1.  Field of the Invention
The invention relates to a watertight connector, a connector housing and a waterproof member for a connector housing. 
2.  Description of the Related Art
A watertight connector is identified by the numeral 101 in FIG.  6 and also is disclosed in Japanese Unexamined Patent Publication No.  8-45601.  The watertight connector 101 has male and female housings 110, 120 that are connectable with each other.  The female housing 120 is formed with a receptacle 122 that defines an engaging space for accommodating the male housing 110.  The female housing 120 also includes a ring-shaped elastic waterproof member 123 mounted near a bottom end of the engaging space.  The male housing 110 is formed with a skirt 112 that can be inserted into the engaging space of the female housing 120.  Thus, the waterproof member 123 is held tightly between the housings 110 and 120 and provides a watertight fit when the housings 110, 120 are connected. 
The waterproof member 123 of the watertight connector 101 has a bulging portion 124 at the bottom of the engaging space.  The bulging portion 124 allows the housings 110, 120 to be held in contact with each other in their assembling directions.  The housings 110, 120 are held by the bulging portion 124, and thus are prevented from shaking.  As a result, fine sliding abrasion caused by fine sliding movements between a female terminal fitting 121 and a male terminal fitting 111 is avoided. 
A slanted surface 112B may be formed at the inner side of a leading end 112A of the skirt 112 to avoid contact with the waterproof member 123 during insertion.  However, the leading end 112A may enter between the bulging portion 124 and an inner wall 122A of the receptacle 122 during the connection of the housings 110, 120.  As a result, the slanted surface 112B may push the bulging portion 124 radially inwardly (see FIG.  7).  Radially inward deformation of the bulging portion 124 may prevent the bulging portion 124 from sufficiently displaying its elasticity, and may reduce its effect against fine sliding abrasion.  Thus, there has been a demand for an improvement. 
In view of the above, an object of the invention is to prevent the leading end of the housing from pushing the bulging portion of a waterproof member radially inwardly. 
The invention is directed to a watertight connector with first and second housings that are at least partly connectable with each other.  A skirt is provided on the first housing and a receptacle is provided in the second housing.  The receptacle includes an engaging space that is dimensioned to receive at least part of the skirt.  A locking means may be provided on at least one of the housings to lock the housings in their mated condition. 
An elastic waterproof member is mounted in the engaging space and can be squeezed between the two housings.  The elastic waterproof member has at least one bulging portion, and at least one bulging portion holding means is formed in the engaging space to prevent the bulging portion from deforming elastically inwardly.  The bulging portion and the bulging portion holding means may be at a bottom of the engaging space. 
The bulging portion holding means has a radially outward portion that bulges out more than its radially inward portion.  Thus, the bulging portion holding means prevents the bulging portion from being pushed radially inward by the skirt of the first housing.  Specifically, at least one step may be formed in the second housing by deepening a radially outward portion at the bottom of the engaging space.  Alternatively, the bottom of the engaging space may be formed with a slanted surface that is inclined with respect to a radially outward direction.  With either design, the bottom is deeper at its radially outer side than at its radially inner side.  This can prevent shaking of the housings in their connected state and therefore can prevent fine sliding abrasion between male and female terminal fittings. 
The bulging portion holding means may be provided over the entire periphery of the bottom portion of the engaging space.  Thus, the prevention of the radially inward elastic deformation of the bulging portion and associated shaking of the housings can be prevented more securely.  Alternatively, a plurality of bulging portion holding means may be spaced circumferentially around the engaging space. 
The bulging portion holding means and the bulging portion may comprise correspondingly shaped slanted surfaces. 
The invention also is directed to a connector housing for a watertight connector.  The housing includes a receptacle for at least partly accommodating a mating portion of a mating connector housing.  The housing also includes an engaging space inside the receptacle.  The engaging space is adapted to receive at least part of the mating portion.  An elastic waterproof member is disposed in the engaging space and can be squeezed between the two housings.  The elastic waterproof member has at least one bulging portion.  At least one bulging portion holding means is in the engaging space to prevent the bulging portion from being elastically deformed radially inwardly. 
According to a preferred embodiment, the bulging portion and the bulging portion holding means are at the portion of the engaging space. 
Preferably, the bulging portion holding means is provided over substantially the entire periphery of the engaging space. 
The invention also is directed to a waterproof member for a watertight connector that can be mounted in an engaging space of a connector housing and squeezed between the connector housing and a mating connector housing of the watertight connector.  The waterproof member comprises at least one bulging portion to be located at the engaging space.  The bulging portion is prevented from being elastically deformed radially inwardly by interaction with at least one bulging portion holding means in the engaging space. 
These and other objects, features and advantages of the present invention will become apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings.  It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments.