Patent Publication Number: US-8966833-B2

Title: Concrete insert

Description:
FIELD OF THE INVENTION 
     This invention relates to an improved concrete insert for attaching concrete panels to buildings. 
     BACKGROUND OF THE INVENTION 
     Current building practices in North America and elsewhere utilize pre-cast concrete wall panels to form the perimeter walls of a building. A plurality of concrete inserts are embedded in the concrete panels when they are pre-cast, such that a substantially flat elongate center portion of each concrete insert is located flush with the intended inside surface of the pre-cast concrete wall panels. An access slot through the elongate center portion of each concrete insert provides access for an attaching bolt to connect with a captive nut, located in an enclosed concrete free channel under the elongate center portion, the enclosed channel commonly referred to as a “nut box”. The nut is selectively positioned under the access slot to receive the inserted attaching bolt. An attaching bolt is typically first inserted through an aperture in a structural member of the building and then secured to the captive nut in the nut box of the concrete insert pre-cast in the concrete wall panel, thus securing the pre-cast concrete wall panel to the structural member of the building, to form the perimeter walls of the building. 
     Concrete inserts typically have a metal, housing formed from a single sheet of plate steel, being bent into an inverted “U” shaped or “V” shaped channel with an open bottom and open ends. The elongate center portion forms the valley of the inverted “U” or “V” shaped channel and opposing longitudinal sides depending from the elongate center portion form the sides of the inverted “U” or “V” shaped channel. The inverted “U” or “V” shaped channel of the nut box only allows the nut to be displaced longitudinally under the open slot in the nut box, and prevents the nut from rotating when an attaching bolt is threaded into the nut. Typically the nut is biased against the bottom of the elongate center portion by a spring compressed between the nut and the bottom wall of a not box insert which covers the open bottom and open sides of the housing, the nut box insert and the housing together forming the not box for keeping wet concrete out of the nut box during the forming process. Although it is been attempted to construct a nut box insert for sealing the bottom and ends of the housing solely with Styrofoam™ foam and dispensing with the spring, due to its lower cost and simplicity, this arrangement does not exert sufficient pressure against the nut to keep it in a preselected position while the concrete panel is attached to a building. Further, such foam is nut box inserts may be deformed or displaced during the forming process potentially allowing wet concrete into the nut box and preventing the nut from, traveling along the nut box under the slot in the elongate center portion thus preventing adjustability of the concrete insert. 
     Accordingly, there exists a need for a concrete insert with a foam nut box insert which sufficiently biases the nut under the nut access slot against the elongate center portion of the concrete insert and resists deformation or displacement during the concrete panel forming process. 
     SUMMARY 
     The invention provides a concrete insert for casting in a concrete wall panel, the concrete wall panel having an inside surface for attachment to a building, the concrete insert comprising, a housing having an elongate center portion and two opposing longitudinal sides, and two opposing longitudinal flanges. The elongate center portion is bounded by opposing outer longitudinal bend lines and having an outer attachment surface for mounting the elongate center portion substantially flush with the inside surface of the concrete wall panel, the elongate center portion defining a longitudinally oriented nut access slot. The opposing longitudinal sides depend inwardly from the opposing outer longitudinal bend lines to opposing inner longitudinal bend lines. The opposing longitudinal flanges depend from opposing inner longitudinal bend lines transversely to the opposing longitudinal sides and extend in mutually divergent relation. The housing and the nut box insert comprise a nut box. A nut defines a threaded aperture. The nut is slidably mounted in the nut box. The housing constrains rotation of the nut for the threaded aperture in the nut to receive a threaded fastener through the nut access slot for attaching the concrete wall panel to the building. The nut box insert comprises at least one resilient layer carried by a compression plate, the compression plate attached to the housing. The compression plate is for compressing the at least one resilient layer against the bottom of the nut for permitting the nut to be slidably located within the nut box and for holding the nut under pressure in a selected location in the nut box for the threaded aperture in the nut to receive the threaded fastener through the nut access slot while the nut is in the selected location. 
     In one aspect the resilient layer comprises resilient end walls compressed against the housing by the compression plate for substantially preventing wet cement from, entering the nut box during casting of the concrete panel. 
