Waterproof connector

Abstract: The invention provides a waterproof connector in which surplus space is removed, and the connector is reduced in size. A housing of a waterproof connector 1 comprises an inner housing 3 and an outer housing 2. A sealing ring 14 is fitted completely into an attachment groove 13 formed in an outer wall face 4A of a terminal housing member 4 of the inner housing 3. As a result, the sealing ring 14 can be provided without increasing the outer circumference of a fitting space 10, and the waterproof connector 1 can be miniaturized. Furthermore, the fitting space 10 has no surplus space corresponding to the thickness of the sealing ring 14. The two housings 2 and 3 are joined together after the sealing ring 14 has been fitted to the inner housing. 3. Consequently, the sealing ring 14 can be attached easily.

Description: TECHNICAL FIELD The present invention relates to a waterproof electrical connector. BACKGROUND TO THE INVENTION A conventional connector 101 is shown in Figures 7 and 8 of this specification. This conventional connector is a waterproof connector employing a configuration whereby a space between a terminal housing member 103 and a skirt member 111 of a corresponding connector 110 is sealed by a sealing ring 102. This sealing ring 102 is annular and is housed within a fitting space 104. When the connector 101 is to be fitted to the corresponding connector 110, the skirt member 111 is inserted into the fitting space 104, and the sealing ring 102 is gripped between inner walls of the skirt member 111 and outer walls of the terminal housing member 103, thereby waterproofing the interior of the connector. In the above configuration, the outer circumference of the fitting space 104 must be increased to the extent of the thickness of the sealing ring 102, thereby requiring the connector 101 to be larger in size. Furthermore, a space 105 is formed within the fitting space 104. This corresponds to the space between an anterior end 102A of the sealing ring 102 and a fitting face 112 of the corresponding connector 110, and has the thickness of the sealing ring 102. This space 105 is surplus space which serves no function for the connector. If removed, the size of the connector could be reduced. The present invention has taken the above problem into consideration, and aims to present a waterproof connector wherein the surplus space is removed, and the connector can thereby have a smaller size. EP-A-0967688 which is considered to represent the closest prior art discloses a connector having an intermediate component between an inner housing for terminals, and an outer housing. An annular seal is provided to seal the three components against moisture ingress. The intermediate component increases the size of the connector. SUMMARY OF THE INVENTION According to the invention there is provided a waterproof connector according to the features of claim 1. Such a connector has no dead space, and can easily be miniaturized. The connector is in two part form, the accommodating member and hood being moulded separately and assembled after positioning of the waterproofing member. Such an arrangement permits convenient assembly of the components. The waterproofing member fits precisely in the associated recess without clearance, and radial faces thereof provide sealing against relatively movable parts of an assembled connector. Furthermore this arrangement provides for easy insertion and retention of the waterproofing member, and with suitable attention to tolerances, may exert an end load on the waterproofing member with a consequent bulging in the radial direction, thus improving the waterproofing ability thereof. BRIEF DESCRIPTION OF DRAWINGS Other features of the invention will be apparent from the following description of several preferred embodiments shown by way of example only in the accompanying drawings in which:- Figure 1 is a disassembled side cross-sectional view of a waterproof connector according to the embodiment of the invention. Figure 2 is a side cross-sectional view showing the waterproof connector of the embodiment in a joined state. Figure 3 is a disassembled side cross-sectional view of a corresponding connector Figure 4 is a side cross-sectional view of the corresponding connector in a joined state. Figure 5 is a side cross-sectional view of the waterproof connector and the corresponding connector prior to being fitted together. Figure 6 is a side cross-sectional view of the waterproof connector and the corresponding connector in a fitted state. Figure 7 is a side cross-sectional view of a prior art waterproof connector. Figure 8 is a side cross-sectional view of the prior art waterproof connector and a corresponding connector in a fitted state. DESCRIPTION OF THE EMBODIMENT The embodiment of the present invention is described below with the aid of Figures 1 to 6. In the description below, mutually fitting sides of a waterproof connector 1 and a corresponding connector 30 are considered to be anterior sides (see Figure 5). The waterproof connector 1 is female, and comprises an inner housing 3 fitted into an outer housing 2. A terminal housing member 4, which is capable of being housed within a skirt member 34 of the corresponding connector 30, is provided in the inner housing 3. A female terminal fitting 20 is housed within a cavity 5 formed within the terminal housing member 4 (see Figures 1 and 2). The outer housing 2 of the waterproof connector 1 has an approximately tubular shape in which both ends in the anterior-posterior direction are open. An anterior end portion of the outer housing 2 forms a hood 6 capable of housing the corresponding connector 30. A posterior end portion of the outer housing 2 forms a housing hole 7 capable of housing a posterior end portion of the inner housing 3. A posterior end