Abstract:
A connector for a weapons test set circuit has a case with an open end and electrical conductors extending from the open end into and through the case. The connector is designed to connect to a rail and has coupling legs for this purpose. Each coupling leg has a base portion located in the case and an extension portion that extends out of the case and diverges from the other extension portion. The base portions can move toward each other or apart from each other along guides and are biased in the apart position. Buttons extend from the base portions out of the case; an operator depresses the buttons to converge the legs to allow insertion or removal of the connector from the rail. Releasing the buttons causes the legs to move to the apart position.

Description:
FIELD OF THE INVENTION 
   The present invention relates to test sets for aircraft weapons systems, and in particular to connectors for said test sets. 
   BACKGROUND OF THE INVENTION 
   An F-16 fighter aircraft has a weapons rail at the end of each wing. The rail receives a missile, such as the AIM-9 (Sidewinder), an air-to-air missile. 
   Inside of the rail are electrical contacts used for firing the weapon. The electrical contacts are connected to a weapons firing circuit, operated from the cockpit of the aircraft. 
   Aircraft weapons systems are frequently tested in order to ensure reliability. The liability can literally be the difference between life and death, as a pilot engaged in air-to-air combat is disadvantaged by a missile that will not fire when commanded to do so. 
   The weapons circuit is tested, when the aircraft is on the ground, by locating a connector in the rail so as to make contact with the electrical contacts. The connector is part of a test set. 
   In the prior art, positioning the test set connector in the rail is time consuming and laborious. The connector is inserted into the end of the rail and then slid to where the contacts are. Unfortunately, the ends of the rail are not normally accessible and are covered by part of the wing, necessitating disassembly of the wing in order to access the end of the rail to allow insertion of the connector. This disassembly adds to the time and labor in testing the weapons circuit. In addition, aircraft maintenance practice prefers that onboard electrical circuits be tested with a minimum amount of disassembly of the aircraft. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a weapons test set connector that can be located in a weapons rail without the need to disassemble parts of the aircraft. 
   The present invention provides a connector for a weapons test circuit comprising a case having an open end. Electrical connectors extend through the case and terminate in contacts at the open end. The contacts are positioned at the open end by an insulating insert. Coupling legs are structured and arranged to couple to a rail. Each coupling leg has a base portion located in the case and an extension portion extending from the base portion. The base portion of each rail moves translationally along a guide in the case. The extension portions extend from the case and diverge from each other. The legs can move to a close position that allows the connector to be inserted into and removed from the rail and the legs can be moved to an apart position to assist in coupling the connector to the rail. 
   In accordance with one aspect of the present invention, the legs are biased in the apart position. 
   In accordance with another aspect of the present invention, the legs are biased in the apart position by way of the spring extending between the base portions. 
   In accordance with still another aspect of the present invention, each leg is shaped like an “L” in transverse cross-section. 
   In accordance with still another aspect of the present invention, the guide comprises two guide members, with the electrical conductors extending between the guide members. 
   In accordance with still another aspect of the present invention, there are provided closure members coupled to the base portions, which closure members extend through the case. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows the end of an aircraft wing and a weapons rail, for which the test set of the present invention is used. 
       FIG. 2  is an end view of the wing of  FIG. 1 , showing part of the rail and a weapons test set, including a connector for the rail. 
       FIG. 3  is a cross-sectional view of the rail of  FIG. 2 , taken through lines III—III thereof, and showing a prior art test connector. 
       FIG. 4  is a cross-sectional view of the test connector of the present invention, in accordance with a preferred embodiment, shown in an engaged configuration for engaging the rail. The cross-section of the test connector is taken through lines IV—IV of  FIG. 6 . 
       FIG. 5  is a schematic view of the test connector of  FIG. 4 , shown with the legs in the retracted position, for removing or installing the test connector in the rail. 
       FIG. 6  is a plan view of the test connector. 
       FIG. 7  is a view of the test connector in the engaged configuration as seen from the rail. 
       FIG. 8  is a cross-sectional view of the test connector, taken through lines VIII—VIII of  FIG. 6 . 
       FIG. 9  is a cross-sectional view of the test connector, taken through lines IX—IX of  FIG. 6 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 and 2  show an aircraft wing  11  and a test circuit  13 , for which the rail connector  15  of the present invention is particularly suited. The aircraft is an F-16 fighter. The end portion of the left wing  11  is shown in  FIG. 1 . The wing  11  has a leading edge  17  and a trailing edge  19 . At the end of the wing  11  is a rail  21 , which rail receives a weapon, such as an AIM-9 missile (also known as a Sidewinder). 
   The test set  13  connects to and checks the electrical circuit  23  that is used to fire the rail-mounted weapon. The electrical circuit extends from the electrical contacts  25  in the rail to the aircraft cockpit (in  FIG. 1 , the electrical circuit is shown schematically). The electrical circuit is accessed by mounting the rail connector  15  in the rail. Mounting the test set rail connector  15  in the rail  21  is the subject of the present invention. 
   Before discussing the specifics of the test set rail connector  15 , the test set  13  will be described, as will the prior art rail connector. The test set  13  contains electrical circuitry to test the continuity, voltages and currents of the aircraft electrical circuit  23 . The test set is conventional. The test set  13  connects to a rotary switch  27 , which rotary switch in turn connects to the rail connector  15 . The rail connector has two electrical contacts that make electrical contact with the two exposed contacts  25  in the rail  21 . The test set  13 , rotary switch  27  and rail connector  15  are connected to one another by cable harnesses  29 . The rail connector  15  is also connected to another cable harness  31 , which cable harness connects to another part of the aircraft electrical circuit. 
