Abstract:
A lever-type electrical connector has matingly engageable first and second connector portions and a lever arm rotatably mounted at an outer surface of the first connector portion. The lever arm has a cam groove extending in a plane perpendicular to the axis of lever arm rotation. The second connector portion has an outwardly projecting follower pin which follows the cam groove to draw the connector portions into mating engagement when the lever arm is rotated with the pin engaged in the cam groove. The lever arm also has a flange portion and the second connector portion has a cover portion which overlies at least a part of the outwardly facing side of the flange portion of the lever arm when the lever arm is rotated with the pin engaged in the cam groove, thereby preventing the lever arm from moving outwardly along its axis of rotation.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a lever-type electrical connector in which a pair of connector housings containing electrical terminals are fitted to each other. Such a connector is used for example to connect wire bundles in a motor vehicle. 
     2. Description of the Related Art 
     A lever-type electrical connector is disclosed in JP-A-4-67582. In this connector, male and female connector housings are fitted to each other and a first one of the housings has a lever. The lever has side arms opposing side surfaces of the first connector housing, and is rotatably supported by a shaft. The side arms have drive releases at their inner faces. The second connector housing has a spring projection at each corresponding side surface. The projections of the second housing lock by a latching action into the respective drive projections when the housings are pushed together. Thereafter, when the lever is rotated, the engagement of the projections and drive recesses acts to draw the connector housings together. 
     However, when the lever is rotated, the lever tends to deform. If this happens, there is a danger that the lever separates from the shaft. To prevent this, a hood is provided on the first connector housing on each side outwardly of the lever to keep the lever in place. The hoods increase the thickness of the connector. Thus, the connector becomes relatively large in its thickness direction. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to prevent the lever separating from the connector while minimising the thickness of the connector. 
     According to the present invention, there is provided a lever-type connector having matingly engageable first and second connector portions and a lever arm rotatably mounted at an outer surface of the first connector portion. The lever arm has a cam groove extending in the plane perpendicular to the axis of lever arm rotation, and the second connector portion has an outwardly projecting follower pin which follows the cam groove to draw the connector portions into mating engagement when the lever arm is rotated with the pin engaged in the cam groove. The lever arm further has a peripheral flange portion, and the second connector portion has a cover portion which overlies at least a part of the outwardly facing side of the flange portion when the lever arm is rotated with the pin engaged in the cam groove, thereby preventing the lever arm from moving outwardly along its axis of rotation. 
     On rotation of the lever arm, the flange portion, which may be thin, is guided behind the cover portion, which may also be thin. Thus, it is possible to prevent the lever arm separating from the first connector portion. The cover portion may lie substantially flush with the lever arm. Accordingly, it is also possible to provide a compact connector. 
     Preferably, the follower pin has an end flange which covers a part of an outwardly facing surface of the lever arm when the lever arm is rotated with the pin engaged in the cam groove, thereby also helping to prevent the lever arm from moving outwardly along its axis of rotation. 
     To minimise thickness of the connector, preferably the cover portion has an outer face which is substantially coplanar with an outer face of the lever arm. Further, preferably the lever arm has a planar outer face and the outwardly facing side of said flange portion is recessed on the lever arm relatively to the planar outer face of said lever arm. 
     To simplify the process of molding of the second connector portion, preferably with respect to the connection direction in which the second connector portion is moved relative to the first connector portion when the two connector portions are drawn into mating engagement by rotation of the lever arm, the cover portion is located on the second connector portion both rearwardly and laterally from the follower pin. For stability of operation, preferably the second connector portion has two such cover portions, which with respect to the connection direction of the connector portions are both located rearwardly from the follower pin and are respectively laterally spaced from the follower pin on opposite sides of the follower pin. 
     Preferably, the second connector portion has two said cover portions laterally spaced to either side of the follower pin. 
     Preferably, the lever-type connector has two said lever arms at respective outer surfaces of opposing side walls of the first connector portion, the two lever arms being connected by an actuator portion whereby both the lever arms are rotatable by moving the actuator portion. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention will now be described by way of non-limitative example, with reference to the accompanying drawings, in which: 
     FIG. 1 is a side view showing the male and female connector housings and the lever of an electrical connector which is an embodiment of the present invention before the connector housings are fitted to each other. 
