US3514917A

US3514917A - Concrete insert

Info

Publication number: US3514917A
Application number: US666698A
Authority: US
Inventors: James Merrill Sr
Original assignee: JAMES MERRILL SR
Current assignee: JAMES MERRILL SR
Priority date: 1967-09-11
Filing date: 1967-09-11
Publication date: 1970-06-02
Anticipated expiration: 1987-06-02

Description

June 2, 1970 J. MERRILL, SR 3,514,917

I CONCRETE INSERT Filed Sept. 11, 1967 3 Sheets-Shect 1 //v l/EA/ r02 JAMES Meek/1.4, 53?.

June 2, 1970 J, ME mL 5R 3,514,917

CONCRETE INSERT Filed Sept. 11, 1967 3 Sheets-Sheet 2 FIG. 7

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June 2, 1970 J. MERRILL. SR 3,514,917

CONCRETE INSERT Filed Sept. 11, 1967 5 Sheets-Sheet :5

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/%Mw ww A Tram/5 United States Patent 3,514,917 CONCRETE INSERT James Merrill, Sr., 1505 Randall Way, West Covina, Calif. 91790 Filed Sept. 11, 1967, Ser. No. 666,698 Int. Cl. E04b 1/38 U.S. Cl. 52704 5 Claims ABSTRACT OF THE DISCLOSURE An insert to be cast in a ceiling-floor slab of a reinforced concrete structure for attaching a load support, such as a hangar, to the slab, the insert having a combined shield and supporting base for supporting the insert on reusable pan joists over which a concrete slurry is poured to form the slab and shielding the load attachment means of the insert against b ockage by the slurry, and the base being plastically deformable or otherwise adjustable to compensate for irregularities in the pan joists. A concrete insert and a load hanger of the character described embodying an acoustic barrier for inhibiting transmission of acoustic vibrations from the supported load to the supporting slab.

This invention relates generally to means for attaching loads to a concrete structure, such as a ceiling-floor slab of a reinforced concrete building structure. The invention relates more particularly to an improved insert and hanger for the purpose described.

As will appear from the ensuing description, the invention may be employed to advantage in a variety of applications. However, the invention finds primary utility in attaching loads, such as water pipes, electrical conduits, and the like to the ceiling-floor slabs of a reinforced concrete building structure. For this reason, the invention will be disclosed in this particular connection.

It is common practice in the building construction trade to attach water pipes, electrical conduits, and the like to an overhead ceiling-floor slab of a reinforced concrete building structure, that is a concrete partition or slab which forms the ceiling of a lower building level and the floor of the adjacent upper level, by means of load hangers which are attached to inserts embedded in the slab. In the present disclosure, these two different attachment means, i.e., the inserts and the hangers, are referred to generically as supports. The present invention is aimed at avoiding or curing certain inherent deficiencies in the existing supports of this class.

Consider first the existing concrete inserts. Generally speaking, the building construction trade employs two different techniques for forming the ceiling-floor slabs of a reinforced concrete building structure. One technique utilizes reusable, so-called pan joists. These joists are essentially metal planks or plates which are supported on a scaffold and joined edge to edge so as to constitute the lower wall of a concrete form. A concrete slurry is poured over these pan joists to form a ceiling-floor slab of a reinforced building structure. Prior to pouring the slab, the slab inserts to be installed are properly located over and supported on the pan joists. Concrete slurry is then poured over the pan joists and about the inserts and allowed to set to produce a finished slab having the inserts embedded therein. After setting, the pan joists and their supporting scaffold are removed for subsequent reuse. Removal of the pan joists exposes the embedded inserts for attachment thereto of ceiling hangers, or the like.

The existing concrete inserts of this kind have several inherent deficiencies. One of these deficiencies resides in the difficulty involved in retaining the inserts in the 3,514,917 Patented June 2, 1970 proper vertical attitude while the slab is being poured. Thus, reusable pan joists are subjected to much abuse and are frequently bent or otherwise deformed in use. As a consequence, when the inserts to be installed in a concrete ceiling-floor slab are supported on the pan joists prior to pouring the slab, the inserts tend to assume a variety of attitudes, depending upon the bends or other irregularities in the pan joists. Various techniques have been devised to compensate for such bends and irregularities, thus to permit the inserts to be initially located in the proper vertical attitude. All of these existing techniques, however, are unsatisfactory owing to their complexity, cost, time consumption, and other factors.

