Patent Publication Number: US-2007120025-A1

Title: Structural beam clamp with cast body

Description:
REFERENCE TO RELATED APPLICATION  
      This application claims priority under 35 USC 119 to U.S. Provisional Patent Application No. 60/736,363, filed Nov. 14, 2005, and to U.S. Provisional Patent Application No. 60/749,227, filed Dec. 9, 2005. Both of the foregoing applications are hereby incorporated in their entireties. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Technical Field of the Invention  
      This invention relates generally to heavy duty structural clamps, and more particularly to clamps using primarily threaded rod for fixing and hanging a variety of items such as pipe, lighting and heating fixtures, duct work, cables or cable trays from a variety of structural members such as beams, struts, Z-purlins, T-bars, or other structural shapes.  
      2. Description of the Related Art  
      Heavy duty clamps such as beam clamps are often used as hangers and have a notch or jaw opening receiving an edge of a structure flange such as a beam. The upper part of the jaw is provided with a clamping bolt or set screw directed to the lower or bottom jaw. A flange fits in the jaw and as the clamping bolt or screw is tightened against the top of the flange the clamp is secured to the flange of the structure. An object supported by the clamp is often supported by a threaded rod which may extend through a nut or thread form in the body of the clamp clear of the edge of the flange. However some clamps secure the rod to a thread form in the bottom of the jaw in alignment with the clamping bolt. Other items are hung or supported with intermediate fixtures to support wiring, conduit, swivel connections or even struts.  
      Due to the continuing popularity of such clamps, it will be appreciated that it would be desirable to have improvements in such clamps, such as in ease or flexibility of use, reduced cost, reduced weight, increased performance, and/or with regard to other factors.  
     SUMMARY OF THE INVENTION  
      According to an aspect of the invention, a structural clamp has a body with an open back portion for receiving a threaded bar or rod to which the clamp is to be coupled. According to one embodiment, the clamp body is secured to the threaded rod by threaded fasteners that bear on top and bottom surfaces of the clamp body. The top and bottom surfaces may have protrusions to lock one or both of the threaded fasteners in place.  
      According to another embodiment, the threaded rod is secured within the clamp body by a clip that is mechanically coupled to the clamp body. The clip may secure the fastener within the clamp body, either in a central hollow within the body, or in a recess in the top or bottom surface of the clamp body. The clip may be configured to secure the fastener within a pocket within a hollow in the clamp body.  
      According to another aspect of the invention, a structural clamp includes a clamp body having a main body portion, and top and bottom flanges protruding from the main body portion. The clamp body has a hollow portion running therethrough, accessible through an open slot in the clamp body.  
      According to yet another aspect of the invention, a structural clamp includes: a cast clamp body having a main body portion, and top and bottom flanges protruding from the main body portion. The clamp body has a hollow portion running therethrough.  
      To the accomplishment of the foregoing and related ends, the invention comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      In the accompanying drawings, which are not necessarily to scale:  
       FIG. 1  is an oblique view showing the front, side, and top of a first embodiment clamp in accordance with the present invention;  
       FIG. 2  is a back view of the clamp of  FIG. 1 ;  
       FIG. 3  is a side view of the clamp of  FIG. 1 ;  
       FIG. 4  is an oblique view showing the front, side, and bottom of the clamp of  FIG. 1 ;  
       FIG. 5  is a partially exploded view of the clamp of  FIG. 1 ;  
       FIG. 6  is an oblique view showing the back, side, and bottom of a first alternate configuration of the clamp of  FIG. 1 ;  
       FIG. 7  is a front view of the first alternate configuration;  
       FIG. 8  is an oblique view showing the front, side, and bottom of a second alternate configuration of the clamp of  FIG. 1 ;  
       FIG. 9  is an oblique view showing the front, side, and top of a second embodiment clamp in accordance with the present invention;  
       FIG. 10  is an oblique view showing the front, side, and bottom of the clamp of  FIG. 9 , with the second fastener loosened;  
       FIG. 11  is a back view of the clamp of  FIG. 9 ;  
       FIG. 12  is a plan view of the clamp of  FIG. 9 ;  
       FIG. 13  is an oblique view showing the front, side, and top of a third embodiment clamp in accordance with the present invention;  
       FIG. 14  is an oblique view showing the front, side, and bottom of the clamp of  FIG. 13 ;  
       FIG. 15  is an oblique view showing the front, side, and top of a fourth embodiment clamp in accordance with the present invention;  
       FIG. 16  is an oblique view showing the back, side, and bottom of the clamp of  FIG. 15 ;  
       FIG. 17  is an exploded oblique view of the clamp of  FIG. 15 ;  
       FIG. 18  is a plan view of a clip that is part of the clamp of  FIG. 15 ;  
       FIG. 19  is an oblique view of an alternative configuration of the clamp of  FIG. 15 , utilizing an alternative clip;  
       FIG. 20  is an exploded oblique view of the configuration of  FIG. 19 ;  
       FIG. 21  is a plan view of the alternative clip of the configuration of  FIG. 19 ;  
       FIG. 22  is an oblique view of another alternative configuration of the clamp of  FIG. 15 , utilizing another alternative clip;  
       FIG. 23  is an exploded oblique view of the configuration of  FIG. 22 ;  
       FIG. 24  is a plan view of the another alternative clip of the configuration of  FIG. 22 ;  
       FIG. 25  is an oblique view of a fifth embodiment clamp in accordance with the present invention;  
       FIG. 26  is an exploded oblique view of the clamp of  FIG. 25 ;  
       FIG. 27  is a plan view of a clip that is part of the clamp of  FIG. 25 ;  
       FIG. 28  is an oblique view of an alternative configuration of the clamp of  FIG. 25 , utilizing an alternative clip;  
       FIG. 29  is an exploded oblique view of the configuration of  FIG. 28 ;  
       FIG. 30  is a plan view of the alternative clip of the configuration of  FIG. 28 ;  
       FIG. 31  is an oblique view showing the front, side, and top of a sixth embodiment clamp in accordance with the present invention;  
       FIG. 32  is an oblique view showing the back, side, and top of the clamp of  FIG. 31 ;  
       FIG. 33  is an exploded oblique view of the clamp of  FIG. 31 ;  
       FIG. 34  is a side exploded view of the clamp of  FIG. 31 ;  
       FIG. 35  is a plan view of a clip that is part of the clamp of  FIG. 31 ;  
       FIG. 36  is an oblique view showing the front, side, and top of an alternative configuration of the clamp of  FIG. 31 , utilizing an alternative clip;  
       FIG. 37  is an oblique view showing the back, side, and top of the configuration of  FIG. 36 ; and  
       FIG. 38  is an exploded oblique view of the configuration of  FIG. 36 . 
