Waterproof electrical connector

Abstract: A waterproof electrical connector includes a housing (20) inserted into a cavity (50) defined in a counterpart of the connector and having a stepped portion (23) in its rear portion such that an enlarged portion (22) is provided by the stepped portion (23), an annular sealing member (40) fitted with the housing (20) through a front portion thereof relative to the direction in which the housing (20) is inserted into the cavity (50) of the counterpart, to abut the stepped portion (23) for sealing a gap between the housing (20) and an inner peripheral wall surface of the cavity (50), and an engagement member (30) engaging an outer periphery of the housing (20) at a position where it abuts one end of the sealing member (40), in a condition that the sealing member (40) is fitted with the housing (20) to abut the stepped portion (23), thereby providing another enlarged portion.

Description: This invention relates to a waterproof electrical connector according to the pre-characterizing part of claim 1. Such an electrical connector is known from US-A-4,944,688 and serves to electrically interconnect electrical circuits or equipment in a severe environmental condition such as in an engine room of an automobile vehicle. The generic US-A-4,944,688 utilizes a sealed connector including a secondary lock located on a mating surface of a housing for locking contacts or terminals in the housing. FIG. 9 illustrates another example of a conventional waterproof connector. A housing 1 of the connector comprises a sleeve 4 having a terminal aperture 3 into which a female terminal member 2 is inserted, and a hood 5 surrounding the sleeve 4. A connector seal 6 is closely attached to an outer periphery of the sleeve 4 between the sleeve 4 and the hood 5. An upper interior of the sleeve 4 serves as the terminal aperture 3. An elastic engagement piece 7 is formed on the bottom of the terminal aperture 3 and an engagement protrusion 8 is formed on a distal end of the engagement piece 7 to protrude into the terminal aperture 3. A counterpart connector 9 to be fitted with the above-described connector is formed into a cylindrical shape so that the sleeve 4 of the connector is inserted into it and so that it is inserted into the hood 5. The connector seal 5 is compressed to be inserted between an inner peripheral face of the connector 9 and an outer peripheral face of the sleeve 4. When the terminal member 2 is thrust into the terminal aperture 3 through its rear opening, a distal end of the terminal member 2 is engaged with the engagement protrusion 8 such that the engagement piece 7 is yielded downwards. When the terminal member 2 is inserted into the terminal aperture 3 to assume a predetermined position, the yielded engagement piece 7 returns to its former state and the engagement protrusion 8 enters an aperture formed in the underside of the terminal member 2 such that the terminal member 2 is held in position. When the waterproof connector is connected to the counterpart connector 9, the waterproof connector is thrust into the connector 9, so that the sleeve 4 invades the cylindrical interior of the connector 9. Then, the connector seal 5 attached to the innermost of the sleeve 4 is thrust between the outer peripheral face of the sleeve 4 and the inner peripheral face of the counterpart connector 9, thereby closely adhering both of them to prevent invasion of water. In the above-described conventional connector, the attachment of the connector seal 5 is troublesome since the connector seal 5 is attached to the innermost of the sleeve 4 surrounded by the hood 5. Furthermore, it is difficult to confirm whether the connector seal 5 assumes its normal position or not. Furthermore, the elastic engagement piece 7 is formed on the cylindrical peripheral wall of the terminal aperture 3, so that the terminal member 2 is held in its normal position. Consequently, the forming of the waterproof connector is difficult and it is restricted in its forming. US-A-5,002,504 discloses an electrical connector latch construction having a secondary latch or engagement member for securing contacts relative to a connector housing. The latch has a latch finger protruding through engagement apertures in the housing for engagement with the contacts, when the latch is fitted onto the housing. In case of US-A-5,002,504 D2 the engagement apertures there only partially penetrate the respective peripheral wall of the connector housing, i.e. they are rectancular through-holes. In case there are somehow misalignments between the terminals with respect to the housing and the position of the engagement member with respect to the housing, respectively, then problems might arise with respect to a proper engagement between the contacts and the latch finger. In other words, in case of US-A-5,002,504 there must be a precise alignment between the apertures of the housing, the engagement portion at the engagement member and a respective recess or shoulder in the terminals in order to achieve the desired holding of the respective terminal. Therefore, an object of the