     In another aspect the compression plate comprises end walls for substantially preventing wet cement from entering the nut box during casting of the concrete panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain embodiments of the invention are illustrated with reference to the accompanying drawings, by way of example only and without limiting other embodiments of the invention that would be understood by those skilled in the art, wherein: 
         FIG. 1  is a perspective view of a prior art concrete insert; 
         FIG. 2  is a perspective view of a first embodiment of the concrete insert. 
         FIG. 3  is a sectional side view of the first embodiment of the concrete insert taken along line  3 - 3  of  FIG. 4 ; 
         FIG. 4  is an end view of the first embodiment of the concrete insert; 
         FIG. 5  is a top view of the first embodiment of the concrete insert; 
         FIG. 6  is a bottom view of the first embodiment of the concrete insert; 
         FIG. 7  is a perspective view of a second embodiment of the concrete insert; 
         FIG. 8  is a sectional side view of the second embodiment of the concrete insert taken along line  8 - 8  of  FIG. 9 ; 
         FIG. 9  is a sectional end view of the second embodiment of the concrete insert taken along line  9 - 9  of  FIG. 8 ; 
         FIG. 10  is a top view of the second embodiment of the concrete insert; 
         FIG. 11  is a bottom view of the second embodiment of the concrete insert. 
         FIG. 12  is a perspective view of a third embodiment of the concrete insert. 
         FIG. 13  is a sectional side view of the third embodiment of the concrete insert taken along line  13 - 13  of  FIG. 12 . 
         FIG. 14  is a perspective view of a fourth embodiment of the concrete insert. 
         FIG. 15  is a sectional side view of the fourth embodiment of the concrete insert taken along line  15 - 15  of  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION 
     Certain exemplary embodiments of the invention are described below with reference to the accompanying drawings. Orientation references relate to the concrete insert as it would be cast in a concrete wall panel, and the wall panel being vertically attached to a building, it being understood that the concrete insert could be used in other orientations. In particular the term outer shall refer to elements closer to the intended mounting surface of the pre-cast concrete wall panels, and the term inner shall refer to elements further away from the intended mounting surface of the pre-cast concrete wall panels (that is inner elements being deeper in the concrete of the concrete panels from the mounting surface of the panels). The terms outwardly and inwardly have corresponding meanings The terms inside and outside do not have corresponding meanings to the terms inner and outer, and the terms inside and outside shall have appropriate meanings as the context permits or requires. 
     The improvements herein to the prior art are best understood by reference to  FIG. 1  showing a prior art concrete insert  20 . Prior art concrete insert  20  comprises a housing  22  having an elongate center portion  24  and longitudinal sides  26  depending from outer longitudinal bend lines  30  and extending to inner longitudinal bend lines  32 . Longitudinal flanges  28  depend from inner longitudinal bend lines  32  transverse to longitudinal sides  26  and extend in mutually divergent relation. Longitudinal flanges may have stud apertures  62 . Longitudinal sides  26  have rebar apertures  60 . Elongate center portion  24  has nut access slot  48  with nut access slot cap  58  (not shown in  FIGS. 2-15  for clarity). Nut access slot cap  58  covers nut access slot  48  when the concrete insert is attached to the form in which concrete panels are cast and left in nut access slot  48  until the concrete hardens and the form is removed. Nut access slot cap  58  may then be removed anytime prior to mounting of the concrete panel (not shown) to the building (not shown). Prior art concrete insert  20  has a prior art plastic nut box insert  34  defining a concrete free nut box  46  or channel. Nut  50  with threaded aperture  52  comprises recessed seat  54  which carries biasing spring  56  which together travel along nut box  46 .  FIG. 1  shows a typical metal prior art housing  22  with open bottom and open ends covered by prior art plastic nut box insert  34 . Prior art nut box insert  34  has bottom  36  supported by punched nut box insert supports  44  and has plastic nut box insert end  38  to prevent wet concrete from entering the nut box, and opposing plastic nut box insert flanges  40  at each end of the housing  22 . Plastic nut box insert flanges  40  have mounting apertures  42  for attaching the concrete insert  20  to a concrete form (not shown) typically by nailing concrete insert  20  to the concrete form through mounting apertures  42 . 
