Abstract:
A drop-in anchor includes a sleeve having a threaded region having an internal thread formed therein and a split region having at least two longitudinal channels formed therein. The channels define sections. The split region has inwardly tapered inner walls. A plug is configured for engagement with the sleeve at the split region. The plug has a top surface and defines a tapered shape. A bolt having a threaded portion and a through-bore extending longitudinally therethrough, is configured for threaded engagement with the sleeve threaded region. A setting member is configured for insertion into the bolt bore. The setting member engages the plug top surface and a force exerted on the setting member drives the plug into the sleeve split region so as to urge the split region sections axially outwardly. A method for securing the anchor in the opening in the structure is also disclosed.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention pertains to drop-in anchors. More particularly, the present invention pertains to a deep set drop-in anchor that properly self-sets even in deeply drilled bores, and is readily removable so that no portion of the anchor extends exteriorly from the structure after use.  
           [0002]    Various types of anchors are in wide-spread use in the construction industry. Typically these anchors are used to provide a means to anchor or secure an object to a structure, such as a wall or floor. In many applications, the object is secured to a solid (e.g., concrete) structure. These anchors are inserted into an opening (e.g., a bore or hole) in the structure and engage the walls of the opening. The anchors can be either removable or non-removable, e.g., permanent.  
           [0003]    Removable anchors are used, in one application, for temporary supports in tilt-wall construction. In such a use, the anchor is used to secure a shoe to a concrete floor that is temporarily brace a wall as wall is being lifted or tilted into position. In this application, once the wall is set and secured in place, the shoe must be removed, as does any part of the anchor that is above the surface of the floor.  
           [0004]    Anchors are known that include a split sleeve having inwardly tapered lower wall an upper threaded portion. A plug is forced into engagement with the tapered lower walls to frictionally engage the sleeve with the walls of the opening. A bolt or threaded rod is then engaged with the sleeve threads to secure the bolt or rod with the anchor.  
           [0005]    Another known type of removable anchor is a pin drive anchor. This type of anchor uses a sleeve that is inserted into a hole or bore formed in the structure. A sectioned or split plug having a reduced diameter is inserted into the sleeve and is set into place by forcing a setting pin or tool against the plug element. The force on the pin urges the sleeve outwardly to engage the inner walls of the bore. The sleeve can include threads for receiving a bolt or like threaded fastener.  
           [0006]    Still another type of removable anchor is a coil anchor. The type of anchor includes a threaded shank and a coil that is wound around a portion of the thread. The shank and coil are inserted into a bore having a predetermined depth. The shank is rotated so that the coil engages the walls of the bore while it is engaged by the shank threads.  
           [0007]    One type of non-removable anchor, referred to as a wedge anchor, includes a split sleeve with a reversed tapered wedge element formed at the end of a threaded shank. The sleeve and shank element are inserted into the bore and the shank is pulled so that the reversed tapered sides of the wedge engage the sleeve and urge the sleeve portions outwardly to engage the inner walls of the bore.  
           [0008]    Each of these types of anchors has its drawbacks. First, the wedge anchor cannot be removed after it is installed. Although this type of anchor has a high pull-out strength, it cannot be used in applications where the anchor is used in a temporary installation and is removed after use.  
           [0009]    The pin drive anchor, although in wide-spread use, must be used with a tool or pin of a predetermined length. In addition, these anchors typically have a limited depth to which they can be installed. This results in reduced loading capabilities.  
           [0010]    Like the pin drive anchor, the coil anchor also has limitations vis-a-vis anchor depth and coil engagement with the bore walls. If the bore depth is too great, and the anchor is not properly set, the shank may not fully engage the coil, thus resulting in less than intended load levels. In addition, these anchors typically require that a high torque be applied to the bolt to properly set the anchor.  
           [0011]    Accordingly, there exists a need for a drop-in anchor that can be removed after use. Desirably, such an anchor includes a wedge or plug that can be properly set within a sleeve regardless of the depth at which the anchor is set. Most desirably, such an anchor uses bolt for both setting the plug (e.g., as a setting tool) and securing an object to the structure in which the anchor is set. Also most desirably, the anchor can be used with a standard a reusable bolt.  
         SUMMARY OF THE INVENTION  
         [0012]    A drop-in anchor includes a partially threaded sleeve, a plug, a threaded shank having a through-bore and a setting member or tool. The present drop-in anchor provides a fastening system in which the fastening member (e.g., the bolt) can be removed after use so that no part of the fastening member does not extends from the structure after removal in which the anchor is installed.  
           [0013]    The anchor sleeve has a threaded region and a split region having at least two longitudinal channels formed therein. The channels define sections. In a current embodiment, the split region has four longitudinal channels defining four substantially identical sections. The split region has inwardly tapered inner walls.  