present invention is to provide a waterproof electrical connector which can be formed readily and wherein the connector seal can be attached readily and reliably. Solution of this object is achieved by what is claimed in claim 1. Accordingly, the present invention provides a waterproof electrical connector comprising: a housing inserted into a cavity defined in a counterpart of the connector; and a generally annular sealing member fitted with the housing at a front portion thereof facing into a direction in which the housing is inserted into the cavity of the counterpart, thereby sealing a gap between the housing and an inner peripheral wall surface of the counterpart's cavity, wherein said housing has a stepped portion in a rear portion thereof facing into the direction in which the housing is inserted into the cavity of the counterpart such that an enlarged portion is provided by the stepped portion, and an engagement member is provided for engaging an outer periphery of the housing, said engagement member abutting at the one end of the sealing member facing into the direction in which the housing is inserted into the cavity of the counterpart, said sealing member being fitted with the housing to abut the stepped portion, thereby providing another enlarged portion, said sealing member being held between said engagement member and said stepped portion. This known waterproof electrical connector (US-A-4,944,688) is furthermore characterized in that said housing includes a pair of terminal apertures into which a pair of terminals is inserted, respectively, said terminal apertures being formed to extend through front and rear ends of the housing in a direction in which the housing is inserted into the cavity of the counterpart, each terminal aperture having an engagement aperture communicating with the outer peripheral surface of the housing, each of said engagement apertures being formed by cutting out its portion continuously from the end of said housing facing into the direction in which the housing is inserted into the cavity of the counterpart towards said stepped portion such that each cutout portion communicates its respective terminal aperture with the upper peripheral surface of said housing; and said engagement member has engagement convex portions invading the terminal apertures through the engagement apertures to thereby engage the terminals, respectively. The engagement apertures run from a portion of the housing adjacent the stepped portion into a direction in which the housing is inserted into the cavity of the counterpart, whereas the engagement apertures communicate the respective terminal apertures with the upper peripheral surface of the housing throughout the entire length thereof. This leads to the result that in case there are somehow misalignments between the terminals with respect to the housing and the position of the engagement member with respect to the housing, respectively, then the latch fingers together with the engagement member can freely run along the engagement apertures in order to engage the terminals in a proper way and to clamp the sealing member between the stepped portion and the engagement member. According to the above-described construction, the sealing member can be reliably attached at its normal position when it is fitted with the outer periphery of the housing and the engagement member is engaged with the housing. Furthermore, the terminals can be engaged at the predetermined positions in the terminal apertures respectively. The invention will be described, merely by way of example, with reference to the accompanying drawings, in which: FIG. 1 is an exploded perspective view of the waterproof electrical connector of an embodiment in accordance with the present invention; FIG. 2 is a transversely sectional view of the connector; FIG. 3 is a sectional view taken along line 3-3 in FIG. 1: FIG. 4 is a sectional view taken along line 4-4 in FIG. 1; FIG. 5 is a rear view of the housing cap employed in the connector; FIG. 6 is a transversely sectional view of the connector with the terminal members inserted into the respective terminal apertures; FIG. 7 is a transversely sectional view of the connector inserted in a cavity of the counterpart; FIG. 8 is an exploded view of a modified form of the connector; and FIG. 9 is a sectional view of a conventional waterproof electrical connector. Embodiments of the present invention will be described with reference to FIGS. 1 to 8. Referring to FIG. 1, the waterproof electrical connector of the embodiment comprises a pair of female terminal members 10, a housing 20 for enclosing the female terminal members 10, a housing cap 30 attached to a front end of the housing 20 to cover it, and a waterproofing connector seal 40 attached to the outer periPherY of the housing 20. Each female terminal member 10 has at its front end a rectangular cylindrical fitting portion 11 formed by bending the front end and an engagement aperture 12 formed in its upper peripheral face. Each female terminal member 10 further has at its rear end a crimping portion 13 where one end of an electrical