Patent Publication Number: US-2021164509-A1

Title: Snap nut concrete anchor assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation application of U.S. non-provisional application Ser. No. 15/923,052 filed Mar. 16, 2018 and the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to anchors for use in concrete substrates. However, the general concept disclosed herein could be used in any application in which a threaded male shaft is to be secured in a threaded female receptacle to another the shaft or the receptacle. 
     Concrete structures are typically formed from concrete substrates, being either the type made off site (commonly known as pre-cast concrete substrates) or the type made on site (commonly known as cast in place (CIP) concrete substrates). Both types of concrete substrates may be reinforced with metal of other suitable materials depending on their intended application. It is often necessary to attach fixtures and fittings to concrete substrates, the nature of which might vary according to the type of structure. For instance, many buildings have floors or walls made from concrete panels from which ducts or other items may be suspended, bridges may include concrete portions from which signage and other items must be hung, and so on. This often requires an anchor to be secured to or within the concrete substrate such that the fixtures and fittings can be mechanically fastened to the anchor. The anchors of interest here are those which are installed during production of the substrate, rather than those retrofitted to the concrete substrate after production. The general process for installing these anchors includes the steps of setting out a form board, mounting the anchor in the desired position on the form board, securing the anchor to the form board, pouring concrete over the form board and the anchor, removing the form board from the set concrete so as to reveal at least a portion of the anchor adjacent the now removed form board. The revealed portion of the anchor may expose a receptacle into which a threaded rod may be received and secured. In other words, these anchors comprise an anchor point accessible from the underside of the concrete substrate and which typically take the form of a threaded bore into which a bolt or threaded shaft can be fastened. 
     Because different structural designs may require different diameter bolts or threaded shafts, numerous anchor designs have been proposed such that a single threaded bore anchor structure mentioned above is able to accommodate different sized/diameter bolts or threaded rods. Typically, such threaded bore structures embody some sort of separable split nut concept in which a threaded bore includes at least two separable threaded parts or portions. The parts are able to be forced apart radially from a central longitudinal axis of the rod or bolt and then are biased back together so that interior female threads of the bore portions complementarily engage the external male threads of the rod or bolt. Many of these designs allow a rod or bolt to be installed by simply forcing the rod or bolt axially into the bore portions spreading the bore portions apart and then allowing the bore portions to be axially biased radially back inward (e.g., by a flexible biasing member) onto the rod or bolt. 
     At least U.S. Pat. Nos. 4,368,606 and 5,468,105 teach the biased split nut concept embodied in an anchor that is attachable to formwork (e.g., wooden formwork). U.S. Pat. No. 4,007,563 discloses an anchor for setting in metal decking. The present application also contemplates replacement of the female thread receptacle disclosed therein with the snap locking system described below. All three patents are incorporated by reference herein in their entirety. 
     While split nut designs provide a certain flexibility with axial installation and even accommodation of multiple thread sizes, this structure can also present some reliability challenges. Specifically, mating between the threads of the rod and nut portions is important, so it is best when the alignment of the separate bore portions is maintained and it would be preferred if the user could have assurances that proper alignment of the portions and complete collapse of portions onto the rod or bolt has occurred. Furthermore, assurances that a user has inserted a rod or bolt a sufficient distance into the anchor is beneficial. 
     It is therefore an object of the present invention to provide an anchor which is easy to install and whose integrity is not affected by careless installation. 
     SUMMARY OF THE INVENTION 
     According to a first aspect of the invention, there is provided a base member connectable to a support member to form an anchor assembly mountable to a form board or metal decking on which wet concrete may be poured during formation of a concrete substrate, the base member includes a mounting portion for mounting the anchor assembly to the form board. The base member may also include a main guide having first and second generally opposed ends, the first end being open to facilitate insertion of the support member into the main guide. The main guide may also including a generally tubular body upstanding from the mounting portion. The tubular body may have an internal cross-section sized and shaped to correspond closely with the cross-section of the support member so as to create a snug fit between the main guide and the support member. 
     Advantageously the base member includes at least one reinforcement member to improve the rigidity and or strength of the main guide. The reinforcement member may comprise at least one web arranged between the main guide and the mounting portion and preferably spaced equidistantly around the main guide. 
     One type of reinforcement member may include at least one rib arranged axially and projecting inwardly. The at least one rib may add increased stiffness and lateral support between the main guide and the support member to resist inadvertent deformation and/or disassembly of those parts. The plurality of ribs circumferentially spaced around the main guide and each disposed between two neighboring channels. 
