A watertight connector, a connector housing and a waterproof member therefor

Abstract: A male housing (10) is provided with an engaging space (34) in which a skirt portion (11) of a female housing (20) can be accommodated. A bottom portion (34A) of the engaging space (34) has its radially outward portion deepened backward to form a stepped portion (35) and a projection (39) formed on a seal ring (36) is fitted in and held by the stepped portion (35). Thus, a force of a slanted surface (11B) formed at a leading end (11A) of the skirt portion (11) to push a bulging portion (38) away radially inwardly is restricted by the presence of the stepped portion (35), thereby avoiding the bulging portion (38) being pushed away radially inwardly. This can securely prevent shaking of the housings (10,20) in their connected state and the fine sliding abrasion between the terminal fittings (12,22).

Description: The present invention relates to a watertight connector, to a connector housing and a waterproof member therefor. FIG. 6 shows a watertight connector disclosed in Japanese Unexamined Patent Publication No. 8-45601. This watertight connector 101 is provided with a pair of male and female housings 110, 120 connectable with each other, and the male housing 120 is formed with a receptacle 122 for accommodating the male housing 110. Inside the receptacle 122 is defined a bottomed engaging space in which a ring-shaped elastic waterproof member 123 is mountable. The male housing 110 is formed with a skirt portion 112 to be inserted into the engaging space, so that the waterproof member 123 is tightly held between the housings 110 and 120 to provide watertightness when the housings 110, 120 are connected. Further, the waterproof member 123 of the watertight connector 101 is provided with a bulging portion 124 which allows the both housings 110, 120 to be held in contact with each other in their assembling directions by being located at the bottom of the engaging space. The housings 110, 120 are prevented from shaking by being elastically held by the bulging portion 124, thereby reducing a problem of fine sliding abrasion caused by fine sliding movements between a male terminal fitting 121 and a male terminal fitting 111. A slanted surface 112B may be formed at the inner side of a leading end 112A of the skirt portion 112 in order to avoid contact with the waterproof member 123 during insertion. However, in such a construction, 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, resulting in an undesirable event where the slanted surface 112B pushes the bulging portion 124 away radially inwardly (see FIG. 7). Upon occurrence of such an event, the bulging portion 124 cannot sufficiently display its elasticity, reducing its effect against the fine sliding abrasion. Thus, there has been a demand for an improvement. US-A-4 917 620, figure 8, discloses a connector according to the preamble of claim 1. US-A-5 399 045 discloses a connector having a pair of housings and a waterproof member to be mounted in an engaging space of one housing. The waterproof member comprises a bulging portion at a rear end thereof which restricts an inserting movement of a skirt portion of the other housing. Although the engaging space of one housing is provided with a slant surface and the shape of the watertight member corresponds to this slanted surface, there is still the danger that the watertight member slips down on the slanted surface and as a consequence the bulging portion may move radially inwards, when the skirt portion of the other housing is pressed aoainst the bulging portion. In order to prevent this, the watertight member is provided with a plurality of projections engaging with through holes of a rear wall of the one housing. However, the arrangement of the plurality of projections on the watertight member and the through holes of the rear wall in the housing lead to the effect that the productions costs are increased, the mountability is rendered complicate and the dimensions of the connector are increased. In view of the above situation, an object of the present invention is to prevent an event where a bulging portion of a waterproof member is radially inwardly pushed away by a leading end portion of a mating housing, while the connector may be manufactured with low manufacturing costs and wherein the mountability thereof is facilitated, while the dimensions are minimized. This object is solved according to the invention by a watertight connector according to claim 1, a combination according to claim 6 and by a waterproof member according to claim 9. Preferred embodiments of the invention are subject of the dependent claims. Here, the bulging portion holding means is a means for preventing the bulging portion from being pushed away radially inwardly by being formed such that its radially outward portion bulges out more than its radially inward portion. Specifically, a stepped portion is formed by deepening a radially outward portion of the bottom portion of the engaging space so that the bottom portion is deeper at its radially outer side than at its radially inner