially the same as the bushing 22, the outturned radial flange 142 being compressed between the waler 128 and the outer side or face of the panel 116 by reason of the ties 135, the cylindrical body portion 140 of the bushing 122 being pressed into the opening 124 in the panel 116 so that the pattern extension 145 projects inwardly into the confines of the concrete wall form as a whole. Instead of providing a sharply defined inturned flange or lip, such, for example, as the lip 44 on each bushing 22, the wall of the extension 145 is progressively thickened in an inward direction so that the slant angle of its inside surface is greater than that of its outside surface, thus establishing a central hole or opening 146 having a diameter which is slightly less than the diameter of the tie rod 120. When the tie rod is projected through this opening 146, the wall of the opening will make sealing engagement with the adjacent outer end portion 138 of the tie rod in close proximity to the breakback 136. In order to facilitate initial projection of the enlarged head 130 on the outer extremity of the adjacent tie rod end portion 138 through the bushing 122, an outwardly tapered pilot surface 147 is formed at the inner rim of the bushing.

The installation and function of the bushing 122 is substantially the same as the installation and function of the bushing 22, the outturned radial flange 142 being securely compressed between the waler 128 and the panel 116 so that the bushing, after initial installation thereof in the opening 124 in the panel, remains a permanent element of the panel of the associated gang form section. As a consequence, after twisting of the adjacent end portion 138 of the tie rod 120 from the concrete-embedded medial portion 137 and removal of the gang form section bodily from the hardened concrete wall, the pattern extension 145 of the bushing 120 will be automatically pulled from its embedded condition within the concrete, thus leaving the frustoconical socket 152 in the adjacent side face of the wall W 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. For example, although the invention is illustrated and described herein as being applicable to tie rods of the so-called buttonhead type, it is within the purview of the invention to design the bushings 22 so that they will accommodate tie rods which are of flat construction or otherwise have varying cross-sectional shapes. Therefore, only insofar as the invention is particularly pointed out in the accompanying claims is the same to be limited.

lclaim:

1. In a concrete wall form, in combination, a panel having an inner side against which concrete is adapted to be poured, and an outer side, a reinforcing waler effectively positioned against said outer side of the panel, said panel and waler being formed with aligned tie rod-receiving openings therethrough, a tie rod having an end portion projecting through said aligned openings and provided on its free extremity with an enlarged head, wedge means interposed between said head and the waler for tensioning the tie rod and also effectively clamping the waler and panel together in assembled relationship, and a tubular resilient elastomeric bushing fitting snugly within the opening in the panel in tie rod-encircling relationship and having an internal diameter appreciably greater than the diameter of the enlarged head, the inner end region of said bushing projecting inwardly and establishing a circular central opening through which the tie rod projects in sealing relationship, said central opening being of a diameter less than the diameter of the tie rod, said inner end region of the bushing being laterally yieldable to permit initial projection of the enlarged head through said central opening.

2. In a concrete wall form, the combination set forth in claim 1 and wherein the inner end region of the bushin is in the form of an inturned radial rim flange which establis es a liplike seal for the tie rod.

3. In a concrete wall form, the combination set forth in claim 2 and wherein said inturned radial rim flange is formed with a series of radial slits therein to enhance the flexibility of the liplike seal.

4. In a concrete wall form, the combination set forth in claim 1 and wherein the inner end region of the bushing is in the form of an inwardly extending tubular frustoconical, pattern forming extension the free end of which establishes said central opening for initial reception of the enlarged tie rod head therethrough.

5. In a concrete wall form, the combination set forth in claim 1 and wherein the outer end of said bushing is provided with an outturned rim flange which projects and is clamped between the opposed sides of the waler and panel.

6. In a concrete wall form, the combination set forth in claim 2 and wherein said inturned radial rim flange is of such thinness that it is capable of slight displacement in an outward direction under the influence of the outward pressure exerted by the poured concrete, thus leaving a small outward bulge in the adjacent side face of the hardened concrete wall resulting from such pouring of concrete.

7. In a concrete wall form, the combination set forth in claim 5 and wherein the inner end region of the bushing is in the form of an inwardly extending tubular frustoconical, pattern-forming extension the free end of which establishes the central opening for initial reception of the enlarged tie rod head therethrough.

8. In a concrete wall form, the combination set forth in claim 17 and wherein the free end of the frustoconical pattern-forming extension is provided with a forwardly tapered pilot surface by means of which said enlarged head on the tie rod may be guided into said central opening.

Claims

2. In a concrete wall form, the combination set forth in claim 1 and wherein the inner end region of the bushing is in the form of an inturned radial rim flange which establishes a liplike seal for the tie rod.