One aspect of this invention is to provide an improved concrete insert which avoids the above problems. According to this aspect, the insert is equipped with a base for supporting the insert on pan joists during pouring of a concrete slurry over the joists to produce a concrete slab. This base is readily adjustable, as by bending or other plastic deformation, to locate the insert in the proper vertical attitude regardless of bends or other irregularities in the pan joists.

Another problem which is frequently encountered with the existing concrete inserts is blockage of the inserts by the concrete. Thus, at least some existing inserts are equipped with a box or housing-like enclosure whose function is to shield the hanger attachment means of the inserts against blockage by the concrete slurry being poured. This enclosure or shield has an open side through which the attachment means are exposed after the pan joists are removed. Much difficulty has been experienced in the past due to leakage of concrete slurry into the open side of the shield. This leakage slurry, when set, had to be chipped away or o'herwise removed to expose the load attachment means of the inserts.

An important aspect of the present invention is to provide a concrete insert which is immune to this problem of concrete blockage. According to this aspect, the invention proivdes an insert having a completely sealed or hermetic enclosure for shielding the insert hanger attachment means against the concrete slurry which is poured about the insert. This hermetic shield has a removable closure, such as a knock-out plug, in one end. The closure is exposed when the pan joists are removed, whereby the hanger attachment means of the insert are exposed by knocking out or otherwise removing the closure.

Sound transmission from the load or loads being supported to the supporting concrete rfloors and ceilings of reinforced concrete structures is a serious problem with the existing concrete inserts and hangers of the kind under discussion. This is due to the fact that the existing inserts and hangers provide a highly effective acoustic transmission path from the load to the slab. According to a further of its aspects, the invention provides an acoustically insulated load support of the character described which embodies an acoustic insulating barrier between the load and the slab toinhibit transmission of acoustic vibrations from the load to the slab. This load support may be either an insert to be embedded in a newly built reinforced concrete structure or a hanger to be attached to inserts embedded in an existing building structure.

A general object of the invention, then, is to provide an improved load support of the character described.

Another object of the invention is to provide a concrete insert to be cast in a ceiling-floor slab of a reinforced concrete building structure poured with the aid of reusable pan joists, which insert is adjustable to compensate for bends or other irregularities in the joists.

Yet another object of the invention is to provide a concrete insert of the character described which is hermetically sealed against blockage of the insert hanger attachment means by the concrete in which the insert is cased.

A further object of the invention is to provide a concrete insert and load hanger of the character described which are acoustically insulated to inhibit transmission of acoustic vibrations from the supported load to the supporting structure.

Other objects, advantages, and features of the invention will become readily evident as the description proceeds.

In the drawings:

FIG. 1 is a vertical section illustrating a pair of the present improved inserts supported on removable pan joists prior to pouring of a concrete slurry over the joists to form a ceiling-floor slab of a reinforced concrete building structure;

FIG. 2 is an enlarged axial section through the righthand insert in FIG. 1;

FIG. 3 is an axial section through a modified acoustically insulated concrete insert according to the invention;

FIG. 4 is a view in side elevation, partly broken away, of a further modified concrete insert according to the invention;

FIG. 5 is a top plan view of the insert in FIG. 2;

FIG. 6 is a vertical section through a further modified concrete insert according to the invention illustrating the insert supported on permanently installed pan joists prior to pouring a concrete slurry over the joists to produce a ceiling-floor slab of a reinforced concrete building structure;

FIG. 7 is a fragmentary enlarged bottom plan view of the insert in FIG. 6;

FIG. 8 is a side elevation of an acoustically insulated hanger according to the invention illustrating the hanger attached to an existing insert in a reinforced concrete building structure;

FIG. 9 is an enlarged bottom plan view of the hanger with parts broken away for the sake of clarity;

FIG. 10 is an enlarged axial section through the hanger; and

FIG. 11 is a side elevation of the hanger.