           [0014]    The plug is configured for engagement with the sleeve at the split region. The plug has a top surface and defining a tapered shape. Preferably, the taper of the plug complements the tapered inner walls of the sleeve split region.  
           [0015]    A shank, preferably formed as a shoulder bolt, has a threaded portion and a through-bore extending longitudinally therethrough. The threaded portion is configured for threaded engagement with the sleeve threaded region. In the preferred embodiment in which a shoulder bolt is used, the bolt shoulder is configured to engage an upper lip of the sleeve to assure proper positioning of the bolt in the sleeve.  
           [0016]    The setting member is configured for insertion into the bolt through-bore. The setting member engages the plug top surface. A force exerted on the setting member drives the plug into the sleeve split region so as to drive the split region sections axially outwardly.  
           [0017]    The setting member can be formed as a pin having a head. Striking the setting member head drives the setting member head into contact with the bolt head and drives the plug into the split region sections which drives the sections axially outward. This secures the anchor in the structure.  
           [0018]    A method for securing an anchor in an opening in a structure is also disclosed.  
           [0019]    These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0020]    The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein:  
         [0021]    [0021]FIG. 1 is a cross-sectional view of a drop-in anchor embodying the principles of the present invention;  
         [0022]    [0022]FIG. 2 is a cross-sectional view of the anchor sleeve;  
         [0023]    [0023]FIG. 3 is a bottom view of the sleeve, as viewing into the split section;  
         [0024]    [0024]FIG. 4 is a cross-sectional view of the threaded shank or shoulder bolt; and  
         [0025]    [0025]FIG. 5 is a top view of the shoulder bolt illustrating the through bore opening in the top of the bolt head; 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]    While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated. It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention”, relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.  
         [0027]    In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.  
         [0028]    Referring now to the figures and in particular to FIG. 1 there is shown a deep-set drop-in anchor  10  embodying the principles of the present invention. The anchor  10  includes a shell or sleeve  12 , a plug  14 , a threaded shank  16  having a bore formed longitudinally there in, indicated at  18 , and a setting pin  20 .  
         [0029]    The anchor  10  is removably set in a structure, such as in an opening O in a concrete floor or wall F. That is, any part or portion of the anchor  10  that would otherwise extend above the surface S of the structure F can be removed after use. This is particularly desirable where the anchor  10  is used in a temporary supporting arrangement as is required in tilt-wall construction.  
         [0030]    It has been found that the present deep-set anchor  10  provides high holding values or pull-out loads with very little displacement until fracture occurs. In fact, tension loads as high as 20,000 pounds have been observed when the anchor  10  is used at a five inch embedment depth, as indicated at D in FIG. 1.  
         [0031]    The sleeve or shell  12  is an annular element having a threaded region  22  and a split region  24 . An outer wall  26  of the sleeve  12  has a constant diameter d 26  along the length l of the sleeve  12  from an upper lip  28  of the sleeve  12  to a lower lip  30  of the sleeve  12 , through both the threaded region  22  and the split region  24 . For purposes of the present disclosure, upper and lower are used in reference to the orientation in which the parts will reside when the anchor is installed in a floor structure.  
         [0032]    An inner wall  32  of the sleeve  12  has a constant diameter d 22  at the threaded region  22  (taking into consideration the threads  34 ) and tapers inwardly through the split region  24 , as indicated at  36 . Thus, as seen in FIG. 2, the diameter d 24  across the inner wall  32  decreases from a point (indicated at  38 ) between the threaded region  22  and the split region  24  to the end of the split region  24 , as at about the lower lip  30 .  
         [0033]    In a current embodiment, the split region  24  includes four elongated channels  40   a - d  extending longitudinally, dividing the split region  24  into four longitudinally extending sections  24   a - d . The channels  40   a - d  are formed about equidistantly about the circumference of the sleeve  12 , or at 90 degrees from adjacent channels. Those skilled in the art will recognize that other split patterns can be used in connection with the present anchor  10  without departing from the scope and spirit of the present invention.  
         [0034]    The plug  14  has a tapered profile the defines tapered sides as indicated at  42  and is configured for insertion into the sleeve  12 . The plug  14  “fits” within the split region  24  and can be formed having a taper  42  that complements the taper  36  of the sleeve  12 , however, such matching tapers  36 ,  42  (i.e., taper angles) are not necessary. A greatest diameter d 14  of the plug  14  is, however, greater than the smallest diameter d 24  of the split region  24  (near the lower lip  30 ) so that the plug  14  interferingly fits within the sleeve  12 .  
         [0035]    The shank  16  includes a threaded end region  44 , an intermediate region  46  and a head  48 . In a current embodiment, the shank  16  is formed as a shoulder bolt, in which the threaded region  44  has a reduced diameter d 44  from the intermediate region d 46 . As such, a shoulder  50  is formed at the juncture of the threaded region  44  and the intermediate region  46 .  
