Abstract:
When a connector housing  20  and an equipment connector  10  are correctly joined, a regulating groove  24 D of a retainer  24  of the housing  20  fits with a rib  16  of the equipment connector  10 , thereby allowing the two housings  10  and  20  to be fitted together. The position of groove  24 D may be varied to suit different positions of rib  16 , thereby permitting a common connector housing to be made suitable for a specific equipment connector having an appropriate rib. The shape of the retainer  24  is simpler than the shape of the housing main body  21 . Consequently, the cost of the mould for the retainer  24  is lower.

Description:
TECHNICAL FIELD 
     The present invention relates to an electrical connector provided with an incorrect-fitting detecting function. 
     BACKGROUND TO THE INVENTION 
     Conventional connectors provided with an incorrect fitting-detecting function include the one described in U.S. Pat. No. 4,772,229. This connector comprises a male housing and a female housing capable of mutually fitting together, ribs which extend in a fitting direction being formed on an inner circumference of a recess of the male housing, and grooves formed on an outer circumference of the female housing fitting with these ribs. The ribs and grooves are provided at positions which differ according to each connection position, thereby preventing incorrect connection of otherwise similar connectors. If the male and female housings are incorrectly fitted together, the ribs do not correspond with the grooves, and consequently strike against anterior end circumference edges of the female housing, thereby preventing fitting. 
     In the case of conventional connectors, a plurality of cavities or the like are provided in the housing in order to allow terminal fittings to be inserted therein. Consequently, the shape thereof is complex, and an expensive mould is required to produce the plastic components for this complex shape. 
     In the conventional connector, the ribs and grooves for detecting incorrect fitting are formed directly on the housing. Consequently, a plurality of different housings must be provided, these having the ribs and grooves in differing locations. That is, there is the additional problem that a plurality of expensive moulds are required when the housings are manufactured. Consequently, production costs increase. 
     The present invention takes the above problem into consideration, and aims to present a connector wherein the production costs are reduced. 
     SUMMARY OF THE INVENTION 
     According to the invention there is provided an electrical connector comprising mutually engageable connector housings, one of the housings having a projection and the other of said housings having a recess engageable with said projection to ensure correct matching of said housings, characterised in that one of said projection and recess is provided on a component attachable to the respective housing. 
     Such a connector permits a common and somewhat complex connector housing to be made unique by the attachment of one of a number of relatively inexpensive components each having unique position for the projection/recess. 
     The attachable component may also comprise a retainer for electrical terminals, and be movable from a temporary position, in which terminals are insertable, to a final position in which terminals are latched. The temporary position preferably prevents full engagement of the housings. The component may be slidable within a slot of the respective housing. 
     Preferably the projection/recess is a rib/groove combination, extending in the fitting direction of the connector housings. Such a rib/groove can be relatively easily formed. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     Other features of the invention will be apparent from the following description of a preferred embodiment shown by way of example only the accompanying drawings in which: 
     FIG. 1 is a diagonal view of an embodiment of the present invention showing a female housing and an electric wire cover in a separated state. 
     FIG. 2 is a diagonal view showing the electric wire cover attached to the female housing. 
     FIG. 3 is a partially cut-away diagonal view showing the female housing in a fitted state with an equipment housing. 
     FIG. 4 is a plan view showing the female housing in the fitted state with the equipment housing. 
     FIG. 5 is a vertical part cross-sectional view of the equipment housing. 
     FIG. 6 is a horizontal part cross-sectional view of the equipment housing. 
     FIG. 7 is front view of the equipment housing. 
     FIG. 8 is a cross-sectional view showing a retainer in a fully engaged state on the female housing. 
     FIG. 9 is a cross-sectional view showing the retainer in a temporarily stopped state on the female housing. 
     FIG. 10 is a partially cut-away front view showing the correctly assembled female housing in a fitted state with the equipment housing. 
     FIG. 11 is a front view showing the detection of the incorrectly assembled female housing which is in a fitted state with the equipment housing. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     An embodiment of the present invention is described below with the aid of FIGS. 1 to  11 . A connector of the present embodiment is provided with female housing  20  and an equipment housing  10 , these being capable of mutually fitting together and being separated. 
     The equipment housing  10  is provided on an outer face of an equipment main body  11 , an outer wall portion of this equipment main body  11  being indented, and an angular tubular shaped hood  12  protruding outwards from circumference edges of this indented portion. A housing main body  21  of the female housing  20  fits within a fitting recess  13  which is composed of the indented portion and the hood  12 . The equipment housing  10  has margin spaces (not shown) for ensuring the formation of the fitting recess  13  which is to be formed in the side of the equipment main body  11 . The fitting recess  13  extends into the interior of the equipment main body  11 . As a result, the hood  12  protrudes only a short distance from the outer face of the equipment main body  11 . Tips of a plurality of male terminal fittings  14 , which have passed through the wall portion, face into the recess  13  of the equipment housing  10 . When the female housing  20  is fitted with the recess  13 , these male terminal fittings  14  make contact with female terminal fittings  22 . 