     According to a second aspect of the invention, there is provided a cast in place anchor assembly comprising a base member as described above and a support member located in the main guide of the base member. The support member may include attachment means accessible through the second end of the main guide. For instance, the support member may comprise a shank having opposed first and second ends. 
     Specifically, the support member includes an outer housing, the outer housing being defined by a longitudinal axis, the outer housing including a wall, the outer housing also including a connector opening at a first end thereof for receiving the threaded shaft/shank, the outer housing further including an assembly opening at a second end opposite the first end thereof, the housing wall including an inner surface defining a inner space. 
     The support member further includes a jaw assembly disposed in the inner space, the jaw assembly including at least one threaded jaw the threads of which selectively engage threads of the shaft, the jaw assembly further including a bias member for biasing the at least one thread jaw toward the longitudinal axis. A holding member is provided that prevents the bias member from moving the at least one threaded jaw toward the longitudinal axis. 
     The jaw assembly may take two different configurations. In a first jaw assembly configuration, the holding member prevents the at least one threaded jaw from moving toward the central longitudinal axis. Furthermore, in the first configuration the threaded shaft is inserted into the connector opening, to contact the holding member to release the at least one threaded jaw to move toward the central longitudinal axis and into biased contact with the threaded shaft to define a second jaw assembly configuration. 
    
    
     
       DRAWINGS 
       By way of example only, embodiments of the present invention will now be described in detail, with reference being made to the accompanying drawings, in which: 
         FIG. 1A  is a first perspective view of an anchor assembly of the present invention; 
         FIG. 1B  is a side perspective cutaway view of the anchor assembly of  FIG. 1  in a pre-snap configuration receiving a threaded shaft; 
         FIG. 1C  is a side perspective cutaway view of the anchor assembly of  FIG. 1  in a post-snap configuration; 
         FIG. 1D  is a side cross-sectional view of the anchor assembly of  FIG. 1  in a pre-snap configuration with a separable support member; 
         FIG. 2A  is top perspective view of the jaw assembly of  FIG. 1B  in a first pre-snap configuration; 
         FIG. 2B  is top perspective view of the jaw assembly of  FIG. 1B  in a first pre-snap configuration with the resilient member and upper guide removed; 
         FIG. 2C  is top perspective view of the jaw assembly of  FIG. 1B  in a second post-snap configuration; 
         FIG. 3  is an exploded perspective view of the individual elements of the jaw assembly of  FIG. 1B . 
         FIG. 4  are top views and top perspective views of the support member of  FIG. 1B  including a portion of the jaw assembly of  FIG. 1B . 
         FIGS. 5A and 5B  are side cross-sectional views of the support member of  FIG. 1B  in the pre-snap configuration. 
         FIGS. 6A and 6B  are side cross-sectional views of the support member of  FIG. 1B  in the post-snap configuration. 
         FIG. 7A  is a side perspective cutaway view of a second embodiment of the present invention; 
         FIG. 7B  is an exploded view of the jaw assembly of  FIG. 7A  of the present invention. 
         FIG. 7C  are top views and top perspective views of the support member of  FIG. 1B  including a portion of the jaw assembly of  FIG. 1B . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIGS. 1A and 1B  show an embodiment of an anchor assembly of the present invention, which is generally indicated as  100 . Anchor assembly  100  includes a support member  210  to be supported within a base member  150 .  FIG. 1B  shows a threaded shaft  50  which may be inserted into anchor assembly  100  in a direction D. Base member  150  may be mounted to a form board (not shown) for defining a perimeter of a poured concrete structure. Base member  150  may include a form engagement support  154  and a raised main guide  158  for receiving and positioning support member  210  relative to the form after assembly. Raised main guide  158  may be further reinforced by ribs or structural aids  160  that hold raised main guide  158  securely relative to base member  150 . Structural aids may come in various forms and may include channels  164  through which fasteners (e.g., nails) pass and then enter the form for securing anchor assembly  100  to the form. Also shown in  FIGS. 1A and 1B  is a plug or cover  260  to be discussed in more detail below. 