    
    
     DETAILED DESCRIPTION  
      A structural clamp has a body with an open back portion or slot for receiving, in a hollow in the body, a threaded rod or bar to which the clamp is to be coupled. The body has one or more protrusions on at least one of the top and bottom surfaces of the body, to engage a first threaded fastener, such as a square nut or hex nut, which is threaded on the threaded rod. The protrusions operate to keep the first threaded fastener in place while a second threaded fastener is tightened against the opposite side of the body. The second fastener may be used in conjunction with a flanged washer, lock washer, or other such auxiliary piece to aid in maintaining the body of the clamp locked in place on the threaded rod. The protrusions act against at least one of the fasteners to prevent the threaded rod from being disengaged from the hollow in the body. The body has a top flange with a threaded hole, and a bottom flange. A clamp screw may be threadedly engaged through the threaded hole in the top flange to bear against a clamped object located between the top and bottom flanges, thereby securely holding the object to the structural clamp. The clamp body may be made by casting.  
      The structural clamp advantageously allows securing of the clamp body to the threaded rod without the need to pass the rod through any hole in the body of the clamp. The fasteners may be pre-positioned on the threaded rod, with the clamp body later attached after installation of the rod to a pipe or other fixture to which the threaded rod will support. The clamp body is placed on the threaded rod between the fasteners, using the open back portion or slot of the body to place the clamp body around the threaded rod, with the rod in the hollow of the body. The body is then pressed against one of the fasteners, which is prevented from rotating by one or more protrusions on the body, while the other fastener is tightened against the body.  
      In an alternative configuration, the structural clamp with the open slot or back end may have a threaded fastener secured in a recess or hollow in the clamp body by a clip that is snapped onto the clamp body. The clip may also aid in securing the threaded rod within a hollow in the clamp body.  
      Referring initially to  FIGS. 1-5 , a clamp  20  is used for securing objects to a threaded rod or bar  22 . The clamp  20  has a clamp body  24  with a main body portion  26  having a top flange  28  and a bottom flange or platform  30  extending therefrom. The clamp body  24  may be cast from a suitable metal, such as a suitable iron or steel.  
      The main body portion  26  has a hollow  32  therein for receiving a portion  34  of the threaded rod  22  between a first fastener  36  and a second fastener  38 . In the illustrated embodiment the first fastener  36  is a square nut and the second fastener  38  is a hex nut, although it will be appreciated that other suitable sorts of fasteners may be employed, some of which are described below with regard to other embodiments. As will be described in greater detail later, the fasteners  36  and  38  are tightened against the main body portion  26  to secure the clamp body  24  to the threaded rod  22 . In general terms, the first fastener  36  is secured by engagement with the main body portion  26  and the second fastener  38  acts as a locknut to tighten both of the fasteners  36  and  38  against the main body portion  26 .  
      The hollow  32  may accessed by an open back or slot  40  in a back surface  44  of the clamp body  24 . This allows the clamp body  24  to be placed on the threaded rod  22  after connection of the threaded rod  22  to a fixture or other equipment, without a need to thread the clamp body  24  over an end of the threaded rod  22 . The fasteners  36  and  38  may be pre-threaded onto the threaded rod  22  before connection of the threaded rod  22  to the fixture or other equipment, perhaps placed at locations where clamps  20  are to be located to secure the threaded rod  22  to a beam or other structure. Later, even after installation of the threaded rod  22 , the clamp body  24  may be placed on the threaded rod  22 , with a portion of the threaded rod  22  passing through the open back or slot  40  and into the hollow  32 .  
      The hollow  32  may have a relatively wide central hollow portion  50 , with a narrowed top guide portion  52  and a narrowed bottom guide portion  54 . The guide portions  52  and  54  may have respective half-cylinder inner surfaces  56  and  58  that may have substantially the same radius as the threaded rod  22 , so that the threaded rod  22  may be secured to the clamp body  24  without relative shifting or rattling between the threaded rod  22  and the clamp body  24 . The central hollow portion  50  may be hollowed out to a greater extent, for example to save weight.  
      A top surface  60  of the main body portion  26  has a pair of protrusions  61  and  62  extending upward therefrom. The illustrated protrusions  61  and  62  are triangular in shape, and are configured to secure the square nut  36  to prevent rotation of the square nut  36  when the square nut is against the top surface. Thus the inner faces  63  and  64  of the protrusions  61  and  62  may be oriented at approximately right angles to one another. It will be appreciated that the protrusions  61  and  62  may have other suitable shapes, suitable for securing a square nut or a fastener having a different shape. Also, there may be a greater or lesser number of protrusions provided on the top surface  60  to secure the fastener  36 . For instance, the protrusions  61  and  62  bear against two faces of the square nut  36 . Additional protrusions may be provided at suitable locations to bear against the other faces of the square nut  36 . Or it may be possible to prevent rotation of the square nut  36  with only a single protrusion.  