portion of the housing hole 7 forms a wide diameter member 7A which is wider in diameter than the narrowest portion of the housing hole 7. A pair of concave retaining recesses 8 are formed in upper and lower faces of the housing hole 7. These engage with retaining protrusions 18 of the inner housing 3 after the two housings 2 and 3 have been fitted together. The inner housing 3 has a cross-sectionally tubular shape and has dimensions whereby it fits precisely within the housing hole 7. The inner housing 3 is fitted from the posterior into the outer housing 2, the anterior end portion of the inner housing 3 protruding into the hood 6. A flange member 9, which is provided at a posterior end of the inner housing 3, extends across the entire opening of the wide diameter member 7A. A pair of retaining protrusions 18 are provided on upper and lower faces of the flange member 9, these engaging with the retaining recesses 8 of the outer housing 2. The cavity 5, for receiving the female terminal fitting 20, is formed within the terminal housing member 4 of the inner housing 3. An upper and lower pair of lance retaining grooves 11, for retaining lances 25 formed on the female terminal fitting 20, are formed in the vicinity of anterior ends of the cavities 5. A retainer through hole 12 passes through left and right side faces of the inner housing 3 at a location to the posterior of the lance retaining grooves 11. This retainer through hole 12 is formed in upper and lower faces of the cavity 5. A concave attachment groove 13 is formed around the entire circumference of an outer wall face 4A of the terminal housing member 4 at a location slightly towards the posterior relative to the centre thereof (in the anterior-posterior direction). The sealing ring 14, which is annular and is made from a resilient material such as rubber, is fitted into this attachment groove 13. An outer circumference face 14B of the sealing ring 14 forms an approximately unified face with the outer wall face 4A of the terminal housing member 4. Furthermore, a plurality of lips 15 are formed on an inner circumference face 14A of the sealing ring 14 and on the outer circumference face 14B thereof, as illustrated. An anterior portion of the female terminal fitting 20, which is attached to the inner housing 3, forms an angular pillar-like connector member 21 into which a tab 42 of a corresponding male terminal fitting 40 can be fitted. A posterior portion of the female terminal fitting 20 forms a barrel member 23 that is joined to the female terminal fitting 20 via a joining member 22 and crimps an end of an electric wire W. In addition to the end of the electric wire W, a waterproof rubber stopper 24 is also crimped by the barrel member 23. This waterproof rubber stopper 24 waterproofs the cavity 5 by fitting tightly with inner walls thereof. Moreover, the pair of lances 25 are formed on upper and lower faces of the connecting member 21. These lances 25 have a cantilevered shape whose base end is at the anterior, and are capable of moving slightly in an up-down direction. The female terminal fitting 20 is maintained in a first retained state by means of posterior ends of the lances 25 catching with posterior walls of the lance retaining grooves 11 of the cavity 5. Then a C-shaped side retainer 16 is pushed in from the side through the retainer through hole 12, an inner side of the C-shape of the side retainer 16 gripping the connecting member 21 of the female terminal fitting 20, and an anterior face of the side retainer 16 making contact with a posterior end of the connecting member 21. This doubly retains the female terminal fitting 20. Next, the corresponding connector 30 will be described. The corresponding connector 30 is a male connector wherein an inner housing 32 is fitted into an outer housing 31, and a male terminal fitting 40 is housed within a cavity 33 formed in the inner housing 32 (see Figures 3 and 4). The outer housing 31 has an approximately tubular shape. The skirt member 34, which can fit into the waterproof connector 1, is formed at an anterior end thereof. The inner housing 32 is housed within this skirt member 34. Furthermore, an electric wire through hole 39, through which an electric wire of the male terminal fitting 40 can be inserted, is formed in a posterior end portion of the outer housing 31. The inner housing 32 has a cross-sectional block shape and has dimensions whereby it fits precisely into the skirt member 34. The cavity 33, which houses a main body 41 of the male terminal fitting 40 (to be described), is provided within the inner housing 32. When the inner housing 32 has been fitted into the skirt member 34, the cavity 33 connects with the electric wire through hole 39. As in the case of the cavity 5 of the waterproof connector 1, upper and lower faces of the cavity 33 are provided with lance retaining grooves 35 and a retainer through hole 36. The male terminal fitting 40 is provided with the tab 42 which protrudes from an anterior end of the box-shaped main body 41, and which makes contact with the female terminal fitting 20 of the waterproof connector 1. As in the case of the female terminal fitting 20, a barrel member 44 is provided at a posterior end of the male terminal fitting 40, being joined thereto via a joining member 43. This barrel member 44 crimps the electric wire W and an end of a waterproof rubber stopper 45. When the male terminal fitting 40 is attached within the cavity 33, lances 46 formed on the main body 41 catch within the lance retaining grooves 35 of the cavity 33, thereby performing a first retaining of the male terminal fitting 40; then a side retainer 38 doubly retains this male terminal fitting 40. Next, the operation and effects of the waterproof connector 1, configured as described above, will be described. When the waterproof