Abstract:
An explosion-resistant connector has a receptacle having a female portion and a first outer portion. A plurality of leads extends through the receptacle into the female portion. An adapter has a hollow portion through which the leads also extend, the adapter attaching to the first outer portion. A potting compound is disposed in the hollow portion about the leads. If an explosion occurs, it occurs on an adapter side of the connector as opposed to a receptacle side of the connector.

Description:
FIELD 
     This invention relates generally to electrical switches and more particularly to explosion-resistant quick-connect conductors. 
     BACKGROUND 
     Electrical actuators may be used in explosion prone areas in which explosive gases, such as oxygen and fuel may cause ignition by arcing of switch contacts or other contacts. Some switches have been developed that contain explosions within a particular area to minimize damage from explosion to areas remote from such explosions. Such connectors must also provide suitable or minimal flame paths that may be generated from such explosions to further minimize damage that may occur. 
     Some explosion-resistant electric conductors use “flying lead” connectors that use a rigid conduit with a concretely set seal that acts as a barrier. In the “flying lead” application, disconnection of the connector without damaging its attendant parts is very difficult if not impossible. 
     SUMMARY 
     According to an embodiment shown herein, an explosion-resistant connector has a receptacle having a female portion and a first outer portion. A plurality of leads extends through the receptacle into the female portion. An adapter has a hollow portion through which the leads also extend, the adapter attaching to the first outer portion. A potting compound is disposed in the hollow portion about the leads. If an explosion occurs, it occurs on an adapter side of the connector as opposed to a receptacle side of the connector. 
     According to an embodiment shown herein, a method for constructing an explosion-resistant connector includes screwing a female receptacle having a plurality of leads extending therein into an adapter having a hollow portion therein through which the leads also extend, fitting a snap ring within a wall of receptacle defining the hollow portion within the adapter, and filling the hollow portion of the adapter with a potting compound. 
     These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a connector shown herein. 
         FIG. 2  shows a connector of  FIG. 1  in conjunction with incoming leads in a conjunction block. 
         FIG. 2A  is a section noted as  2 A of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIG. 1 , an explosion-resistant connector  10  is shown. The connector  10  has an off the shelf circular pin and sleeve receptacle  15  (herein after referred to as receptacle) and National Pipe Thread Tapered (NPT) threaded adapter (hereinafter referred to as an adapter) and a plurality of leads  25  or wires. The adapter  20  has a plurality of axially drilled holes  30  to attach to a connecting nut  35  as shown in  FIG. 2  and as will be discussed infra. 
       FIG. 2  shows a cross-sectional view of the connector  10  of  FIG. 1  in conjunction with a socket block  40  and a schematically-shown junction box  45 . 
     The receptacle  15  has a first end  50  of leads  25  extending axially within a cup-like enclosure  60 , which acts as a female portion of the connector  10 , towards the socket block  40 , which acts as a male portion. The leads  50  extend through a body  55  of the receptacle  15  and are soldered or otherwise attached to wires  51  and through the adapter  20  as will be discussed infra. The enclosure  60  has a circular wall  65  and has a threaded surface  70 . The body  55  has a threaded surface  75  on a circumferential wall  77  thereof. 
     The adapter  20  has a hexagonal outer wall  80  that has a threaded first inner bore  85 . A second inner bore  87  is contiguous to the first inner bore  85  and is disposed axially away from the socket block  40 . The second inner bore  87  has a smaller diameter than the first inner bore  85 . A portion  95  tapers towards the junction box  45  and joins with a third inner bore  100  that has a smaller diameter than the second inner bore  87 . A threaded outer wall  105  encloses a piece of the portion  95  and the third inner bore  100 . The leads  25  extend through the first, second and third inner bores  85 ,  87 ,  100  and through the portion  95  for insertion on the junction box  45 . The junction box  45 , shown schematically, has an opening  110  that is threaded for mating with the threaded outer wall  105 . 
     Referring to  FIG. 2A , a ring  103 , which is made out of a spring steel or other suitable material, is snap inserted into the third inner bore  100  into a groove  109 , which may be square or other shaped for retention therein. The groove  109  is wider than the ring  103 . 
     The socket block  40  has a plurality of openings  115  that are sized to connect with and electrically conduct with the first ends  50  of the leads  25 . The socket block  40  is attached to a cable  121  that may be flexible. The socket block  40  fits within enclosure  60 . The nut  35  has an inner bore  120  that is threaded to screw onto threaded surface  70 . A shoulder  125 , which has a smaller diameter than the inner bore  120 , abuts an extension  130  on the socket block  40  if the nut  35  is screwed onto the threaded surface  70  to hold the socket block  40  on the receptacle  15 . 
     Both the nut  35  and the adapter  20  each have an opening  135  and  30 , respectively, so that a connecting wire  145  may be threaded therethrough after connection of the nut  35  to the threaded surface  70  of the receptacle  15  to ensure, after being pulled taut that the socket block  40  is not disconnected from the adapter  20 . 
     The adapter  20  has an opening  150  through which a set screw  155  may be inserted and torqued down against the receptacle to ensure that the adapter  20  does not disconnect from the receptacle  15  after connection thereto. 
     To construct the connector  10 , the receptacle  15  is screwed into the adapter  20 . Teflon tape (not shown) may be placed between the receptacle  15  and the adapter  20  to minimize leakage of potting compound  160  before it is cured. The set screw  155  is screwed into the opening  150  against threaded surface  70  and  75  that ensure that the adapter  20  and the receptacle  15  do not separate. A potting compound  160 , which may be epoxy based such as Stycast® epoxy from Emerson &amp; Cuming, is then induced into the bores  85 ,  87 ,  100  and portion  95  of the adapter  20 . After the potting compound  160  sets, the connector  10  is screwed into opening  110  of the junction box  45 . The socket block  40  may then be inserted into the receptacle  15  in which the first ends  50  fit within openings  115 . Nut  35  screws onto surface  70  of the receptacle  15  and the shoulder  125  impinges against extension  130  to fix the socket block  40  within the receptacle  15 . The nut  35  acts as a clamp thereby to force connection of the socket block  40  to the receptacle  15 . Wire  145  is then threaded through axial openings  135  and  30  in the nut  35  and the adapter  20  respectively to act as a visible cue that the nut  35  is properly connected to the receptacle  15  and to minimize a probability that the nut  35  would unscrew from the receptacle  15 . 
     The potting compound  160  cooperates with the material of the adapter  20  and the snap ring  103  to form a bond within the receptacle so that any explosion that occurs to the right of junction box  45 , as shown in the drawing, does not escape through the connector  10  to the left side of the junction box  45 . One of ordinary skill in the art will recognize that the junction box  45  is representative of any wall that may minimize the forces of an explosion from moving from one side to another side to protect componentry and other parts on the other side of the wall. 
     By using this type of connector  10 , should the connector  10  have to be removed, the wire  145  may be cut and removed and the nut  35  may be unscrewed from the receptacle  15 . The connector  10  may then be unscrewed from the junction box  45  to enable repair or replacement thereof. 
     Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments. 
     The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.