1.  Field of the Invention
The invention relates to an improved connector of a lever type which may be connected together using "lever action". 
2.  Statement of the Prior Art
The above connector has an advantage in that it may be connected or disconnected with a small amount of force.  Such connectors are particularly used in a multiple-pole connector having 20 (twenty) or more poles.  The basic principle for such connectors is based on "lever action".  Such connectors are well known and disclosed for example in Japanese Patent Public Disclosure No.  4-627724. 
For convenience of illustration, a prior art lever connector will be first explained below with reference to FIGS.  13A-13D. FIGS.  13A-13D are schematic side elevational views showing operation of the prior art lever connector. 
In FIGS.  12A-12D, a female connector housing 1 into which a female terminal is housed is shown in the upper portion, and a male connector housing 2 into which a male terminal is housed is shown in the lower portion.  The female connector housing 1 is insertable within the male connector housing 2.  A lever 3 is mounted on the male connector housing 2.  The lever 3 is pivotable about a support axis 2a and has a cam groove 3a for effecting "lever action".  The female connector housing 1 includes a cover 4 having a cam receiving protrusion 4a. 
In order to connect the housing 1, 2 together, the cam receiving protrusion 4a of the cover 4 attached to the female housing 2 is fitted into the cam groove 3a of the lever 3, as shown in FIG.  13B. Then, the lever 3 is rotated as shown by an arrow mark in the drawing so that the position or posture of the lever 3 is changed so that shown in FIG.  13D, via FIG.  13C. By this, the cam receiving protrusion 4a, and thus the cover 4, is displaced downwardly as viewed in the drawing by means of a lever action of the cam groove 3a.  Consequently, the female connector housing 1 is inserted in the male connector housing 2 in its entirety, so that a plurality of terminals of both connector housings are coupled. 
In order to conduct connection procedure of such a connector, the cam receiving protrusion 4a is first inserted in the cam groove 3a, and then the lever 3 is rotated so as to displace the cam receiving protrusion downwardly.  Accordingly, it is necessary for the cam receiving protrusion 4a to be securely advanced into the cam groove 3a, in order to rotate the lever 3. 
It is noted, however, that the cam receiving protrusion 4a is not always securely advanced into the cam groove 3a, when the female connector housing 1 is simply inserted into the male connector housing 2.  It is also possible for the cam receiving protrusion 4a, even when it is once advanced properly, to be disengaged from the cam groove 3a prior to necessary pivot operation of the lever 3. 
Under the circumstances, it is necessary for an operator to conduct a complicated operation as follows.  In order to connect or combine the pair of connector housings, the female housing 1 is inserted into the male housing 2, and then, the cam receiving protrusion 4a is securely advanced into the cam groove 3a by applying a finger or fingers on the lever 3, while holding the female housing 1 with the opposite hand.  After confirming that the cam receiving protrusion 4a has been properly inserted into the cam groove 3a, the lever 3 should be raised with the female housing 1 being lightly held. 
In order to avoid such a complicated or wearisome procedure, it is preferred that the female housing 1 having been inserted into the male housing 2 be temporarily held in a position. 
A principal concept conceivable to achieve the above construction is to provide mating engagement pawls on the pair of connector housings 1, 2.  With such a construction, it is necessary to mold engagement pawls in an undercut configuration.  This requires a complicated mold die for forming connector housings, thus increasing costs for such die.  It also requires a number of holes to be punched in the connector housings, thus reducing strength of the connector housings.