This invention relates to a waterproof connector suitably used, for example, for interconnecting wire harnesses in an automobile, and more particularly to an improved packing for forming a watertight seal between fitting portions of connector housings.
FIGS. 8 to 10 show the construction of a conventional waterproof connector.
The waterproof connector 1 shown in these Figures is disclosed in Japanese Patent Unexamined Publication No. Hei 7-142116, and is used for interconnecting wire harnesses in an automobile.
In this waterproof connector 1, a watertight seal between a male connector housing 2 and a female connector housing 3 is formed by a packing 4 interposed between the male and female connector housings 2 and 3.
The male and female connector housings 2 and 3 are molded of a synthetic resin having an excellent insulating property, and the packing 4 is molded of synthetic rubber or the like which is easily elastically deformable.
The male connector housing 2 includes an inner tubular portion 7 having terminal receiving chambers 6 for respectively receiving and holding connection terminals (not shown), an outer tubular portion 12 formed around the inner tubular portion 7 to form a fitting space 10 therebetween for receiving a generally-tubular, housing fitting portion 8 of the female connector housing 3, and a lock arm 17 which has a support post portion 14 (see FIG. 10) extending upright from the outer peripheral surface of the inner tubular portion 7, and an arm portion 15 extending from a distal end of the support post portion 14 in a direction of fitting and withdrawing of the two connector housings relative to each other (that is, in a direction (right-left direction in FIG. 10) of the axis of the inner tubular portion 7).
As shown in FIG. 8, the lock arm 17 is provided at the upper side of the inner tubular portion 7. As shown in FIG. 10, the arm portion 15 of this lock arm 17 is connected to the distal end of the support post portion 14 at its central portion in the direction of fitting and withdrawing of the two connector housings relative to each other, and when a rear end 15a of the arm portion 15 is depressed as indicated by arrow "a", the arm portion 15 is pivotally moved or turned about a fulcrum defined by a portion where the arm portion 15 is connected to the support post portion 14, so that a front end of the arm portion 15 is lifted as indicated by arrow "b".
The female connector housing 3 includes the generally-tubular, housing fitting portion 8 for being inserted into the fitting space 10, and has a retaining hole 8a which is retainingly engaged with an engagement projection 15b, formed on the front end of the arm portion 15, when the housing fitting portion 8 is inserted a predetermined amount into the fitting space 10. The retaining hole 8a is formed through an distal end portion of the housing fitting portion 8.
Although not shown in the drawings, terminal receiving chambers, corresponding respectively to those of the inner tubular portion 7, are formed in an inner end portion of the housing fitting portion 8.
The packing 4 is beforehand mounted on the outer periphery of the inner tubular portion 7, and closes a gap between the housing fitting portion 8 inserted in the fitting space 10, and the inner tubular portion 7, thereby forming a watertight seal between the fitting portions of the connector housings. The packing 4 includes a tubular portion 19 fitted on the outer peripheral surface of the inner tubular portion 7 in intimate contact therewith, and retaining pawls 23 which extend radially outwardly from an insertion-side end 19a of the tubular portion 19, and are engaged respectively in packing retaining holes 21 formed in the outer tubular portion 12, the insertion-side end 19a being held against an inner end wall of the fitting space 10.
The pair of retaining pawls 23 are formed respectively on opposite (right and left) sides of the tubular portion 19 at the insertion-side end 19a.
A pair of protuberances 19b are formed on that portion of the outer peripheral surface of the tubular portion 19 disposed adjacent to a front end thereof, and these protuberances 19b enhance the intimate contact of the packing 4 with the housing fitting portion 8. Grooves 19c are formed in the inner peripheral surface of the tubular portion 19, and are engaged respectively with projections 25 formed on the outer peripheral surface of the inner tubular portion 7.
In the above waterproof connector 1, before the male and female connector housings 2 and 3 are fitted together, the packing 4 is fitted on the inner tubular portion 7 of the male connector housing 2, as shown in FIG. 9.
For fitting the packing 4, the packing 4 is first fitted on the distal end portion of the inner tubular portion 7, and then end surfaces 23a of the retaining pawls 23 are pushed by a jig or the like until the insertion-side end 19a of the tubular portion 19 is brought into engagement with the inner end wall of the fitting space 10, with the retaining pawls 23 received respectively in the packing retaining holes 21 in the male connector housing 2.
Thereafter, the housing fitting portion 8 of the female connector housing 3 is inserted into the fitting space 10, so that the gap between the housing fitting portion 8 and the inner tubular portion 7 is closed by the packing 4, thereby forming a watertight seal between the fitting portions.
When the housing fitting portion 8 is inserted a predetermined amount into the fitting space 10, the engagement projection 15b of the lock arm 17 is engaged in the retaining hole 8a formed in the female connector housing 3, thereby locking the two housings in a mutually-fitted condition, as shown in FIG. 10.
For releasing the mutual fitting between the housings, the rear end 15a of the lock arm 17 is depressed in the direction of arrow "a", so that the engagement projection 15a is disengaged from the retaining hole 8a, and in this condition the female connector housing 3 is withdrawn from the male connector housing 2.
The retaining pawls 23, formed on the tubular portion 19 at the insertion-side end 19a, are engaged respectively in the packing retaining holes 21 in the male connector housing 2, and therefore the packing 4 will not be disengaged from the male connector housing 2 during the operation of releasing the mutual fitting between the housings.
In the installation of wire harnesses in a vehicle, it is not easy to secure a sufficient space for mounting and receiving connectors and so on. Therefore, it is always important that the connector, used for connecting the wire harnesses together, should have a compact design.
In the above waterproof connector 1, however, the support post portion 14 of the lock arm 17 formed on the male connector housing 2 must be disposed rearwardly of the insertion-side end 19a of the packing 4 (that is, adjacent to the rear end of the male connector housing 2), as clearly seen from FIG. 10. The support post portion 14 need to have a predetermined thickness to have a required strength.
As a result, there has been encountered a problem that the axial length of the male connector housing 2 is increased, so that the size of the housing is increased.