     FIG. 2 is a top view of the male connector housing of FIG.  1 . 
     FIG. 3 is a top view of the female connector housing of FIG.  1 . 
     FIG. 4 is a side view showing the connector housings of FIG. 1 being fitted to each other. 
     FIG. 5 is a side view showing the connector housings of FIG. 1 fully fitted together. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the embodiment, as shown in FIG. 1, the lever-type electrical connector has a female housing  20  (i.e. a first connector portion) and a male housing  10  (i.e. a second connector portion) to be fitted to the female housing  20 . The terms “male” and “female” refer to the forms of the terminals housed in the housings (see below). 
     The male housing  10  is in this embodiment installed on a printed wiring board (not shown). As shown in FIGS. 1 and 2, the male housing  10  has a rectangular body plate  11  extending from side to side and a hood part  12  which is approximately rectangular in shape. A plurality of tab-shaped male metal terminal fittings  14  extend perpendicularly from the body plate  11  and project in two rows into the hood part  12  from a rear wall thereof. The rear end of each male terminal metal fitting  14  is connected to an electrically conductive path on the printed wiring board. 
     The female housing  20  also has a body plate  21  extending from side to side. A terminal accommodating part  22  which in use can be fitted into the hood part  12  of the male housing  10  extends from the bottom surface of the body plate  21 . Cavities corresponding to the male metal terminal fittings  14  are formed in the terminal accommodating part  22 . Female metal terminal fittings (not shown) fixed to terminals of electric wires (not shown) are inserted into the respective terminal-receiving cavities from the rear side thereof. On fitting the terminal accommodating part  22  in the hood part  12 , the female metal terminal fittings are connected with the corresponding male metal terminal fittings  14 . 
     Both the male and female housings  10 ,  20  as so far described may be formed as one-piece mouldings of synthetic resin. 
     A cover  25  is detachably installed on the upper surface of the body plate  21  of the female housing  20 . 
     One side surface of the cover  25  has a wire take-out opening  27 . An adjacent face  26  of the cover has an opening towards the body plate  21 . The cover  25  accommodates the electric wires which extend from the terminal cavities and which are bundled together. The bundled electric wires are bent over and extend through the take-out opening  27  in a direction perpendicular to a fit-in direction of the housings  10 ,  20  (i.e. the direction of movement as the housings are drawn together). The cover  25  has an inclined surface  28  at the side opposite the take-out opening  27 . 
     A lever  30  for assisting the fitting together and separation of the housings  10 ,  20  is installed on the female housing  20 . The lever  30  has a pair of parallel spaced planar lever arms  31 . Each planar lever arm  31  has an arm portion  33  extending from an approximately circular driving portion  32 . As also shown in FIG. 3, an operating or actuator portion  34  connects the distal ends of the two arm portions  33  together so that as a whole the lever  30  has an inverted U-shape. 
     The lever arms  31  sandwich the long sides of the female housing  20  and the cover  25 , as shown in FIG. 3. A bearing hole  36  is formed somewhat offset from the centre of the driving portion  32  of each lever arm  31 . A shaft  35  extends from each side surface of the cover  25 . By fitting the shafts  35  into the bearing holes  36 , the lever  30  is supported by the shaft  35  so that it is rotatable on the female connector portion between a starting position shown in FIG. 1 and a fully fitted-in position shown in FIG.  5 . 
     In the starting position, the operating portion  34  abuts the upper surface of the cover  25 , and the lever  30  is prevented from rotating clockwise (according to the view of FIG.  1 ). A part-spherical first projection  37 A formed on the side surface of the cover  25  fits into a first locking hole  37 B of the arm  33 , to hold the lever  30  releasably in the starting position. 