wire W, with which a rubber plug 14 is fitted, is crimped such that the wire W is connected to the terminal member 10. The housing 20 is formed into a rectangular solid having a rectangular section. The housing 20 is divided into a front slender body portion 21 and a rear enlarged lock portion 22. A stepped portion 23 is formed between the body portion 21 and the lock portion 23. An elastic locking piece 24 is formed on one side of the lock portion 22. Referring now to FIGS. 1 and 2, the housing 20 has two terminal apertures 25 extending lengthwisely therethrough and disposed in parallel with a dividing wall 26 provided therebetween. Each terminal aperture 25 has a square aperture portion 25a in which the front fitting portion 11 of the terminal member 10 is enclosed. Each terminal aperture 25 further has a circular aperture portion 25b in which the rear pressing portion 13 of the terminal member 10 is enclosed. The rubber plug 14 is closely attached to the circular aperture portion 25b. Each of the square and circular aperture portions 25a, 25b is open at the front and rear ends of the housing 20. Each square aperture portion 25a has an engagement aperture 27 formed by cutting out its Portion from the end of the housing 20 to its upper Peripheral face continuously. Two mount apertures 28 and two lock apertures 29 both communicating with the respective terminal apertures 25 are formed in the right-hand and lefthand sides of the housing 20. The housing cap 30 is formed into the shape of a cap and is fitted with the body portion 21 of the housing 20 from its front end. The housing cap 30 comprises a lid portion 31 abutting the distal end of the body portion 21 and a cylindrical portion 32 facing the periphery of the body portion 21. An upper half portion near the open end of the cylindrical portion 32 serves as a retainer portion 34 which is opened and closed by hinge portions 33. Two engagement convex portions 35 are formed on the inner face of the retainer portion 34 so as to assume respective positions where they face the respective engagement apertures 27. The engagement convex portions 35 invade the terminal apertures 25 to engage the engagement apertures 12 of the terminal members 10 respectively. Two attachment pieces 36 are also formed on the inner face of the retainer portion 34 so as to assume respective positions where they face the respective lock apertures 29 of the body portion 21. The attachment pieces 36 invade the respective lock apertures 29 to be engaged therewith. Two engagement protrusions 37 are formed on the inner peripheral face of the cylindrical portion 32 so as to assume respective positions where they face the respective mount apertures 28 of the body portion 21. The engagement protrusions 37 invade the respective mount apertures 28 to be engaged therewith. The lid portion 31 has two windows 38 through which male terminals (not shown) are inserted into the terminal apertures 25 respectively. The connector seal 40 is formed into an annular shape and has an inner diameter determined so that it is closely attached to the outer periphery of the body portion 21. A middle portion of the connector seal 40 has a thickness larger than its front and rear open ends. The length of the connector seal 40 is determined so as to be approximately equal to the length from the end of the cylindrical portion 32 of the housing 30 to the stepped portion 23 when the housing cap 30 is attached to the body portion 21 of the housing 20. A counterpart member to which the above-described connector is connected has a cavity 50 into which the housing 20, to which the housing cap 30 and the connector seal 40 are attached, is inserted. An inner peripheral wall of the cavity 50 continuously extends in the direction of its depth from its opening 52. A pair of male terminal members 53 projects from a rear wall of the cavity 50 toward its opening. The operation of the waterproof electrical connector will be described. In assembling the above-described connector, the body portion 21 of the housing 20 is fitted into the annular connector seal 40 from its front end and then, thrust until the rear end face of the connector seal 40 abuts the stepped portion 23. The body portion 21 is then inserted into the cylindrical portion 32 of the housing cap 30. When the body Portion 21 is inserted such that its distal end abuts the inner face of the lid Portion 31 of the housing cap 30, the engagement protrusions 37 formed on the inner peripheral surface of the cylindrical portion 32 invade the mount apertures 28 formed in the body portion 21 to be engaged therein, respectively, thereby holding the housing cap 30 in position. The end face of the housing cap 30 abuts the front end face of the connector seal 40 when the housing cap 30 is held in position, so that the connector seal 40 is held between the stepped portion 22 and the end face of the cylindrical portion 32 around the body portion 21. In this while, the retainer 34 is held in a raised state by means of the hinge portion 33, as shown in FIG. 6. The distal ends of the wire W, to which the rubber plug 14 is