Abstract:
A swivel connector for a pre-conditioned air (PCA) hose for an aircraft comprises an inner tube, an outer tube, and a bearing between the inner and outer tube such that an air hose mounted to the inner tube can rotate relative to an aircraft mounting affixed to the outer tube, to remove kinks or twists in the hose without disconnection.

Description:
RELATED APPLICATIONS 
       [0001]    The present invention claims priority to U.S. Ser. No. 61/236,363 filed Aug. 24, 2009, the disclosure of which is hereby incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention generally relates to ground-based conditioned air systems for aircraft. 
       BACKGROUND 
       [0003]    It is generally known to supply commercial aircraft with conditioned air for heating and cooling when the aircraft is stationary at a gate. In this application, the term gate is meant to refer to any place that an aircraft receives or discharges passengers or cargo. This may be by way of a telescoping corridor, stairs, or any other facility. Typically, conditioned air is supplied to the aircraft from a pre-conditioned air (PCA) unit that has a ducting system associated with the gate that is a part of the airport terminal. The air is delivered from the gate to the aircraft with a flexible and usually insulated air hose. When not in use, the hose is stored under the terminal. When hooked up to an aircraft the blowers of the PCA are energized, and air flows to the aircraft. This means it is unnecessary for the airplane&#39;s fuel powered auxiliary power unit (APU) to produce conditioned air for the stationary aircraft. 
         [0004]    A problem exists in that planes arriving at a gate are of different sizes and their hose attachment ports are located at different distances from the gate. Therefore the hose at the gate, having one end connected to the source of preconditioned air, must be at least long enough to service the type of aircraft having its connection point the furthest away. This means that for many arriving aircraft the ground crew is using a longer than necessary hose. The ground crew must attempt to lay the hose along the tarmac in a path that will not result in hose kinks that would decrease the quantity of air delivered. The hose must also stay away from the paths of ground crews and support vehicles. Although the crew attempts to lay the hose in a pattern that will not kink, they are often not successful. Usually they are working with a deflated hose, and the kink does not form until the PCA unit is turned on and the hose inflates. As illustrated in prior art  FIG. 1 , when a kink  1  is present in a PCA hose  2  hooked to an aircraft  3 , a member of the ground crew must unhook the prior art hose connector  4  from the aircraft connector  5  so that the hose can be rotated to remove the kink. Then the hose connector  4  is reattached to the aircraft connector. This is time consuming and involves trial and error. 
         [0005]    Previous attempts have been made at solving this problem, for example U.S. Pat. No. 6,182,721 to Gregoryk and published U.S. patent application Ser. No. 11/753,382 to Gosis et. al. are for swivel hose connectors, but these devices have their drawbacks. 
       SUMMARY OF THE INVENTION 
       [0006]    Previous is needed is an improved connector that either on its own, or with manual help, can swivel so that the hose can be rotated and un-kinked without needing to be disconnected from the aircraft. To that end, a swivel connector having an inner tube adapted for connection to a PCA air hose, and an outer tube adapted for connection to the PCA input connector on an aircraft, are fit together so that the inner tube may rotate while the outer tube is clamped to the PCA input connector on the aircraft. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention. 
           [0008]      FIG. 1  is a perspective view of prior art as described in the background section. 
           [0009]      FIG. 2  is a perspective view of an embodiment of a swivel connector of the current invention in use. 
           [0010]      FIG. 3A  is a cross-sectional view of a swivel connector embodiment of the current invention brought in proximity to a connector on an aircraft. 
           [0011]      FIG. 3B  is  FIG. 3A  after connection and clamping to the connector on the aircraft. 
           [0012]      FIG. 4  is a cross-sectional view as indicated in  FIG. 3A . 
           [0013]      FIG. 4A  is a detail exploded functional view as indicated in  FIG. 4 . 
           [0014]      FIG. 5  is a perspective view of the swivel connector of  FIG. 3A . 
       
    
    
