Patent Publication Number: US-6336822-B1

Title: Handle operated power connector

Description:
RELATED APPLICATION 
     The present application claims priority from U.S. Provisional Application Serial No. 60/117,288 filed Jan. 26, 1999 entitled “Handle Operated Power Connector”, and Design Application Serial No. 29/099,681 filed Jan. 26, 1999 entitled “Lever Operated Power Connector, the disclosures of which are incorporated by reference herein in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to electrical connectors, and more particularly, to electrical power connectors. 
     BACKGROUND OF THE INVENTION 
     Electrical power connectors for connecting a receptacle and plug are known. These connectors are used in transit applications, power applications, light rail applications, tractor trailer trucks and buses, among other applications. 
     Power connectors, by virtue of their wire size, are inherently large and bulky. The cables used with power connectors are heavy and cumbersome. Traditional methods for coupling connectors of these types are via thread or bayonet coupling or locking levers. All are very difficult to implement as the contacts, due to their size, have very high insertion and extraction forces. The weight of the cable connector, its physical size, and its location on a panel or a vehicle make it very difficult to align and couple. 
     In many instances, to couple an electrical power connector becomes a two-man operation—one to hold and guide the plug and a second to activate the coupling mechanism. Bayonet or lever-lock is preferred over threads as the activation requires less movement of the coupling mechanism. A bayonet lock requires only a portion of a turn, but is difficult to accomplish because the entire plug has to be aligned with the receptacle and then the plug including cables has to be held in place while a coupling ring has to be rotated to effect mating between the plug and receptacle. A thread usually requires three or more turns. A lever connector is generally rectangular with two hasps on the side which need to be activated nearly simultaneously in order not to “cock” the plug into the receptacle. 
     Accordingly, a need exists in the art for an electrical power connector which requires less than one turn to couple. A further need exists for an electrical power connector in which coupling can be accomplished by a single person. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an electrical power connector in which the electrical connector can be coupled by a single person. 
     It is another object of the present invention to provide an electrical power connector in which coupling between a plug and receptacle requires less than 360° rotation of the coupling mechanism. 
     It is another object of the present invention to provide an electrical power connector in which a plug can be coupled to a receptacle in 120° rotation or less. 
     It is yet a further object of the present invention to provide an electrical power connector having a receptacle with a bayonet ramp and a plug having a coupling ring with a handle. 
     These and other objects of the present invention are accomplished by providing an electrical power connector having a plug and receptacle. The plug includes a coupling ring having a handle extending radially therefrom. The coupling ring is freely rotatable within limits on the plug when the plug is not coupled to the receptacle. The receptacle includes one or more bayonet ramps to which the coupling ring can be coupled. Advantageously, the plug can be coupled to the receptacle with 120° rotation or less by rotating the coupling ring 120° or less. The plug and receptacle each include a colored locking indicator to indicate to the person coupling the plug to the receptacle that the receptacle and plug are properly aligned to each other when coupled. Also an audible indication of locking is provided when the electrical plug and receptacle are fully coupled. 
     Advantageously, the coupling ring, with a handle, allows the user to hold and guide the connector with one hand and couple it with the other. The arrangement of the present invention limits the travel of the coupling ring and handle such that it can be easily located in the proper position for coupling. Once the connector is positioned for alignment—moving the handle in an arc of 90° to 120° allows the bayonet ramps to engage and supply the mechanical advantage to couple and uncouple easily. A clamping mechanism built into the panel or undercarriage, nests and holds the handle in place so it cannot be inadvertently uncoupled. 
     These and other objects of the present invention are achieved by an electrical power connector including a plug having at least one contact and a receptacle including a corresponding at least one contact. The receptacle has at least one ramp. The plug and the receptacle have an unmated condition and a mated condition. A coupling ring has a handle extending therefrom and includes at least one locking pin. A first stop and a second stop are each positioned in either the coupling ring and the receptacle such that said coupling ring is rotated less than 360° to move the connector from the unmated condition to the mated condition. 
