Concrete insert

Dec. 8, 1970 f. k. knohl 3,545,152

CONCRETE INSERT

Filed July 3, 1968

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His Attys

United States Patent Office

3,545,152

Patented Dec. 8, 1970

3,545,152 CONCRETE INSERT Friedrich Karl Knohi, Roselle, III., assignor to Illinois Tool Works Inc., Chicago, Ill., a corporation of Delaware

Filed July 3, 1968, Ser. No. 742,437 Int. Cl. E04b 2/20, 2/48

U.S. Cl. 52—367 11 Claims

ABSTRACT OF THE DISCLOSURE

An insert for pre-cast concrete or the like provides an exposed surface relative to one face of the concrete for attachment to a fastening element which secures a wood, metal or concrete section to the pre-cast concrete, the exposed surface of the insert having a concrete void immediately behind it which offers substantially no resistance to the fastening element which is attached to the insert.

In assembling wood, metal and concrete sections to a concrete support, it has been the practice to drill holes in the concrete support into which are placed fastener devices which anchor themselves to the concrete support and at 25 the same time provide attachment or fastening means which secures the wood, metal or concrete section to the concrete support. It will be readily apparent that drilling holes in a concrete support is time consuming, and further, fastener devices for mounting in such holes have been difficult to assemble to the concrete support as well as to the section which is assembled thereto. As a result, various types of concrete inserts have been developed which can be placed within the concrete support prior to its hardening so as to be captured thereby while permitting access thereto for attaching various types of wood, metal and concrete sections to the concrete support. While concrete inserts have provided effective individual attachment means, they generally require special mounting techniques prior to the pouring of the concrete to properly expose the 40 insert for the subsequent fastening that is required. The time and expense inherent in such special mounting techniques has limited broader and consistent uses of concrete inserts in the construction industry. Further, the special mounting techniques for concrete inserts have imposed 45 additional limitations on the fastening techniques to be employed as well as the versatility of the concrete insert to the many possible uses that may be required.

Accordingly, it an object of the present invention to provide an insert for pre-cast concrete or the like which overcomes the above-mentioned deficiencies.

More particularly, it is an object of the present invention to provide an insert for pre-cast concrete or the like which is capable of self-positionment and exposure of a surface thereof relative to one face of the pre-cast concrete to facilitate attachment of a fastening element thereto, and at the same time provide a concrete void immediately behind the exposed surface which offers substantially no resistance to a fastening element assembled to the concrete insert.

Another object of the present invention is the provision of an insert for pre-cast concrete or the like which affords wide flexibility in both site alignment as well as the assembly of sections made from different types of material to the pre-cast concrete at a variety of locations.

Other objects of the present invention include the provision of insert for pre-cast concrete or the like which is of light weight and simple construction, capable of being manufactured and then assembled to a concrete support by fast, efficient and economical techniques, affords durability in use over long periods, and is otherwise well adapted for the purposes intended.

The above and other objects of the present invention are attained by the provision of an insert for pre-cast concrete or the like which includes a top wall and side wall depending therefrom on opposite sides thereof to define a ₅ channel-shaped member, and a floating element mug within the channel-shaped member to position at least outer marginal surfaces of the top wall thereof substantially flush with the top surface of the concrete adjacent the insert prior to the setting of the concrete, the floating element also being capable of providing a concrete void immediately behind the top wall of the channel-shaped member and having substantially no resistance to a fastening element driven therein during attachment thereof to the top wall of the channel-shaped member. The floating ele15 ment, which may also be characterized as the secondary element of the concrete insert, may also be capable of being received and retained by the channel-shaped member.

Reference is now made to the drawings wherein: 20 FIG. 1 is a perspective view of the preferred form of concrete insert which is constructed in accordance with the teachings of the present invention;

FIG. 2 is a fragmentary perspective view illustrating the manner in which concrete inserts, either in block or in strip form, of the type depicted in FIG. 1 are capable of being mounted into a pre-cast concrete support or the like;

FIG. 3 is an enlarged fragmentary end elevational view as viewed along line 3—3 in FIG. 2;

FIG. 4 is an end elevational view showing the manner in 30 which a fastening element is mounted relative to the concrete insert and holds a pre-cast concrete panel relative to the pre-cast concrete support in which the concrete insert is mounted; and

FIG. 5 is an end elevational view showing a modified 35 form of concrete insert which is used in conjunction with a corrugated metal panel and concrete support assembly.

Reference is first made to FIGS. 1-3 for a description of the preferred embodiment of the present invention. As best seen in these figures, the concrete insert 10 includes a primary metal channel-shaped member 12 into which is mounted a secondary element 14 which is designed to provide floatation of the concrete insert 10 prior to setting of the concrete into which it is positioned and at the same time provide a concrete void immediately behind the top wall 16 of the channel-shaped member for reasons which will appear hereinafter. Although the secondary element 14 can be configured or made from any material which will provide floatation and concrete void features just mentioned, it has been found that foamed polystyrene 50 block material which is illustrated in FIGS. 1-4 of the drawings or gypsum are preferred constructions. The foamed polystyrene blocks 14 are formed in a generally rectangular cross-sectional shape and mounted within the channel-shaped member 12 as illustrated in the drawings.