Referring to FIGS. 1 and 2 of the drawings, there is illustrated to a concrete insert 10 according to the invention which is designed to be cast in a concrete slab 12 that is made by pouring a concrete slurry over reusable pan joists 14 which are joined side by side to provide the bottom wall of a concrete slab form. The insert 10 has a body 16 including an upper load bearing member 18 and a lower supporting base 20. Extending into the lower end of the load bearing member 18 is a threaded bore 22. This bore forms an attachment means for securing a pipe hanger, or the like, to the insert after the latter has been set in the concrete slab 12.

In use, the insert 10 is supported on the pan joist 14, in the manner illustrated in FIG. 1. A concrete slurry is then poured over the joists and about the insert and allowed to set to form a completed ceiling-floor slab 12. After the slab has properly set, the pan joists are removed for subsequent reuse. Removal of the joists exposes the installed inserts for attachment thereto of hangers, or the like, which carry the loads to be supported.

As noted earlier, one of the problems encountered in installing inserts of the character described resides in the fact that the reusable pan joists 14 are frequently bent or otherwise deformed in use. As a consequence, it is difficult to locate all of the inserts in the proper vertical attitude prior topouring the concrete slurry over the joists and about the inserts to form a slab. In FIG. 1, for example, the portion of the pan joists 14 on which the left hand insert 10 is supported in FIG. 1 is level. Accordingly, location ofthis left-hand insert in its proper vertical attitude presents no problem. However, the portion ofthe pan joists on which the right-hand insert is supported in FIG. 1 is bent. As a consequence, the insert must be provided with some type of compensating adjustment to enable the insert to be located in the proper vertical attitude regardless of bends or other irregularities in the pan joists. According to the present invention, this adjustment is furnished by the insert base 20. In this regard, for example, it will be observed that the supporting bases of the two inserts 10 illustrated in FIG. 1 are, in effect, adjusted to two different settings which enable both in serts to be located in the proper vertical attitude even though the inserts are not both supported on level portions of the pan joists.

Referring now in more detail to the drawings, the load bearing member 18 of the present insert 10 is fabricated from metal or other relatively strong material and has a generally inverted conical shape. The hanger attachment means or threaded bore 22 of the insert extends axially into the normally lower, small diameter end of the member. If desired, the upper large diameter end of the member may be provided with outwardly directed flanges 24 to provide firm anchorage of the insert in the concrete slab 12. The lower supporting base 20 of the illustrated concrete insert 10 serves a two-fold function. First, it provides an adjustable support for the insert which enables the attitude of the insert to be adjusted, in the manner just explained. As will appear presently, this adjustment is accomplished by plastic deformation or bending of the base. Secondly, the supporting base of the insert provides a hermetic enclosure or shield which prevents entrance of concrete slurry into the hanger supporting bore 22 of the insert when the latter is cast in the concrete slab 12.

To these ends, the supporting base 20 of the insert 10 comprises a conical sleeve 26, the upper small diameter end of which is adhe'sively bonded or otherwise sealed to the lower small diameter end of the load bearing member 18 of the insert, about the lower open end of the insert bore 22. The lower, large diameter end of the sleeve 26 is closed by a wall 28. Extending through this wall is an opening 30 containing a removable closure 32. The illustrated closure is a knock-out plug which is sealed about its periphery to the wall of the opening 30, in such a way that the plug may be easily pushed out from the opening. It is evident at this point, therefore, that the supporting base 20 of the insert 10 provides a generally cup-like hermetic enclosure or shield about the lower open end of the insert hanger attachment bore 22 for shielding this bore against the entrance of concrete slurry. Accordingly, there is no possibility of blockage of the bore by the slurry when the insert is cast in the concrete slab 12, in the manner explained earlier.

As explained above, a second function of the supporting base 20 is to permit adjustment of the attitude of the insert 10 when the latter is supported on the pan joists 14, thus to permit the insert to be located in the proper vertical attitude regardless of irregularities in the pan joist. To this end, the supporting base or shield 20 is molded from a suitable flexible plastic which may be deformed, in the manner illustrated in FIGS. 1 and 2, to provide the required attitude compensating adjustment for the insert. In some cases, the plastic material of the supporting base may be sufficiently non-elastic, i.e., plastically deformable, to enable the base to retain its deformed or bent shape. In other cases, it may be desirable to mold plastically bendable elements or wires 34 within the walls of the base, as illustrated in FIG. 2, to aid the base in retaining its bent shape.

