Patent Publication Number: US-6341968-B1

Title: Lever-type connector

Description:
TECHNICAL FIELD 
     The present invention relates to a lever-type electrical connector. 
     BACKGROUND OF THE INVENTION 
     A conventional lever-type connector is described in JP-10-334987. In this connector, one of a pair of housings capable of mutually fitting together and being separated supports a lever in a manner whereby it can be pivoted. The other housing is provided with a cam pin which fits with a cam groove in the lever. When the two housings are to be fitted together, the two housings fit shallowly together while the lever is in a stand-by state. As a result, the cam pin enters an anterior edge position of the cam groove. From this state, the lever is pivoted to a fitting position. The fitting together of the cam groove and the cam pin draws the two housings together, these two housings then reaching a fitted state. If the lever is pivoted from this fitted state in the opposite direction, the fitted together cam groove and cam pin cause the two housings to move to the shallow fitting position. From this position, the cam pin can be removed from the anterior edge position of the cam groove, and the two housings can be separated. 
     When the lever is returned to the stand-by position and the two housings are to be separated, the cam pin remains fitted with the cam groove if the lever is misaligned from the stand-by position in the direction of the fitting position. Consequently, the two housings cannot be separated. As a result, smooth operation is impeded. The present invention has been developed after taking the above problem into consideration, and aims to present a lever-type connector wherein the separation operation of the two housings can be performed smoothly. 
     SUMMARY OF THE INVENTION 
     According to the invention there is provided a lever type electrical connector comprising a pair of mutually engeageable housings, one of the housings having a pivotable lever defining a cam track, and the other of the housings having a cam follower engageable with the cam track whereby pivoting of the lever from a stand-by position to a fitted position causes said cam follower to be drawn along said cam track, thereby drawing said housings together from shallow to deep engagement characterised in that said lever has identifying means adapted to permit visual confirmation of the respective position of said cam track and cam follower. 
     Such an arrangement permits the position of the cam follower to be viewed, and accordingly the lever can be placed in the correct position for smooth reception and disengagement of the cam follower and cam track. 
     Preferably a portion of the cam track is open, and a portion is occluded, the transition between open and occluded portions defining a visual marker for the cam follower. The cam follower is preferably occluded in the stand-by position of the lever. 
     The occluded portion may comprise a bridge linking both sides of said cam track, thus providing additional reinforcement. The bridge may completely occlude one end of the cam track, and the transition between open and occluded portions may be defined by a straight edge. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features of the invention will be apparent from the following description of a preferred embodiment shown by way of example only in the accompanying drawings, in which: 
     FIG. 1 is a disassembled diagonal view showing a lever housing of a first embodiment of the invention; 
     FIG. 2 is a diagonal view showing an attached state of the lever housing; 
     FIG. 3 is a diagonal view showing the lever housing in a fitted state with a machine housing; 
     FIG. 4 is a plan view showing the lever housing in a fitted state with the machine housing; 
     FIG. 5 is a partially enlarged plan view showing the lever housing and the machine housing in a shallowly fitted state; 
     FIG. 6 is a partially enlarged plan view showing the lever housing in a separated state from the machine housing; 
     FIG. 7 is a partially enlarged plan view showing the lever housing and the machine housing in a shallowly fitted state and a lever being in a state whereby it is misaligned from a stand-by position in the direction of a fitting position; 
     FIG. 8 is a cross-sectional view showing FIG. 5 along the line X—X; 
     FIG. 9 is a cross-sectional view showing FIG. 6 along the line Y—Y; 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     An embodiment of the present invention is explained below with the help of FIGS. 1 to  9 . 
     A connector is provided with two housings capable of mutually fitting together and separating. These consist of a lever housing  20  and a component housing  10 . 
     The housing  10  is provided on an outer face of a component main body  11 . A portion of an outer wall of the main body  11  has a concave shape, and an angular tubular hood  12  protrudes towards the exterior from a circumference edge of this concave portion (not shown). The concave portion and the hood  12  form a concave fitting member  13 . Tips of a plurality of male terminal fittings (not shown) are in the interior of this concave fitting member  13 . When the lever housing  20  is fitted with the concave fitting member  13 , the male terminal fittings make contact with female terminal fittings of the lever housing  20 . 