      A bottom surface  70  of the main body portion  26  also has a pair of protrusions  71  and  72  extending therefrom. The protrusions  71  and  72  may be identical to the protrusions  61  and  62  on the top surface  60 . Having identical (or substantially identical) protrusions on both the top surface  60  and the bottom surface  70  allows flexibility in use of the clamp  20 . For instance, the clamp body  24  may be inverted from the illustrated embodiment, with rotation of the square nut  36  prevented by engagement with the protrusions  71  and  72  when the square nut  36  is pressed up against the bottom surface  70  (which, because of the inversion of the clamp body  24 , has now become an upper surface). As another alternative, the protrusions  71  and  72  allow the positions of the fasteners  36  and  38  to be switched, with the square nut  36  placed below the clamp body  24  and the hex nut  38  placed above the clamp body  24 .  
      In addition to allowing flexibility in placement of the clamp  20 , the protrusions  71  and  72  may aid in keeping the clamp  20  secured to the threaded rod  22 . The protrusions  71  and  72  may serve to restrain the hex nut  38  from pulling out and away from the clamp body  24 . Although the bearing of the protrusions  61  and  62  on the faces of the square nut  36  may be sufficient to keep the clamp  20  secured to the threaded rod  22 , interaction of the protrusions  71  and  72  with the hex nut  38  may provide an additional measure of securement.  
      The protrusions  61 ,  62 ,  71 , and  72  may be located relative to the guide portions  52  and  54  of the hollow  32  such that the threaded rod  22  is touching, or close to touching, the surfaces  56  and  58  when the protrusions  61  and  62  engage faces of the square nut  36 . The result is a secure connection between the clamp  20  and the threaded rod  22 .  
      The clamp  20  may have an additional fastener component  78  between the hex locknut  38  and the bottom surface  70  of the main body portion  26 . The additional component  78  may function to aid in locking the hex locknut  38  in place by resiliently deforming and exerting a force, in a direction along the axis of the threaded rod  22 , against both the hex locknut  38  and the main body portion  26 . This keeps the hex nut  38  pressed against threads of the threaded rod  22 , and thereby prevents the hex nut  38  from loosening over time. In addition, the additional fastener component  78  may engage the protrusions  71  and  72  to aid in keeping the clamp  20  secured to the threaded rod  22 .  
      The additional fastener component  78  may also serve as a spacer, maintaining clearance between the bottom surface  70  and the second fastener  38 . In installation of the clamp  20 , the second fastener  38  must be free to rotate until the clamp body  24  is secured between the first fastener  36  and the second fastener  38 . One way to accomplish this is by configuring the protrusions  71  and  72  so that the protrusions  71  and  72  do not interfere with rotation of the second fastener  38 . This configuring is of course done in conjunction with selection of a fastener type (hex nut, square nut, etc.) for use as the second fastener  38 . An alternative is to have the additional fastener component  78  be at least as thick as the height of the protrusions  71  and  72 . This prevents any interference with the rotation of the second fastener  38  that the protrusions  71  and  72  might otherwise make. With an additional fastener component that provides sufficient spacing to clear the protrusions  71  and  72 , the second fastener  38  may be selected from a wider range of fasteners, and may indeed be of the same type as the first fastener  36  (e.g., both fasteners may be square nuts).  
      A wide variety of suitable additional fastener components  78  may be used to accomplish one or more of the above functions. Only some of the wide variety of possible additional fastener components are described herein. It will be appreciated that multiple additional fastener components (e.g., a pair of stacked washers) may be used in a single installation. Alternatively, the additional fastener component  78  may be omitted entirely, if desired.  
      In the embodiment illustrated in  FIGS. 1-5 , the additional fastener component  78  is an external toothed lock washer  80  having a deformable bowed central section  82  ringed on the outside by teeth  84 . The central section  82  is resiliently compressed as the hex nut  38  is tightened toward the bottom surface  70 , thereby causing the central section  82  to apply a force against the hex nut  38  that keeps the hex nut  38  from loosening. The external teeth  84  of the lock washer  80  may engage the protrusions  71  and  72 .  
      The top flange  28  has a central threaded hole  88  for receiving a clamp screw  90 . The clamp screw  90  engages the threaded hole  88 , directed toward a flat upper surface  96  of the bottom flange  30 . The clamp screw  90  is used to secure a structural member, such as a beam flange, in a jaw opening  94  between the top flange  28  and the bottom flange upper surface  96 . A clamp screw locknut  98  may be used to aid in locking the clamp screw  90  in place.  
      The bottom flange  30  protrudes further from the main body portion  26  than does the top flange  28 . The top flange  28  has a rounded distal end  100 , and the bottom flange  30  has a rounded distal end  102 . Respective rounded shoulders  108  and  110  are present at the transition between the flanges  28  and  30 , and a middle part  112  of the main body portion  26 . The bottom flange  30  may have a hollowed-out portion  116  on its underside, with extraneous material omitted in order to save weight.  
      To secure the clamp  20  to the threaded rod  22 , first the fasteners  36  and  38  are threaded on the rod  22  at opposite sides of the portion  34  of the threaded rod  22  upon which the clamp  20  is to be secured. Then the threaded rod  22  is inserted into the hollow  32  in the main body portion  26  of the clamp body  24 , with the rod  22  passing through the open end or slot  40  in the back surface  44  of the clamp body  24 . This may be done by movement of the threaded rod  22 , such as with placement of the threaded rod  22  into engagement with a clamp that is already mounted to a beam or other structure. Or engagement may be accomplished by movement of the clamp body  24 , such as by engaging an unattached clamp body onto a stationary threaded rod.  