     In the fully fitted-in position, the leading edge of the arm portion  33  strikes against a projecting stopper  38  formed on the side surface of the cover  25 , and thus the lever  30  is prevented from rotating further counterclockwise (according to the view of FIG.  5 ). A rectangular second projection  39 A with ramp top surfaces formed just above the stopper  38  fits into a second locking hole  39 B of the arm portion  33 . In this manner, the lever  30  is held in the fully fitted-in position, but can be released by application of force. 
     A cam groove  40  taking a curved path tending towards the bearing hole  36  is formed on the driving portion  32  of the lever arm  31 . The entrance  41  of the cam groove  40  opens on the peripheral edge of the driving portion  32 . As shown in FIG. 1, when the lever  30  is located at the starting position, the entrance  41  of the cam groove  40  is positioned below the shaft  35  and opens downwardly. The outer side of the entrance  41  is covered with a thin closing portion  42 . 
     The male housing  10  has at each side a follower pin  44  that can be snugly fitted in the respective cam groove  40 . The follower pin  44  is close to the top edge of the hood part  12  and is centrally located relative to the long sides of the hood part  12 . The length of the follower pin  44  is such that when the follower pin  44  is fitted in the cam groove  40 , the outer end of the follower pin  44  is slightly inward from the outer surface of the lever arm  31 . 
     A flange portion  45  is formed at a predetermined spacing from the cam groove  40  along the periphery of the driving portion  32  of the lever arm  31 . The outer surface of the flange portion  45  is spaced inwardly from the plane of the outer surface of the remainder of the driving portion  32  by half the thickness of the driving portion  32 . 
     Cover or receiving portions  47 A,  47 B are formed at the lower edge of each long side of the hood part  12 . More specifically, the receiving portions  47 A and  47 B are disposed to either side of the follower pin  44  as seen looking in the axial direction of the pin  44 . The outer surface of each of the receiving portions  47 A and  47 B is flush with the general outer surface of the lever arm  31  when the housings  10 ,  20  are fitted to each other. The edge of each of the receiving portions  47 A and  47 B is circular arc-shaped in correspondence with the stepped edge of the driving portion  32  from which the flange portion  45  extends. A guide groove  48  is thus formed inwardly of the receiving portions  47 A and  47 B between the portions  47 A and  47 B and the sidewall of the hood portion  12 . The flange portion  45  of the lever arm  31  can enter the guide groove  48  and can slidingly move therein on rotation of the lever  30 . 
     A narrow recessed retaining flange  50  of constant width is formed on the lever arm  31  at the radially inward edge of the cam groove  40  of the lever arm  31 . 
     A flange  51  is formed at the outer end of the follower pin  44 . The flange  51  projects only from the upper peripheral edge of the end of the follower pin  44  (as seen in FIG.  1 ), that is, the flange extends around only the upper half the circumference of the follower pin  44 . One side of the flange  51  is partly obliquely cut out in order that the flange can fit to the lever arm  31 . When the follower pin  44  moves along the cam groove  40 , the flange  51  rides over the retaining flange  50 . In other words, the retaining flange  50  is retained by the flange  51  to prevent outward movement of the lever arm. 
     The receiving portions  47 A and  47 B are spaced from either side of the follower pin  44  (as seen looking in the fitting direction of the housings  10 ,  20 ) and the flange  51  projects only from the upper peripheral edge of the end of the follower pin  44 , mainly in order to simplify the tooling for shaping the male housing  10 . This is for the following reason. 
     In large part, the final shape of the male housing  10  is formed by a molding die that opens and closes in the fitting direction of the two housings  10  and  20 . However, because the follower pin stands proud of the male housing  10 , it is necessary to shape the lower surface of the follower pin  44  by means of a sliding mould part that moves in a direction perpendicular to the page on which FIG. 1 is drawn. If, for example, the receiving portions  47 A and  47 B were continuous and the flange  51  projected from the lower peripheral edge of the end of the follower pin  44 , an undercut would need to be formed by a tool moving in the plane of the page on which FIG. 1 is drawn. Therefore, a tool that moves only in the direction perpendicular to the page on which FIG. 1 is drawn would be insufficient for completing the shaping of the male housing  10 . Consequently, the tooling to form the housing would be more complicated. 