     With respect to the following embodiments of the invention, it is to be understood that the inventive concrete insert would usually be sold with an access slot cover  58  installed therein, however access slot covers may be sold separately, and installed as required. Such access slot covers  58  could also be reusable. Alternatively, the user may supply their own means for sealing nut access slot ( 128 ,  228 ,  328 ,  428 ) before forming, such as by the application of a strip of duct tape over the elongate center portion ( 104 ,  204 ,  304 ,  404 ). However, preferably a plastic access slot cover  58  is mounted in nut access slot ( 128 ,  228 ,  328 ,  428 ) during manufacture, such as by a friction fit, for removal after forming. 
       FIG. 2  is a perspective view of a first embodiment of a concrete insert, namely, concrete insert  100 . Concrete insert  100  has a housing  102  comprising a substantially flat elongate center portion  104 , having an outer attachment surface which is usually substantially flush with the mounting surface of the concrete wall panel in which concrete insert  100  is to be used. Housing  102  also has mounting flanges  105  each comprising mounting flange aperture  106 , for mounting concrete insert  100  to a form. Mounting flanges  105  extend longitudinally from each end of elongate center portion  104 , preferably, but not necessarily co-planer with elongate center portion  104 . 
     Elongate center portion  104  is longitudinally bounded by substantially parallel outer longitudinal bend lines  110  and has a longitudinally oriented nut access slot  128  therebetween for the insertion of a threaded fastener, usually a bolt or threaded rod (not shown). Opposing longitudinal sides  107  (of Housing  102 ) depend inwardly from outer longitudinal bend lines  110  (preferably in mutually divergent relation, although opposing longitudinal sides  107  may be parallel to each other for example), to inner longitudinal bend lines  112  (preferably parallel to outer longitudinal bend lines  110 ), and terminate at transverse opposing longitudinal flanges  108  depending from inner longitudinal bend lines  112  and extending in mutually divergent relation (preferably parallel to elongate center portion  104 ). Opposing longitudinal sides  107  are delineated from longitudinal flanges  108  by inner longitudinal bend lines  112 . Longitudinal flanges  108  may be provided with stud apertures  134 . 
     Compression plate  116  is attached between longitudinal sides  107  by compression plate supports  117  or other conventional means such as riveting, bolting, welding or the like, which compression plate  116  carries on its inside surface a compression pad  118 . Compression plate  116  and compression pad  118  together form nut box insert  114 , located above rebar apertures  132 . Compression pad  118  need not necessarily be made of foam rubber but can be made of any resilient layer or layers capable of biasing nut  126  against the inside surface of elongate center portion  104  for selectively locating and maintaining the threaded aperture  127  of nut  126  in a preselected position under nut access slot  128  for receiving a bolt, threaded rod or other threaded fastener, for attaching the concrete wall panel to a building, typically through an aperture in a fixed position in a structural member of a building, typically a steel girder. 
     A nut  126  is slideably mounted in nut box  124  on bottom portion  120  of compression pad  118 , which in turn is carried by compression plate  116 . The preferably square nut  126  is supported in sliding frictional engagement along the inside surface of bottom portion  120  of compression pad  118  and the inside surface of elongate center portion  104 . Compression pad  118  has enlarged end portions  122  for preventing entry of wet cement into the nut box  124  during casting of concrete panels. End portions  122  are compressed by compression plate  116  against opposing sides  107  and elongate center portion  104  between nut access slot  128  and mounting flanges  105  to prevent wet concrete from entering the nut box during concrete panel forming. Compression pad end portions  122  may also be sized to ensure that threaded aperture  127  of nut  126  is always under nut access slot  128 . Nut  126  is readily longitudinally repositioned in nut box  124  by finger or other pressure. It is to be understood that preferably square nut  126  need not be square but may be in any shape to operably engage the inside surfaces of longitudinal sides  107  to constrain the nut  126  from turning in nut box  124  upon receiving a threaded fastener through nut access slot  128 . 
     Compression pad  118  may comprise one or more portions or sections, with each section or portion comprising one or more layers. For example bottom portion  120  and end portions  122 , of compression pad  118  may be separate pieces, although it is preferable for bottom portion  120  and end portions  122  to be unitary. Alternatively, compression pad  118  may comprise layers of different materials, either separate or unitary. Bottom portion should be sufficiently resilient to hold nut  126  firmly in place while receiving a threaded fastener while still not making the positioning of nut  126  by hand difficult or impossible. Alternatively if strong positioning strength is required tools may be required to position nut  126 . Further end portions  122  may be sized or contoured to best mate with the inside walls of longitudinal sides  107  and elongate center portion  104 , when sufficiently compress to prevent the seepage of wet concrete into nut box  124 . Porous foam is preferably not used even if significantly compressed due to the possibility of leaking. Foam rubber has been found to be particularly advantageous due to compression properties, both for biasing nut  126  and compressing end portions  122 , as well as being substantially non-porous. 