The metal channel-shaped member may be made from sheet steel such as AISI 1010 in suitable thicknesses as desired. The channel-shaped member 12 is formed by suitable dies as a one-piece construction and includes a top wall 16 with side walls 18 depending therefrom on op60 posite sides thereof, each side wall 18 terminating in a foot portion 20 at the free extremity thereof which may be aligned, if desired, with the lower face of the foamed polystyrene block 14. Each of the side walls 18 flare or taper downwardly and outwardly from adjacent the junc65 ture with the top wall 16 to facilitate introduction of the foamed polystyrene block 14 within the channelshaped member. It will· be noted that each of the side walls 18 immediately adjacent the juncture with the top wall 16 first are directed downwardly for a short dis70 tance, then proceed downwardly and outwardly as illustrated. This permits the foamed polystyrene block to completely underlie the top wall 16 if it is configured to fill

3,545, 3 up the space as illustrated in the drawings so that there will be no concrete immediately below the top wall 16 of the channel-shaped member.

The downward and outward tapering or flare of the majority of the side walls 18, together with the laterally _routwardly directed foot portion 20 associated with each side wall 18, provides a construction which can be securely retained in a concrete support 22 as best seen in FIGS. 2-3 upon hardening thereof.

Preferably, the channel-shaped member includes means ₁₀for holding the foamed polystyrene block 14 therewithin. As shown in the drawing, such means may comprise an integral tab 24 struck from each of the side walls 18 and extending upwardly and inwardly relative thereto for engaging and retaining the foamed polystyrene block 14 ₁₅within the channel-shaped member as best seen in FIG. 3 of the drawing. It is to be noted that each of the tab means is integrally hinged relative to a respective side wall along a line generally coincident with the juncture of the side wall 18 and associated foot portion 20. Thus, each 20 of the tabs 24 are flexibly and hingedly mounted so as to provide the desired flexibility upon mounting of the foamed polystyrene block 14 within the channel-shaped member, but upon the complete interfitting movement of such components, the tabs 24 on each of the side walls 18 25 function as struck elements to prevent removal of the foamed polystyrene block 14. In this way, the foamed polystyrene block 14 is captured by the channel-shaped member 12 so that there will be no disassembly during use of the concrete insert. 30

The apertures 26 in each of the side walls 18 which are formed by the integral tabs 24 being struck from the side walls 18 enhances the retention of the concrete insert within a concrete support 22. It will be readily understood that the concrete can easily flow through the apertures 35 26 so as to be positioned on opposite sides of each side wall 18, foot portion 20 and tab 24 as best seen in FIG. 3 to effectively retain the insert within the concrete support.

Since the channel-shaped member 12 and its associated foamed polystyrene block 14 are light weight in construe- 40 tion, the concrete insert 10 will float during the concrete pour such that the top wall 16 of the channel-shaped member 12 can be positioned flush with the top surface or outer face of the concrete support 22. This is important in providing a large surface area over which a fastening ₄device, such as the self-drilling and tapping screw 28 shown in FIG. 4, can be attached to the top wall of the channel-shaped member 12. For a specific description of one type of self-drilling and tapping screw, reference is made to U.S. Pat. 3,125,923. Where such a fastening ele- ₅θ ment is used for attachment to the top wall of the channelshaped member 12, it is also important that there be a concrete void immediately behind the top wall 16 which offers substantially no resistance to a fastening element driven therein during attachment to the top wall 16.

Thus, in assembling a concrete section 30 to a concrete support 22 having a concrete insert 10 as shown in FIG. 4 of the drawings, a fastener device such as the selfdrilling and tapping screw 28 must be capable of penetrating the top wall 16 and attach itself relative thereto by ₆θ tapping threads in the aperture which is formed by the self-drilling fastener 28 without encountering any substantial resistance beneath the top wall 16 of the channelshaped member 12 which could substantially hinder and reduce the desirability of using the concrete insert 10. All θof the above features are obtained with the use of the concrete insert of the present invention. It will be noted that the concrete section 30 has a tapered hole 32 which aids in aligning the self-drilling and tapping fastener 28 or other equivalent fastener device during attachment to the concrete insert.

The concrete insert 10 of the present invention can be formed into short sections as shown at the left hand side of FIG. 2 or, alternatively, may be formed into elongated metal strips which are shown at the right hand side of 75

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FIG. 2. The concrete insert can be formed in a variety of configurations, including closed figures, if such is desired.

Although the foamed polystyrene block 14 functions well in achieving the desired purposes, there are other ways of achieving the desired end. One example is shown in FIG. 5 of the drawings wherein the foamed polystyrene block or secondary element 14 is replaced by a complementary channel-shaped element 34 which is inverted with respect to the channel-shaped member 12, but is positioned within and retained by the channel-shaped member 12 in substantially the same manner as the foamed polystyrene block 14 in the FIGS. 1-4 embodiment. The inverted channel-shaped element 34, as will be seen in FIG. 5 of the drawings, clearly provides a concrete void immediately behind the top wall 16 of the channel-shaped member 12 which offers no resistance to a fastening element such as the self-drilling and tapping screw 32.

FIG. 5 also illustrates the use of the concrete insert 10 attaching corrugated metal strips 34 to the concrete support 22 by way of the self-drilling and tapping fastener 32 as illustrated. Thus, the concrete insert 10 provides the capability of attaching sections of different material and configurations to a concrete support as will be readily apparent.

While a self-drilling and tapping fastener 32 may be used in conjunction with the concrete insert 10, it is also possible that various types of fastening devices may be captured within or attached to the top wall 16 of the channel-shaped member to permit attachment of various types of sections to the concrete support in which the concrete insert 10 is positioned. Other types of fastening components or extensions, either integral with or attached to the top wall 16 of the channel-shaped member 12 may be used as desired.

From the foregoing, it will be appreciated that the concrete insert of the present invention affords wide flexibility in attaching various types of sections to a concrete support over a wide range of locations, without sacrificing economy, simplicity in construction or ease of intended use of the device. While the preferred embodiments of this invention have been shown and described herein, it is obvious that many structural details may be changed without departing from the spirit and scope of the appended claims.