US3391514A - Structural fasteners - Google Patents

Description

July 9, 1968 w. H. HALL, JR

STRUCTURAL FASTENERS 2 Shets-Sheet 1 Filed June 1-, 1966 July 9, 1968 w. H. HALL, .1R 3,391,514

TTTTTTTTTTTTTTTTT RS 2 Shee Z n :5T-j fa United States Patent Ofi ice 3,391,514 Patented July 9, 1968 3,391,514 STRUCTURAL FASTENERS Wiliiam H. Hall, Jr., West Hartford, Conn., assignor to Structural Fasteners, Inc., West Hartford, Conn., a corporation of Connecticut Filed June 13, 1966, Ser. No. 557,173 12 Claims. (Cl. 52-599) ABSTRACT OF THE DISCLQSURE A structural fastener of the type which ltypically will be embedded in concrete, the fastener comprising a support member and a threaded male member which extends therethrough, the suppor-t member being comprised of a plastic material and supporting the threaded end of the male member adjacent to and above a form prior to the pouring of the concrete. The support member is designed to absorb impact during pouring of the concrete and to prevent seepage from the concrete from contacting the threads at the load engaging end of the male member. The support member is typically affixed to the form over which the concrete is poured by means of an adhesive and provides the sole means for support of the male member prior to and during the pouringy of the concrete, the support member serving no useful purpose once the concrete has set and the form has been stripped.

This invention relates to structural fasteners. More particularly, this invention is directed to the supporting of articles from structures comprised of a mass of coalesced material. Accordingly, the general objects of this invention are to provide new and improved methods and a,- paratus of such character.

While not limited thereto in its utility, the present invention is particularly well suited for use in the supporting of objects from floor or wall constructions comprised of concrete. It is known in the art to make provision for the supporting of objects such as livht fixtures, conduits and the like from the underside of concrete slabs by partially embedding members known as inserts in the concrete. Hangers for the objects to be suspended are thereafter attached to the exposed portion of the embedded concrete inserts. A typical prior art anchor bolt type fastener or concrete insert is disclosed in U.S. Patent No. 1,960,728 issued May 29, 1934, to E. C. Cannon. Prior art inserts of the type exemplified by the Cannon patent have inherent diiiciencies. Firstly, it is necessary to provide a support member to hold the insert in the desired position prior to the pouring of the concrete. In the past, these support members have typically been comprised -of metallic or Wooden elements which were affixed to the removable forms on which the concrete was poured. In the case of forms comprised of Wood, the support members were affixed thereto by means of nails or screws. In the case of removable steel forms, mounting of the support members was a far greater problem. In either case, installation of the prior art supports was a relatively expensive process in terms of man hours. Secondly, it has been considered desirable to try to recover the support members for reuse when the forms were stripped from the concrete. The recovery and cleaning added to the expense of the use of these devices. Thirdly, prior art threaded -male type inserts required the provision of holes in the forms on which the concrete was poured; the threaded portion of the insert extending from the underside of the form. Also, with male inserts, thread fouling which necessitated a clean- CTI ing operation after the concrete had set was an ever present problem. The fouling of the threads on the male inserts resulted from seepage of water containing suspended particles to the inside of the support member from the uncoalesced concrete.

In an attempt to overcome the inherent deficiencies of anchor bolt type male fasteners of the type described above, there has been a trend to the use of channel-type mem-bers which are embedded in the concrete. For an example of such channel-type inserts, reference may be had to U.S. Patent No. 1,035,525, issued Aug. 13, 1912, to W. W. Bright. While the channel-type inserts provide an advantage in flexibility over the anchor `bolt type concrete insert, the channel-type inserts suffered from many of the disadvantages noted above. Further, the hangers which are suspended within the prior art channels carry the hanging load to the insert (channel) rather than directly to the concrete itself. Accordingly, a heavy load may cause distortion or tearing of the insert. The tearing or distorting can be eliminated, at the expense of a substantial increase in weight, by resort to heavy gauge materials. Accordingly, an added disadvantage of substantial weight is also characteristic of prior art inserts of both unitary and channel configuration.

The present invention overcomes the aforementioned disadvantages of the prior art `by providing apparatus which is intended to be embedded in part in material such as concrete, said insert being light weight, easy to install and having desirable load bearing characteristics.

It is therefore, an object of this invention to provide an improved structural fastener.

It is another object of this invention to provide a structural fastener which is designed to 'be embedded in part in a structural member and which is easier to install on a form than prior art devices of such character.