       FIG. 3  is a sectional side view of concrete insert  100  taken along line  3 - 3  of  FIG. 4 , and shows the same features as in  FIG. 2 .  FIG. 4  is an end view of concrete insert  100  and shows the same features as in  FIG. 2 .  FIG. 5  is a top plan view of concrete insert  100  and shows the same features as in  FIG. 2 .  FIG. 6  is a bottom plan view of concrete insert  100  and shows the same features as in  FIG. 2 . 
       FIG. 7  is a perspective view of a second embodiment of the concrete insert, namely, concrete insert  200 . Concrete insert  200  is identical to concrete insert  100  except that concrete insert  200  shows the ends of longitudinal sides  207  extending inwardly from the ends of elongate center portion  204  in mutually divergent relation. Accordingly, compression plate  216  and end portions  222  of compression pad  218  need not extend longitudinally past the perpendicular extensions of the ends of elongate center portion  204  so that mounting flange apertures  206  of mounting flanges  205  are not blocked by compression plate  216  or end portions  222  of compression pad  218 . 
     Concrete insert  200  has a housing  202  comprising a substantially flat elongate center portion  204 , having an outer attachment surface which is usually substantially flush with the mounting surface of the concrete wall panel in which concrete insert  200  is to be used. Housing  202  also has mounting flanges  205  each comprising mounting flange aperture  206 , for mounting concrete insert  200  to a form. Mounting flanges  205  extend longitudinally from each end of elongate center portion  204 , preferably, but not necessarily co-planer with elongate center portion  204 . 
     Elongate center portion  204  is longitudinally bounded by substantially parallel outer longitudinal bend lines  210  and has a longitudinally oriented nut access slot  228  therebetween for the insertion of a threaded fastener, usually a bolt or threaded rod (not shown). Opposing longitudinal sides  207  (of Housing  202 ) depend inwardly from outer longitudinal bend lines  210  (preferably in mutually divergent relation, although opposing longitudinal sides  207  may be parallel to each other for example), to inner longitudinal bend lines  212  (preferably parallel to outer longitudinal bend lines  210 ), and terminate at transverse opposing longitudinal flanges  208  depending from inner longitudinal bend lines  212  and extending in mutually divergent relation (preferably parallel to elongate center portion  204 ). Opposing longitudinal sides  207  are delineated from longitudinal flanges  208  by inner longitudinal bend lines  212 . Longitudinal flanges  208  may be provided with stud apertures  234 . 
     Compression plate  216  is attached between longitudinal sides  207  by compression plate supports  217  or other conventional means such as riveting, bolting, welding or the like, which compression plate  216  carries on its inside surface a compression pad  218 . Compression plate  216  and compression pad  218  together form nut box insert  214 , located above rebar apertures  232 . Compression pad  218  need not necessarily be made of foam rubber but can be made of any resilient layer or layers capable of biasing nut  226  against the inside surface of elongate center portion  204  for selectively locating and maintaining the threaded aperture  227  of nut  226  in a preselected position under nut access slot  228  for receiving a bolt, threaded rod or other threaded fastener, for attaching the concrete wall panel to a building, typically through an aperture in a fixed position in a structural member of a building, typically a steel girder. 
     A nut  226  is slideably mounted in nut box  224  on bottom portion  220  of compression pad  218 , which in turn is carried by compression plate  216 . The preferably square nut  226  is supported in sliding frictional engagement along the inside surface of bottom portion  220  of compression pad  218  and the inside surface of elongate center portion  204 . Compression pad  218  has enlarged end portions  222  for preventing entry of wet cement into the nut box  224  during casting of concrete panels. Compression pad end portions  222  may also be sized to ensure that threaded aperture  227  of nut  226  is always under nut access slot  228 . Nut  226  is readily longitudinally repositioned in nut box  224  by finger or other pressure. It is to be understood that preferably square nut  226  need not be square but may be in any shape to operably engage the inside surfaces of longitudinal sides  207  to constrain the nut  226  from turning in nut box  224  upon receiving a threaded fastener through nut access slot  228 . 
