Abstract:
A tool for clamping onto a strut for holding objects such as pipes in place while they are being attached to the struts is disclosed. The clamp has opposing jaws, which are drawn together by movement of a handle, for pinching the lips of the strut and holding firmly thereto while holding objects adjacent the clamp. A handle on the clamp locks into a pinching position and can be released by opposite motion of the handle. Various attachments to the clamp housing can be used for holding different objects. The clamp has adjustable jaw positions for adjustable pinch strengths. The jaws are biased together when not engaging the strut to allow easy access to the strut for engaging the strut lips or removing the clamp from the strut. Use of the clamp allows one man to install pipes faster safer and easier and without the aid of a helper.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a clamp for releasably engaging struts and temporarily supporting pipes adjacent thereto until a permanent connection can be made. 
     2. Description of the Related Art 
     In construction of buildings struts are used to hold pipes, electrical conduit and other objects. For example, installing a long, heavy length of pipe to struts hanging from the ceiling currently takes two people, one at each end of the pipe. One person will hold the pipe on one end and the other person will connect the pipe to the previous section and make a permanent connection to the strut. The second person can then connect his end of the pipe to the strut. Typically these pipes are attached to the ceiling or a wall thus requiring two ladders or lifts and the coordinated movements of two people. If one end of the pipe is dropped it can be dangerous and can damage objects below. It is desired to have a device which will temporarily hold a pipe adjacent a strut in a secure manner to eliminate the need for a second person during installation of the pipe. It is further desired to have a simple tool for aligning the pitch of the pipes. 
     SUMMARY OF THE INVENTION 
     A clamp for attachment to struts is provided wherein two opposing jaws are drawn together and locked into position on the lips of the strut. The clamp has attachments for holding pipes or other devices needed for construction. 
     The clamp allows one person to do the job of two people by holding one end of a pipe adjacent a strut while the other end is being worked on. The clamp improves the safety of the handling of the pipes, while saving time by making it quicker to install pipe. The clamp can be used in all positions, be installed with one hand, will lock in place and stay tight. The clamp has adjustable pinch strength and can be used on horizontal or vertical installations. The clamp has a fixed jaw and a movable jaw, which engages and holds the lip of a strut. A handle on the clamp pulls the jaws together and locks them into place to fix the clamp to the struts. Attachments to the clamp hold pipes or other objects in place while being connected to the struts allowing one man to do the work of two or more men. 
     Attachments to the clamp allow for holding pipes or other objects until they are permanently attached to the struts. Other attachments to the clamp are used for leveling or pitching the pipes. A laser attached to a clamp can provide a site line for pipes or for positioning of struts. A trapeze strut can be adjusted on its rods for height by use of a laser for sighting pitch of the strut locations for pipes to rest on the struts. 
     OBJECTS OF THE INVENTION 
     It is an object of the invention to safely yet temporarily attach pipes to struts during the permanent installation process. 
     It is an object of the invention to hold pipes level for level installation. 
     It is an object of the invention to hold pipes at predetermined angles for pitched installation. 
     It is an object of the invention to provide the clamp with accessories for use in hanging objects from struts. 
     It is an object of the invention to provide the clamp with accessories for aligning or angling two struts for connection. 
     It is an object of the invention to allow one person to hang pipe from struts. 
     It is an object of the invention to allow quick and easy leveling of the strut hangers themselves. 
     It is an object of the invention to quickly and easily attach the clamp to a strut. 
     It is an object of the invention to quickly and easily remove the clamp from a strut. 
     It is an object of the invention to provide the clamp various easy to attach accessories allowing multiple uses for the clamp. 
    
    
     Other objects, advantages and novel features of the present invention will become apparent from the following description of the preferred embodiments when considered in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the clamp on a strut ready to receive a pipe, conduit or other products. 
     FIG. 2 is a top view of a portion of the clamp engaging a strut with the jaws in a closed position. 