side. Accordingly, the bulging portion holding means for preventing the bulging portion of the waterproof member from being elastically deformed radially inwardly is provided at the bottom portion of the engaging space. Thus, the bulging portion of the waterproof member is prevented from being pushed away radially inwardly. This can prevent shaking of the housings in their connected state and fine sliding abrasion between male and female terminal fittings. The bulging portion holding means is provided over the substantially entire periphery of the engaging space, preferably of the bottom portion of the engaging space. Accordingly, the bulging portion holding means is provided over the entire periphery of the bottom portion of the engaging space. Thus, an effect of preventing the radially inward elastic deformation of the bulging portion can be made more secure, thereby securely preventing the housings from shaking in their connected state. Most preferably, a locking mechanism is provided on at least one of the housings for locking the housings with or at least partly into each other. The bulging portion is to be located at a bottom portion of the engaging space, and wherein the bulging portion holding means is provided at the bottom portion of the engaging space. The bulging portion holding means is provided over the substantially entire periphery of the engaging space, preferably of the bottom portion thereof. 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 embodiments are separately described, single features thereof may be combined to additional embodiments, as long as they fall under the scope of the claims. FIG. 1 is a plan view of a female and a male housings of a watertight connector according to the invention in their connected state, FIG. 2 is a section of the female and male housings of the watertight connector according to the invention before they are connected, FIG. 3 is a section of the female and male housings of the watertight connector according to the invention in their connected state, FIG. 4 is a section of a female and a male housings of a watertight connector according to a comparative example before they are connected, FIG. 5 is a section of the female and male housings of the watertight connector according to the comparative example in their connected state, FIG. 6 is a section of a prior art watertight connector, and FIG. 7 is an enlarged view of a portion of a seal ring of the prior art connector. <First Embodiment> A first preferred embodiment of the invention is described with reference to FIGS. 1 to 3. FIG. 1 is a plan view showing a watertight connector according to this embodiment in its assembled state. This watertight connector 1 is provided with a male or first connector housing (hereinafter, "male housing") 10 and a female or second connector housing (hereinafter, "female housing") 20 at least partly connectable with each other. In the following description, sides of the respective housings 10, 20 to be connected with the mating housing 20, 10 are referred to as front. First, the male housing 10 is described. The male housing 10 is unitarily or integrally formed e.g. of a synthetic resin into a substantially rectangular parallelepipedic shape, and is provided with a preferably substantially tubular skirt portion or receptacle 11 which is open forward (see FIG. 2). A plurality of male terminal fittings 12 project at specified intervals in widthwise direction (direction perpendicular to the plane of FIG. 2) from the bottom wall of the skirt portion 11. A pair of left and right or lateral guide walls 13 extending substantially in forward and backward directions are formed preferably substantially parallel to each other in the widthwise center of the upper surface of the skirt portion 11, and a lock portion 14 engageable with a lock arm 29 of the female housing 20 projects between the two guide walls 13. Further, a slanted surface 11B is formed at the inner side of a leading end 11A of the skirt portion 11 to avoid interference of the skirt portion 11 with a seal ring or seal member 36 during insertion into an engaging space 34 of the female housing 20. Next, the female housing 20 is described. The female housing 20 is unitarily or integrally formed e.g. of a synthetic resin into a substantially rectangular parallelepipedic shape, and is internally formed with a terminal accommodating portion 21 to be at least partly fitted into the skirt portion 11 of the male housing 10. The same number of cavities 25 as the male terminal fittings 12 of the male housing 10 are formed substantially in conformity with the positions of the male terminal fittings 12 to accommodate female terminal fittings 22. Each female terminal fitting 22 is or can be inserted into the corresponding cavity 25 preferably from behind, and is substantially elastically locked by a locking portion 26 projecting in the cavity 25 so as not to come out of the cavity 25 preferably backward. The female terminal fittings 22 are doubly locked by a retainer, preferably a front retainer 27 mounted before or intersecting the cavities 25. A front part of each