     Compression pad  218  may comprise one or more portions or sections with each section or portion comprising one or more layers. For example bottom portion  220  and end portions  222 , of compression pad  218  may be separate pieces, although it is preferable for bottom portion  220  and end portions  222  to be unitary. Alternatively, compression pad  218  may comprise layers of different materials, either separate or unitary. Bottom portion should be sufficiently resilient to hold nut  226  firmly in place while receiving a threaded fastener while still not making the positioning of nut  226  by hand difficult or impossible. Alternatively if strong positioning strength is required tools may be required to position nut  226 . Further end portions  222  may be sized or contoured to best mate with the inside walls of longitudinal sides  207  and elongate center portion  204 , when sufficiently compressed to prevent the seepage of wet concrete into nut box  224 . Porous foam is preferably not used even if significantly compressed due to the possibility of leaking. Foam rubber has been found to be particularly advantageous due to compression properties, both for biasing nut  226  and compressing end portions  222 , as well as being substantially non-porous. 
       FIG. 8  is a sectional side view of concrete insert  200  taken along line  8 - 8  of  FIG. 9 , and shows the same features as in  FIG. 7 .  FIG. 9  is a sectional end view of concrete insert  200  and shows the same features as in  FIG. 7 .  FIG. 10  is a top plan view of concrete insert  200  and shows the same features as in  FIG. 7 .  FIG. 11  is a bottom plan view of concrete insert  200  and shows the same features as in  FIG. 7 . 
       FIG. 12  is a perspective view of a third embodiment of the concrete insert, namely, concrete insert  300 . Concrete insert  300  has a housing  302  comprising a substantially flat elongate center portion.  304 , having an outer attachment surface which is usually substantially flush with the mounting surface of the concrete wall panel in which concrete insert  300  is to be used. 
     Elongate center portion  304  is longitudinally bounded by substantially parallel outer longitudinal bend lines  310  and has a longitudinally oriented nut access slot  328  therebetween for the insertion of a threaded fastener, usually a bolt or threaded rod (not shown). Opposing longitudinal, sides  307  (of Housing  302 ) depend inwardly from outer longitudinal bend lines  110  (preferably in mutually divergent relation, although opposing longitudinal sides  307  may be parallel to each other for example), to inner longitudinal bend lines  312  (preferably parallel to outer longitudinal bend lines  310 ), and terminate at transverse opposing longitudinal flanges  308  depending from inner longitudinal bend lines  312  and extending in mutually divergent relation (preferably parallel to elongate center portion  304 ). Opposing longitudinal sides  307  are delineated from longitudinal flanges  308  by inner longitudinal bend lines  312 . Longitudinal flanges  308  may be provided with stud apertures  334 . 
     Compression plate  316  is attached between longitudinal sides  307  by compression plate supports  317  or other conventional means such as riveting, bolting, welding or the like. Attached to Compression plate  316  are opposing compression plate ends  323  for covering the open ends of housing  302  bounded by compression plate  316 , opposing sides  307  and elongate center portion  304  between nut access slot  328  and mounting flanges  305  to prevent wet concrete from entering the nut box  324  during concrete panel forming. Attached to compression end plates  323  are opposing mounting flanges  305  each comprising mounting flange aperture  306  for mounting concrete insert  300  to a form. Mounting flanges  305  extend longitudinally from each end of elongate center portion  304 , preferably, but not necessarily co-planer with elongate center portion  304 . 
     Compression plate  316  carries on its inside surface a compression pad  318 . Compression plate  316 , compression plate ends, compression plate mounting flanges  305  and compression pad  318  together form nut box insert  314 , located above rebar apertures  332 . Compression pad  318  need not necessarily be made of foam rubber but can be made of any resilient layer or layers capable of biasing nut  326  against the inside surface of elongate center portion  304  for selectively locating and maintaining the threaded aperture  327  of nut  326  in a preselected position under nut access slot  328  for receiving a bolt, threaded rod or other threaded fastener, for attaching the concrete wall panel to a building, typically through an aperture in a fixed position in a structural member of a building, typically a steel girder. 