It is also an object of this invention to provide a cony crete insert which is lighter in weight than prior art devices of such character.

It is yet another object of this inven-tion to provide a concrete insert which is of lighter Weight and is easier to install on a form than prior art devices of such character and which provides for load supporting by a member directly embedded in the concrete.

It is another object of this invention to provide a threaded male concrete insert which does not require defacing of the form on which it is positioned, such defacing usually taking the form of a pattern of holes.

It is a further object of this invention to provide a concrete insert which has a plurality of load supporting elements, is light weight, can be easily and rapidly positioned on the forms over which the concrete is to be poured and in which the load bearing elements are embedded directly in the concrete.

It is still another object of this invention to provide a concrete insert having means for supporting the load bearing member during the pouring of the concrete, which supporting means may be left embedded in the concrete without constituting an economic disadvantage.

It is another object of this invention to yprovide a light Weight concrete insert which defines a channel having a plurality of threaded male load bearing elements disposed therein, said elements being embedded directly in the concrete and said channel defining member lbeing left in the concrete Without constituting an economic disadvantage.

These and other objects of the present invention are realized by providing a concrete insert comprising a threaded male member and spacer-support means therefor, the combination being designed for positioning on a removable form prior to the pouring of concrete or other coalescable material thereover. The spacer-support means is molded from a plastic material and is affixed to the removable form by means of an adhesive. The threaded male member, which comprises the element from which object hangers are later mounted, passes through an aperture in the molded support means so that its threaded end is positioned adjacent to the form. The `opposite or unthreaded end of the male member, which opposite end is of other than circular cross section, is spaced from the molded support means on the side away from the form and will thu-s be embedded in the concrete. The suspended load is connected to the threaded end of the thus embedded male member and is transmitted directly to the concrete via the male member; the means supporting the male member on the form prior to pouring of the concrete being left in place and not serving any purpose once the concrete has hardened.

This invention may be better understood and its numerous advantages will become apparent to those skilled in the art by reference to the accompanying drawing wherein like reference numerals refer to like elements in the various figures and in which:

FIGURE 1 is a plan view of a first embodiment of this invention positioned on a removable form prior to the deposition of a coalesable material thereover.

FIGURE 2 is a bottom view of the embodiment of FIGURE 1.

FIGURE 3 is a cross-sectional view of the embodiment of FIGURE 1 after the structural material has been been poured and coalesced and the form stripped.

FIGURE 4 is a cross-sectional side view of a second embodiment of this invention in position in a structure of poured concrete.

FIGURE 5 is a perspective view, partially in section, of a third embodiment of this invention positioned on a removable form.

Referring now to FIGURE 1, a first embodiment of the present invention comprising a threaded male member, bolt 10, and supporting means 12 is shown. Elements and 12 cooperate to form a novel concrete insert or structural fastener which is depicted as being positioned upon a removable form 14. In the embodiment of FIGURE l, supporting means 12 is substantially cupshaped and has a main body portion 16. Extending downwardly and outwardly from body portion 16 is fiange or leg means 18 which defines the sides of the cup. Leg means 18 has an outwardly extending foot portion 20 which supports the insert on form 14 prior to the pouring of a `coalescable material thereover. Support means 12 is fabricated from a plastic material such as polyethylene and is formed into the desired shape by injection molding or other suitable technique. ln order to enhance the resistance of support element 12 to crushing, the outer walls of leg portion 18 are molded in a parabolic shape as shown. That is, in cross section, the outer surface of support means 12 defines a half a parabola with the apex cut off. The body portion 16 of support means 12 is provided with a centrally located aperture for receiving bolt 10. In the usual instance, the aperture for bolt 10 will be formed during the molding process. However, the aperture could be produced by drilling body portion 16 either at the factory or in the Ifield. In any event, the aperture provided in body portion 16 of support member 12 is slightly smaller in diameter than the diameter of bolt 10.

Bolt 10 may be any standard steel bolt having a head which is of other than circular cross section. Preferably, bolt 10 will have a hexagonal shaped head as shown. Bolt 10 must be sufficiently long to enable the head to be displaced from body portion 16 of support member 12 when its threaded end is adjacent the form 14. ln practice, it has been found preferable to have at least half of bolt 10 extend past the top of support member 12. Bolt 10 is threaded so as to enable connection to a hanger for an object to be suspended from the structure after the structural material has been deposited, set and form 14 removed. In practice, it has been found preferable to extend the thread at least half way up the bolt so that the portion of the bolt disposed within the aperture in body portion 16 of support member 12 is threaded` The threads will thus engage the walls of the aperture and will prevent seepage of water from the concrete onto the exposed threads.