     FIG. 3 is a side schematic view of the clamp. 
     FIG. 4 is a side perspective view of the clamp. 
     FIG. 5 is a top cross section view of the tension pin engaging the main actuating arm and the jaws extended to the open position. 
     FIG. 6 is a side view of the clamp with a pipe holding attachment. 
     FIG. 7 is a top view of the clamp with a pipe holding attachment. 
     FIG. 8 is a side view of a pipe holding attachment. 
     FIG. 9 is a bottom perspective view of the clamp with an attachment arm integral with the housing. 
     FIG. 10 shows a clamp housing with posts for engaging pipes therebetween. 
     FIG. 11 shows a laser attachment on a clamp for sighting the pitch of pipes on a trapeze strut. 
     FIG. 12 shows a laser attachment on a clamp for sighting the pitch for pipes with struts attached to a wall or ceiling. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In construction projects gas pipes, water pipes, compressed air pipes, ducting, electrical conduit, fire sprinklers, hoses, cables, struts, supports, and other items are connected to or held by struts. The struts may be vertical or horizontal. Long heavy length of pipe generally require a two man crew to install the pipe, one to hold one end of the pipe and the other to hold the other end and attach it to an adjoining pipe and or secure it to a strut. Struts have a standardized shape the cross section of which can be seen in FIG.  1 . 
     FIG. 1 shows a clamp  10  attached to a vertical strut  80  secured to a wall, for holding pipes horizontally along the wall  400 . A pipe holding attachment  40  on clamp  10  defines a square bounded by the clamp  10  on the bottom, the pipe holding attachment  40  on the top and one side and the strut  80  on the other side into which a pipe may be held, such that the pipe cannot escape the area. In this manner the pipe may be held in place on one end, rather than have an assistant hold it, while being connected to another pipe and/or secured to a strut on the other end. Similarly the clamp, used in pairs can hold both ends of a pipe to make it easier to work on the pipe for connection to other pipes or securing the pipe to a strut. 
     Although pipes are used herein as the object held by the clamp electrical conduit or any other object can be held by this device. 
     FIG. 2 shows the means of engaging the clamp  10  to strut  80 . Struts  80  such as those made by Unistrut®, B-Line® and other manufacturers, have a C shapes with lips  82  curved inward at each end. Clamp  10  has a fixed jaw  60  and a moveable jaw  62  for engaging the lip  82  of the strut  80 . In an alternative embodiment moveable jaw  62  has lip portion  162  for wrapping around the lip  82  of the strut  80  for a better grip and stronger hold. 
     Fixed jaw  60  and moveable jaw  62  can have a roughened or textured surfaces  260  and  262  respectively to obtain a better grip on and hold the lips  82  on struts  80 . 
     The moveable jaws  62  are optionally biased by spring  126  to be pulled toward one another when not engaging strut  80  to better insert the moveable jaws  62  into or extract them from the strut  80 . As shown when the movable jaws  62  are drawn toward fixed jaws  60  the ramped portion  170  engages spreader pin  25  and moves the moveable jaws  62  apart as they transition from the thin portion  172  to the thick portion  174 . Thus as the movable jaws  62  are pulled toward the fixed jaws  60  they are pushed apart to engage the lips  82  of the strut  80 . Note that the inside width of the clamp housing  20  equals the width of the spreader pin  25  and the thick portion  174  of the moveable jaw arms  64  on movable jaw  62 . 