     A nut  326  is slideably mounted in nut box  324  on bottom portion  320  of compression pad  318 , which in turn is carried by compression plate  316 . The preferably square nut  326  is supported in sliding frictional engagement along the inside surface of bottom portion  320  of compression pad  318  and the inside surface of elongate center portion  304 . Compression pad  318  may have has enlarged end portions  322  for sealing any gaps between compression plate ends  323  and housing  302  for preventing entry of wet cement into the nut box  324  during casting of concrete panels. Compression pad end portions  322  may also be sized to ensure that threaded aperture  327  of nut  326  is always under nut access slot  328 . Nut  326  is readily longitudinally repositioned in nut box  324  by finger or other pressure. It is to be understood that preferably square nut  326  need not be square but may be in any shape to operably engage the inside surfaces of longitudinal sides  307  to constrain the nut  326  from turning in nut box  324  upon receiving a threaded fastener through nut access slot  328 . 
     Compression pad  318  may comprise, one or more portions or sections, with each section or portion comprising one or more layers. For example bottom portion  320  and end portions  322 , of compression pad  318  may be separate pieces, although it is preferable for bottom portion  320  and end portions  322  to be unitary. Alternatively, compression pad  318  may comprise layers of different materials, either separate or unitary. Bottom portion should be sufficiently resilient to hold nut  326  firmly in place while receiving a threaded fastener while still not making the positioning of nut  326  by hand difficult or impossible. Alternatively if strong positioning strength is required tools may be required to position nut  326 . Further end portions  322  may be sized or contoured to best mate with the inside walls of longitudinal sides  307  and elongate center portion  104 , when sufficiently compress to prevent the seepage of wet concrete into nut box  324 . Porous foam is preferably not used even if significantly compressed due to the possibility of leaking. Foam rubber has been found to be particularly advantageous due to compression properties, both for biasing nut  326  and compressing end portions  322 , as well as being substantially non-porous. 
     Alternatively, the mounting flanges  105  of concrete insert  100  may be used in concrete insert  300 , in which case compression plate mounting flanges  305  (which would otherwise be attached to compression plate ends  323 ) would be omitted. 
       FIG. 13  is a sectional side view of concrete insert  300  taken along line  13 - 13  of  FIG. 12 , and shows the same features as in  FIG. 12 . 
       FIG. 14  is a perspective view of a fourth embodiment of the concrete insert, namely, concrete insert  400 . Concrete insert  400  is identical to concrete insert  300  except that concrete insert  400  shows the ends of longitudinal sides  407  extending inwardly from the ends of elongate center portion  404  in mutually divergent relation. Accordingly, compression plate  416  and end portions  422  of compression pad  418  need not extend longitudinally past the perpendicular extensions of the ends of elongate center portion  404  of  FIG. 14  so that mounting flange apertures  406  of mounting flanges  405  are not blocked by compression plate  416  or end portions  422  of compression pad  418 . 
     Elongate center portion  404  is longitudinally bounded by substantially parallel outer longitudinal bend lines  410  and has a longitudinally oriented, nut access slot  428  therebetween for the insertion of a threaded fastener, usually a bolt or threaded rod (not shown). Opposing longitudinal sides  407  (of Housing  402 ) depend inwardly from outer longitudinal bend lines  410  (preferably in mutually divergent relation, although opposing longitudinal sides  407  may be parallel to each other for example), to inner longitudinal bend lines  412  (preferably parallel to outer longitudinal bend lines  410 ), and terminate at transverse opposing longitudinal flanges  408  depending from inner longitudinal bend lines  412  and extending in mutually divergent relation (preferably parallel to elongate center portion  404 ). Opposing longitudinal sides  407  are delineated from longitudinal flanges  408  by inner longitudinal bend lines  412 . Longitudinal flanges  408  may be provided with stud apertures  434 . 
     Compression plate  416  is attached between longitudinal sides  407  by compression plate supports  417  or other conventional means such as riveting, bolting, welding or the like. Attached to Compression plate  16  are opposing compression plate ends  423  for covering the open ends of housing  402  bounded by compression plate  416 , opposing sides  407  and elongate center portion  404  between nut access slot  428  and mounting flanges  405  to prevent wet concrete from entering the nut box  424  during concrete panel forming. Attached to compression end plates  423  are opposing mounting flanges  405  each, comprising mounting flange aperture  406 , for mounting concrete insert  400  to a form. Mounting flanges  405  extend longitudinally from each end of elongate center portion  404 , preferably, but not necessarily co-planer with elongate center portion  404 . 