       FIGS. 1B-1D  show perspectives cross-sectional view of the support member  210  of  FIG. 1A .  FIG. 1B  has an axis A-A. Support member  210  includes an outer housing  230  and a jaw assembly  250 . Outer housing  230  includes side walls  232  and a flange  238  which extends radially outward from side wall  232 . An underside of flange  238  provides a bearing surface for resisting pull out of support member  210  from the concrete. Plug  260  may serve as a cover that locks (e.g., threadably) into flange  238  for access to an interior of support member  210 . Side wall  232  includes and inner surface  240  that defines an inner space  244 .  FIG. 1D  shows how side wall  232  may also include upper and lower portions  233  and  234  respectively. Furthermore, upper portion  233  and lower portion  234  may connect at respective female and male threads  235  and  236 . Inner surface  240  may also include an incline surface portion  237  that narrows in diameter toward an insertion end  212  of support member  210 . 
     When assembled, jaw assembly  250  is located within inner space  244  as shown in  FIGS. 1B &amp;1C .  FIGS. 2A-2C  show jaw assembly  250  assembled outside of support member  210 . In addition,  FIG. 3  shows individual elements of Jaw assembly  250  in perspective. Jaw assembly  250  includes a first jaw  300 A and second jaw  300 B. Each of jaws  300 A and  300 B include interior threads  302 , inclined surfaces  304 , biasing notches  306  and alignment holes  308 . Jaws  300 A and  300 B are assembled into a generally cylindrical arrangement as shown in  FIGS. 2A-2C . A resilient bias member  310  surrounds jaws  300 A,  300 B and bias jaws  300 A,  300 B toward central axis A-A. Openings  308  simultaneously receive an alignment pin  320 . Alignment pin  320  links jaws  300 A,  300 B to limit the relative movement (e.g., relative axial movement) between jaw  300 A and jaw  300 B during operation. 
     Jaw assembly  250  also includes a holding member  340 . Holding member  340  can assume at least two positions within jaw assembly  250  (discussed in further detail below). Holding member  340  includes a bottom surface  342 , lower members  343 , resilient legs  344 , and a spring guide  346 . Lower member  343  of holding member  340  extends at a bottom of holding member  340  to surround or trap pin  320  within holding member  340 . A resilient member  350  is disposed in inner space  244  between cover  260  of outer housing  230  and holding member  340  to bias holding member  340  downward toward and against or around alignment pin  320 . An upper guide  360  is also disposed in inner space  244  between outer housing  230  and holding members  340 . Upper guide  360  includes an inner wall  362  that defines an opening  364 . Opening  364  serves as a means of accommodating and confining or guiding resilient member  350  radially such that inner wall  362  restricts radial movement of holding member  340 . In turn spring guide  346  of holding member  340  confines resilient member  350  to axial movement. 
       FIG. 4  shows an anti-rotational feature of the present invention. Specifically,  FIG. 4A  shows a perspective view of jaws  300 A and  300 B assembled together with alignment pin  320  passing through alignment holes  308 . Alignment pin  320  extends past a radial extent of jaws  300 A and  300 B. Side wall  232  includes an axially extending slots  370 . During assembly, a portion of jaw assembly  250  is inserted into inner space  244 . As this insertion occurs cantilevered portions of alignment pin  320  extend into slots  370  so that alignment pin  320  cannot rotate relative support member  210 . Since jaws  300 A and  300 B are also unable to rotate relative to alignment pin  320 , jaws  300 A,  300 B are also unable to rotate relative to support member  210 . Alignment pin  320  therefore limits and/or resists relative axial misalignment of jaws  300 A and  300 B as well as limits and/or resists rotation (R, see  FIG. 4 ) of jaws  300 A,  300 B relative to support member  210  in a plane through pin  320  and through central longitudinal axis A-A or about an axis perpendicular to both A-A and a longitudinal axis of alignment pin  320 . Said another way, alignment pin  320  limits rotational R misalignment of jaws  300 A,  300 B relative to central axis A-A. Such limits allow rotation, but maintain jaws  300 A,  300 B generally symmetrical relative to central axis A-A. 
       FIGS. 1B, 1D, 2A, 2B, 5A and 5B  each show jaw assembly  250  in a first pre-snap configuration. On the other hand,  FIGS. 1C, 2C, 6A, and 6B  each show jaw assembly  250  in a second post-snap configuration.  FIGS. 5A and 5B  show jaw assembly  250  in the pre-snap configuration with a bottom  342  of holding member  340  still positioned below a bottom surface  309  of slot  307 .  FIGS. 6A and 6B  show jaw assembly  250  in the post-snap configuration with a bottom  342  of holding member  340  above or clearing a bottom surface  309  of slot  307 . 