      After the threaded rod  22  is in the hollow  32 , the clamp body  24  is moved along the threaded rod  22  until the top surface  60  of the clamp body  24  is pressed against the square nut  36 , with the protrusions  61  and  62  bearing against faces of the square nut  36  to prevent rotation of the square nut  36 . If necessary, orientation of the clamp body  24  or the square nut  36  may be adjusted to allow proper engagement of the protrusions  61  and  62  and the faces of the square nut  36 .  
      Once the square nut  36  is secured by the protrusions  61  and  62 , the hex locknut  38  is tightened to press the lock washer  80  against the bottom surface  70  of the clamp body  24 . The compressed lock washer  80  provides a force against the tightened hex locknut  38  to keep the locknut  38  from loosening, thereby securing the clamp  20  to the threaded rod  22 .  
      As discussed earlier, one advantage of the clamp  20  is that it does not have to be threaded along the threaded rod  22 , reducing installation time and increasing flexibility. The increase of flexibility may occur in that the clamp  20  may be installed after the threaded rod  22  has been put in place. There also may be increased flexibility regarding the order in which the clamps  20  are secured to the threaded rod  22 . As long as the fasteners  36  and  38  are pre-threaded onto the threaded rod  22  at an appropriate location, additional of the clamps  20  may be secured anywhere along an already-secured threaded rod, even between already-installed clamps.  
      The clamp  20  may be secured to structural members, such as the flange of a beam or other structure member. The threaded rod  22  may be used for fixing and hanging a variety of items such as pipes, lighting and heating fixtures, duct work, cables or cable trays from a variety of structural members such as beams, struts, Z-purlins, T-bars, or other structural shapes.  
       FIGS. 6 and 7  show an alternative configuration of the clamp  20 , in which the additional fastener component  78  is a flat toothed washer  130  having a flat central portion  132  ringed by external teeth  134 . The washer  130 , unlike the bowed washer  80  ( FIG. 1 ) does not provide a force against the hex locknut  38  to aid in preventing the hex locknut from loosening. Still, the flat washer  130  prevents direct contact between the hex locknut  38  and the bottom surface  70  of the clamp body  24 , which might otherwise gouge the bottom surface  70 . The teeth  134  may engage the protrusions  71  and  72  to prevent rotation of the washer  130  as the hex locknut  38  is tightened up against it.  
       FIG. 8  shows another alternative configuration of the clamp  20 , in which the additional fastener component  78  is a split lock washer  140 . The lock washer  140  resiliently compresses as the hex locknut  38  is tightened against it, providing a force against the tightened hex locknut  38  that prevents loosening of the locknut  38 . It will be appreciated that many varieties of other washers and spacers are alternatives to the various illustrated embodiments.  
      What follows now are various alternate embodiments of the invention. Many of the features of the alternate embodiment clamps described below may be similar to corresponding features of the clamp  20 . Discussion of these similar features is abbreviated or omitted in the below description of the alternate embodiment clamps, although it will be understood that the alternate embodiment clamps may include other features corresponding to those of the clamp  20 . In addition, it will be appreciated that various features from the various embodiments may be combinable with one another.  
       FIGS. 9-12  show an alternate embodiment, a clamp  220  with protrusions configured to engage a hex nut to prevent rotation of the hex nut while the clamp  220  is being secured to a threaded rod  222 . The clamp  220  has a clamp body  224 , which may be formed by casting, that has a main body portion  226 , with a hollow  232  therein accessed by an open back portion or slot  240 . The clamp body  224  has a top flange  228  and a bottom flange  230  defining a jaw opening  294  therebetween. The top flange  228  has a threaded hole  288  for receiving a clamp screw  290  for clamping objects in the jaw opening  294 , between the clamp screw  290  and an upper surface or platform  296  of the bottom flange  230 . A clamp screw locknut  298  may be used to lock the clamp screw  290  in place.  
      The clamp body  224  has protrusions  261  and  262  on an upper surface  260  of the main body portion  226 . The protrusions  261  and  262  are configured to engage faces of a hex nut  236  employed as a first fastener, to prevent rotation of the hex nut  236  when it is engaged with the protrusions  261  and  262 . The protrusions  261  and  262  have respective elongate bar portions  265  and  266  and respective angled projections  267  and  268  extending inward from the bar portions  265  and  266  toward a symmetry plane of the clamp body  224 . The elongate bar portions  265  and  266  have respective inner faces  263  and  264  that are substantially parallel to one another, and spaced so as to engage a pair of diametrically-opposed faces of the hex nut  236 . The inner faces  263  and  264  may each have an extent at least as long as a corresponding face of the hex nut  236 . Thus the inner faces  263  and  264  may each engage substantially all of different faces of the hex nut  236 . The angled projections  267  and  268  are configured to engage an additional pair of adjacent faces of the hex nut  236 , with respective inner faces  267   a  and  268   a  angled at approximately 120° to one another. Thus together the protrusions  261  and  262  are configured to engage four faces of the hex nut  236 , so as to prevent the hex nut  236  from rotating when the top surface  260  of the clamp body  224  is pressed up against the hex nut  236 .  
      It will be appreciated that the configuration of the projections  261  and  262  shown in the figures and described above is only one possible specific configuration for the projections  261  and  262 , and that other configurations for engaging the hex nut  236  are possible. To give one example, the angled projections  267  and  268  could be omitted entirely, relying on only the elongate bar portions  265  and  266  to prevent rotation of the hex nut  236 .  
      Protrusions  271  and  272 , substantially identical to the protrusions  261  and  262 , are provided on a bottom surface  270  of the clamp body  224 . A second fastener  238 , a modified hex nut, is configured to press against the bottom surface  270 , to secure the clamp  224  to the threaded rod  222 . The second fastener  238  has hexagonal lower portion  274  and a round upper portion  276 . The hexagonal lower portion  274  may have substantially the same size as the hex nut  236 . The round upper portion  276  has a smaller diameter than the hexagonal lower portion  274 , and has a thickness that may be at least as much as the height of the protrusions  271  and  272 . The round upper portion  276  is configured to be able to rotate without engaging the protrusions  271  and  272 . This allows the modified hex nut  238  to be threaded along the threaded rod  222  until it fully engages the bottom surface  270  of the clamp body  224 . The round upper portion  276  may be fabricated by machining a portion of a hex nut that is substantially identical to the hex nut  236 .  