     Compression plate  416  carries on its inside surface a compression pad  418 . Compression plate  416 , compression plate ends, compression plate mounting flanges  405  and compression pad  418  together form nut box insert  414 , located above rebar apertures  432 . Compression pad  418  need not necessarily be made of foam rubber but can be made of any resilient layer or layers capable of biasing nut  426  against the inside surface of elongate center portion  404  for selectively locating and maintaining the threaded aperture  427  of nut  426  in a preselected position under nut access slot  428  for receiving a bolt, threaded rod or other threaded fastener, for attaching the concrete wall panel to a building, typically through an aperture in a fixed position in a structural member of a building, typically a steel girder. 
     A nut  426  is slideably mounted in nut box  424  on bottom portion  420  of compression pad  418 , which in turn is carried by compression plate  416 . The preferably square nut  426  is supported in sliding frictional engagement along the inside surface of bottom portion  420  of compression pad  418  and the inside surface of elongate center portion  404 . Compression pad  418  may have has enlarged end portions  422  for sealing any gaps between compression plate ends  423  and housing  402  for preventing entry of wet cement into the nut box  424  during casting of concrete panels. Compression pad end portions  422  may also be sized to ensure that threaded aperture  427  of nut  426  is always under nut access slot  428 . Nut  426  is readily longitudinally repositioned in nut box  424  by finger or other pressure. It is to be understood that preferably square nut  426  need not be square but may be in any shape to operably engage the inside surfaces of longitudinal sides  407  to constrain the nut  426  from turning in nut box  424  upon receiving a threaded fastener through nut access slot  428 . 
     Compression pad  418  may comprise one or more portions or sections, with each section or portion comprising one or more layers. For example bottom portion  420  and end portions  422 , of compression pad  418  may be separate pieces, although it is preferable for bottom portion  420  and end portions  422  to be unitary. Alternatively, compression pad  418  may comprise layers of different materials, either separate or unitary. Bottom portion should be sufficiently resilient to hold nut  426  firmly in place while receiving a threaded fastener while still not making the positioning of nut  426  by hand difficult or impossible. Alternatively if strong positioning strength is required tools may be required to position nut  426 . Further end portions  422  may be sized or contoured to best mate with the inside walls of longitudinal sides  407  and elongate center portion  404 , when sufficiently compressed to prevent the seepage of wet concrete into nut box  424 . Porous foam is preferably not used even if significantly compressed due to the possibility of leaking. Foam rubber has been found to be particularly advantageous due to compression properties, both for biasing nut  426  and compressing end portions  422 , as well as being substantially non-porous. 
     Alternatively, the mounting flanges  105  of concrete insert  100  may be used in concrete insert  400 , in which case compression plate mounting flanges  405  (which would otherwise be attached to compression plate ends  423 ) would be omitted. 
       FIG. 15  is a sectional side view of concrete insert  400  taken along line  15 - 15  of  FIG. 14 , and shows the same features as in  FIG. 14 . 
     The above embodiments are to be understood as examples and not as limiting the scope of the invention. 