It is now evident that when the present insert 10 is supported on the pan joists 14, the supporting base 20 of the insert may be deformed to locate the insert in the proper vertical attitude, regardless of bends or other irregularities in the joist. In this regard, for example, it will be observed that the left-hand insert 10 in FIG. 1 assumes a vertical attitude without any deformation of its supporting base, while location of the right-hand insert in FIG. 1 requires one side of its supporting base to be deformed to locate the insert in the proper vertical attitude. When the concrete slurry is poured over the pan joist 14, the slurry flows about the body of the inserts to eflect firm anchorage of the latter in the finished concrete ceiling-floor slab 12. This slab will also contain suitable reinforcing means, such as metal reinforcing rods, which have been omited from the drawings for the sake of clarity. It is evident that because of the nonuniform cross-section of the load bearing member 18 of each insert, that is the changing cross-section of the member in planes normal to its vertical axis, the latter is firmly anchored against pulling from the slab 12 when the latter finally sets. This firm anchorage of the load bearing member in the slab is enhanced by the flanges 24. In addition to supporting the insert in the proper vertical attitude during pouring of the concrete slurry about the insert, the insert base 20 serves as a shield which permits the entrance of the slurry into the hanger attachment bore 22 of the load bearing member 18. Accordingly, it is unnecessary to remove concrete from this opening before using the insert.

After the slab 12 is properly set, the pan joists 14 are removed for subsequent reuse. When the joists are thus removed, the lower end of each installed insert is exposed at the under side of the slab. As a consequence, the closureor knock-out plug 32 of each insert may be pushed out to expose the hanger attachment bore 22 of the insert through its hollow supporting base 20. Accord ingly, a threaded hanger rod, or the like, may be inserted through the base opening 30 and threaded upwardly into the bore 22 to effect firm attachment of the rod to the load bearing member 18 of the insert, and thereby to the concrete slab 12.

As noted earlier, transmission of acoustic vibrations from the supported load to the supported concrete ceilingfloor slab is a problem with the existing inserts and hangers. According to a further feature of the present invention, this problem is alleviated to a high degree by providing an acoustic insulating barrier between the load and slab. FIG. 3, for example, illustrates a modified concrete insert 10a according to the invention embodying such an acoustic insulating feature. This modified insert is identical to the insert 10 just described except for this acoustic insulation feature. Accordingly, it is unnecessary to describe the modified insert in detail. Suflice it to say that the load bearing member 18a of the insert 10a is composed of an outer conical shell 36a an inner conical element 38a and an intervening conical barrier or sleeve 40a of suitable acoustic insulating material, such as rubber or plastic. The outer sleeve 36a and inner element 38:: are fabricated from metal or other relatively strong material. The inner element contains the threaded hanger attachment bore 22a of the insert. Preferably, the

several parts

36a, 38a, and 40a of the load bearing member 18 are adhesively bonded or otherwise joined to one another. If desired, a cover plate 42a may be secured across the top of the load bearing member 18a, as shown.

The modified insert 10a is installed and used in precisely the same way as the earlier described insert 10. Accordingly, it is unnecessary to repeat, in detail, the insert installation procedure. Suflice it to say that when the insert 10a is properly installed, the acoustic insulating barrier' 40a inhibits the transmission of acoustic vibrations from the supported load to the supporting concrete slab 12.

The modified concrete insert 10b illustrated in FIG. 4 is substantially identical to the insert 10a just described. The major difference between the two inserts resides in the fact that the threaded hanger attachment bore 22b of the insert 10b extends all the way through the load bearing member 18b of the insert to provide more secure attachment to the threaded hanger rod, or the like, to be attached to the insert. The modified insert 10b is installed and used in precisely the same way as the earlier inserts of the invention. Accordingly, it is unnecessary to repeat the installation procedures. Suffice it to say that the modified insert 10b is acoustically insulated by the insert 10a, just described. Accordingly, it will be understood that the insert 10b inhibits the transmission of acoustic vibrations from the supported load to the supporting slab 12.

As noted earlier, the pan joists 14 illustrated in FIG. 1 are reusable and, therefore, are removed from the completed concrete slab 12. In other cases, permanently installed pan joists may be employed. FIG. 6 illustrates a modified pan joist 140 of this type. In this case, a number of the pan joists 140 are installed on a scaffold (not shown) and joined side by side in much the same way as the pan joist 14. The concrete slurry is then poured over the joists and allowed to set to form a completed concrete slab 12. The joists 140' are left in place to be permanent parts of the completed slab.