     FIG. 3  shows the prior art rail connector  33  in the aircraft rail  21 . The rail forms somewhat of a “C” shape ( FIG. 3  shows a backward “C”), having a narrow opening  37  and a wider inside chamber  39 . The opening  37  and the chamber  39  extend for the length of the rail. The electrical circuit contacts  25  are located in the rail, inside the chamber  39 . The prior art rail connector  33  has a case  41  and two legs  43 . The case  41  extends into the opening  37  of the rail  21 . The legs are on opposite sides of the case and diverge with respect to one another. The legs  43  cooperate with the rail so as to hold the test connector in place. On the opposite side of the case from the two legs, a coupler  45  is provided. The coupler  45  receives wires that connect to the rail contacts. The coupler couples to test set harnesses  29 ,  31  (see  FIG. 2 ). 
   The legs  43  are fixed to the case  41 . The only way to install or remove the prior art rail connector  33  is from an end  47  (see  FIG. 1 ) of the rail  21 . The present invention allows the rail connector  15  to be installed or removed from the rail at an intermediate location of the rail. 
   Referring to  FIGS. 4 and 5 , the rail connector  15  of the present invention provides legs  51  that are movable with respect to the case  53 . Normally, the legs  51  are separated by a distance (see  FIG. 4 ) suitable for coupling to the rail  21 . This is known as the apart position. The legs  51  can be brought closer (see  FIG. 5 ) so as to decrease the distance between the legs. This position, known as the close position, allows the rail connector to be inserted into, or removed from, the rail  21  through the narrow opening  37 , at or near the rail contacts  25 . Thus, access to an end  47  in the rail  21  is not necessary to insert or remove the rail connector  15 . 
   The rail connector  15  will now be described in detail. Referring to  FIG. 4 , the rail connector  15  has legs  51 , a case  53 , an insert  55 , a tube  57  and a coupler  59 . 
   The case  53  or body forms a box or housing that is open on one side. The case  53  has an interior cavity  61 . The legs  51  extend from the cavity  61  out through the open side. The insert  55  is also located in the case, so as to be flush with the case edges that define the open side. The insert  55  is retained within the case by a tray  63 . The ends of the tray are secured to the sides of the case  53  between the legs  51 . 
   The insert  55  is an insulator and has two contacts  65  mounted therein. As shown in  FIG. 4 , the contacts  65  extend through the insert  55  into the tray  63 . The contacts  65  are exposed on the outside of the insert  55 . The tray  63  is in contact with the inside of the insert  55 . On the inside of the tray, each contact is secured to the insert by a screw  67 , a washer  69 , a terminal  71  and a shoulder washer  73  (see  FIG. 8 ). The shoulder washer  73  fits in the opening of the tray  63 . The interior of the tray can be potted. As shown in  FIGS. 4 and 8 , a wire  75  extends from the terminal through the tube and into the coupler. Each contact  65  has its own wire  75 . 
   The tube  57  extends from the tray  63  through the case  53  into the coupler  59 . The end  77  of the tube  57  is enlarged in diameter and receives an O-ring. The end of the tube  77  and O-ring are received by a cylindrical opening  79  in the coupler  59  which coupler communicates with the longitudinal opening  81  through the coupler  59 . The coupler connects to the harnesses  29 ,  31  (see  FIG. 2 ). The coupler is secured to the case by screws (not shown). 
   The insert  55 , contacts  65 , tube  57  and coupler  59  are fixed relative to the case  53 . 
   The insert  55  is shaped like an “H” in plan view, as shown in  FIG. 7 . Thus, the insert  55  has slots  83  therein. The slots  83  allow the legs  51  to move closer together. 
   Each leg  51  has a base portion  91  and an extension portion  93  (see  FIG. 4 ). Both portions  91 ,  93  are plates and are oriented perpendicular to each other, so as to form an “L” shape when viewed in cross-section, as shown in  FIG. 4 . The base portions  91  are located inside of the case  53 , while the extension portions  93  extend from the case to engage the rail  21 . 
   Each base portion  91  has two holes  95  formed therethrough. The holes  95  receive guides  97 . In the preferred embodiment, the guides  97  are shafts that extend from one side wall of the case to the opposite side wall, where the ends of the shafts are secured by screws  99 . The base portion  91  is thicker at the holes  95  so as to provide a longer hole and therefore a longer bearing surface against the respective shaft. The tube  57  and the wires  75  therein extend between the shafts  97  (see  FIG. 9 ). Helical springs  101  extend along the shafts  97  between the leg based portions. The springs  101  bias the legs in the apart condition, shown in  FIG. 4 , wherein the base portions  91  contact the case  53  wall. Each base portion  91  couples to a closure member, such as a button  103 . The button  103  extends through the case and is accessible from the outside. As shown in  FIG. 9 , the buttons  103  are aligned on the same axis; this requires less force to move the legs to the close position. 
   The base portions  91  have notches (not shown) formed therein, which notches receive the insert  55 . 
   In operation, the rail connector  15  is positioned at a location along the rail  21  by the contacts  25 . To install the rail connector, the buttons  103  are depressed by the operator into the case  53 . This action forces the leg base portions  91  together translationally along the shafts  97 ; the legs  51  retract to the close position. The connector can now be placed into the rail. 
   Releasing the buttons  103  allows the springs  101  to extend the legs to the apart position, wherein the rail connector is secured to the rail. To move the rail connector along the length of the rail, the buttons are depressed slightly to loosen the coupling between the legs and the rail and the connector can be repositioned. Once the connector is repositioned, such as on the contacts  25 , the buttons are released. The circuit test can now be conducted. 
   Removing the rail connector from the rail involves the same process of retracting the legs by pressing the buttons, wherein the connector is then pulled out of the rail. 
   The foregoing disclosure and showings made in the drawings are merely illustrative of the principles of this invention and are not to be interpreted in a limiting sense.