Abstract:
A tube connector for quickly and releasably coupling tubes. The connector is a fully integrated device which connects tubes, end-to-end, by binding to them in spigot fashion with an arbor, traveling nut and expandable collet assembly.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention generally relates to a device for releasably connecting two axially aligned tubes. The invention is specifically directed to a generally linear device having opposing end portions which are to be inserted into the open ends of tubes and then radially expanded by a hand-actuated mechanism. 
         [0002]    There are various types of connector apparatuses of the prior art which are adapted to facilitate the quick releasable coupling of tubes. Many such connectors employ bolts, screws or pins which must be inserted through compatible holes in the tubes in order to secure a connection. Unfortunately, shear stress often makes these fastening objects susceptible to yield or even catastrophic failure that eventually necessitates their replacement, if not rendering more serious consequences. Furthermore, since pins, bolts, etc. are generally removable from the connector devices, they can be easily misplaced. 
         [0003]    Therefore, it can be appreciated that there exists a need for a truss connector apparatus that is adapted to facilitate a secure coupling of tubes without employing any loose parts that can be misplaced or damaged. The truss connector of the present invention substantially fulfills this existing need. 
       SUMMARY 
       [0004]    The present invention is a mechanical device for rigidly joining open-ended pipes and tubular objects generally. The constituent major components of a preferred embodiment of the invention include: a pair of arbors, a pair of collets, a pair of traveling collet nuts, a key member and a rotable handwheel for turning the key member, all mounted on a differential screw. One arbor, collet and traveling nut sit side-by-side along a proximal segment of the screw while the other arbor, collet and traveling nut sit side-by-side along its distal segment. The key member is stationed generally within a middle segment of the screw. The rotable handwheel is axially movable within the middle segment, and the handwheel features a taper for receiving the key member. 
         [0005]    Both combinations of arbor, collet and nut act as inserting members for being plugged into tubes that the connector device is joining. The handwheel, when engaged with the key member, functions as a means for driving the collet nuts to and fro along the screw and ultimately causing radial expansion of the collets and their consequential binding to the tubes&#39; interior walls. In fact, the present connector facilitates a rigid joining of two tubes by a user following the three successive steps of: (1) slipping the ends of both tubes over the proximal and distal segments of the connector, thereby disposing the connector&#39;s arbors, collets and collet nuts within the tubes; (2) sliding the handwheel toward the key and eventually fitting the key into a matching slot along the handwheel; and (3) turning the handwheel (and therefore the screw itself) to propel the collet nuts against the collets, eventually causing radial expansion of the collets and friction binding the expanded collets to the interior walls of the tubes. 
         [0006]    It is, therefore, an object of the present invention to provide a tube connector device that rigidly binds tubes together while effectively eliminating the possibility of connection failure due, specifically, to yielding or shearing of the connector&#39;s fastening components. 
         [0007]    It is another object of the present invention to provide a tube connector device does not employ any loose or unattached parts that can be easily lost. All of the instant connector&#39;s components can remain integrated within a single physical apparatus before, during and after the connector is applied in use. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view of the tube connector of in a disassembled state; 
           [0009]      FIG. 2  is a perspective view of the connector when fully assembled; 
           [0010]      FIG. 3  is a perspective view of two tubes being coupled by the connector; and 
           [0011]      FIG. 4  is an exploded view of the key member and the arbor to which the key member attaches. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0012]    A preferred embodiment of the tube connector  1  of the present invention is illustrated in the accompanying  FIG. 1  as fully assembled and  FIG. 2  in an unassembled state. The connector  1  is comprised of metal components which are mounted on an elongate differential screw  2 . As shown in  FIG. 2 , the screw  2  comprises three distinct linear segments: a threaded proximal segment  4 , a reversely threaded distal segment  8  and an unthreaded middle segment  6 . 
         [0013]    Referring back to  FIG. 1 , arranged consecutively along the proximal segment, from near the proximal end of the screw  2  toward its middle segment, are a traveling collet nut  26 , a collet  24  and an arbor  22 . Similarly, arranged along the distal segment, from near the distal end inward, are another collet nut  26 , collet  24  and arbor  22 . At both ends of the differential screw  2  are welded-on retaining rings  30  or some other retaining parts for preventing the adjacent collet nuts  26  from traveling off the screw  2 . 
