Electrical noise-reducing assembly and member

Abstract: An electrical noise-reducing member (30) comprises concentric inner (32) and outer (31) cylindrical portions. The outer cylindrical portion is of electrical noise-reducing magnetic material, and the inner cylindrical portion is of elastically deformable material and has a longitudinal through-hole (35). In use, an electrically conductive element (20C), such as a connector terminal, is inserted into the through-hole to elastically secure the element to the noise-reducing member.

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an electrical connector including an electrical noise-reducing member. Description of the Related Art In a known electrical connector, to reduce high-frequency noise signals, such as "spikes", transmitted in a conductive element (e.g. a terminal fitting or an electrical wire), the conductive element is inserted into a cylinder of ferromagnetic material which absorbs the noise signal. A connector having such a construction is disclosed in EP-A-969568. As shown in present Fig. 4, this known connector 1 has a housing 2 made of synthetic resin and a cylindrical body of magnetic material 3 integrated with the housing 2 at the rear portion thereof by insert molding. A plurality of L-shaped terminal fittings 4 are mounted on the housing 2, with the rear portion of each terminal fitting 4 inserted into a through-hole 3A of the magnetic material 3 and extending from the rear of the housing 2. The body of magnetic material 3 acts as the noise-reducing member. However, because the housing 2 and the magnetic material 3 are formed by insert molding, a complicated molding die is needed for the housing 2 and the magnetic material 3. Thus, the manufacturing cost of the connector 1 is high. Alternatively, the body of magnetic material may be installed on the housing after molding, an elastically deformable lance for locking the body to the housing being formed integrally with the housing by one-piece molding. However, a complicated molding die for the connector and the lance is also needed and thus the manufacturing cost of the connector is high. SUMMARY OF THE INVENTION It is an object of the present invention to provide a noise-reducing member which can be relatively easily installed on a conductive element. The present invention provides an electrical connector as set out in claim 1. Preferably the elastically deformable member is of rubber. The noise-reducing member is elastically secured to the conductor by inserting the conductor element into the through-hole of the elastically deformable member. Thus, noise-reducing material can be installed on the conductor by a simple operation, and a complicated construction can be avoided. Preferably the body of magnetic material and the electrically deformable member are cylindrical, e.g. circularly cylindrical. Here the word "cylindrical" is used in its proper broad sense, including not only circularly cylindrical bodies but also other cylindrical shapes, e.g. a square cylinder. The electrical noise-reducing member may be carried on a single electrical conductor or a plurality of electrical conductors, as described below. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will now be described by way of non-limitative example with reference to the accompanying drawings, in which:- Fig. 1 is a perspective view of a connector which is an embodiment of the present invention. Fig. 2 is a perspective view of the noise-reducing member in the connector of Fig. 1. Fig. 3 is a perspective view of another method of installing the noise-reducing member on a conductive wire. Fig. 4 is a sectional view showing a known connector described above. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in Fig. 1, the connector of the embodiment of the invention has a housing 11 made of molded synthetic resin. A hood part 12 in which a mating connector (not shown) is to be fitted in use is formed on the front side of the housing 11. A flat part 13 is formed on the rear side of the housing 11. A pair of box-shaped mounting portions 14 are located at the lower end of the rear side of the flat part 13. A screw hole 14A is formed in each mounting portion 14. The housing 11 can be secured to a substrate (not shown), e.g. a vehicle body by inserting screws into the screw holes 14A, to fix the mounting portions 14 to the substrate. The housing 11 has five terminal press-fit holes 16 formed thereon. Each terminal press-fit hole 16 extends from the bottom surface of the hood part 12 to the rear surface of the flat part 13, with the terminal press-fit hole 16 penetrating through the flat part 13. Terminal fittings 20A - 20E are pressed into the terminal press-fit holes 16 respectively to penetrate therethrough. Each of the terminal fittings 20A - 20E is formed of conductive metal sheet. The conductive metal sheet is bent in the shape of an "L" at a bend 21 to divide it into a horizontal part 22 and a vertical part 23. The terminal fittings 20A - 20E have the same construction except that the horizontal part 22 of each of the terminal fittings 20D and 20E is longer than that of each of the terminal fittings 20A - 20C. A tab (not shown) is formed at the front end of the horizontal part 22. The tab projects into the hood part 12 and is connectable with a female terminal fitting (not shown) accommodated inside the mating connector which is fitted in the hood part 12. A projection (not shown) is formed widthwise at a base portion of the tab and pressed into the terminal press-fit hole 16 of the housing 11. A part of the horizontal part 22 projects from the flat part 13. The vertical part 23 extends downward from the bend 21. The lower end portion of the vertical part 23 is formed as a connection part 25 which has a smaller width than the vertical part 23 and which is connectable for example with a circuit mounted on a substrate (not shown). An electrical noise-reducing member 30 is installed selectively on any one of the terminal fittings 20A - 20E, according to need. In the embodiment, the noise-reducing member 30 is installed on the terminal fitting 20C. As shown in Fig. 2, the noise-reducing member 30 is cylindrical, in this case circularly cylindrical, and has a double construction. That is, the noise-reducing member 30 has a body of noise-reducing magnetic material 31 provided at the outer side thereof (to form an outer cylindrical portion), and an installing material 32 provided at the inner side thereof (to form an inner cylindrical portion). The installing material 32 is used to install the noise-reducing member 30 on any one of the terminal fittings 20A - 20E. The cylindrical magnetic material body 31 is made of a ferromagnetic material such as ferrite and has a through-hole 33. Suitable magnetic materials for this purpose are known to the