connector 1 is to be assembled, the sealing ring 14 is fitted into the attachment groove 13 formed in the inner housing 3. Next, the female terminal fitting 20 is inserted from the posterior into the cavity 5 until it reaches its correct position; it is retained in this position by the lances 25 and the side retainer 16. Then the inner housing 3 is inserted into the outer housing 2 from its posterior side, an anterior end 9A of the flange member 9 striking against a retaining wall 7B, and the retaining protrusions 18 engaging with the retaining holes 8. This maintains the inner housing 3 in a latched state. When the two housings 2 and 3 are in a joined state, a fitting space 10 is formed in the space between the anterior portion of the inner housing 3 and the hood 6. The skirt member 34 of the corresponding connector 30 can be fitted into this fitting space 10. In this manner, the housing of the waterproof connector 1 is separated into the inner housing 3 and the outer housing 2, the sealing ring 14 first being fitted into the attachment groove 13 formed in the inner housing 3, then these two housings 2 and 3 being joined together. Consequently, the sealing ring 14 can be fitted easily compared to the case where the housing is not formed as separate components. When the waterproof connector 1 is fitted to the corresponding connector 30, the skirt member 34 of the corresponding connector 30 is inserted into the fitting space 10 of the waterproof connector 1. As shown in Figure 6, after the two connectors 1 and 30 have been correctly fitted together, the male and female terminal fittings 20 and 40 make contact, and a locking member 37 provided on the skirt member 34 of the corresponding connector 30 engages with a groove member formed in the hood 6 of the waterproof connector 1, this maintaining the two connectors 1 and 30 in an unremovable state. Furthermore, the lips 15 on the inner circumference face 14A and the outer circumference face 14B of the sealing ring 14 are pushed resiliently against the attachment groove 13 and an inner wall face of the skirt member 34, thereby maintaining the waterproof state. The attachment groove 13 is concave in the outer wall face 4A of the terminal housing member 4, and the sealing ring 14 is attached in a manner whereby it is fitted totally within the attachment groove 13, the outer circumference face 14B of the sealing ring 14 forming an approximately unified face with the outer wall face 4A of the terminal housing member 4. As a result, the fitting space 10 is exactly large enough to house the skirt member 34 of the corresponding connector 30, and there is no need to provide any space to accommodate the thickness of the sealing ring 14. Consequently, the sealing ring 14 is attached without increasing the outer diameter of the fitting space 10, thereby allowing the waterproof connector 1 to be miniaturized. Furthermore, there is no surplus space within the fitting space 10 corresponding to the thickness of the sealing ring 14. Furthermore, the present invention is not limited to the embodiment described above with the aid of figures. For example, the possibilities described below also lie within the technical range of the present invention. In addition, the present invention may be embodied in various other ways without deviating from the scope thereof. (1) The waterproof connector of the embodiment described above employs side-type retainers 16. However, the present invention is equally suitable for a waterproof connector employing a retainer attached from the posterior of the housing, this being inserted into the cavity and directly retaining the terminal fitting. (2) The sealing ring 14 is described as separate component in the embodiment described above. However, this sealing ring could be co-moulded in respective recesses.

Claims: A waterproof connector (1) comprising a terminal accommodating member (3) adapted to house a terminal fitting, a hood (2) surrounding said accommodating member (3), an annular fitting space (10) formed between said hood (2) and accommodating member (3), a corresponding connector (30) having a tubular mouth (34) being insertable along a fitting axis into said fitting space (10), and an annular waterproofing member (14) being provided at said fitting space (10), one of the inner and outer circumferential faces of said waterproofing member (14) forming a sealing face with the corresponding connector (30) characterized in that said terminal accommodating member (3) is a unitary one piece component and is insertable into said hood (2), and that an outer wall face of said accommodating member (3) is provided with an annular groove (13) extending around the entire circumference thereof, said groove having opposed radially extending walls to house said waterproofing member (14), and to restrain said waterproofing member against axial movement. A connector according to claim 1 wherein said accommodating member (3) is latchable within said hood (2). A connector according to any preceding claim wherein said hood is tubular. A connector according to any preceding claim wherein said hood (2) includes a latching recess (17) and said corresponding connector (30) includes a projection (37) latchable in said latching recess (17) to retain said connector (1) and corresponding connector (30) in an engaged condition. A connector according to any preceding claim wherein said waterproofing member (14) is accommodated in said recess (13) without clearance. A connector according to any preceding claim wherein said waterproofing member includes circumferentially extending lips (15) to improve sealing thereof.

Inventors: NAKAMURA HIDETO, NAKAMURA, HIDETO, Nakamura, Hideto, c/o Sumitomo Wiring Syst. Ltd
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 2001
Main classification: H01R13
IPC codes: H01R13