Abstract:
A molded insulating connector body is pinned to the housing of an electrical device such as a switch, indicating light, instrument, gauge or the like to selectively provide a particularly keyed connector body to devices of the same type by a pin which extends through holes in the device terminals and correspondingly aligned openings in the connector body. The pin is retained in place by a collar which envelopes the electrical device body and is threadably attached thereto.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to electric devices which are connected in an electric circuit by plug-in electric connectors which attach to the terminals of the device. Plug-in connectors which are part of an electrical wiring harness such as for vehicle application, are often keyed to insure that the respective wires of the harness are connected to the proper device. In certain instances, the same electrical device may be used in a plurality of applications, the only difference being a requirement for different keying at the plug-in connector body of the device. If the connector body is an integral part of the molded housing of the device, such requirement for different keying in the connector body requires a different device housing and therefore, a different device. 
     SUMMARY OF THE INVENTION 
     This invention provides an electric device having a connector body attached to the device by a pin which extends through the connector body and the device terminals, the pin being retained in place by a protective collar which envelopes the device and overlies the openings in the connector body in which the pin is disposed, blocking removal of the pin. The connector body may be selectively chosen from a plurality of connector bodies, each having different keying. In a preferred embodiment the collar is threadably attached to a threaded bushing of the device and may be screwed tightly down upon the connector body to provide a sealed superstructure for the device. 
     These and other advantages of the invention will become more apparent when reading the following description and claims in conjunction with the accompanying drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a cross sectional view taken along the center line of an electric switch assembly constructed in accordance with this invention; 
     FIG. 2 is a lower end view of the switch assembly of FIG. 1 showing the open end of the connector body and switch terminals of a first form of keying for the connector body; 
     FIG. 3 is a view like FIG. 2, but showing a second form of keying for the connector body; and 
     FIG. 4 is an exploded isometric view of the major components of the electric switch assembly embodying this invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     This invention can be used with various types of electric devices such as switches, indicators, lamps, gauges and the like. To illustrate the invention, it is shown in conjunction with a self contained pushbutton switch 2 shown in FIGS. 1 and 4. Switch 2 comprises an insulating base 4 to which a pair of electric terminals 6 are affixed, the inner ends of the terminals functioning as stationary contacts for the switch. A movable contact 8 is mounted on a movable insulating contact carrier assembly 10 which is biased away from the stationary contacts by a spring 12 located in a central cavity of the base 4. The movable contact carrier assembly 10 is freely guided for movement within a metal cover 14 which is attached to base 4 by clinching over a pair of tabs such as 14a shown in FIG. 4. A threaded bushing 16 is attached to the cover 14 at the end remote from base 4 by spinning over a reduced diameter portion of the bushing 16. A pushbutton operator plunger 18 is slidably captured within the threaded bushing 16 and biased outwardly thereof by a helical compression spring 20 which bears between the movable contact carrier assembly 10 and the interior of pushbutton 18. Depression of pushbutton 18 compresses spring 20 which overcomes the oppositely directed force of spring 12 to drive the movable contact carrier assembly 10 and movable contact 8 thereof into bridging engagement with the stationary contact portions of terminals 6, thereby closing a circuit between the two terminals. 
     A molded insulating connector body 22 is provided for attachment to switch 2 to provide a receptacle for a mating plug-in connector (not shown). Referring to FIG. 1, the connector body 22 has a central cavity 22a open to one end thereof. The opposite end of connector body 22 is substantially closed and has a pair of projections 22b extending from the closed end. That end of the connector body is provided with holes 22c adjacent each of the projections 22b. The inside edges of projections 22b are channeled to nest around the narrowed projecting portions of terminals 6, the terminals 6 also extending through holes 22c into cavity 22a of connector body 22. The projections 22b each have openings 22d. Terminals 6 have holes 6a formed in a wider portion of the terminal which is inset within the base 4 of switch 2 (see particularly FIG. 4), but exposed by rectangular recesses 4a adjacent the terminals 6 and open to the lower end of base 4. 
     A disc 24 of insulating material has an oblong opening 24a which is complemental to the outer profile of the two projections 22b and the interconnecting land between these projections. Disc 24 is placed over projections 22b to rest against a shoulder 22e on connector body 22, thereby providing a large circular sealing surface on the connector body 22. The connector body 22 is inserted over the lower end of switch 2 whereby the terminals 6 are received through openings 22c in the connector body. The projections 22b nest over the narrowed portions of terminals 6 and within the recesses 4a of base 4 mechanically interlock the connector body on the switch 2. An insulating pin 26 is inserted through openings 22d and holes 6a to pin the connector body 22 to the switch terminals 6 and therefore to the switch 2. 
     A hexagonal shaped collar 28 having a threaded bushing 28a at one end and a cylindrical cavity 28b open to the opposite end is disposed over switch 2. Threaded bushing 28a is internally threaded to engage with the threaded bushing 16 of switch 2 whereby the collar 28 is threadably attached to the switch 2. Collar 28 envelopes switch 2 and the projections 22b of connector body 22, overlying the openings 22d and the opposite ends of pin 26 to prevent removal of the pin and therefore to prevent disassembly of the connector body 22 from the switch 2. Collar 28 is threadably rotated against a surface of member 24 and in turn against the shoulder 22e of connector body 22 to provide a seal and additional stability to the assembly. 
     As seen in FIGS. 2 and 3, the interior surface of cavity 22a of connector body 22 is provided with a key structure which requires that the mating plug-in part be formed with a complemental key structure. In the examples shown, the key is a rib 22f in a first connector body 22g shown in FIG. 2, the rib 22f extending in the direction toward the open end of connector body 22. A second connector body 22h is shown in FIG. 3 having a different type of keying wherein a pair of parallel ribs 22j are provided in the interior surface of cavity 22a of connector body 22. Thus a switch assembly can be provided using the same switch 2 but selectively provided with different keying for the plug-in connector by pinning a selected connector body to the switch. 
     The embodiment shown and described herein is a preferred embodiment and represents the best known mode of carrying out the invention at the time of filing this application. However, it is to be understood that the invention is susceptible of various modifications without departing from the scope of the appended claims. For example, the single pin 26 could be substituted for by a pair of pins separately inserted from either direction at the outsides of projections 22b. Such pins could be made to snap into place within the holes 22d, therefore obviating the need of a collar. The collar 28 could be attached to the switch only around the area of the projections 22b and could be affixed to the switch 2 in several ways, including a threaded coupling between the collar and the projections 22b. The collar could also be snap fit to the projections 22b with suitable structural modifications to both the collar and the projections. The keying structure has been illustrated as comprising one or more ribs extending substantially axially of the switch assembly. However, the interior shape per se of the cavity 22a and the exterior shape of the mating plug could equally serve as a keying structure, as well as many other shapes or locations of ribs that may be added to the interior surface of cavity 22a.