      It will be appreciated that many variants are possible for the clamp  220 . An additional fastener component, such as a suitable one of the additional fastener components  78  described above, may optionally be used in conjunction with the second fastener  238 . With or without an additional fastener component, other configurations may be used for the second fastener  238 .  
      The clamp  220  may be installed on the threaded rod  222  in a manner similar to that described above with regard to the clamp  20 .  
       FIGS. 13 and 14  show another embodiment, a clamp  420  for engaging a threaded rod  422 . Unlike the clamp  20  and clamp  220 , the clamp  420  does not rely on fasteners, such as the fasteners  36 ,  38 ,  236 , and  238 , to hold it in place on the threaded rod  422 . However, the clamp  420  is required to be threaded onto the threaded rod  422 , which is another difference compared to the clamp  20  and the clamp  220 .  
      The clamp  420  has a clamp body  424 , which may be formed by casting, that has a main body portion  426 , with a through hole  433  for receiving the threaded rod  422  therethrough, and for threadedly engaging a portion of the threaded rod  422 . The clamp body  424  has a top flange  428  and a bottom flange  430  defining a jaw opening  494  therebetween. The engagement of the objects in the jaw opening  494  is similar to the engagement of objects in the jaw opening  94  and jaw opening  294 . The top flange  428  has a threaded hole  488  for receiving a clamp screw  490  for clamping objects in the jaw opening  494 , between the clamp screw  490  and an upper surface or platform  496  of the bottom flange  430 . A clamp screw locknut  498  may be used to lock the clamp screw  496  in place.  
      The through hole  433  may have an enlarged central hollow within the main body portion  426 , with a narrower top hole or passage  500  and a narrower bottom hole or passage  502  on opposite sides of the central hollow. One of the holes  500  and  502  is internally threaded to engage threads on the threaded rod  422 , while the other of the holes  500  and  502  is smooth, to allow unhindered passage of the threaded rod  422  therethrough. The threaded hole may be either the top hole  500  or the bottom hole  502 . Alternatively, both of the holes  500  and  502  may be threaded. As another alternative, the entire through hole  433  may have a substantially constant diameter throughout its length, with all or a portion internally threaded for engaging the threaded rod  422 .  
      The clamp body  424  has a top surface  460  with a top chamfered shoulder  510  around the top hole  500 . A bottom surface  470  of the clamp body  424  has a bottom chamfered shoulder  512  around the bottom hole  502 . The chamfered shoulders  510  and  512  aid in guiding an end of the threaded rod  422  into the through hole  433  for the clamp body  424  to be threaded onto the threaded rod  422 . Optionally, one or both of the chamfers  510  and  512  may be omitted.  
      The clamp body  424  may be made of malleable cast iron. The clamp body  424  may be electro zinc plated.  
      Alternatively, the clamp body  424  may be modified such that both of the holes  500  and  502  are smooth holes. In such a case one or more fasteners, such as nuts, may be used to secure the clamp  420  to a threaded rod.  
      What follows now are additional embodiments sharing a common concept that differs in some ways from that of the embodiments described above. The following embodiments utilize a cast body with an open back end, with a separate clip that engages the cast body. The clip is used to retain the threaded rod within the body.  
       FIGS. 15-17  show a clamp  620  that has a clamp body  624  with an open back or slot  640  in a clamp body back surface  644  for receiving therein a threaded rod  622  therein. The clamp body  624  has a central main body portion  626  with a central hollow  650  therein for receiving both the threaded rod  622  and a fastener  637  coupled to the threaded rod  622 . The fastener  637  may be a hex nut that is threaded onto the threaded rod  622 .  
      The central hollow  650  is bordered by a pair of parallel walls  722  and  724  spaced so as to bear on and secure diametrically opposed faces of the fastener  637 . The walls  722  and  724  prevent the fastener  637  from being turned when it is in the central hollow  650 . A central hollow middle section  726  and a central slot portion  728  are open all the way, between the walls  722  and  724 , along the clamp body back surface  644 . The walls  722  and  744  may have chamfered back edges at the central hollow middle section  726 , to urge the fastener  637  into the central hollow middle section  726 . However, upper inward protrusions  732  and  734  protrude inward from upper sections of the walls  722  and  724 , narrowing an upper slot portion  736  of the slot  640  in an upper section  738  of the central hollow  650 . The upper slot portion  736  is wide enough to admit the threaded rod  622 , but is not wide enough to allow the fastener  637  to pass through. Thus the upper hollow section  738  functions as an upper pocket that may be used to retain the fastener  637  within. The fastener  637  may be inserted into the middle hollow section  726  through the central slot portion  728 , and then moved upward into the upper pocket  738 . As long as the fastener  637  is in the upper pocket  738 , it is unable to pass through the slot  640 , and remains within the central hollow  650 .  
      Similarly, a lower section  748  of the central hollow  650  is a lower pocket which can be used to retain the fastener  637  within. A lower slot portion  746  is too narrow to allow the fastener  637  to pass, due to the presence of lower protrusions  742  and  744  protruding inward into the slot  640  from back ends of the walls  722  and  724 .  
      Above the upper pocket  738  is an upper cylindrical surface  750 , and below the lower pocket  748  is a lower cylindrical surface  752 . The cylindrical surfaces  750  and  752  may be used to bear against surfaces of the threaded rod  622 . This may aid in supporting the threaded rod  622  and in keeping the threaded rod  622  from wobbling within the clamp body  624 . The cylindrical surfaces  750  and  752  also block upward movement of the fastener  637  out of the upper pocket  738 , and downward movement of the fastener  637  out of the lower pocket  748 .  