female terminal fitting 22 is in the form of a substantially rectangular column which serves as a connecting portion 23 for receiving the male terminal fitting 12, and one end of a wire W is connected with a rear part thereof. Further, the rear surface of each female terminal fitting 22 is covered by a waterproof rubber plug 24. The rubber plug 24 is formed with an insertion hole through which the wire W is insertable and whose edges can be held in sealable contact with the outer surface of the wire W. The inside of each cavity 25 can be held watertight by holding peripheral edges 24A of the rubber plug 24 in sealable contact with an inner wall 25A of the cavity 25 when the female terminal fitting 22 is fitted into the cavity 25. The female housing 20 is formed with a preferably substantially tubular receptacle 28 in such a manner as to substantially surround the terminal accommodating portion 21. The receptacle 28 projects forward of the female housing 20, and the bottomed engaging space 34 into which the skirt portion 11 of the male housing 10 is fittable is defined between an inner circumferential surface 28A of the receptacle 28 and an outer circumferential surface 21A of the terminal accommodating portion 21. The lock arm 29 elastically deformable in vertical direction (or toward and away from the terminal accommodating space 21 or the cavities 25) is provided on the upper surface of the receptacle 28. This lock arm 29 is narrow in forward and backward directions, and is inclinable preferably like a seesaw about a supporting point 30 preferably located substantially in the same position as the bottom of the receptacle 28. The upper surface of the receptacle 28 around the lock arm 29 projects upward, thereby forming a projecting portion 33, and the two guide walls 13 and the lock portion 14 of the male housing 10 can be accommodated inside the projecting portion 33. The projecting portion 33 is formed with an escape groove 33A which is open at the rear end of the projecting portion 33 so as to permit an upward pivotal movement of the front end of the lock arm 29. A pushing portion 31 for unlocking the lock arm 29 is provided on the upper surface of the rear end of the lock arm 29. A groove 32 engageable or bringable into interaction or cooperation with the lock portion 14 of the male housing 10 is formed in a position of the lock arm 29 slightly behind its front end. The seal ring (corresponding to a preferred waterproof member) made e.g. of an elastic material (e.g. rubber) is or can be mounted preferably substantially at the bottom end of the engaging space 34. The seal ring 36 is preferably ring-shaped, and the inner circumferential surface thereof is or can be held in sealable contact with the outer circumferential surface 21A of the terminal accommodating portion 21 while the rear end thereof is or can be held in sealable contact with a bottom portion 34A of the engaging space 34. Further, a plurality of lips 37 are formed on the inner and outer circumferential surfaces of the seal ring 36. A bulging portion 38 projects radially outwardly from the outer circumferential surface of the substantially rear end of the seal ring 36. The bulging portion 38 projects up to a position where its projecting end is or can be in contact with the inner circumferential surface 28A of the receptacle 28, and is squeezed preferably between the bottom portion 34A of the engaging space 34 and the leading end 11A of the skirt portion 11 when the housings 10, 20 are connected with each other. A surface of the rear end of the bulging portion 38 in contact with the bottom portion 34A of the engaging space 34 projects backward over its entire periphery to form a projection 39. On the other hand, a radially outward portion of the bottom portion 34A of the engaging space 34 is deepened backward over its entire periphery to form a stepped portion 35 (corresponding to a preferred bulging portion holding means). When the seal ring 36 is mounted, the projection 39 of the seal ring 36 is fitted or inserted or pressed into the stepped portion 35. Next, the action and effects of this embodiment thus constructed are described. In order to connect the male and female housings 10, 20, the skirt portion 11 of the male housing 10 is at least partly inserted into the engaging space 34 of the female housing 20. At this time, the skirt portion 11 can be smoothly inserted without getting caught by the lips 37 formed on the seal ring 36 since the slanted surface 11B is formed at the leading end 11A of the skirt portion 11. On the other hand, the lock portion 14 of the male housing 10 comes into contact with the lock arm 29 of the female housing 20, thereby elastically pivoting the lock arm 29 to move onto the lock portion 14. When the housings 10, 20 are properly substantially connected, the male and female terminal fittings 12, 22 are connected and the lock arm 29 is elastically restored substantially to its original position to engage the lock portion 14 in the groove 32 to lock the housings 10, 20 into each other as shown in FIG. 3. Further, watertightness is provided by squeezing