FIGS. 6 and 7 illustrate a modified, acoustically insulated insert for use with such permanent pan joist installations. This modified insert is identical to the insert 10a, illustrated in FIG. 3, except for the omission on the lower supporting base and shield of the insert and the elongation of the insert supporting flanges 24c, whereby these flanges may extend over two adjacent tubular sections of the pan joists 140, as shown. When making the concrete ceiling-floor slab 12, the pan joists 140 are first installed on top of a suitable supporting scaffold (not shown) and are joined side by side to form the lower boundary wall of a concrete form for this slab. The inserts 10c are then placed in position on the pan joists, in the manner illustrated in FIG. 6. Thus, when properly installed, the supporting flanges 240 of each insert overlie, in supporting engagement, two adjacent tubular sections of the joists and the lower end of the main body of the insert protrudes through an opening in the intervening web joining the tubular joist sections. A concrete slurry is now poured over the pan joists in such a way that the slurry flows into the channels between the adjacent tubular joist sections and around the inserts 100 within these channels. The inserts are thereby anchored in the finished slab 12. It is evident, of course, that inserts "designed for this latter method of installation do not require the lower supporting base and shield embodied in the earlier forms of the invention. Thus, in this latter method of installation, the pan joists 14c, which remain as an integral part of the finished slab 12, serve as shields to prevent the entrance of concrete slurry into the threaded hanger attachment bore of the inserts.

Reference is now made to FIGS. 8 through 11 which illustrate an acoustically insulated hanger 100 according to the invention which is adapted to besecured or attached to an insert 102 embedded within an existing concrete ceiling-floor slab 104. Insert 102 is conventional and thus need not be explained in detail. Suflice it to say that the insert embodies a sheet metal housing 106 which is embedded within the slab 104. This housing contains a cavity having an open lower end bounded by upwardly presented shoulders 108. Supported on these shoulders is a nut 110.

The present hanger 100 comprises a main body 112 which is similar to those of the present concrete inserts. Thus, the hanger body 112 includes an outer conical shell 114, an inner conical core 116, and an intervening barrier or sleeve 118 of acoustic insulating material. Extending axially through and opening through the lower end of the inner core 116 is a threaded bore As in the acoustically insulated inserts of the invention, the outer shell 114 and inner core 116 are composed of a relatively strong material, such as metal. The intervening acoustic insulating barrier or sleeve 118 is composed of a suitable acoustic insulating material, such as rubber. Extending diametrically across and welded to the upper edge of the outer hanger body shell 114 is a rigid yoke 122. Rigidly joined to and extending from the center of this yoke, along the axis of the hanger body 112, is a threaded stud 124.

In use, the upper stud 124 of the hanger 100 is threaded in the preinstalled insert nut 110. The hanger than depends below the concrete slab 104, as shown. A threaded hanger bolt 126 attached to the load to be supported is then threaded in the lower bore 120 of the hanger. It will now be understood, therefore, that the load is supported on the slab 104 through the intervening hanger 100 of this invention. This hanger, being acoustically insulated in the same way as the earlier concrete inserts of the invention, inhibits the transmission of acoustic vibrations from the load to the concrete slab.

It is now evident, therefore, that the invention herein described and illustrated is fully capable of attaining the several objects and advantages preliminarily set forth.

Although specific embodiments of the present invention have been illustrated and described herein, it will be understood that the same are merely exemplary of presently preferred embodiments capable of attaining the objects and advantages hereinbefore mentioned, and that the invention is not limited thereto; variations will be readily apparent to those versed in the art, and the invention is entitled to the broadest interpretation within the terms of the appended claims.