attached, are crimped on the crimping portions 13 of the terminal members 10, respectively. Then, the terminal members 10 are inserted into the terminal apertures 25 from the side of the fitting portions 11 with engagement apertures 12 directed upwards, respectively. When the terminal members 10 are inserted deep into the respective terminal apertures 25, the hinge portion 33 is bent so that the retainer portion 34 is thrust toward the body portion 21. Then, the engagement convex portions 35 of the retainer 34 invade the engagement apertures 12 of the terminal members 10 through the engagement apertures 27 to be engaged with the terminal members 10, respectively. The attachment pieces 36 formed on the inner peripheral face of the retainer 34 invade the respective lock apertures 29 of the body portion 21 when the retainer portion 34 is fully bent. so that the retainer 34 is incorporated with the cylindrical portion 32 so as to be held closed. The waterproof connector assembled as described above is inserted through the opening 52 into the cavity 50 of the counterpart member from the side of its housing cap 30. The connector seal 40 held around the body portion 21 is held between the outer face of the body portion 21 and the inner face of the inner wall 51, thereby sealing a gap therebetween. Male terminal members 53 of the counterpart member invade the terminal apertures 25 through the windows 38 of the housing cap 30 and are further fitted into the fitting portions 11 of the female terminal members 10. respectively, thereby being connected to the same, as shown in FIG. 7. According to the above-described connector, the work for attaching the annular connector seal to the housing body portion 21 can be simplified since the body portion 21 is exposed outwards. Subsequently, the housing cap 30 is engaged with the body portion 21 such that the connector seal 40 is held between the stepped portion 22 and the end face of the cylindrical portion 32. Consequently, the fallout of the connector seal during transfer of the connector and failure in mounting of the connector seal can be prevented. Furthermore, should the failure in the mounting of the connector seal occur, the failure can be visually found easily since the connector seal is attached around the housing 20 and accordingly, the connector seal is reattached with ease. FIG. 8 illustrates a modified form of the waterproof connector. In the foregoing embodiment, a part of the cylindrical portion 32 of the housing cap 30 is opened and closed. The engagement protrusions 35 advance into and retreat out of the terminal apertures respectively in association with the part of the cylindrical portion 32 opened and closed. In the modified form, notches are formed to extend from the open end of the cylindrical portion 132 of the housing cap 130 toward the lid portion 131, whereby two elastic lance pieces 134 are provided to be opposite the engagement apertures 127 of the housing 120 respectively. The engagement protrusions 135 are formed on the inner faces of the lance pieces 134 respectively. Each engagement protrusion 135 is perpendicular at the side of the depth and inclined at the side of the open end. According to the above-described construction, the housing 120 is inserted from the distal end of the body portion 121 into the cylindrical portion 132 of the housing cap 130 after connector seal 140 has been attached around the body portion 121 of the housing 120. In this case, the engagement protrusions 135 of the lance pieces 134 are inserted along the respective engagement apertures 127 each extending to the distal end of the body portion 121. The terminal members 110 are inserted into the respective terminal apertures 125 when the engagement protrusions 135 has been inserted such that the engagement protrusions 137 has been engaged in the mount apertures 128 of the body portion 121, respectively. The distal ends of the terminal members 110 abut the engagement protrusions 137 in the terminal apertures 125 as the terminal members 110 are inserted into the terminal apertures 125, respectively. However, since the terminal members 110 abut the inclined faces of the engagement protrusions 137, respectively, the terminal members 110 are inserted into the respective terminal apertures 125 such that the lance pieces 134 are elastically deformed to be extruded from the respective terminal apertures 125. The engagement protrusions 137 are opposite to the respective engagement apertures 112 when the terminal members 110 has been inserted to assume the normal positions. The lance pieces 134 act to return to the former shape such that the engagement protrusions 137 engages the respective engagement apertures 112. Each terminal member 110 can be prevented from falling out since the perpendicular face of each engagement protrusion 137 abuts the edge portion of the engagement aperture 112. The foregoing disclosure and drawings are merely illustrative of the principles of the present invention and are not to be interpreted in a limiting sense. The only limitation is to be determined from the scope of the appended claims.