the seal ring 36 between an inner circumferential surface 11C of the skirt portion 11 and the outer circumferential surface 21A of the terminal accommodating portion 21 while deforming the lips 37 formed on the seal ring 36. The leading end 11A of the skirt portion 11 is or can be elastically pushed against the bulging portion 38 of the seal ring 36, and the male housing 10 is pushed back by an elastic restoring force of the bulging portion 38, with the result that the lock portion 14 is elastically pressed against a front wall surface 32A of the groove 32. In this way, the housings 10, 20 are prevented from shaking in their connected state. In this embodiment, the radially outward portion of the bottom portion 34A of the engaging space 34 is deepened backward (or away from the male connector housing 10 or in an insertion direction of the male connector housing 10 into the female connector housing 20) to form the stepped portion 35, and the projection 39 formed on the seal ring 36 is fitted in and held by the stepped portion 35. Thus, a force of the slanted surface 11B of the skirt portion 11 to push the bulging portion 38 away radially inwardly is restricted by the presence of the stepped portion 35, thereby avoiding the bulging portion 38 being pushed away radially inwardly. This can prevent shaking of the housings 10, 20 in their connected state and fine sliding abrasion between the terminal fittings 12, 22. The stepped portion 35 is preferably formed over the substantially entire periphery of the bottom portion 34A of the engaging space 34. This securely prevents the bulging portion 38 from being pushed away radially inwardly and the housings 10, 20 from shaking in their connected state. However, two or more stepped portion 35 may be separately provided in a spaced manner, preferably in a substantially equally circumferential space manner. Comparative example Next, a comparative example is described with reference to FIGS. 4 and 5. FIG. 4 shows a watertight connector 2 according to the comparative example. Similar to the first embodiment, this watertight connector 2 is comprised of a male or first housing 40 and a female or second housing 50 at least partly connectable with each other. In the comparative example, the same or similar construction as the first embodiment is not described by identifying it by the same reference numerals. A main difference between the first embodiment and the comparative example lies in the construction of the bulging portion holding means. Specifically, in this embodiment, the bottom portion 34A of the engaging space 34 defined in the receptacle 28 of the female housing 50 is formed into a slanted portion 51 (corresponding to a preferred bulging portion holding means) preferably inclined radially outwardly so that the bottom portion is deeper along a longitudinal or axial direction thereof at its radially outer side than at its radially inner side. On the other hand, the surface of the rear end of the bulging portion 38 in contact with the slanted portion 51 of the engaging space 51 is formed into a slanted surface 52, so that the slanted surface of the seal ring 36 preferably substantially conforms or corresponds to the slanted portion 51 when the seal ring 36 is mounted. When the housings 40, 50 are properly connected with each other as shown in FIG. 5, the leading end 11A of the skirt portion 11 is substantially elastically pressed against the bulging portion 38 of the seal ring 36 and the male housing 40 is pushed back by an elastic restoring force of the bulging portion 38 to elastically push the lock portion 14 against the front wall surface 32A of the lock arm 29. In this way, the housings 40, 50 are prevented from shaking in their connected state. In this comparative example, the bottom portion 34A of the engaging space 34 is formed into the slanted portion inclined radially outwardly and the seal ring 36 is formed with the slanted surface 52 formed on the seal ring 36 to be pressed against the slanted portion 51. Thus, a force of the slanted surface 11B of the skirt portion 11 to push the bulging portion 38 away radially inwardly is restricted by the presence of the slanted portion 51, thereby avoiding the bulging portion 38 being pushed away radially inwardly. This can prevent shaking of the housings 40, 50 in their connected state and fine sliding abrasion between the terminal fittings 12, 22. The present invention is not limited to the above described and illustrated embodiment. For example, the following embodiments are also embraced by the technical scope of the present invention as defined in the claims. Beside the following embodiments, various changes can be made without departing the scope of the present invention as defined in the claims. Although the skirt portion 11 is provided in the male housing 10, 40 and the engaging space 34 is defined in the female housing 20, 50 in the foregoing embodiments, the constructions of the skirt portion and the engaging space are not limited to those of the foregoing embodiments, and may be provided in the opposite housings according to the present invention.

