Abstract:
A truss union connector for releasably coupling the ends of two axially aligned pipes, where the connector has simple construction and is operable easily and quickly by actuating a simple knob. This truss union connector is optionally combined with a truss mount where one of the coupled pipes is mounted to a truss. The connector includes a set of split cylindrical shell segments that engage outer surfaces of the ends of the coupled pipes by dimples extending radially inward from the split shell segments into holes in the walls of the pipe surfaces, resulting in a secure but rapid coupling and de-coupling assembly.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention is in the field of union connectors for releasably coupling the ends of two pipes and of a combination of a union connector and a truss mount which is releasably connectable to a truss, such union connectors being commonly used to support lighting fixtures from overhead horizontal trusses or from vertical trusses.  
           [0002]    Truss union connectors, particularly in combination with truss mounts, are used commonly to support lighting fixtures used in trade shows, theaters, clubs or other environments. In many of these situations time is critically important as during installation or assembly and disassembly when sets are changed during a theatre production or where displays are set up or removed at trade shows.  
           [0003]    Often at theater and trade show sites there is shortage of tools during the set-up or change-over transitions. Thus, it is desired to have the simplest connector structures which are quick and easy to use, and reliable. Some prior art structures focus primarily on accuracy or positioning and security of attachment, and unfortunately produce structures that are complex in terms of components and manufacture and either difficult and/or time-consuming to use. Typically, in prior art structures, achievement of one objective often dictates failure of another. For example, many prior art structures utilize bolts as the basic fastening elements which usually extend transversely and completely through a pipe perpendicular to its axis, as seen in U.S. Pat. No. 6,030,142, U.S. Pat. No. 5,184,911, U.S. Pat. No. 4,901,970 U.S. Pat. No. 5,609,436, and U.S. Pat. No. 5,536,102. While these prior art patents are primarily for coupling a pipe to another structure as opposed to coupling two pipes in end-to-end orientation, and while they may allege to be simple and easy to use and suitable for rapid installation, each disclosure has either multiple parts or a design which not suitable for easy and quick use in an awkward overhead position. As indicated above, bolts and pins in prior art devices invariably extend fully through the connected elements, thus necessitating more time and dexterity to assure proper orientation of components and full engagement and subsequent disengagement. This is both frustrating and costly where assembly or disassembly takes extensive time while subsequent phases must wait.  
           [0004]    The relevant prior art concerns not only truss union connectors for removable attachment of pipe extension components of lighting fixtures and the like to existing pipe elements, but also to truss mounts for removable attachment of these truss union connectors to trusses which include common ladder type and triangular type trusses and other related structures.  
         SUMMARY OF THE INVENTION  
         [0005]    This invention is a connector for releasably coupling the ends of two axially aligned pipes, where the connector has simple construction and is operable easily and quickly by actuating a simple knob. This connector is optionally combined with a truss mount where one of the coupled pipes is mounted to a truss. The new connector includes a set of split cylinder shell segments that engage the outer surfaces of the ends of the coupled pipes. These shells engage the pipes easily, quickly and securely primarily by use of short dimples that extend from the bore surface of the split cylinder shell segments radially inward into holes in the walls of the pipes. Numerous variations of this coupling concept are possible such as dimples extending radially outward from the pipes into holes in the shell segments. For convenience of manufacture the holes may extend completely through the pipe or shell wall respectively, or the holes may be replaced with shallow recesses or grooves in the surface receiving the dimples or other projections.  
           [0006]    It is an object of this invention to provide a coupling which is simple to manufacture and to operate, and which can be assembled and disassembled very quickly and easily even in overhead or other awkward positions.  
           [0007]    It is a further object to have a coupling assembly which is integrated such that its components will not fall apart while the unit is being used to join pipes. In one embodiment the coupling assembly is fixed in part to a first pipe end and adaptable to receive and releasably engage the end of another pipe. Such assembly is readily operable to receive the second pipe and easily closable into a secure coupling while the components are not able to fall apart or become mis-oriented. In one preferred embodiment the coupled pipes are coaxial and of the same diameter; however, in other embodiments the pipes may be non-coaxial and of different diameters.  