         [0014]    The arbors  22  each comprise a tubular section  22   a  and a generally conical tapered section  22   b , and they are oriented such that their tapered ends abut the collets  24 . The collets  24  are each shaped such that one end wedges over the adjacent arbor&#39;s tapered section  22   b  while the opposite end wedges over the adjacent traveling nut  26 . O-rings  32  circumscribe and compress the middles of the collets  24  to further facilitate wedging action. 
         [0015]    The screw&#39;s middle segment  6  is defined, essentially, as the linear portion of the screw  2  that sits between the arbors  22 . At one edge of the middle segment  6 , abutting the tubular end of an arbor  22 , is a washer  28 . Another washer  28  is stationed at the opposite end of the middle segment  6 . Immediately next to one washer  28  is a key member  14 . In a preferred embodiment of the connector  1 , the key  14  is simply a short stud that screws into and protrudes from the tubular end of an arbor  22 , as shown in exploded view in  FIG. 4 . This embodiment of a key  14  pierces a matching bore in the adjacent washer  28  and projects into the middle segment  6  of the screw  2 . However, the key device  14  can conceivably take on a number of alternative embodiments of articles stationed within, or immediately adjacent to, the screw&#39;s middle segment  6 . In any event, the key is fixedly attached to the screw  2  such that the screw  2  will rotate when force acting upon the key  14  revolves the key  14  around the screw axis. 
         [0016]    A knurled handwheel  18  is loosely mounted along the screw&#39;s middle segment  6  such that a user may slide the handwheel  18  back and forth between the two washers  28 . The handwheel  18  features a notch or slot  20  for fitting the key  14  within. Therefore, as illustrated in  FIG. 3 , the handwheel  18  may be engaged with the key  14  by simply aligning the key slot  20  with the key  14  and then sliding the handwheel  18  over the key  14  so that the key  14  lodges into the slot  20 . 
         [0017]    The connector  1  joins separate tubes  100 , 200  at their ends by friction binding itself to their respective interior walls in spigot fashion. A first tube  100  is slid over the proximal segment  4  of the screw  2  such that the end of the tube  100  meets the proximal side washer  28 , and the second tube  200  is fitted over the distal segment  8  in like fashion. Thus, in addition to fitting over much of the length of the screw  2 , the tubes  100 , 200  engulf the pairs of arbors  22 , collets  24  and collet nuts  26 . In fact, the arbors&#39; tubular sections  22   a  are a push fit within the tubes  100 , 200 . 
         [0018]    Once the connector  1  is properly disposed within the tubes  100 , 200  and the handwheel  18  is engaged with the key device  14  as illustrated in  FIG. 3 , a user secures the connector  1  to the tubes  100 , 200  by actuating the collet nuts  26 . Specifically, the user turns the rotatable handwheel  18  clockwise. This handwheel  18  rotation revolves the key  14  around the screw axis and thereby rotates the screw  2 . However, due to friction between the abutting collet nuts  26  and collets  24 , the collet nuts  26  are inhibited from rotating with the screw  2 . Instead, both nuts  26  are drawn inward, pressing the collet nuts  26  against the collets  24  and, in turn, the collets  24  against the arbors  22 . As the differential screw  2  continues to be rotated, the collet nuts  26  wedge under the collets  24  while the collets  24  wedge over the arbors&#39; tapered sections  22   b . The collets&#39; ends radially expand and friction-bind themselves to the interior walls of the tubes  100 , 200 . 
         [0019]    When the collets  24  are sufficiently bound to the tubes  100 , 200 , the user discontinues turning the handwheel  18  and slides it off of the key  14 . Disengaging the handwheel  18  from the key  14  prevents the handwheel  18  from causing any reverse rotation of the screw  2  and resulting contraction of the collets  24 . Of course, to detach the connector  1  from the tubes  100 , 200 , the user simply re-engages the handwheel  18  to the key  14  and then turns the handwheel  18  counterclockwise. This causes the collet nuts  26  to travel outward and relieves sandwiching pressure exerted on the collets  24 , allowing the collets  24  to radially contract. 
         [0020]    Although the present invention has been described in considerable detail and with reference to and illustration of a preferred version, it should be understood that other versions are contemplated as being a part of the present invention.