     However, in the embodiment of the drawings, the receiving portions  47 A and  47 B are formed to either side of the follower pin  44 , and the flange  51  projects only from the upper peripheral edge of the end of the follower pin  44 . Thus, in the region X (shown by a broken line in FIG.  1 ), between the lower surface of the follower pin  44  and each of the receiving portions  47 A and  47 B, there is no undercut in the plane of the page on which FIG. 1 is drawn, and a single sliding die part may be employed to define the region X. 
     Accordingly, to form the male housing  10 , a molding die that opens and closes in the fitting direction is employed, having at the region X a sliding mould part which moves in the direction perpendicular to the page on which FIG. 1 is drawn. In this way the male housing  10  is shaped using relatively simple tooling. 
     The operation of the lever-type connector of the embodiment having the above-described construction is described below. 
     To fit the housings  10 ,  20  to each other, the lever  30  is first held in the starting position, as shown in FIG.  1 . The entrance  41  of the cam groove  40  then opens downwardly. As indicated by the arrow of FIG. 1, the terminal accommodating part  22  of the female housing  20  is fitted in the hood part  12  of the male housing  10 . As a result, the follower pin  44  enters the entrance  41  of the cam groove  40 , the flange  51  rides on the retaining flange  50 , and the front end of the flange portion  45  of the lever arm  31  enters the guide groove  48  of the left receiving portion  47 A. 
     The lever  30  is then rotated counterclockwise, as shown in FIG.  4 . As a result the follower pin  44  presses against the edge at the cam groove  40 , and the housings  10 ,  20  are pulled towards each other by a camming action. Meanwhile, the retaining flange  50  of the cam groove  40  is retained behind the flange  51  of the follower pin  44 , and the flange portion  45  of the lever arm  31  moves along the guide groove  48  overlain by each of the left receiving portion  47 A and the right receiving portion  47 B. When the lever  30  is rotated to the final position, shown in FIG. 5, the housings  10 ,  20  are fully connected together. 
     To separate the housings  10 ,  20  from each other, the lever member  30  is rotated clockwise from the position shown in FIG.  5 . The follower pin  44  gradually moves toward the entrance  41  of the cam groove  40 , and the housings  10 ,  20  are separated from each other due to a reverse camming action. Meanwhile, the retaining flange  50  of the cam groove  40  is held behind the flange  51  of the follower pin  44 , and the flange portion  45  of the lever  31  moves along the guide groove  48  of each of the receiving portions  47 A,  47 B. When the lever member  30  is rotated to the starting position, the follower pin  44  reaches the entrance  41  of the cam groove  40 . By pulling the female housing  20  from the male housing  10 , the housings  10 ,  20  can then be separated from each other. 
     As described above, in the illustrated embodiment, during the rotation of the lever  30 , the flange  45  formed on the peripheral edge of the lever  31  enters the guide groove  48  of each of the receiving portions  47 A,  47 B, and the retaining flange  50  of the cam groove  40  is held against the inner surface of the flange  51  of the follower pin  44 . Thus, the lever arms  31  are effectively prevented from being pulled apart and can be prevented from being removed from the shafts  35 . 
     In particular, the receiving portions  47 A,  47 B are provided not on the female housing  20  carrying the lever  30 , but on the male housing  10 , and the flange portion  45  enters under the receiving portions  47 A,  47 B. The receiving portions  47 A,  47 B are proud of the side surface of the male housing  10  (hood part  12 ) by a distance approximately equal to the thickness of the lever arm  31 . 
     This contributes to the miniaturization of the connector. 
     In addition, the cam groove  40  of the lever arm  31  is externally visible, and thus the position of the follower pin  44  in the cam groove  40  is visible. Thus, an operator can easily determine how far the housings are fitted together, which facilitates mating and separating operations. 
     The following embodiments are included in the technical scope of the present invention. 
     (1) The lever may be installed not on the female housing but on the male housing. 
     (2) The connector may be a wire-to-wire type connector. 
     While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.