     The female housing  20  comprises a housing main body  21  into which the female terminal fittings  22  (shown in FIG. 8 and 9) are inserted, an electric wire cover  23  attached to the housing main body  21 , and a retainer  24  attached to the housing main body  21  to indicate incorrect fitting. A tubular fitting member  25  surrounds an outer circumference of the housing main body  21 . This tubular fitting member  25  extends in an anterior direction from a posterior end of the housing main body  21 . However, the length of the tubular fitting member  25  is such that the extending end thereof reaches a location behind an anterior end face of the housing main body  21 . Consequently, approximately half of the anterior side of the housing main body  21  is exposed. When the two housings  10  and  20  are fitted together, the tubular fitting member  25  fits with an outer circumference of the hood  12  of the equipment housing  10 . Furthermore, the portion of the outer circumference of the housing main body  21  surrounded by the tubular fitting member  25  has a ring-shaped sealing member  26  attached thereto. This sealing member  26  seals the space between an inner circumference face of the hood  12  of the equipment housing  10  and the outer circumference of the housing main body  21 . 
     The retainer  24  is attached from the side (from a direction at right angles to a direction of fitting of the two housings  10  and  20 ) to the protruding portion of the housing main body  21  (to the anterior of the sealing member  26 ). The retainer  24  comprises a U-shaped attachment member  24 A and a plate-like stopping member  24 B which extends from the attachment member  24 A. The retainer  24  is attached by inserting the stopping member  24 B into a retainer attachment hole  27  in the housing main body  21 . As shown in FIG. 9, when the retainer  24  is in a temporarily stopped state, through holes  24 C of the retainer  24  fit with terminal housing members  28  of the housing main body  21 , thereby allowing the female terminal fittings  22  to be inserted into the terminal housing member  28 . When the retainer  24  is moved into a fully stopped state, as shown in FIG. 8, hole edges of the through holes  24 C move into the terminal housing members  28  and engage with the female terminal fittings  22 . By this means, the female terminal fittings  22  are prevented from moving in a direction of removal. 
     Furthermore, when the retainer  24  is in the temporarily stopped state, the attachment member  24 A thereof protrudes to an exterior face of the housing main body  21 . Consequently, the attachment member  24 A interferes with the hood  12  of the equipment housing  10  if an attempt is made to fit the two housings  10  and  20  together. Fitting is thereby prevented. That is, an abnormality in the attaching state of the retainer  24  allows one to detect whether the fitting operation of the two housings  10  and  20  is correct. 
     The electric wire cover  23  guides electric wires (not shown), attached by crimping to the female terminal fittings  22 , in a specified direction from a rear face of the housing main body  21 . A lever  29  is attached to side faces of the electric wire cover  23 . The lever  29  has an operating member  29 A and a pair of arms  29 B which extend from both sides of the operating member  29 A. Supporting axes  30  of the electric wire cover  23  fit into axis receiving holes  29 C formed in the arms  29 B, thereby supporting the lever  29  in a pivotable state. Cam grooves  29 D are formed in the arms  29 B, these cam grooves  29 D fitting with cam pins  15  formed on outer faces of the hood  12  of the equipment housing  10 . The fitting or separating operation of the two housings  10  and  20  can be performed easily and with little operating force by pivoting the lever  29  when the cam pins  15  are in a fitted state within the cam grooves  29 D. Moreover, the tubular fitting member  25  is provided with recessed grooves  31  to prevent the tubular fitting member  25  from interfering with the cam pins  15 . 
     The shape of the housing main body  21  and the number of terminals of the female housing  20  which is fitted with the equipment housing  10  are standardised with respect to other equipment housings (not shown) and other female housings  20  fitting with other male housings (not shown). For this reason, a means is provided to prevent fitting from occurring when components have been incorrectly assembled. That is a rib  16  (an incorrect-fitting preventing means of the present invention) is formed within an inner circumference of the fitting groove member  13  of the equipment housing  10 , this rib  16  extending in a fitting direction of the two housings  10  and  20 . The location of the rib  16  is such that it will fit with the incorrect-fitting preventing means of the female housing  20 . An anterior end of the rib  16  is located behind the anterior end of the hood  12 . Consequently, the rib  16  does not interfere with the supporting members when the two housings  10  and  20  are in a fitted state. 