      With reference now in addition to  FIG. 18 , a clip  754  is used to secure the threaded rod  622  and the fastener  637  within the clamp body  624 . The clip  754  has a pair of inner gripping legs  758  and  760 , and a pair of outer gripping legs  762  and  764 . A central spine  766  couples together the inner legs  758  and  760 , and the outer legs  762  and  764 . The inner legs  758  and  760  fit into the central hollow middle section  726  when the clip  754  is installed on the clamp body  624 . The inner legs  758  and  760  resiliently grip the threaded rod  622 , aiding in preventing wobbling of the threaded rod  622 . The inner legs  758  and  760  also block movement of the fastener  637  into the central hollow middle section  726  from the pockets  738  and  748 .  
      The outer legs  762  and  764  resiliently grip side surfaces of the main body portion  626  of the clamp body  624 . The outer legs  762  and  764  have respective windows or cutouts  768  and  770  therein shaped to receive respective protrusions  772  and  774  on side surfaces of the main body portion  626 . The clip  754  is installed by pushing it onto the clamp body  624 , toward the clamp body back surface  644 . The outer legs  762  and  764  resiliently bend outward as the clip  754  is installed on the clamp body  624 . Once the clip  754  is pushed in far enough, the outer legs  762  and  764  snap into place around the protrusions  772  and  774 , with the protrusions  772  and  774  in the windows  768  and  770 . This securely holds the clip  754  to the clamp body  624 . The outer legs  762  and  764  have outturned front flanges  778  and  780 . The protrusions  772  and  774  have chamfered back edges  782  and  784 . The outturned flanges  778  and  780  and the chamfered back edges  782  and  784  facilitate bending the outer legs  762  and  764  out and around the protrusions  772  and  774  as the clip  754  is installed. To release the clip  754  from the clamp body  724 , the outturned front flanges  778  and  780  may be pulled outwards until the outer legs  762  and  764  clear the protrusions  772  and  774 . Then the clip  754  can be pulled off of the clamp body  624 .  
      The clamp  620  may be secured to a beam flange or other structure in a manner similar to that of the other embodiments described above. That is, the clamp body  624  has a top flange  628  and a bottom flange  630  defining a jaw opening  694  therebetween. The top flange  628  has a threaded hole  688  for receiving a clamp screw  690  for clamping objects in the jaw opening  694 , between the clamp screw  690  and an upper surface or platform  696  of the bottom flange  630 . A clamp screw locknut  698  may be used to lock the clamp screw  696  in place.  
      In installation of the clamp  620  onto the threaded rod  622 , first the threaded rod  622  and the fastener  637  are inserted into the slot  640 . The fastener is inserted into the middle slot portion  728 , which may be the only portion of the slot  640  that is wide enough for passage of the fastener  637 . Then the clamp  620  and/or the threaded rod  622  are moved, so as to locate the fastener  637  in one of the pockets  738  or  748 . Then the clip  754  is installed by pressing it onto the clamp body  624 , securing the fastener  637  in one of the pockets  738  or  748 . The threaded rod  622  is secured by the cylindrical surfaces  750  and  752  and by the inner legs  758  and  760 . Thus the clamp  620  may be secured to threaded rod  622  even after the threaded rod  622  has been installed, even if other items have been coupled to the threaded rod  622  above and below the clamp  620 .  
       FIGS. 19-21  show a variation of the clamp  620  which utilizes a clip  755  having a somewhat different design from that of the clip  754  ( FIG. 18 ). The clip  755  uses the same resilient outer legs  762  and  764  as the clip  754 , which grip the protrusions  772  and  774  on the sides of the central body portion  626  of the clamp body  624 . Inner legs  759  and  761  of the clip  755  do not resiliently grip the threaded rod  622 , but rather are straight legs that protrude from the clip central spine  766  into the middle hollow section  726 . The inner legs  759  and  761  keep the fastener  637  in the pockets  738  or  748 .  
      The clip  755  includes a pair of L-shape or dogleg extensions  786  and  787  that protrude from the top and bottom of the clip central spine  766 . The extensions  786  and  787  have respective legs  788  and  789  and rod-engaging tabs  790  and  791 . The legs  788  and  789  are connected to opposite ends of the central spine  766 , and are directed inward toward the threaded rod  622  when the clip  755  is installed. The tabs  790  and  791  are bent free ends of the extensions  786  and  787 . The tabs  790  and  791  may be angled substantially at right angles or other suitable angles to the legs  788  and  789 . The tabs  790  and  791  bear against the threaded rod  622  when the clip  755  is installed. The threaded rod  622  is secured top and bottom between respective of the tabs  790  and  791  and the cylindrical surfaces  750  and  752 . This keeps the threaded rod  622  from wobbling.  
       FIGS. 22-24  show another variant of the clamp  620 , which utilizes a smaller clip  756 . The clip  756  has a pair of resilient rod-gripping legs  763  and  765  emanating from a central clip body  767 . The legs  763  and  765  may be similar to the inner legs  758  and  760  of the clip  764  ( FIG. 18 ), being configured to be pressed onto and grip the threaded rod  622  within the middle hollow section  726 . The legs  763  and  765  prevent entry of the fastener  637  into the middle hollow section  726 . Although the clip  756  does not constrain movement of the threaded rod  622 , it will be appreciated that the clip  756  is lighter and easier to manufacture than the clips  754  and  755 . In addition, the clip  756  allows the clamp body protrusions  772  and  774  to be omitted.  
      The clamp body  624  (as with the other clamp bodies described herein), may be made by casting out of any of a variety of suitable materials, such as ductile iron. The clips  754 ,  755 , and  756  may be made out of spring steel.  