     DETAILED DESCRIPTION 
       [0015]      FIG. 2  illustrates a swivel connector  10  on the PCA hose  2  connected to the aircraft  3  at the aircraft connector  5 . As indicated by the arrows, the hose rotates relative to the stationary aircraft  3  and aircraft connector  5 , so there is no kink in the pca hose  2 . Depending upon where the kink is located and other factors such as the temperature and pliability of the hose, this may happen freely from the force of the flowing air. If rotation does not happen freely, then a member of the ground crew may grab the hose and rotate it. It is not necessary to loosen the swivel connector  10  from the aircraft connector  5  to do so. The workings and structure of the swivel connector  10  will be described with reference to the figures that follow. 
         [0016]    As seen in  FIGS. 3A-5 , The swivel connector  10  has an outer tube  12  with a flange  14  and an inner tube  16  with a strap recess  18  holding the PCA hose  2  shown in phantom. Between the outer tube  12  and inner tube  16  are stainless steel balls  20  that cooperate with an outer groove  22  in the outside surface of the inner tube  16  and an inner groove  24  in the inside surface of the outer tube  12  to form two bearings, a proximal bearing  26  and a distal bearing  28 . In this application the term proximal means in proximity to the source of PCA air, and distal means distant from the source of PCA air. The grooves are acting as inner and outer bearing races. In one embodiment, the inner tube  16  and the outer tube  12  are each made of Aluminum T-6061 material, while the balls  20  are stainless steel. However other materials may also be used. In addition, these assembled-in-place bearings  26 ,  28  may instead be pressed-in or otherwise preassembled bearings, but this would likely add to the overall bulk of the swivel connector  10 . The balls  20  maintain a clearance  30  ( FIG. 4A ) between the inner tube  16  and outer tube  12 . However in other embodiments, where bushings may be used instead of bearings, there might not be any clearance  30 . For example, a machined ridge (not shown) integral with the inner tube  16  may slide against the outer tube  12  surface. 
         [0017]    Further, although the embodiment described has two ball bearings  26  and  28 , other combinations, for example one ball bearing and one cylindrical roller bearing, or one or more bushings in addition to, or in place of bearings, are also within the bounds of the current invention. In addition, the quantity of two is used for an example, and is not limiting. 
         [0018]    Two clamps  32  are mounted on the outer tube  12  in a way that does not affect the outer tube  12  roundness or interfere with swivel rotation. To that end ( FIGS. 4 and 5 ) the clamps  32  are held to a clamp mount  34  by fasteners  36 . The clamp mount  34  is held to the outer tube  12  by welding. This is just one way of attaching the two clamps  32 . Other methods of construction would be apparent to one skilled in the art. 
         [0019]    The clamps  32  have a handle  38  a link  40  and bushing  42  with an internally threaded shaft  44  passing through the bushing  42 . A bolt  46  that passes through a claw  48  is engaged with the threads (not shown) of the shaft  44 . The claw  48  passes through the flange  14  at flange slots  50 . A gasket  52  is distal of the flange  14  to seal against the aircraft connector  5 . In one embodiment, the design of the interface between the aircraft connector  5  and the swivel connector  10  is standardized, and conforms to specification MS33562D. 
         [0020]    The inner tube  16  and the outer tube  12  will not separate because the balls  20  in the inner grooves  24  and outer grooves  22  keep them in the fixed relationship. 
         [0021]    The swivel connector  10  is assembled by placing the two tubes  12 , 16  in the relationship shown, and then pouring in the balls  20  through a load port  54  having threads  55 . A load plug  56  having threads  57  is tightened in the load port  54  to seal the balls  20  in place. If the load plug  56  is too long, its end  58  would interfere with the movement of the balls  20 . If it is too short, it would allow the balls  20  to bump against the edges of the load port  54  as they pass by. For at least those reasons, shims  60  or other devices are used to set the insertion length of the load plug  56 . The load port  54 , load plug  56 , and shims  60  described is just one embodiment of how to load and retain the balls  20 . Other ways are contemplated. As with any device used on an airport tarmac, caution is exercised to avoid releasing hard objects that may later be sucked into a jet engine. Appropriate safeguards such as locking features would be used on the fasteners  36  and the load plugs  56 . 
         [0022]    In use, the handle  38  is first placed in a distal position as seen in  FIG. 3A  when the ground crew person engages the claws  48  with the aircraft connector  5 . Then the ground crew person moves the handles  38  to the position of  FIG. 3B , pulling the claws  48  proximally thus causing the outer tube  12  to move distally and squeeze the gasket  52  between the aircraft connector  5  and the swivel connector  10  to make a sealed connection. The threaded connection at the bolt  46  provides adjustability so that the movement of the handle  38  can be set to provide the necessary amount of gasket squeeze. When installed to the aircraft  3 , the inner tube  16  may rotate within the outer tube  12  as needed to remove any kinks  1 . This rotation may occur freely from the pressure in the PCA hose  2 , or may be aided by a ground crew member grabbing the pca hose  2 . In some embodiments, the inner tube  16  may have protrusions or other handles so it is not necessary to grab the PCA hose  2 . 
         [0023]    The invention has been described herein with reference to specific embodiments, and those embodiments have been explained in substantial detail. However, the principles of the present invention are not limited to such details which have been provided for exemplary purposes.