         [0036]    The threaded region  44  is formed with threads  52  that complement (i.e., threadedly engage) the sleeve threads  34 . As such, as seen in FIG.  1 , the shoulder bolt  16  threads into the upper end (e.g., threaded region  22 ) of the sleeve  12 . The head  48  can be formed having a hexagonal shape, such as that of a convention bolt, to permit the use of conventional tools, wrenches, ratchets and the like, to (threadedly) engage and disengage the bolt  16  and sleeve  12 .  
         [0037]    The bolt  16  includes the through-bore  18  extending longitudinally therethrough. The bore  18  is configured for slidingly receiving the setting pin or like setting tool. The exemplary setting pin  20  includes a setting end  56  and head  58  opposing the setting end  56 . The setting end  56  is configured for engaging the plug  14 , and the head  58  is configured for being struck (as with a hammer) and for coming into contact with the bolt head  48 .  
         [0038]    In use, the plug  14  is inserted into the sleeve  12  and the bolt  16  is threaded into the sleeve  12  until the shoulder  50  engages the upper lip  28  of the sleeve  12 . The anchor  10  is then inserted into the bore O in the structure F to a desired depth D. With the anchor  10  at the desired depth D, the pin  20  is inserted into the bolt bore  18 , until the setting end  56  engages the plug  14 . It will be recognized by those skilled in the art that the pin  20  can be inserted into the bolt  16  before installation of the anchor  10  in the structure bore O. It will also be recognized by those skilled in the art that prior to setting the anchor  10 , the pin setting end  56  will rest on the plug top surface  60  and that the pin head  58  will not be fully seated on the bolt head  48 . That is, the pin head  58  will be spaced from or above the bolt head  48 .  
         [0039]    With the entire assembly (i.e., sleeve  12 , plug  14 , bolt  16  and pin)  20  in place at the desired depth D in the bore O, the pin  20  is struck to drive the plug  14  into the sleeve  12 . The tapered wall  42  of the plug and the taper  36  of the sleeve  12  engage one another which wedges the plug  14  in the sleeve  12 . Because of the interfering fit between the plug  14  and the sleeve section  24   a - d , the sleeve sections  24   a - d  are urged outwardly, into engagement with the walls W of the structure bore O. This sets or secures the sleeve  12  in place in the structure F.  
         [0040]    Once the anchor  10  is set in the structure F, the pin  20  can be removed from the bolt  16  and the bolt  16  can be removed from the sleeve  12 . The bolt  16  can be used, as part of the temporary support, or a more conventional (non-through-bore) bolt can be threaded into the sleeve  12  for the temporary support. The shoulder bolt  16  and setting pin  200  can then be reused for the installation of another sleeve  12 . After use, the bolt  16  (which ever is used) can be removed from the sleeve  12  so that no part of the anchor  10  extends above the surface S of the structure F.  
         [0041]    Those skilled in the art will recognize that in proper use, the anchor  10  (prior to setting) will be inserted in to the structure bore O so that the bolt head  48  is in contact with the surface S of the structure F. This will assure proper positioning (e.g., depth) of the anchor  10  in the structure F. Those skilled in the art will also appreciate that unlike with the use of coil anchors, over-drilling (the depth of) the structure bore O will have no adverse effect on the use or integrity of the anchor  10 . As such, less consideration need be given to the maximum depth of the structure bore O.  
         [0042]    A method for securing an anchor  10  in an opening O formed in a structure F includes inserting the tapered plug  14  into the sleeve  12  and threading a shoulder bolt  16  into the sleeve  12  until the shoulder  50  contacts the upper lip  28  of the sleeve  12 . The sleeve  12  and bolt  16  are positioned the opening O in the structure F. The setting pin  20  is inserted in the bolt through-bore  18 , and is then forced downward (as by striking with a hammer), toward and into contact with the top surface  60  of the plug  14 . This drives the plug  14  into the split region  24 , which in turn drives the split region sections  24   a - d  axially outwardly to secure the sleeve  12  in the opening O.  
         [0043]    As will be appreciated by those skilled in the art, positioning the setting pin  20  in the bolt through-bore  18  can be carried out before or after the sleeve  12  and bolt  16  are positioned in the opening O in the structure F. Preferably, the anchor  10  is positioned in the opening O such that the bolt head  48  is positioned against a surface S of the structure F surrounding the opening O.  
         [0044]    Still another advantage of the present anchor  10  is that it is readily inspectable. That is, because the plug  14  is properly set when the pin  20  is fully forced downward, by noting that the pin head  58  is flush with the bolt head,  48 , it can be readily, visually determined that the anchor  10  is properly set.  
         [0045]    All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically do so within the text of this disclosure.  
         [0046]    From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.