     The foregoing and other objects of the present invention are achieved by an electrical connector including a plug having at least one male contact and at least one pin and a receptacle including a corresponding at least one female contact and at least one corresponding ramp for receiving the at least one locking pin. A handle is operatively associated with one of the plug and the receptacle and has a first surface and a second surface. A first surface and a second surface are each connected to one of the plug and the receptacle. The first surface and the second surface are circumferentially spaced from each other less than 360°. The plug and the receptacle are in an unmated condition when the first surface of the handle abuts the first surface. When the handle is rotated, the plug and the receptacle are brought into a mated condition when the second surface of the handle abuts the second stop. 
     The foregoing and other objects of the present invention are achieved by a method of coupling an electrical connector. The electrical connector includes a plug and a receptacle. The plug is aligned with the receptacle. The plug has at least one alignment key. The receptacle has a corresponding at least one keyway. A coupling ring is moved to a first circumferential position. The plug is mated to the receptacle when the coupling ring is rotated less than 360° to a second circumferential position. 
     Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein the preferred embodiments of the invention are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description thereof are to be regarded as illustrative in nature, and not as restrictive. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is illustrated by way of example, and not by imitation, in the figures of the accompanying drawings, wherein elements having the same reference numeral designations represent like elements throughout and wherein: 
     FIG. 1 is a perspective view of the lever operated power connector according to the present invention with a plug and a receptacle being shown in a coupled position; 
     FIG. 2 is a side perspective view of the lever operated power connector of FIG. 1 with the plug and receptacle being shown in an uncoupled position; 
     FIG. 3 is a front view of the plug and coupling ring according to the present invention; 
     FIG. 4 is a side cross-sectional elevational view of the plug taken along lines  4 — 4  in FIG. 3; 
     FIG. 5 is a perspective view of the intermediate portion of FIG. 4; 
     FIG. 6 is a cross-sectional view of the intermediate portion taken along lines  6 — 6  in FIG. 5; 
     FIG. 7 is a front elevational view of the receptacle of the handle operated power connector of FIG. 1; and 
     FIG. 8 is a top plan view of the receptacle of FIG.  1 . 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Referring first to FIG. 1, a lever-operated electrical power connector, generally indicated at  20 , is depicted in accordance with the principles of the present invention. Although the lever-operated electrical power connector is depicted in a horizontal orientation, it should be understood that the present invention is operable in any orientation and accordingly terms such as “left” and “right” as used herein are to be construed in the relative sense. The electrical power connector  20  includes a plug  22  and a receptacle  30 . The plug  22  includes a cylindrical body  24 . The receptacle  30  includes a cylindrical receptacle housing  32  which includes an outwardly extending rectangular flange  34  located at a central portion thereof. The receptacle  30  is fixedly secured via the flange  34  to a mounting surface such as on a truck, bus or train. 
     The plug  22  includes a collar assembly  40  including an annular coupling ring  42  having a radially outwardly extending handle  44  extending therefrom. The annular coupling ring  42  is freely rotatable on the body  24  within predefined limits as explained in detail below. The length of handle  44  can be selected depending upon the force required to effect connection between the plug  22  and the receptacle  30 . Similarly, the amount of rotation of the handle  44  can be varied depending on the application between the plug  22  and receptacle  30 . Also, any number of handles can be used. As depicted in FIG. 1, the electrical power connector  20  is shown in a coupled position with the plug  22  coupled to the receptacle  30 . An alignment pin  54  extends outwardly from the annular coupling ring  42 . A boss  56  acting as a protruding marker or indicator extends outwardly from the receptacle housing  32 . As depicted in FIG. 1, pin  54  and boss  56  are aligned. The handle  44  is depicted in a coupled orientation. Pin  54  and boss  56  are preferably colored. A rear cylindrical portion  70  of receptacle  30  extends behind the mounting surface. 
     A locking mechanism  300  built into the panel or under-carriage of a vehicle such as a light rail car, can be moved into a position to nest and hold the handle  44  in place so it cannot be inadvertently uncoupled when the handle  44  is moved into the coupled position. This locking mechanism  300  can be of any known structure and can include a lock, for example, a key operated padlock for preventing malicious disengagement of the receptacle of the plug  22  and receptacle  30 . 