Support means 12 and bolt 10 are usually assembled at their point of manufacture and, once on the construction site, the insert is positioned Von form 14 at a point corresponding to a location on the structure from which it is desired to later suspend an object. It is, of course, understood that in actual practice a plurality of the inserts of the embodiment of FIGURE 1 would be positioned on form 14, usually in a grid pattern. The insert is held in place on the form by means of an adhesive. Typically, this adhesive will comprise a double faced pressure sensitive tape such as No. 411 available from the Minnesota Mining and Manufacturing Corporation. Such a tape is shown at 22 in FIGURES l and 5. The tape will be appiied to the insert as a step in the manufacture thereof. Thus, in the field, it is merely necessary to peel a protective paper from the second face of tape 22 and apply the insert to the form 14 at the desired position. ln some cases, for example when form 14 is very dirty, it may be necessary to enhance the securing action of the adhesive by stapling the flanged foot portion 20 of support means 12 to the form.

It should be noted that slipping or tipping of the member 12 is prevented both by the adhesive and by bolt 10 which contacts the upper face of tape 22 and is locked in member 12 by its threads. It is further worthy of note that the adhesive serves the added purpose of preventing leakage of water from the uncoalesced concrete into the area, surrounding the threaded end of bolt 10, defined by leg means 1S. As previously noted, should this water contact the threads on the bolt, fouling may occur due to deposition of sand and other material suspended in the water.

FIGURE 3 shows the insert of FIGURE 1 after the coalescable material 24, in this case concrete, has been poured and hardened and form 14 stripped away. A particularly novel feature of this invention is that object hangers may be readily attached to the exposed threaded end of bolt 10 and the bolt itself acts as the load supporting element. Due to the irregular shape of the head of bolt 10, the bolt will be held firmly by the concrete in which it is embedded and will not turn when hanger-s or other objects are turned thereon. The support means 12 is left in place in the concrete as shown. It should be noted that, due to its material strength and configuration, and also due to the strength of the bond established between the support member and form, the insert will neither move nor collapse when concrete or other material is poured thereover. While the polyethylene support means may be more expensive than similar metallic devices, use thereof is nevertheless economical for several reasons. First, due to its lower weight, substantial savings in shipping costs are realized. Secondly, since the material is flexible, it will spring back to its original shape if accidently kicked or subjected to other impact prior to the pouring of the concrete or if distorted during the pouring. Metallic support means, on the other hand, are often dented thus requiring time consuming reshaping if discovered prior to pouring or, if not discovered, rendering the insert unusable. Another important benefit derived from use of flexible support means is that any impact on the support means, such as occurs during the pour, will not be immediately transmitted to the adhesive. if a rigid support means was employed, stresses caused by impact would immediately tend to cause fracture of the adhesive. As previously noted, use of the inserts of the present invention also obviates the necessity of defacing the forms. Since there is no need to provide holes for the inserts, future use of the forms is not limited or dictated by a pattern of holes.

Referring now to FIGURE 4, a concrete insert comprising a pair of support elements 3G and 32, each identical to support means 12 of the embodiment of FIGURE 1 are shown. Support elements 30 and 32 are joined by a web member 34. The entire device is injectioned molded as a unit and, when embedded in concrete 36 as shown, assures proper spacing between the load supporting threaded male members 38 and 40. In order t-o suspend a hanger member 42 from the structure comprising concrete slab 36, a pair of drilled, internally threaded members 44 and 46 are respectively turned onto the exposed, threaded ends of members 3S and 40. The hanger 42 is locked against the end of members 44 and 46 disposed away from the slab by means of lock nuts 52 and 54.

FIGURE 5 depicts an embodiment of the present invention having a channel 'configuration positioned on a removable form 60. The bolt supporting member 62 of this channel-shaped embodiment is comprised of polyethylene extruded so as to have the same cross section as the single units of the FIGURE l embodiment. As with the other embodiments, the channed-shaped bolt supporting member is held at the desired point on a wooden form prior to the pouring of concrete by means of a suitable adhesive. As noted above, this adhesive can be a double faced pressure sensitive tape 22 which spans the entire area between the outer edges lof feet 64. In actual practice, a plurality of inserts of the type shown in FIG- URE 5 will be positioned on the form in parallel relationship to one another- Typically, bolts 66 will be positioned l2 inches apart in each of channel shaped members 62. The channel shaped members will be spaced on the form at regular intervals, in standard practice usually two or four feet on centers. This results in a grid pattern of load supporting elements.