Claims: A watertight connector (1; 2), comprising: a pair of housings (10, 20) at least partly connectable with each other, a skirt portion (11) provided in one (10) of the pair of housings (10, 20), a receptacle (28) provided in the other (20) of the pair of housings (10, 20) for at least partly accommodating the skirt portion (11) of the one housing, an engaging space (34) defined inside the receptacle (28) and adapted to at least partly receive the skirt portion (11), an elastic waterproof member (36) to be mounted in the engaging space (34) and squeezable between the two housings (10, 20) and having at least one bulging portion (38) to be located in the engaging space (34), characterized in that at least one bulging portion holding means (35) is provided as part of the engaging space (34) and comprises at least one stepped portion (35), formed in that a radially outward portion of the bottom portion (34a) of the engaging space is deepened backwardly, provided over the substantially entire periphery of the engaging space (34) for preventing the bulging portion (38) from being elastically deformed radially inwardly; and in that the remaining, radially inward portion of the bottom portion (34A) of the engaging space (34) and the bottom portion of the stepped portion (35) of the bulging portion holding means (35) are substantially normal to the connecting direction. A watertight connector according to claim 1, wherein a plurality of bulging portion holding means (35) are provided circumferentially spaced in a preferably regular manner at the engaging space (34). A watertight connector according to one or more of the preceding claims, wherein a locking mechanism (14; 29) is provided on at least one of the housings (10, 20) for locking the housings (10, 20) with each other. A combination of a connector housing (20) and an elastic waterproof member (36) for a watertight connector (1), the combination comprising: a receptacle (28) for at least partly accommodating a mating portion (11) of a mating connector housing (10), an engaging space (34) defined inside the receptacle (28) and adapted to at least partly receive the mating portion (11), wherein the elastic waterproof member (36) is to be mounted in the engaging space (34) and substantially squeezable between the two housings (10, 20) and has at least one bulging portion (38) to be located in the engaging space (34), characterized in that at least one bulging portion holding means (35; 51) is provided as part of the engaging space (34) and comprises at least one stepped portion (35), formed in that a radially outward portion of the bottom portion (34a) of the engaging space is deepened backwardly, provided over the substantially entire periphery of the engaging space, for preventing the bulging portion (38) from being elastically deformed radially inwardly; and the remaining radially inward portion of the bottom portion (34A) of the engaging space (34) and bottom portion of the stepped portion (35) of the bulging portion holding means (35) are substantially normal to the connecting direction. A waterproof member (36) for a watertight connector (1), which is to be mounted in an engaging space (34) of a connector housing (20) and squeezable between the connector housing (20) and a mating connector housing (10) of the watertight connector (1), comprising: at least one bulging portion (38) formed on a radially outward substantially entire periphery of the waterproof member to be located in the engaging space (34), characterized by a projection (39) projecting backward from the rear end of the bulging portion (38) to be fitted into a stepped portion (35) of at least one bulging portion holding means (35) provided as part of the engaging space (34), formed in that a radially outward portion of the bottom portion (34a) of the engaging space is deepened backwardly, for preventing the bulging portion (38) from being elastically deformed radially inwardly by interaction with the at least one bulging portion holding means (35), wherein the bottom portion of the stepped portion (35) of the bulging portion holding means (35) and the remaining radially inward portion of the bottom portion (34A) of the engaging space (34) are substantially normal to the connecting direction.

Inventors: MAKITA YASUMITSU, MAKITA, YASUMITSU
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 2001
Main classification: H01R13
IPC codes: H01R13