     Referring now to FIG. 2, the electrical power connector  20  is depicted with the plug  22  and receptacle  30  in an uncoupled position. In FIG. 2, the handle  44  is depicted in an uncoupled orientation. As depicted in FIG. 3, the plug body  24  includes a insulator  46  including three spaced male contacts  48 ,  50 ,  52  which are secured to the body  24  in a conventional manner such as by compression conformal fit. A fourth position  172  for a male contact is depicted and this position is not used in the depicted invention and is instead filled with a hole plug. 
     Returning to FIG. 2, the receptacle  30  includes a forward cylindrical portion or wall  60  and the rear cylindrical portion  70 . The forward cylindrical portion  60  extends forwardly from the flange  34  for mating with the plug  22 . The rear cylindrical portion  70  extends rearwardly from the flange  34  for connection to a backshell (not shown). The receptacle  30  includes three female contacts  62 ,  64  (see FIG.  7 ),  66  having corresponding positions to the contacts  52 ,  48 ,  50  in the plug  22 . A fourth position  172  for a female contact is depicted which is not used in the depicted invention. Other contact configurations and number of contacts can be used with the subject matter of this invention. Also, the gender of the contacts can be reversed. The contacts  62 ,  64 ,  66  are secured to the receptacle  30  in a conventional manner such as by compression conformal fit. The mounting flange  34  includes four holes for bolting the flange to a vehicle such as a light rail car or to any other stationary mounting surface. 
     The forward cylindrical portion  60  includes three bayonet ramps  112 ,  114 ,  116  (see FIG.  2 ). Each bayonet ramp  112 ,  114 ,  116  has an opening  118  extending rearwardly from a forward surface  120  of the housing  30 . Each of the bayonet ramps  112 ,  114 ,  116  spirals rearwardly from the forward surface  120  approximately 120° in the circumferential direction in a clockwise direction as depicted in FIG.  2 . The ramps  112 ,  114 ,  116  must each spiral in the same direction although the ramps could also spiral in a counter clockwise direction. Each of the ramps  112 ,  114 ,  116  extends inwardly from an outer surface  122  of cylindrical portion  60  and each ramp has a rear surface  124 , a front surface  126  and an outwardly facing surface  128 . As depicted in FIG. 3, preferably three inwardly extending pins  222  in the collar assembly  40  ride in one or more of the bayonet ramps  112 ,  114 ,  116 , respectively, and terminates its travel at a terminal end of bayonet ramp  112 ,  114 ,  116 . Any number of ramps and pins could be used. The pins  222  are spaced at 120° apart and are press fit or staked into the annular coupling ring  42 . 
     As depicted in FIG. 2, extending outwardly from an inner surface  130  of the cylindrical portion  60  are a plurality of keyways  160 ,  162 ,  164  (see FIG.  7 ). Keyways  160 ,  162 ,  164  provide alignment of the plug  22  to the receptacle  30 . It should be understood that any number of keyways can be used in this application. 
     Refer now to FIGS. 3 and 4 depicting the details of the plug  22 . Plug  22  includes an electrically insulative central body portion  200 , an intermediate portion  210  and an outer body portion or backshell  220 . The backshell  220  can screw on to the rear cylindrical portion  70  The male contacts  48 ,  50 ,  52  are compression conformal fit into through bores of the central body portion  200 . The central body portion  200  is located radially inwardly from intermediate portion  210  and is connected thereto using a snap ring  230 . The outer body portion is threadedly engaged with the intermediate portion  210 . The coupling ring  42  includes a shoulder  232  positioned between the intermediate portion  210  and the outer body portion for axially retaining the coupling ring  42 . 
     As depicted in FIG. 3, pins  222  extend radially inwardly from annular coupling ring  42 . As depicted in FIG. 4, an annular recess  180  is formed between forward most portions of the annular coupling ring  42  and the intermediate portion  210 . Intermediate portion  210  extends forwardly relative to annular coupling ring  42 . 
     As depicted in FIG. 3, three keys  240 ,  242  and  244  extend radially outwardly from intermediate portion  210  into the annular recess  180 . Key  240  can be aligned with keyway  160 , key  242  can be circumferentially aligned to keyway  162  and key  244  can be aligned with keyway  164  by rotating the body  24 . Although keys  240 ,  242 ,  244  are depicted for use with the plug  22  and keyways for use with the receptacle, it should be understood that the keys and keyways could be reversed and other alignment means could also be used. 