     The lever housing  20  consists of a housing main body  21  which houses the plurality of female terminal fittings (not shown) and fits with the concave fitting member  13 , an electric wire cover  22  which attaches to the housing main body  21 , and a lever  23  attached to the electric wire cover  22 . A cylindrical fitting member  24  surrounds an outer circumference of the housing main body  21 . When the two housings  10  and  20  are fitted together, this cylindrical fitting member  24  fits over an outer circumference of the hood  12 . 
     The electric wires (not shown) protrude from a rear face of the housing main body  21 . The electric wire cover  22  guides the electric wires along this rear face in a transverse direction so that they do not interfere with the lever  23 . The lever  23  has an inverted U-shape and is attached to side faces of the electric wire cover  22 . The lever  23  consists of a pair of plate-shaped arms  26  which extend from both edges of an operating member  25 , and is capable of being pivoted from a stand-by position (see FIGS. 2,  5  and  6 ) to a fitting position (see FIGS.  3  and  4 ). Axle receiving holes  27  of the arms  26  fit with supporting axles  28  of the electric wire cover  22 , thereby maintaining the lever  23  in this pivotable manner. Cam grooves  29  are formed in the arms  26 , these cam grooves  29  fitting with cam pins  14  formed on outer faces of the hood  12  of the component housing  10 . Anterior end portions of the cam grooves  29  open into side circumference faces of the arms  26 . When the lever  23  is in the stand-by position, the position of anterior end openings  29 A is such that the cam pins  14  will not interfere with the cam grooves  29  as the two housings  10  and  20  are being fitted together or separated, and smooth insertion or removal can be achieved. Furthermore, the cylindrical fitting member  24  is provided with recessed grooves  30 , thereby preventing interference between the cam pins  14  and the cylindrical fitting member  24  when the cam pins  14  are inserted into the cam grooves  29 . 
     When the two housings  10  and  20  are to be fitted together, the lever housing  20  is fitted shallowly together with the component housing  10  while the lever  23  is in the stand-by state. The cam pins  14  are inserted into anterior edge positions of the cam grooves  29  (see FIG.  5 ). From this state, the lever  23  is rotated to the fitting position. Thereupon, the fitting together of the cam grooves  29  and cam pins  14  draws the lever housing  20  into the component housing  10 , and a correctly fitted state is achieved (see FIG.  4 ). Further, if the lever  23  is rotated back to the stand-by position from this correctly fitted state, the fitting together of the cam grooves  29  and the cam pins  14  pushes the lever housing  20  out of the concave fitting member  13  of the component housing  10 . The two housings  10  and  20  thereby return to their shallowly fitted state. The cam pins  14  fit with the anterior end openings  29 A of the cam groove  29 . Consequently, if the two housings  10  and  20  are pulled apart from this state, the cam pins  14  are removed from the cam groove  29 , and the two housings  10  and  20  are separated (see FIG.  6 ). 
     If, as shown in FIG. 7, the lever is not returned to the correct stand-by position when the two housings  10  and  20  are to be separated, the cam pins  14  interfere with side edges of the cam grooves  29 , thereby hindering the separation of the two housings  10  and  20 . However, the present embodiment deals with this problem. The lever  23  is provided with an identifying means  31  which allows the positional relationship between the lever  23  and the cam pins  14 , relative to direction of rotation of the lever  23 , to be identified visually when the two housings  10  and  20  are in the shallowly fitted state. The configuration of this identifying means  31  is described below. 
     The cam grooves  29  pass from inner side faces of the arms  26  to outer side faces thereof, these cam grooves  29  extending along almost the entire range of arms  26 , with the exception of anterior ends thereof. If the cam grooves  29  are viewed cross-sectionally from approximately a right angle to their direction of rotation, the groove width of the cam grooves  29  appears step-shaped, outer side faces thereto being broader than inner side faces. Each cam pin  14  consists of a small diameter member  14 S and a large diameter member  14 L. The small diameter member  14 S fits with a narrow width member  29 S of each cam groove  29 , and the large diameter member  14 L fits with a broad width member  29 L of each groove  29 . The large diameter members  14 L make contact with an axial direction with outer faces of the narrow width members  29 S, the arms  26  thereby preventing the cam pins  14  from moving outwards relative to the axial direction, and thereby maintaining the fitted state of the cam pins  14  and the cam grooves  29 . 