     The mechanics of tightening the clamp  10  are shown in FIG.  3 . The clamp can be adjusted to tighten on any size strut  80  by turning adjustment screw  14 . Adjustment screw  14  limits the travel of foot  15  in housing  20  and thereby fixes the position of maximum travel of jaw  62  and sets the pinch strength of the clamp  10 . Foot  15  is pivotally connected at point  38  to swing arm  17 , which is pivotally connected at point  30  to cam  18  on handle  12 . Swing arm  17  passes thought slot  22  (see FIG. 9) in housing  20  to connect to pivot point  38  on foot  15 . Handle  12  is pivotally connected at point  32 , to actuating arm  68  which rotates on pivot point  34 , on housing arm  28 . The actuating arm  68  passes through slot  22  in housing  20  and is pivotally connected, at pivot point  36 , to movable jaw arm  64  in housing  20  for locking the movable jaw  62  in place relative to fixed jaw  60 . The actuating arm  68  is shown curved, but it could be straight, such that as the handle  12  is pulled toward the housing  20  it passes a locking point when pivot point  32  is aligned with pivot point  30 . At that point, pivot point  30  goes past the straight line between pivot points  32  and  38 . The handle  12  then cams over center in the arc it swings thorough and the last part of the handles&#39; stroke is devoted to locking the handle  12  in place. The handle stop  16  is adjustable to limit the movement of the handle  12  toward the housing  20 . The handle  12  is shown as being straight but it may be curved or angled. 
     The actuating arm  68  is pivotally connected to the moveable jaw arms  64  by floating tension pin  36 . As best seen in FIG. 5 the actuating arm  68  preferably has a curved surface for engaging the tension pin  36  allowing the tension pin to rock such that the moveable jaw arms  64  can independently engage the strut  80  while the moveable jaws  62  are being pulled backwards toward fixed jaws  60 . 
     As best seen in FIG. 2 showing the jaws  60 ,  62  in a locked position on strut  80  the moveable jaw arms  64  preferably have a straight narrow section  172 , a curved section  170 , and a straight thick section  174 . The difference in thicknesses on the length of the moveable jaw arms  64  are for adjusting the width of the moveable jaws for engaging the struts  80 . When the jaws  62  are not engaging the struts  80  they are able to move toward each other for entering or exiting the strut. The jaw arms  64  on either side of the spreader pin  25  are in the narrow portion  172  during this phase of operation as shown in FIG.  5 . As the moveable jaw arms  64  are retracted by handle  12  the spreader pin  25  engages the curved section  170  pushing the moveable jaw arms  64  apart until the thick portion  174  is reached which maximizes the spreading of the moveable jaw arms  64 . The thick portion  174  of moveable jaw arms  64  plus the spreader pin  25  approximates the width of the inside of the housing  20 . The jaws  62  are spread apart to engage the strut lip  82  when the spreader pin  25  is adjacent the thick portion  174  of moveable jaw arms  64 . A spring  126  can be used to pull the moveable jaw arms together when spreader pin  25  is adjacent the narrow portion  172  of moveable jaw arms  64 . 
     The moveable jaw arms  64  have jaws  62  for engaging the lips  82  of strut  80 . Alternatively the moveable jaw arms  64  may have a lip  162  for hooking over the lips  82  of the strut for a more secure connection. Further, roughened surface area  260  on fixed jaw  60  can enhance the grip of the jaws  60 ,  62  on strut  80 . 
     Return spring  50  extends between the actuating arm  68  and the spreader pin  25  to bias the handle  12  in the unlocked position with the narrow portion  174  of moveable jaw arms  64  adjacent spreader pin  25  for ease of inserting or extracting the jaws  62  into the strut  80 . 