     A circumferentially extending slot  250  is depicted in FIG.  4 . An inwardly extending member  252  extends from the annular coupling ring  42  into the slot  250  as depicted in FIG.  4 . The inwardly extending member  252  can be, for example, a set screw which is screwed into annular ring  42 . Following the insertion of member  252  into the slot  250 , the handle  44  can be welded onto the annular coupling ring  42  to prevent the inadvertent removal of member  252 . A spring loaded clip  260  positioned between intermediate portion  210  and collar assembly  40  biases the coupling nut away from the receptacle  30  and the plug  22  forward to the receptacle  30  to guarantee a seal between plug  22  and receptacle  30  and to lock the pins  222  into the detents at the end of ramps  112 ,  114  and  116 . It should be understood that positions of the slot  250  and the member  252  could be reversed. For example, the slot  250  could be in the coupling ring  42  and the member  252  could extend from the intermediate portion  210 . 
     A seal  280 , such as an O-ring can be positioned at the bottom of the annular recess  180  as depicted in FIG.  4 . The surface  120  of the receptacle  30  is brought into sealing contact with the seal  280  thereby sealing the plug  22  and receptacle  30  from the environment. This is important because of the high voltage and/or current being used with the electrical connector  20 . 
     Refer now to FIG. 5 where the intermediate portion  210  is depicted alone for clarity. As depicted in FIG. 5, intermediate portion  210  includes a centrally located slot  250 . At opposite ends of slot  250  is a first stopper  261  and a second stopper  262 . As depicted in FIG. 6, slot  250  preferably extends for an angle of 120° between the first stopper  261  and the second stopper  262  although any angle less than 360° can be used. 
     A side elevational view of the receptacle  30  is depicted in FIG. 7. A plurality of electrical connectors or contacts  48 ,  50 ,  52  are located within the plug  22 . These contacts  48 ,  50 ,  52  are respectively coupled to one of the female contacts  62 ,  64 ,  66 , respectively shown in FIG.  7 . 
     In FIG. 4, the plug  22  is depicted. The pins  222  extend radially inwardly from an outer diameter of the coupling assembly  40  for engagement with bayonet ramps  112 ,  114 ,  116  (see FIG.  2 ). 
     In operation, the collar assembly  40  is rotated using the handle  44  to the counter-clockwise position depicted in FIG.  2 . The plug  22  is brought into engagement with the receptacle  30  and the keys  240 ,  242 ,  244  are circumferentially aligned with one of the keyways  160 ,  162 ,  164 , respectively. The coupling assembly  40  and the pins  222  are aligned with openings  118  of bayonet ramps  112 ,  114 ,  116  because the plug  22  is aligned with the receptacle  30 . The handle  44  is then rotated clockwise 120° from the position depicted in FIG. 2 to the position depicted in FIG.  1 . The pins  222  engage the front surfaces  126  and provide a camming action forcing the plug  22  into the mated position with the receptacle  30 . The connector  20  provides an audible sound when the plug  22  is coupled to the receptacle  30 . The male contacts  52 ,  48 ,  50  engage and frictionally mate with the corresponding female contacts  66 ,  64 ,  62 . Although a clockwise rotation is depicted in FIGS. 1 and 2, the invention can also utilize ramps which would provide rotation in a clockwise direction. 
     Advantageously, the ramps  112 ,  114 ,  116  and pins  222  provide a camming action. The slot  250 , pin  252  and surfaces  261 ,  262  limit the travel of the handle  44  to less than 360°, and preferably between 90° and 120°. 
     Alternatively, the coupling ring and bayonet ramps could be reversed and positioned on the receptacle  30  and plug  22 , respectively. 
     It will be readily seen by one of ordinary skill in the art that the present invention fulfills all of the objects set forth above. After reading the foregoing specification, one of ordinary skill will be able to affect various changes, substitutions of equivalents and various other aspects of the invention as broadly disclosed herein. It is therefore intended that the protection granted hereon be limited only by the definition contained in the appended claims and equivalents thereof.