           [0008]    A still further object is to combine this coupling assembly with a truss mount which is releasably connectable to a ladder truss, triangular truss or other structure and simultaneously serves to couple ends of two aligned pipes.  
           [0009]    An additional object is for the assembly to be operable by rotation of a single thumbscrew. In one embodiment the thumbscrew, when initially turned, rotates the thumbscrew shaft into a distal nut where the shaft locks; further rotation of the thumbscrew causes the thumbscrew to move axially on the shaft and drive the shells tightly against the coupled pipes.  
           [0010]    A further embodiment utilizes a set of split cylinders or shells which when assembled into a connector define a split cylinder separated by a central axial plane. The shells when assembled define an outer cylinder concentric about the adjacent ends of the end-to-end pipes, and each shell overlies said opposing pipe ends. These pipe ends are slightly spaced apart, and a bolt fastener extends transversely through and engages said two shells and extends between the terminal ends of said adjacent but spaced apart pipe ends. To retain said pipe ends from moving axially away from each other, each pipe end has at least one set of holes extending radially inward and situated axially inward from its terminal end, and each shell has extending from its base surface two axially spaced dimples extending radially inward. In use one shell has one dimple extending through the radial hole of one pipe and the other dimple extending through the radial hole of the other pipe, these transverse projections from the shells into the pipes serving to bar axial displacement of the pipes relative to each other. The second shell has two generally similar inward projections except that one is a dimple for releasably coupling to one pipe and the other projection is a bolt or rivet permanently securing the shell to the end of one pipe. The transverse central bolt, preferably has at its top end a socket head drivable by an Allen wrench with external threads for cooperation with a wing nut, and at its bottom end threads to engage a nut or other threaded receptacle. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is an assembly in exploded perspective view of the new truss union connector in combination with a truss mount;  
         [0012]    [0012]FIG. 2 is a front elevation view of a fragmentary ladder truss with the combination truss connector and truss mount secured thereto;  
         [0013]    [0013]FIG. 3 is an end elevation view of FIG. 2;  
         [0014]    [0014]FIG. 4 is a sectional view of the truss connector of FIGS. 1 and 2 in open condition;  
         [0015]    [0015]FIG. 5 is a sectional view of the truss connector of FIGS. 1, 2 and  5  in closed condition;  
         [0016]    [0016]FIG. 6 is a sectional view taken along line  6 - 6  in FIG. 5, showing one fixed fastener and one dimple-in-hole arrangement;  
         [0017]    [0017]FIG. 7 is a sectional view taken along line  7 - 7  in FIG. 5, showing the central bolt;  
         [0018]    [0018]FIG. 8 is an assembly in exploded perspective view of a second embodiment of the truss connector in a T-configuration for releasably coupling a simple pipe end to a transverse pipe;  
         [0019]    [0019]FIG. 9 is a sectional view taken along line  9 - 9  in FIG. 4 showing a more detailed view and variation of the molded bosses in the split cylindrical shells, through which the central fastening bolt extends, in open condition; and  
         [0020]    [0020]FIG. 10 is a sectional view similar to FIG. 9 showing the structure in closed condition. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]    The drawings disclose an illustrative embodiment of the present invention which serves to exemplify the various advantages and objects hereof, and are as follows:  
         [0022]    [0022]FIG. 1 shows in exploded view an assembly  10  of a truss union connector  11  in combination with a truss mount  12 . The truss mount is formed of upper saddle part  13  and lower saddle part  14  situated on junction post  15 . In use the truss mount  12  is releasably secured to a ladder truss  16 , as seen in horizontal orientation in FIGS. 2 and 3 or to another form of truss which may be oriented vertically, horizontally or otherwise. This truss mount will be described in further detail later below.  