     Many types of attachments may be used on the housing  20 . As best seen in FIG. 8,  6 ,  1  and  4  a pipe holding attachment  40 ,  140  may be bolted at apertures  43 ,  45 ,  143 ,  145  to the housing  20 . A pipe may be inserted into the area bordered by strut  80 , housing  20  and attachment  40 ,  140 . Attachment  40 ,  140  may be a variety of shapes including C shaped or L shaped. When attachment  40  is C shaped as in FIG. 4, it forms a square with sides  44 ,  42 ,  46  on C shaped attachment  40  and the strut  80 , to insert pipes into as shown in FIG. 1 and 6. When an L shaped attachment is used the top portion is open making it easier to insert the pipes as shown in FIG.  8 . Alternatively an L shaped attachment  140 , having apertures  143  and  145  for connecting the attachment to the housing  20  of clamp  10 , has an arm  142  perpendicular to the housing  20 . A pipe  100  can rest between the strut  80  and arm  142  on the base portion  141  of L shaped attachment  140 . A spring loaded swing arm  145  on the L shaped attachment  140  allows a pipe to enter the attachment from the top by depressing the swing arm  145 . Swing arm  145  will then allow a pipe to be captured as in the C shaped attachment  40 . When swing arm  145  is swung downward to admit pipe  100 , spring  144  will pull the swing arm  145  back to engage pin  149  leaving swing arm  145  in a position perpendicular to arm  142  and preventing pipe  100  from being removed from the capture area. 
     Although bolts through apertures  143  and  145  can hold attachment  140  in place along the side of the clamp housing  20  other methods of placing attachments on the housing may be used. The attachment points may also be varied on the housing  20 . For example the attachment point can be on the top, or either side, or other location, of the housing  20  and be permanently or removeably attached. As shown in FIG. 9 attachment  40  may be integral with housing  20 . 
     FIG. 10 shows an alternative for positioning pipes relative to the housing  20 . One or more posts  500  can be attached to the housing  40  such as by insertion into apertures  510  shown on the top of housing  40  or by posts  500  on pads  520  sliding in tracks  530  and locked into position by position lock  540 . Pipes can be held in position either between adjacent posts  500  or between a post  500  and the strut  80  or between a post and an attachment  40 ,  140 . 
     Other attachments for use with the clamp  10  such as a laser for leveling or angling (pitching) the pipes can be used. Therefore when it is desired to (pitch) angle a drain pipe for better drainage the attachment may be used to sight the angle. 
     For positioning pipes a laser attached to one clamp can be used to set the position of other clamps. The clamps once attached can then have the pipes held in the correct position for level or (pitched) angled piped. 
     For example in FIG. 11 a series of trapeze struts  300  are used to hold pipes  330  from a ceiling. The trapeze struts  300  have threaded rods  310  attached to a ceiling and are adjustably connected to struts  320  by nuts  315 . By adjusting the nuts  315  on the threaded rods  310  the struts  320  may be moved upward or downward on the threaded rods  310 . 
     A clamp  10  having a laser  340  attached to the housing  20 , is connected to strut  320  and laser beam  345  having an adjustable pitch is used for sighting the position of the next strut  321 . The pitch adjustment of the laser  340  can be used to adjust the second strut  321  to be level with or pitched up or down from the first strut  320 . The second strut  321  may have a clamp  10  with a target attachment  350  having gradient lines  360  thereon for adjusting the pitch of the second strut  321  relative to the first strut  320 . 
     Similarly in FIG. 12 the struts  410  and  411  are attached to a wall  400 . Clamps  10  with laser attachment  340  and target attachment  350  are used on the struts to position the pipes  430  being attached to the wall  400 . Clamps  10  are moved to positions for supporting the pipes  430  at the desired pitch and the pipes are then rested on the clamps  10  and then attached to the struts  410  and  411 . 
     Another attachment can be used for making angles connections between struts. A clamp at the end of one strut can hold a connector for two struts for assembling the struts either straight or at angles. 
     The struts  80  may be used horizontally or vertically along walls or ceilings in conjunction with the clamp  10 . 
     The clamp  10  may be made in various sizes to fit the sizes of the struts  80  they are to engage. 
     The clamps  10  can be used with pipe piers having a cross section with lips similar to struts  80  for the clamp jaws  60 ,  62  to engage. Thus pipes  100  on pipe piers can be held in place in with clamps  10  and aligned using laser attachments  340  in the same manner as with struts  80 . Pipe piers are commonly used in the building industry for holding pipes on rooftops and in above ground installations. 
     Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.