      Turning now to  FIGS. 25 and 26 , a clamp  820  has a clamp body  824  that clamps to a beam flange or other structure. The clamp body  824  has an open slot  840  along a back surface  844 . The open slot  840  is for receiving a threaded rod  822  and a fastener  837 , such as a hex nut, that is threaded on the rod  822 . The threaded rod  822  and the fastener  837  are received into a central hollow  850  of the clamp body  824 . The fastener  837  fits into a middle central hollow  926 , with faces of the fastener  837  secured between parallel walls  922  and  924  along opposite sides of the middle central hollow  926 . The bearing of the parallel walls  922  and  924  on diametrically-opposed faces of the fastener  837  keeps the fastener  837  from rotating within the middle central hollow  926 . Unlike the clamp  620  ( FIGS. 15-17 ), the fastener  837  is retained in the middle central hollow  926  when the threaded rod  822  and the fastener  837  are secured within the clamp body  824 . The clamp body  824  does not have anything corresponding to the pockets  738  and  748  of the clamp body  624  ( FIGS. 15-17 ).  
      The clamp body  824  has upper cylindrical surfaces  950  and lower cylindrical surfaces  952  for engaging surfaces of the threaded rod  822 . There may be respective upper and lower hollows  951  and  953  in the vicinity of the cylindrical surfaces  950  and  952 , in which the hollows are expanded in order to reduce weight of the clamp body  824 .  
      With reference now in addition to  FIG. 27 , a clip  954  is used to retain the threaded rod  822  and the fastener  837  in the central hollow  850 . The clip  954  has a clip central body  966  and a pair of gripping legs  962  and  964  emanating from the clip central body  966 . The central clip body  966  fits over a middle part of the clamp body back surface  844 . Specifically, the clip central body  966  covers the middle central hollow  926  so that the fastener  837  is retained within the middle central hollow  826 .  
      The gripping legs  962  and  964  may be substantially the same as the outer gripping legs  762  and  764  of the clip  754  ( FIGS. 15-18 ). That is, the gripping legs  962  and  964  resiliently grip side surfaces of the main body portion  826  of the clamp body  824 . The gripping legs  962  and  964  have respective windows or cutouts  968  and  970  for receiving protrusions  972  and  974  on side surfaces of the main body portion  826 . The gripping legs  962  and  964  have outturned front flanges  978  and  980 , and the protrusions  972  and  974  have chamfered back edges  982  and  984 .  
       FIGS. 28-30  show a variation of the clamp  820  which utilizes a clip  955 . The clip  955  uses the same resilient legs  962  and  964  as the clip  954  ( FIGS. 25-27 ), which grip the protrusions  972  and  974  on the sides of the central body portion  826  of the clamp body  824 . The clip  955  also includes a pair of L-shape or dogleg extensions  986  and  987  that protrude from the top and bottom of the clip central body  966 . The extensions  986  and  987  may be similar to the extensions  786  and  787  of the clip  755  ( FIGS. 19-21 ). The extensions  986  and  987  have respective legs  988  and  989  and rod-engaging tabs  990  and  991 . The legs  988  and  989  are connected to opposite ends of the clip central body  966 , and are directed inward toward the threaded rod  822  when the clip  955  is installed. The legs  988  and  989  have a trapezoidal shape, narrowing from a relatively wide end where the legs  988  and  989  are connected to the clip central body  966 , to a relatively narrow end where the tabs  990  and  991  are connected to the legs  988  and  989 . The tabs  990  and  991  are bent free ends of the extensions  986  and  987 , and may suitably be angled to the legs  988  and  989 . The tabs  990  and  991  bear against the threaded rod  822  when the clip  955  is installed. The threaded rod  822  is secured top and bottom between respective of the tabs  990  and  991  and the cylindrical surfaces  950  and  952 .  
       FIGS. 31-34  illustrate another embodiment, a clamp  1020 . The clamp  1020  includes a clamp body  1024  that has an open slot  1040  along a clamp body back surface  1044 . The open slot  1040  is configured for receiving a threaded rod  1022 , and a fastener  1036  threaded onto the rod  1022 . The fastener  1036  may be a hex nut or square nut. The clamp body  1024  has a central hollow  1050  for retaining the threaded rod  1022  therein. An upper cylindrical surface  1150  and a lower cylindrical surface  1152  are configured to engage and support the threaded rod  1022  when the threaded rod  1022  is in the hollow  1050 .  
      The clamp body  1024  includes a top fastener-receiving recess  1065  in a top surface  1060  of the clamp body  1024 . The recess  1065  may be have a pair of parallel walls  1066   a  and  1066   b  for engaging respective diametrically-opposed faces of the fastener  1036 . The walls  1066   a  and  1066   b  prevent rotation of the fastener  1036  when the fastener  1036  is within the recess  1065 . The recess  1065  may have a generally rectangular shape, with flanges  1067   a  and  1067   b  along the back surface  1044  to prevent the fastener  1036  from being pulled out the recess  1065  through the slot  1040 . The recess  1065  may have a rounded or chamfered shoulder  1069  along the clamp body top surface  1060 . The shoulder  1069  may facilitate placement of the fastener  1036  within the recess  1065 , guiding the fastener  1036  into the recess  1065  as the threaded rod  1022  is pulled downward through the hollow  1050  of the clamp body  1024 .  
      In installation of the clamp  1020 , the threaded rod  1022  is passed through the slot  1040  into the hollow  1050 , with the fastener  1036  above the clamp body  1024 . The threaded rod  1022  is then pulled downward to bring the fastener  1036  into the recess  1065 . This clamps the fastener  1036  between the walls  1066   a  and  1066   b  of the recess  1065 , preventing rotation of the fastener relative to the clamp body  1024 .  