expert. The installing material 32 is formed cylindrically by molding an elastic material such as a rubber and has an installing through-hole 35 at its centre. The installing material 32 is fitted in the through-hole 33 by press-fitting. The inner diameter of the installing through-hole 35 is slightly smaller than the width of the vertical part 23 of each of the terminal fittings 20A - 20E. Thus, by inserting the vertical part 23 of any one of the terminal fittings 20A - 20E into the through-hole 35 by press fitting, the installing material 32 is vertically slidable on the vertical part 23 and can be elastically locked to any one of the terminal fittings 20A -20E. To assemble the connector 10 of the embodiment, after the housing 11 is formed by molding a suitable material, the terminal fittings 20A - 20E are inserted into the terminal press-fit holes 16 respectively by press fitting before bending them at the bend 21. The terminal fittings 20A - 20E projecting rearward from the housing 11 are bent downward at the bending position 21 with a jig. In this manner, a semi-finished molded product having the housing 11 and the terminal fittings 20A - 20E mounted thereon is obtained. Then, the electrical noise-reducing member 30 is installed on any one (20C in the embodiment) of the terminal fittings 20A - 20E of the semi-finished molded product. First, the connection part 25 of the terminal fitting 20C is inserted into the through-hole 35 of the installing material 32. Then, the noise-reducing member 30 is slid upward on the vertical part 23, and then stopped at an appropriate position. The installing material 32 elastically grips the vertical part 23. Consequently, the noise-reducing member 30 is fixed in its desired position on the terminal fitting 20C. This completes the assembly of the connector 10. If electric current flowing through the terminal fitting 20C includes a high-frequency noise during the use of the connector 10, the magnetic material 31 absorbs the noise, achieving noise reduction. In this embodiment, by inserting the terminal fitting 20C into the installing material 32 of the noise-reducing member 30, the installing material 32 can be elastically locked to the terminal fitting 20C. That is, the magnetic material 31 can be installed on the terminal fitting 20C in a simple manner. In comparison with the known device of Fig. 4, this eliminates the need for forming the magnetic material integrally with the housing by insert molding or forming an elastically deformable lance integrally with the housing to lock the magnetic material to the housing. Therefore, the molding die for the housing 11 can be simplified, which allows the manufacturing cost of the connector to be reduced. Further, the installing material 32 is made of elastic material such as rubber and is elastically locked to any one of the terminal fittings 20A - 20E inserted into the installing hole 35 by press fitting. Therefore, it is a straightforward process to install the noise-reducing member 30 on any one of the terminal fittings 20A - 20E. Further, the noise-reducing member 30 is removably installed on any one of the terminal fittings 20A - 20E. Thus, for example, the noise-reducing member 30 may be installed initially on any one of the terminal fittings 20A - 20E of the housing 11. However, the noise-reducing member 30 can then be transferred to any other of the terminal fittings 20A - 20E at a later stage of fabrication e.g. according to a specific noise-reducing requirement for the electrical circuit. The initial installation and later fabrication may occur at different sites, and transporting the noise-reducing member 30 carried on a terminal fitting is more convenient than transporting the noise-reducing member separately from the housing between the sites. A typical application of the invention is in a DC electrical circuit, such as in an automobile, e.g. in a radio power circuit. The scope of the present invention is not limited to the above-described embodiment, and the following embodiments for example are included in the scope of the present invention. (1) In the above-described embodiment, the present invention is applicable to the connector 10 which, in use, is installed on a substrate, but the noise-reducing member of the present invention is also applicable to other kinds of connectors. (2) In the above-described embodiment, the terminal fittings 20A - 20E are installed on the housing 11 by press-fitting a part of each thereof into the housing 11, but they may be installed on the housing 11 by other methods. For example, they may be incorporated integrally with the housing 11 by insert molding. (3) In the above-described embodiment, one noise-reducing member 30 is installed on one terminal fitting 20C. But within the present invention, a plurality of the noise-reducing members 30 may be installed on one connector. Further, a plurality of terminal fittings or other conductors may be secured to one electrical noise-reducing member by inserting the conductors thereinto; in this case, the body of magnetic material may have a plurality of through-holes each containing an elastically deformable member gripping the respective electrical conductor in the through-hole, or the body may have one through-hole having an elastically deformable member itself having plural through-holes gripping the respective electrical conductors.

Claims: An electrical connector having a moulded housing (11); a plurality of elongate conducting terminal members (20A-20E) extending from said housing; and a noise-reducing assembly installed on one of said terminal members, the noise-reducing assembly comprising an electrical noise-reducing member (30) comprising a body (31) of magnetic material having at least one through-hole, through which the terminal member (20C) extends, characterised in that : the noise reducing assembly also has an elastically deformable member (32) fixed in said through-hole; the noise reducing assembly is adapted to fit a single selected terminal member; the elastically deformable member is adapted to be elastically locked to the selected terminal member prior to mounting of the body of magnetic material; and the body of magnetic material is fixed in a desired position with respect to the electrical conductor solely by virtue of the grip between the elastically deformable member and the electrical conductor. An electrical connector according to claim 1, wherein said body (31) of magnetic material and said elastically deformable member (32) are both circularly cylindrical. An electrical connector according to claim 1 or claim 2, wherein said elastically deformable member (32) is made of rubber.

Inventors: ASAO KAZUHIRO, ASAO, KAZUHIRO
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 2001
Main classification: H01R13
IPC codes: H01R13, H05K9, H01F17