         [0023]    The union connector  11  as seen in FIGS.  1 - 7  is formed from a set of shells, left shell  20  and right shell  21 , which together define a split cylinder  22  (seen in FIGS. 6 and 7) cut by an axial plane into the two half or slightly less than half-cylinders  20 ,  21 . When assembled together, these shells form the split sleeve  22  situated closely and concentrically about the ends  24 ,  25  of two axially aligned pipes  26 ,  27  respectively. These pipes are axially aligned about a central axis and have terminal ends  28 ,  29  respectively which are adjacent, end-to-end. These pipe ends  28 , 29  are spaced apart a distance sufficient to allow for the central fastening sub-assembly  32 , which includes a threaded bolt  34 , an acorn nut  36  which fits into a recess  38  dimensioned to prevent rotation of nut  36 , and thumbscrew  40  threadedly engaged to bolt  34 .  
         [0024]    As seen in FIGS. 4 and 5, lower pipe  27  has opposite radial holes  41 ,  42 , and left and right shells  20 ,  21  respectively have radial dimples  43 ,  44  which are dimensioned and situated to fit into holes  41 ,  42  when the shells are closed. This radially-extending dimple-to-hole connection in the closed condition seen in FIG. 5 locks the lower pipe  27  to the coupling and prevents relative axial displacement. The upper end of sleeve  20  has a similar dimple  45  which fits into hole  46 . It is significant to note that FIG. 4 shows the shells  20 ,  21  in open condition somewhat like an open alligator mouth that easily receives the end  29  of pipe  25  and then recloses as seen in FIG. 5 and is locked by simple rotation of thumbscrew  40 .  
         [0025]    Also, as seen in FIGS. 4, 5, and  6  the upper pipe  26  has addition lock hole  47  aligned with and radially opposite dimple  45 , and right shell  21  has lock hole  48  that aligns with lock hole  47 , and bolt  49  extends through both holes  47  and  48  and is fixedly secured by nut  50 . Bolt  49  could be replaced by a rivet or by adhesive or other fastening means, since the object is to fixedly secure one of the shells to one of the pipes being coupled.  
         [0026]    As seen in FIG. 4 the right shell  21  is secured to upper pipe  26 , and left shell  20  is displaced angularly from the coupled right shell and pipe  26 , while left shell  20  is prevented from totally separating or falling apart from the right shell  21  by the central bolt  34  whose bottom end  34 B is threadedly engaged to nut  36 .  
         [0027]    In operation the shells  20  and  21  are partially separated until there is sufficient space for lower pipe  27  to be moved axially upward into the recess of base formed by shells  20  and  21 . As an option, shell  20  could be displaced laterally without angulation. Hole  42  in pipe  27  slips onto dimple  44  of the right shell, and then the central bolt is operated, as described in greater detail below, to pull shell  20  transversely toward shell  21  until dimple  43  slips into hole  41 , and dimple  45  slips further into hole  46 , and the two left and right sleeves become snugly fitted onto pipes  26  and  27 .  
         [0028]    A coil spring  55  seen in FIGS. 4, 5 and  7  has relaxed length greater than the space L, seen in FIG. 7 between bosses  56 ,  57  of shells  20  and  21 . Thus, as the bolt  34  is loosened by thumbscrew  40 , the coil spring  55  urges the shells apart, with the result that they separate by themselves and thus easily provide the space between them to receive the lower pipe for coupling as described above.  
         [0029]    When the coupling begins and after the lower pipe is inserted and engages the dimples  43  and  44 , the initial rotation of thumbscrew  40  causes rotation of bolt  34  whose end  34 E is drawn into the acorn nut  36 , pulling shell  21  snugly toward pipe  21 . Further rotation of thumbscrew  40  rotates bolt  34  which forces shell  20  also into a tight fit against pipes  26 ,  27 .  
         [0030]    From this structural arrangement there are numerous benefits. First, this assembly allows coupling of two pipes that can be done easily and quickly. Since one shell, namely  21  is initially secured to one pipe  26 , and since the left shell  20  is loosely coupled to the right shell  21  by central bolt  34 , which is also coupled to the left shell, the assembly components will not fall apart or become inoperably displaced when coupling is begun.  
         [0031]    Second, the coil spring or other separation means automatically urges the shells into an open condition feasible to receive the second pipe, which is lower pipe  27  in the case herein illustrated. Thus, the lower pipe  27  can be easily, quickly and securely captured by the shells.  