     The retainer  24  for stopping the female terminal fittings  22  functions as an incorrect-fitting preventing means for the female housing  20 . As described above, this retainer  24  is formed as a component separate from the housing main body  21 . An outer face of the attachment member  24 A of the retainer  24  has a regulating groove  24 D which extends in the direction of fitting of the two housings  10  and  20 . This regulating groove  24 D is located so that it will fit with the rib  16  of the equipment housing  10 . 
     The female housing  20  of the present embodiment has a standardised number of terminals and a standardised housing shape. However, the other female housings  20  that fit with other equipment housings  10  (not shown) or other male housings (not shown) each have their regulating groove  24 D located in a position which differs from the location of the regulating groove  24 D of the female housing  20  of the present embodiment. 
     If the equipment housing  10  and the female housing  20  are correctly assembled and fitted together, the location of the rib  16  and the location of the regulating groove  24 D coincide and, as shown in FIG. 10, these incorrect-fitting preventing means fit together, thereby allowing the fitting operation of the two housings  10  and  20  to occur. In contrast, if the equipment housing  10  of the present embodiment is incorrectly fitted with a different female housing  20 , the location of the regulating groove  24 D does not coincide with the location of the rib  16 . Instead, as shown in FIG. 11, the regulating groove  24 D is formed at a different location. Consequently, the rib  16  and the anterior end of the retainer  24  interfere and the fitting operation of the two housings  10  and  20  is halted. In this manner, it is possible to detect whether the fitting together of the two housings  10  and  20  is correct or incorrect. 
     In the present embodiment, the retainer  24 , which is the incorrect-fitting preventing means of the female housing  20 , is formed as a component separate from the housing main body  21 . Consequently, even if a plurality of housings  10  and  20  are to be fitted together, the housing main bodies  21 , the electric wire covers  23  and the levers  29  are all standardised components, and one mould can be used for their manufacture. As a result, compared to the case where differing complex-shaped moulds must be produced for housing main bodies  21  provided with terminal housing members  28 , tubular fitting member  25  etc., the cost of the mould can be reduced. Although one requires a plurality of types of retainers  24  which have their regulating grooves  24 D in differing locations according to the type of assembly required, the U-shaped attachment member  24 A and the stopping member  24 B provided with the through holes  24 C of the retainer  24  have a comparatively simple shape. The cost of a mould for the retainer  24  is lower than the cost of a mould for the housing main body  21 . Consequently, when the female housings  20  are manufactured with a plurality of differing regulating grooves  24 D, the overall cost of moulds for the present embodiment can be reduced. 
     Further, the retainer  24 , which is the incorrect-fitting preventing means of the female housing  20 , also has the function of retaining the female terminal fittings  22 . Consequently, the number of components is reduced compared to the case where an incorrect-fitting preventing means of the female housing  20  and a retainer  24  are separate components. 
     Moreover, the equipment main body  11  has spaces so that the housing main body  21  of the female housing  20  can fit therewith. Consequently, the entirety of the equipment housing  10  has a shape whereby it fits into the inner side of the equipment main body  11 . As a result, the protruding distance of the hood  12  which fits into the tubular fitting member  25  of the female housing  20  can be decreased. Moreover, the protruding length of the tubular fitting member  25  of the female housing  20  which fits with the exterior of the hood  12  is made to correspond with the protruding length of the hood  12 , and is thereby also decreased. 
     The present invention is not limited to the embodiments described above with the aid of figures. For example, the possibilities described below also lie within the technical range of the present invention. In addition, the present invention may be embodied in various other ways without deviating from the scope thereof. 
     (1) In the embodiment described above, the incorrect-fitting preventing means formed as a component separate to the housing main body has configuration appropriate only for a female housing. However, according to the present invention, an incorrect-fitting preventing means formed as a component separate to a housing main body may equally well have a configuration suitable for both a female housing and an equipment housing, or for only an equipment housing. 
     (2) In the embodiment described above, the incorrect-fitting preventing means also functions as a retainer. However, according to the present invention, the incorrect-fitting preventing means may be a component which does not also serve the function of retainer (for retaining the terminal fittings). 
     (3) In the embodiment described above, the retainer is attached to the housing main body in a direction which is at right angles with the direction of fitting of the housing main body. However, according to the present invention, the retainer may also be attached to the housing main body from an anterior direction. 
     (4) The present embodiment describes a water-proof connector. However, the present invention is also suitable for a connector which is not water-proof. 
     (5) The present embodiment describes a lever-type connector. However, the present invention is also suitable for connectors other than a lever-type connector.