While preferred embodiments have been shown and described, various modifications and substitutions may be made without departing from the spirit and scope of this invention. For example, while emphasis has been placed on the use of threaded male members as the load bearing elements, a snap on or quick connect design can be incorporated into the exposed end of the load bearing element in place of the threads. Accordingly, it is to be understood that this invention has been described by way of illustration rather than limitation.

What is claimed is:

1. Apparatus for suspending articles from a structure consisting of a mass of coalesced material comprising:

a load supporting member adapted to be partially embedded in the coalesced material, said load supporting member comprising a threaded male member having a first end of other than circular cross-section; and

means for holding said load supporting member prior to deposition of said material thereover, said holding means having an apertured body portion and iiange means extending downwardly and outwardly therefrom, said flange means having a portion being adapted to rest upon a form, said male member extending through said aperture in sealing relationship therewith and being supported solely by said body portion with its axis substantially perpendicular to the surface of a form upon which said flange means rests, the threaded end of said male member being disposed intermediate of said flange means and adjacent and above the form, the first end of said male member being spacially displaced from said body portion, said holding means preventing seepage of or from said material from contacting the threaded portion of said male member disclosed intermediate of said flange means.

6 2. The apparatus of claim 1 wherein said holding means comprises:

an insert formed from a plastic material, said plastic material engaging a plurality of threads of said male member where said male member passes through said aperture in said body portion of said holding means.

3. The apparatus of claim 2 wherein said plastic material is polyethylene.

4. The apparatus of claim 2 further comprising:

adhesive means positioned on the portions of said flange means adapted to rest upon a form. 5. The apparatus of claim 4 wherein said adhesive means comprises:

a double faced pressure sensitive tape. 6. The apparatus of claim 4 wherein said moldable plastic holding means comprises:

an apertured body portion having curved outer walls, leg means extending downwardly and outwardly from said body portion, said leg means defining a space therebetween, the outer surface of said leg means and said body portion defining a smooth surface having the shape of a portion of a parabola; and

foot means extending outwardly from the bottom of said leg means, said foot means being adapted to rest upon a form and to support said holding means with the axis tof the aperture in said body portion perpendicular to the form.

7. The apparatus of claim 6 wherein said leg means and body portion define a substantially cup shaped member.

8. The apparatus of claim 6 wherein said leg means and body portion define a channel shaped member, said member having a plurality of apertures therein.

9. rIhe apparatus of claim 7 wherein said foot means defines a longitudinally extending web member, said web member extending to a second holding means.

10. A structural fastener comprising:

an insert support member, said support member being comprised of a plastic material and having an apertured body portion and a flange means extending downwardly therefrom, said flange means being adapted to rest on the upper side of a removable form;

adhesive means affixed to at least those portions of said fiange means which are intended to contact a form, said adhesive means serving to secure said support member on a form; and

a load supporting insert, said insert having a first end portion adapted to be embedded in a mass of coalesced material and a second end portion adapted to be engaged by a suspended load, said second end portion passing through said aperture in said body portion of said support member and terminating lnterrnediate said flange means and adjacent to and above a form, the cross-sectional area of said second end portion being greater than the cross-sectional area of said aperture whereby said insert is held firmly and supported solely by said support member.

11. The article of claim 10 wherein said insert support member comprises:

an apertured body portion having curved outer walls;

leg means extending downwardly and outwardly from said body portion, said leg means defining a space therebetween; and

foot means extending outwardly from the bottom of said leg means, said foot means being adapted to rest upon a form and to support said insert with the axis of the aperture in said body portion perpendicular to the form.

12. The article of claim 11 wherein an outer surface of said leg means and said body portion define a smooth surface having the shape of a portion of a parabola.

(References on following page) References Cited UNITED STATES PATENTS Keith 52-699 Kelly 52--699 Curley 52-699 Phillips 52--699 Rapp 52-704 XR McNair 52-706 XR 8 FOREIGN PATENTS 591,036 8/1947 Great Britain. 1,333,580 6/1963 France.

909,298 10/1962 Great Britain.

BOBBY R. GAY, Prilzary Examiner.

A. M. CALVERT, Assistant Examiner.

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