         [0032]    Third, the thumbscrew permits an easy and rapid final tight lock; the thumbscrew  40 ,  34  in combination with the coil spring  55  further permits an easy and rapid disassembly since the shells will pop open from the spring until the dimples withdraw from the holes  41 ,  42  in the lower pipe.  
         [0033]    Fourth, the very simple dimple-hole combination allows extremely quick coupling and decoupling without any binding or unhooking, so that lighting fixtures or other components can be positioned and secured and subsequently removed with no requirement of special tools or of any tools, and no special skills or experience, and with little expenditure of time, energy or other cost.  
         [0034]    Fifth, the parts are simple and inexpensive to manufacture and components, if damaged, can be easily replaced.  
         [0035]    Sixth, the thumbscrew and central bolt can be designed and adapted to provide a warning stop when adequate tightening has been achieved.  
         [0036]    The truss mentioned earlier is seen is FIGS. 2 and 3 is a ladder truss  16  which is generally flat, with upper and lower rails  16 A,  16 B, and inclined support struts  16 C. The upper and lower saddles  13 ,  14  each have a concave or cylindrical surface  13 A,  14 A as seen in FIGS. 1 and 3 for engagement with the upper and lower rails  16 A,  16 B formed in this case from round pipes. For convenience of use, upper saddle  13  is locked in place on post  15  by set screw  13 B, and lower saddle  14  is slidable on post  15  until it simply engages lower rail  16 B, at which time its thumbscrew  16 C is tightened to lock the lower saddle in place and thereby to releasably lock the truss mount  12  onto truss  16 . In the embodiment shown in FIGS.  1 - 3  the lower end  15 A of post  15  corresponds to the upper pipe  26  in FIGS.  3 - 7 . The lower pipe  25  in FIG. 1 utilizes the same reference numbers as used in FIGS.  4 - 7 , namely, terminal end  29  and hole  41 .  
         [0037]    [0037]FIG. 8 shows a T-configuration variation  60  of the present invention where the set of shells  61 ,  62  forming the split cylinder include right angle portions  63 ,  64  for coupling aligned pipe ends  65 ,  66  and transverse pipe end  67 . Structural features of this embodiment are essentially the same as corresponding parts in FIGS.  1 - 7 . Shell  61  has a pair of dimples (not seen) which engage holes  68 ,  69  in pipes  65 ,  66 . Shell  62  has a dimple  70  and a hole  71  for fixedly joining shell  62  to pipe end  65 . Shell  61  further includes thumbscrew  72  and its threaded shaft  73  which corresponds to the similar releasable fastening means in FIGS.  1 - 7 . As evident, this embodiment can provide quick and secure releasable connection of two or three pipes.  
         [0038]    [0038]FIG. 9 shows structure that corresponds to bosses  56 ,  57  of shells  20 ,  21  in FIG. 7, but shows a more detailed structure of the internal bosses now designated  56 ,  57 . Other corresponding parts retain the same reference numbers, such as coil spring  55 , bolt  34  and thumbscrew  40 . Bolt  34  is threaded along its length, with threads  34 A at the end engaging nut  36 , and threads  34 B at the head end engaging the bore of the thumbscrew. At the top end  34 C of the bolt is a socket for receiving an Allen wrench.  
         [0039]    As described earlier, initial rotation of the thumbscrew causes initial rotation of the bolt  34  into the nut  36  until the bolt bottoms tightly in the nut. Further, rotation of the thumbscrew or drive wheel  40  with respect to the now-anchored bolt draws the thumbscrew toward the nut, thus urging the two shells toward each other and tightly against the enclosed axially aligned pipe ends, with the dimples engaging the holes in the pipe walls. Also, as described earlier, coil spring  55  urges the shells apart, as seen in FIG. 9 so that the coupled pipe can be inserted when the connector is in open condition.  
         [0040]    Although not shown herein, this connecting assembly could be adapted to couple pipes not in axial alignment and/or not of the same diameter.  
         [0041]    Now that the preferred embodiments of the present invention have been shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is to be limited only by the appended claims, and not by the foregoing specification.