     The operation of jaw assembly  250  in support member  210  will now be described with reference to the Figures. As mentioned above, jaw assembly  250  can take two configurations. In operation, a user desires to secure a threaded rod  50  to and in a jaw assembly  250  disposed in a support member  210  that has been encased in cured concrete. For example, support member  210  is secured in a ceiling slab so that an end  212  of holding member  210  is at a lower edge of the ceiling slab exposing access opening  214 . A user may then, for example, look up from a lower floor, extend the threaded rod  50  into access opening  214 , and secure the rod to jaw assembly  250  in the following manner. 
     Referring to  FIGS. 1B, 1D, 2B, 2C, 5A and 5B  which display the pre-snap configuration, radial biasing member  310  biases each jaw  300 A,  300 B toward central axis A-A. Furthermore, holding member  340  is located between and separates or stops jaws  300 A and  300 B against a biasing force of biasing member  310 . In other words, holding member  340  is disposed between jaws  300 A,  300 B so that bias member  310  biases jaws  300 A and  300 B against holding member  340 .  FIGS. 2A &amp; 2B  also show the notch  307  in an upper portion of each of jaws  300 A and  300 B. In addition, as mentioned above, each notch  307  includes a bottom surface  309 . A portion of holding member  340  extends below bottom surface  309  and is therefore, in the pre-snap configuration, is positioned between jaws  300 A and  300 B. 
     Furthermore, in the pre-snap configuration, longitudinal biasing member  350  forces holding member  340  downward and in contact with alignment pin  320 . Specifically holding member  340  is forced by longitudinal biasing member  350  so that resilient legs  344  remain extended around alignment pin  320 . Side walls  362  of upper guide  360  surround and are generally adjacent to bias member  350  and holding member  340  and so keep them aligned during any axial movement. 
     During rod installation, rod  50  is extended into inner space  244  until it engages lower member  343  of holding member  340 . As rod  50  passes through jaws  300 A,  300 B, jaws  300 A,  300 B are kept in alignment (e.g., axial) by alignment pin  320 . In other words, alignment pin permits, but limits relative axial miss alignment between jaws  300 A and  300 B. The user then continues to insert rod  50  by pushing holding member  340  upward in direction D away from and relative to jaws  300 A,  300 B and against the biasing force of longitudinal resilient member  350 . Also overcome by the pushing force is the friction between holding member  340  and jaws  300 A and  300 B generated by bias member  310 . Lower member  343  may also limit any upward movement of holding member  340  as rod  50  moves holding member  340  upward relative to jaws  300 A and  300 B. Resilient legs  344  which initially surround alignment pin  320  now flex outward to release alignment pin  320  and then back inward as holding member  340  is pushed away from alignment pin  320 . While resilient legs  344  are flexible, they possess sufficient strength such that a significant and noticeable rod  50  force must be exerted on holding member  340  by rod  50  of a user to overcome alignment pin  320 /holding member  340  locking forces. Specifically, at least a biasing force of legs  344 , a frictional force between holding member  340  and jaws  300 A and  300 B, and a biasing force of biasing member  350  must be overcome to suddenly release alignment pin  320  from the lock of legs  344 . 
     When holding member  340  is pushed up sufficiently so that bottom surface  342  of holding member  340  is above bottom surface  309  of notch  307 , holding member  340  has cleared jaws  300 A and  300 B and resilient member  310  suddenly biases internal threads  302  of jaws  300 A,  300 B together until internal threads  302  engage external threads of rod  50  with a sudden impact. Again, alignment pin  320  minimizes or limits the possible misalignment (e.g., axial) of jaws  300 A,  300 B so that internal threads on both jaw  300 A and jaw  300 B effectively engage external jaws of rod  50 . After snapping, holding member  340  is then accommodated in notch  307  as shown best in  FIG. 2B . 
       FIGS. 2C, 6A and 6B  show the configuration of jaw assembly  250  in the post-snap configuration. After holder  340  is displace from between jaws  300 A,  300 B, and jaws  300 A and  300 B snap/collapse onto rod  50 , jaws  300 A and  300 B prevent axial removal of rod  50  from support member  210  except by rotation.  FIG. 5A  shows rod  50  engaging holding member  340  pre-snap and  FIG. 6A  shows rod  50  secured in jaws  300 A,  300 B post-snap. Furthermore, when rod  50  is loaded in a direction opposite direction D, inclined surface  304  of jaws  300 A,  300 B engages inclined surface  237  of inner space  244 . The result of the interaction of these inclined surfaces is that a downward loading of rod  50  in a direction opposite D results in a force on jaws  300 A,  300 B toward central axis A-A. Such a radially inward force prevents jaws  300 A,  300 B from separating and axially releasing rod  50 . 