Claims: A waterproof electrical connector comprising: a housing (20) inserted into a cavity (50) defined in a counterpart of the connector; and a generally annular sealing member (40) fitted with the housing (20) at a front portion thereof facing into a direction in which the housing (20) is inserted into the cavity (50) of the counterpart, thereby sealing a gap between the housing (20) and an inner peripheral wall surface of the counterpart's cavity (50), wherein said housing (20) has a stepped portion (23) in a rear portion thereof facing into the direction in which the housing (20) is inserted into the cavity (50) of the counterpart such that an enlarged portion (22) is provided by the stepped portion (23), and an engagement member (30) is provided for engaging an outer periphery of the housing (20), said engagement member (30) abutting at the one end of the sealing member (40) facing into the direction in which the housing (20) is inserted into the cavity (50) of the counterpart, said sealing member (40) being fitted with the housing (20) to abut the stepped portion (23), thereby providing another enlarged portion, said sealing member (40) being held between said engagement member (30) and said stepped portion (23), characterized in that said housing (20) includes a pair of terminal apertures (25) into which a pair of terminals (10) is inserted, respectively, said terminal apertures (25) being formed to extend through front and rear ends of the housing (20) in a direction in which the housing (20) is inserted into the cavity (50) of the counterpart, each terminal aperture (25) having an engagement aperture (27) communicating with the outer peripheral surface of the housing (20), each of said engagement apertures (27) being formed by cutting out its portion continuously from the end of said housing (20) facing into the direction in which the housing (20) is inserted into the cavity (50) of the counterpart towards said stepped portion (23) such that each cutout portion communicates its respective terminal aperture (25) with the upper peripheral surface of said housing (20); and said engagement member (30) has engagement convex portions (35) invading the terminal apertures (25) through the engagement apertures (27) to thereby engage the terminals (10), respectively. The connector according to claim 1, characterized in that the engagement member (30) is formed into the shape of a cap covering the front end of the housing (20) facing into the direction into which the housing (20) is inserted into the cavity (50) of the counterpart. The connector according to claim 1 or 2, characterized in that the engagement convex portions (35) of the cap-shaped engagement member (30) are formed to advance into and retreat out of the engagement apertures (27), respectively. The connector according to anyone of the preceeding claims, characterized in that the cap-shaped engagement member (30) has cylindrical portions (32) opposite the peripheral face of the housing (20), each cylindrical portion (32) having a part (34) opened and closed by means of a hinge (33), and the engagement convex portions (35) are formed on the inner peripheral face of the engagement member (30). The connector according to anyone of the preceeding claims, characterized in that each engagement aperture (27) extends to the front end of the housing (20) facing into the direction in which the housing (20) is inserted into the cavity (50) of the counterpart. The connector according to anyone of the preceeding claims, characterized in that each engagement aperture (27) extends to the front end of the housing (20) facing into the direction in which the housing (20) is inserted into the cavity (50) of the counterpart, and that each engagement convex portion (35) is formed on the inner periphery of a cylindrical portion (32) of the cap-shaped engagement member (30) opposed to the periphery of the housing (20) so that each engagement convex portion (35) faces the engagement aperture (27). The connector according to claim 1, characterized in that the cap-shaped engagement member (130) has cylindrical portions (132) opposite the peripheral face of the housing (120), each cylindrical portion (132) having a notch forming an elastic piece (134) and the engagement convex portions (135) are formed on inner peripheral surfaces of the elastic pieces (134) so as to be opposed to the engagement apertures (127), respectively. The connector according to claim 7, characterized in that each engagement aperture (127) extends to the front end of the housing (120) facing into the direction in which the housing (120) is inserted into the cavity of the counterpart. The connector according to claim 1, characterized in that the engagement member (230) is formed into the shape of a ring inserted into the housing from the front end of housing (220) facing into the direction in which the housing (220) is inserted into the cavity of the counterpart.

Inventors: TANAKA TSUTOMU, TANAKA, TSUTOMU
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1993
Main classification: H01R13
IPC codes: H01R13