     A protruding end face  14 T of each cam pin  14  is located at a position inwards from an outer face  26 F of each arm  26  (see FIGS.  8  and  9 ), a gap thereby occurring between the two faces  14 T and  26 F. The identifying means  31  is provided by means of this gap. The identifying means  31  consists of a plate-like covering member  32  and an exposing aperture  33 . The covering member  32  is provided at the anterior end openings  29 A which open into the outer circumference faces of the arms  26  of the cam groove  29 . The aperture  33  adjoins, in the direction of rotation of the lever  23 , the covering member  32 . The covering member  32  is thinner than the gap between the outer face  26 F of the arm  26  and the protruding end face  14 T of the cam pin  14 . An outer face of the covering member  32  forms a unified face with the outer face  26 F of each arm  26 , and the covering member  32  has a bridge shape which joins both side edges of the anterior end openings  29 A of the cam grooves  29 . Further, the configuration of the covering member  32  is such that it entirely covers the cam pins  14  (see FIG. 5) only when the lever  23  is in the correct stand-by position (when the two housings  10  and  20  are to be separated from their shallowly fitted state, this is the state whereby the cam pins  14  pass the anterior end openings  29 A without interfering with the groove ends of the cam grooves  29  and can be removed to the exterior of the arms  26 ). The aperture  33  is formed on a portion of the area in the cam grooves  29  which opens towards the outer faces  26 F of the arms  26 . If the lever  23  is slightly misaligned from the correct stand-by position in the direction of the fitting position, the aperture  33  allows a portion of the cam pin  14 , which was entirely covered by the covering member  32 , to protrude and be visible (see FIG.  7 ). 
     Next, the operation of the present embodiment is explained. 
     If the lever  23  is returned to the correct stand-by position when it is rotated from the fitted state to the stand-by position, and the two housings  10  and  20  come to be in the shallowly fitted state, the cam pins  14  are entirely covered by the covering members  32 . However, if the lever  23  is misaligned from the correct stand-by position in the direction of the fitting position, a portion or the entirety of the cam pins  14  protrude and are visible. That is, the identifying means  31  make it possible to ascertain whether the lever  23  has been returned to the correct stand-by position by visually examining the positional relationship of the cam pins  14  and the lever  23 . Consequently, the lever  23  can reliably be pivoted to the correct stand-by position when the two housings  10  and  20  are to be separated from the shallowly fitted state, and the cam pins  14  are prevented from interfering with the groove ends of the anterior end openings  29 A of the cam grooves  29 . 
     Furthermore, the covering member  32  has a bridge shape which joins both side edges of the cam grooves  29 . Consequently, the covering member  32  also performs a strengthening function and thereby prevents a change of shape of the lever  23 , which may result in the opening width of the cam grooves  29  becoming wider or narrower. Moreover, in the case of a configuration where the aperture constituting the identifying means has a small opening and the cam grooves do not protrude in their entirety to the outer side faces of the arms, the lever may be incorrectly believed to be in the correct stand-by position when the lever has been displaced from the correct stand-by position and the exposing member should have but does not expose the cam pins. However, in the present embodiment, the cam grooves  29  open almost entirely into the outer faces  26 F of the arms  26  and the aperture  33  is joined to the opening space of the cam grooves  29 . Consequently, when the lever  23  is not in the correct stand-by position the cam pins  14  will definitely protrude so as to be visible within the cam grooves  29 . As a result, it is possible to reliably identify whether the lever  23  is in the correct stand-by position. 
     Furthermore, 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 embodies in various other ways without deviating from the scope thereof. 
     (1) In the above embodiment, the identifying means has a configuration whereby the cam pins are entirely covered when the lever is in the correct stand-by position, and a portion of the cam pin is visible when the lever is slightly misaligned towards the fitting direction from the correct stand-by position. However, according to the present invention, this configuration may equally well be the opposite of the above embodiment, with the entirety of the cam pins protruding and being visible when the lever is in the correct stand-by position, and a portion of the cam pins being covered when the lever is misaligned from the correct stand-by position. Moreover, an indicator with calibrations or the like may be provided on the outer face of the lever, this allowing one to judge the location of the lever relative to the location of the cam pins. 
     (2) The above embodiment describes a lever-type connector used for an apparatus, whereby the housing which does not have the lever provided thereon is formed in a unified fashion with the electrical component. However, the present invention is also suitable for a lever-type connector not used for a component, such as a wire-to-wire lever-type connector. 
     (3) In the above embodiment, the covering member has a bridge shape which joins both side edges of the cam grooves. However, according to the present invention, the covering member may equally well have a cantilevered shape, extending from only one of the side edges of the cam grooves.