What is claimed is:

1. An insert for attaching a load to the underside of an overhead concrete slab which is cast by pouring a concrete slurry into a confining form having a lower boundary wall, said insert comprising:

an insert body including a main load bearing member having a normally lower end and a supporting base secured to said member,

said load bearing member having a longitudinal axis and including attachment means on said axis at the lower end of said member for securing said load to said load bearing member in suspended position below said member, and

said supporting base having normally lower downwardly presented surface means at the lower end of said member disposed in a plane transverse to said axis and adapted to be placed in supporting contact with the upper side of said boundary wall to support said insert on said wall while said concrete slurry is poured into said form and about said insert to anchor the insert in the finished slab, and supporting base including a plastically deformable portion for adjusting the angle between said surface means and axis and retaining said surface means in adjusted angular relation to said axis.

2. An insert for attaching a load to the underside of an overhead concrete slab which is cast by pouring a concrete slurry into a confining form having a lower boundary wall, said insert comprising:

said load bearing member having a longitudinal axis and including attachment means on said axis at the lower end of said member for securing said load to said load bearing member in suspended position below said member,

said supporting base having normally lower downwardly presented surface means at the lower end of said member disposed in a plane transverse to said axis and adapted to be placed in supporting contact with the upper side of said boundary wall to support said insert on said wall while said concrete slurry is poured into said form about said insert to anchor the insert in the finished slab, and said supporting base including adjustable means for adjusting the angle between said surface means and axis and retaining said surface means in adjusted angular relation to said axis,

said supporting base comprising a plastically deformable sleeve coaxially secured at one end to the lower end of said load bearing member about said attachment means and extending below said member, and a lower wall member closing the lower end of said sleeve and adapted to seat against said boundary wall, whereby said lower wall member is exposed at the underside of said finished slab when said boundary wall is removed, and said lower wall member having an opening to provide access to said attachment means when said boundary Wall is removed, and said wall member providing said surface means and said sleeve being bendable to adjust the angle between said wall member and said axis, whereby said sleeve constitutes said adjustable means.

3. An insert according to claim 2 including:

removable closure means sealing said opening.

4. An insert to be embedded in a concrete slab for attaching a load to said slab, comprising:

an outer rigid conical sleeve member, an inner rigid core member concentrically positioned within and having approximately the same cone angle as said outer member, and an intervening conical acoustic insulating sleeve of substantially uniform wall thickness positioned between said members for inhibiting transfer of acoustic vibrations between said mem bers,

first attachment means at the large end of said outer sleeve member,

second attachment means at the small end of said core member and accesible through an opening in the small end of said outer sleeve member,

said attachment means being adapted for connection to said load and concrete slab, respectively, in a manner such that said core member is subjected to a longitudinal force directed toward said opening, and the diameter of said opening being substantially smaller than the diameter of the large end of said core member, whereby said members are positively restrained against axial separation under load and said insulating sleeve is subjected substantially only to a compression loading,

said first attachment means comprising laterally projecting lugs on said outer sleeve member for effecting firm anchorage of said outer sleeve member in said slab, and

said second attachment means comprising a threaded bore extending axially into the small end of said inner core member.

5. A hanger to be attached to an insert embedded within a concrete slab for anchoring a load to said slab, comprising:

an outer rigid conical sleeve member, an inner rigid core member concentrically positioned within and having approximately the same cone angle as said outer member, and an intervening conical acoustic insulating sleeve of substantially uniform wall thickness positioned between said members for inhibiting transfer of acoustic vibrations between said members, first attachment means at the large end of said outer sleeve member,

second attachment means at the small end of said core member and accessible through an opening in the small end of said outer sleeve member,

said attachment means being adapted for connection to said load and concrete slab, respectively, in a manner such that said core member is subjected to a longitudinal force directed toward said opening, and the diameter of said opening being substantially smaller than the diameter of the large end of said core member, whereby said members are positively restrained against axial separation under load and said insulating sleeve is subjected substantially only to a compression loading.

said first attachment means comprising a threaded stud on the common axis of said members and secured to the large end of said outer sleeve member for threaded engagement with said insert, and

said second attachment means comprising a threaded bore extending axially into the small end of said 9 10 inner member for receiving a threaded hanger bolt FOREIGN PATENTS attached to said 888,202 1/1962 Great Britain.

BOBBY R. GAY, Primary Examiner UNITED STATES PATENTS 5 A. M. CALVERT, Assistant Examiner 1,145,385 7/1915 Marble 52-707 3,290,851 12/1966 Sherburne 52701 US. Cl. X.R. 1,088,290 2/1914 McAllister 52-707 52 707 References Cited