     PARTS LIST 
     
         
           20  PRIOR ART CONCRETE INSERT 
           22  HOUSING 
           24  ELONGATE CENTER PORTION 
           26  LONGITUDINAL SIDES OF HOUSING 
           28  LONGITUDINAL FLANGES 
           30  OUTER LONGITUDINAL BEND LINES 
           32  INNER LONGITUDINAL BEND LINES 
           34  PRIOR ART PLASTIC NUT BOX INSERT 
           36  BOTTOM OF NUT BOX INSERT 
           38  NUT BOX INSERT ENDS 
           40  NUT BOX INSERT FLANGES 
           42  MOUNTING APERTURES (IN NUT BOX INSERT FLANGES) 
           44  PUNCHED NUT BOX INSERT SUPPORTS 
           46  NUT BOX 
           48  NUT ACCESS SLOT 
           50  NUT (WITH SPRING RECESS) 
           52  THREADED APERTURE (OF NUT) 
           54  RECESSED SEAT (OF NUT) 
           56  BIASING SPRING 
           58  NUT ACCESS SLOT CAP 
           60  REBAR APERTURES 
           62  STUD APERTURES 
           100  FIRST EMBODIMENT OF CONCRETE INSERT 
           102  HOUSING, 
           104  ELONGATE CENTER PORTION 
           105  MOUNTING FLANGES 
           106  MOUNTING FLANGE APPERTURES 
           107  LONGITUDINAL SIDES OF HOUSING 
           108  LONGITUDINAL FLANGES 
           110  OUTER LONGITUDINAL BEND LINES 
           112  INNER LONGITUDINAL BEND LINES 
           114  COMPOUND NUT BOX INSERT 
           116  COMPRESSION PLATE 
           117  COMPRESSION PLATE SUPPORTS 
           118  COMPRESSION PAD 
           120  BOTTOM PORTION (OF COMPRESSION PAD) 
           122  END PORTIONS (OF COMPRESSION PAD) 
           124  NUT BOX 
           126  NUT 
           127  THREADED APERTURE (OF NUT) 
           128  NUT ACCESS SLOT 
           132  REBAR APERTURES 
           134  STUD APERTURES 
           200  SECOND EMBODIMENT OF CONCRETE INSERT 
           202  HOUSING 
           204  ELONGATE CENTER PORTION 
           205  MOUNTING FLANGES 
           206  MOUNTING FLANGE APPERTURES 
           207  LONGITUDINAL SIDES OF HOUSING 
           208  LONGITUDINAL FLANGES 
           210  OUTER LONGITUDINAL BEND LINES 
           212  INNER LONGITUDINAL BEND LINES 
           214  COMPOUND NUT BOX INSERT 
           216  COMPRESSION PLATE 
           217  COMPRESSION PLATE SUPPORTS 
           218  COMPRESSION PAD 
           220  BOTTOM PORTION (OF COMPRESSION PAD) 
           222  END PORTIONS (OF COMPRESSION PAD) 
           224  NUT BOX 
           226  NUT 
           227  THREADED APERTURE (OF NUT) 
           228  NUT ACCESS SLOT 
           232  REBAR APERTURES 
           234  STUD APERTURES 
           300  THIRD EMBODIMENT OF CONCRETE INSERT 
           302  HOUSING 
           304  ELONGATE CENTER PORTION 
           305  COMPRESSION PLATE MOUNTING FLANGES 
           306  COMPRESSION PLATE MOUNTING FLANGE APPERTURES 
           307  LONGITUDINAL SIDES OF HOUSING 
           308  LONGITUDINAL FLANGES 
           310  OUTER LONGITUDINAL BEND LINES 
           312  INNER LONGITUDINAL BEND LINES 
           314  COMPOUND NUT BOX INSERT 
           316  COMPRESSION PLATE 
           317  COMPRESSION PLATE SUPPORTS 
           318  COMPRESSION PAD 
           320  BOTTOM PORTION (OF COMPRESSION PAD) 
           322  END PORTIONS (OF COMPRESSION PAD) 
           323  COMPRESSION PLATE ENDS 
           324  NUT BOX 
           326  NUT 
           327  THREADED APERTURE (OF NUT) 
           328  NUT ACCESS SLOT 
           332  REBAR APERTURES 
           334  STUD APERTURES 
           400  FOURTH EMBODIMENT OF CONCRETE INSERT 
           402  HOUSING 
           404  ELONGATE CENTER PORTION 
           405  COMPRESSION PLATE MOUNTING FLANGES 
           406  COMPRESSION PLATE MOUNTING FLANGE APPERTURES 
           407  LONGITUDINAL SIDES OF HOUSING 
           408  LONGITUDINAL FLANGES 
           410  OUTER LONGITUDINAL BEND LINES 
           412  INNER LONGITUDINAL BEND LINES 
           414  COMPOUND NUT BOX INSERT 
           416  COMPRESSION PLATE 
           417  COMPRESSION PLATE SUPPORTS 
           418  COMPRESSION PAD 
           420  BOTTOM PORTION (OF COMPRESSION PAD) 
           422  END PORTIONS (OF COMPRESSION PAD) 
           423  COMPRESSION PLATE ENDS 
           424  NUT BOX 
           426  NUT 
           427  THREADED APERTURE (OF NUT) 
           428  NUT ACCESS SLOT 
           432  REBAR APERTURES 
           434  STUD APERTURES