     The fact that jaws  300 A and  300 B do not engage rod  50  until threaded rod  50  is inserted completely into the threads promotes a maximum thread engagement in the post-snap configuration. In other words, the present invention which triggers engagement only if at least a minimum predetermined rod insertion length is achieved lessens the possibility of an inadequate thread engagement during installation. Furthermore, a sudden impact of jaws  300 A and  300 B on rod  50  transfers energy to and along rod  50  to a hand of an installer to indicate to the installer that jaws  300 A and  300 B have engaged and rod  50  has been inserted sufficiently into opening  214 . Furthermore, the sudden release of legs  344  can be an indication to an installer that a minimum insertion length has been achieved. 
     The snap-nut assembly described above may be utilized in any anchoring system in which it is desired to axially secure a shaft such as a threaded shaft to a support structure. Therefore, the snap-nut assemblies disclosed herein may be integrated into various anchoring or connection systems including metal deck anchoring systems such as described in U.S. Pat. No. 4,007,563 to Nakagawa and which is incorporate herein by reference in its entirety. 
       FIG. 7A-7C  show an alternate embodiment of the anchor assembly of  FIGS. 1A and 1B . The anchor assembly is generally shown at  700  and is similarly to anchor assembly  100  as it also includes adjustable position locking threaded jaws. Anchor assembly  700  includes a support member  710 . Support member  710  includes a flange  738  at an upper end or assembly end. Support member  710  also includes a lower end or insertion end  712  with an insertion opening  714 , and an inner space  744  for receiving a jaw assembly  750 . Flange  738  includes a central cover  760  that defines an upper flange end of inner space  744 . Cover  760  is removable and lockable (e.g., with threads) to offer access to inner space  744  for assembly. Inner space  744  includes an inward facing inclined surface  737 . Inclined surface  737  slants downward from flange  738  toward a central longitudinal axis A-A of anchor assembly  700 . Jaw assembly  750  includes jaws  700 A and  700 B. Jaws  700 A and  700 B each include inner threads  702 , a radially inward inclined outer surface  704 , and an alignment passage  708 . Jaw assembly  750  also includes an alignment pin  720 , an alignment stop  740 , and a biasing member  755 . Biasing member  755  may be any resilient object such as a coil, leaf or wave spring that compresses to generate a continuous reactive biasing force. Biasing member  755  could also be a resilient solid member such as a piece of rubber (e.g., tube shaped). Alignment stop  740  includes a bottom surface  742 , an opening or passage  745  that could be a through passage, and a sidewall  746 . 
     When jaw assembly  750  is assembled, jaws  700 A and  700 B are positioned in inner space  744  such that outer surface  704  complementarily engages inclined surface  737 . Alignment pin  720  passes through openings  708  in jaws  700 A and  700 B and through stop  740 . Biasing member  755  is compressed between cover  780  and a top of each jaw  700 A and  700 B. The compressed biasing member  755  reacts to, forces, or urge jaws  700 A and  700 B longitudinally toward insertion end  712 . Because the inclined surfaces  737  are slanted or inclined inward, biasing member  755  ultimately also urges jaws  700 A and  700 B radially inward toward central longitudinal axis A-A. 
     Alignment pin  720  passes through stop  740  which at least in part serves to stabilize pin  720 . In addition, the arrangement of pin  720  relative to stop  740  avoids any direct contact between rod  50  and pin  720 . Alignment pin  740  also passes through jaws  700 A and  700 B such that alignment pin  720  limits any possible axial misalignment between jaws  700 A and  700 B. Alignment pin  720  may also be sized in openings  708  of jaws  700 A and  700 B to allow jaws  700 A and  700 B a limited freedom to pivot during insertion of rod  50  in order to most effectively accommodate rod  50 . 
     During installation, an installer inserts a rod  50  into insertion opening  714 . Rod  50  urges jaws  700 A and  700 B radially toward an assembly end and axially apart against the biasing force of biasing member  755 . Rod  50  is inserted into support member  710  until an end of rod  50  engages a bottom  742  of stop  740 . Bias member  775  continuously biases jaws  700 A,  700 B toward central axis A-A until rod  50  contacts a bottom  742  of alignment stop  740 . Rod  50  can then no longer be axially removed from support member  710 , but can only be removed from support member  710  by thread rotation. 
     The present invention disclosure may include written description and drawings that describe features in one embodiment that are not disclosed in another embodiment. The present invention contemplates interchanging such features.