      The clamp body  1024  may have a bottom fastener-receiving recess  1075  in a bottom surface  1070  of the clamp body  1024 . The bottom recess  1075  may be substantially identical to the top recess  1065  in both shape and function. The placement of the recesses  1065  and  1075  on opposite ends of the clamp body  1024  advantageously allows the clamp body  1024  to be flipped over. Alternatively, the fastener  1036  may be secured at either side of the clamp body  1024 .  
      Referring now in addition to  FIG. 35 , a clip  1154  is used secure the threaded rod  1022  and the fastener  1036 . The clip  1154  has a clip central body  1166  and a pair of gripping legs  1162  and  1164  emanating from the clip central body  1166 . The clip central body  1166  fits over a middle part of the clamp body back surface  1044 . The gripping legs  1162  and  1164  may be similar in configuration and function as the outer gripping legs  762  and  764  ( FIGS. 15-18 ) and the gripping legs  962  and  964  ( FIGS. 25-27 ). The gripping legs  1162  and  1164  resiliently grip side surfaces of a main body portion  1026  of the clamp body  1024 . The gripping legs  1162  and  1164  have respective windows or cutouts  1168  and  1170  for receiving central protrusions  1172  and  1174  on side surfaces of the main body portion  1026 . The gripping legs  1162  and  1164  have outturned front flanges  1178  and  1180 . The central protrusions  1172  and  1174  have chamfered back edges  1182  and  1184 .  
      The clip  1154  includes an L-shape or dogleg extension  1186  emanating or protruding from a bottom end of the clip central body  1166 . The extension  1186  may be similar to the extensions  786  and  787  of the clip  755  ( FIGS. 19-21 ). The extension  1186  has a leg  1188  and a rod-engaging tab  1190 . The leg  1188  is bent inward from the bottom end of the clip central body  1166 , directed inward toward the threaded rod  1022  when the clip  1154  is installed. The leg  1188  has a trapezoidal shape, similar to the legs  988  and  989  of the clip  955  ( FIGS. 28-30 ). The tab  1190  is a bent free end of the extension  1186 . The tab  1190  bears against the threaded rod  1022  when the clip  1154  is installed.  
      The clip  1154  also has a top fastener-retaining flange  1192  for retaining the fastener  1036  within the recess  1065 . The flange  1192  is bent inward from a top end of the clip central body  1166 , in the same general direction as the gripping legs  1162  and  1164 . The flange  1192  has a U-shape notch  1193  in its distal end, with flange legs  1194  and  1195  passing around either side of the threaded rod  1022 . The flange legs  1194  and  1195  have respective upturned distal tips or ends  1196  and  1197 . The upturned tips or ends  1196  and  1197  facilitate proper installation of the clip  1154  onto the clamp body  1024 , allowing the flange  1192  to more easily slide up onto the top surface  1060  of the clamp body  1024 . When the clip  1154  is installed, the threaded rod  1022  is engaged by a curved inner edge  1198  of the U-shaped notch  1193 .  
      The gripping legs  1162  and  1164  secure the clip  1154  to the clamp body  1024 . The top flange  1192  secures the fastener  1036  within the clamp body recess  1065  when the clip  1154  is secured to the clamp body  1024 . The inner edge  1198  of the top flange notch  1193  aids in securing the threaded rod  1022 , preventing the threaded rod  1022  from wobbling. The extension  1186  also aids in securing the threaded rod  1022 , with the tab  1190  pressing against the threaded rod  1022 . At the top of the clamp  1020 , the threaded rod  1022  is secured between the upper cylindrical surface  1150  and the notch inner edge  1198 . At the bottom of the clamp  1020 , the threaded rod  1022  is secured between the lower cylindrical surface  1152  and the tab  1190  of the extension  1186 .  
       FIGS. 36-38  show a variant of the clamp  1020 , with a clip  1155  used to secure the threaded rod  1022  and the fastener  1036 . The clip  1155  includes a top flange  1200  for securing the fastener  1036  within the recess  1065  in the clamp body  1024 . The top flange  1200  includes flange legs  1201  and  1202  on either side of a U-shape notch  1203 . When the clip  1155  is installed on the top surface  1060  of the clamp body  1024 , the threaded rod  1022  is received in the notch  1203 , with a curved inner edge  1204  of the notch  1203  engaging the threaded rod  1022  to help secure the threaded rod  1022  in place.  
      Side flanges  1205  and  1206  are bent downward from the respective sides of the top flange  1200 . The side flanges  1205  and  1206  have respective windows  1207  and  1208 . The windows  1207  and  1208  are configured for receiving and securing therein top protrusions  1209  and  1210  on opposite sides of the clamp body  1024 . The protrusions  1209  and  1210  may be secured within the windows  1207  and  1208  in a manner similar to that of other embodiments described herein. The top protrusions  1209  and  1210  have respected chamfered back edges  1211  and  1212 . The chamfered back edges  1211  and  1212  aid in urging the side flanges  1205  and  1206  resiliently outward as the clip  1155  is installed onto the clamp body  1024 .  
      The clamp body  1024  may have bottom protrusions  1213  and  1214  that may be substantially identical in placement and configuration to the top protrusions  1209  and  1210 . The bottom protrusions  1213  and  1214  allow the clip  1155  to alternatively be used to secure the fastener  1036  within the bottom recess  1075 . As another alternative, a pair of clips  1155  may be secured to both sets of the protrusions  1209 / 1210  and  1213 / 1214 , to provide additional support for the threaded rod  1022 .  
      A rod-engaging extension  1215  extends downward and inward from a back end of the top flange  1200 . The extension  1215  includes a downward-bent leg  1216  extending from the top flange  1200 , and an inward-bent tab  1217  extending from the leg  1216 . A distal edge  1218  of the tab  1217  engages the threaded rod  1022 , to aid in holding the threaded rod  1022  in place.  
      It will be appreciated that many alternatives and combinations may be made using various suitable features of the various embodiments.  
      Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.