Patent Publication Number: US-4734053-A

Title: Electrical connector

Description:
This application is a continuation of application Ser. No. 879,222, filed May 30, 1986, now abandoned. 
    
    
     This invention relates to an electrical connector to be mounted on a printed circuit board, and more particularly an electrical connector for a resilient flat cable. 
     Recently, there has been increased usage for a resilient flat cable which can be connected to electrical wiring for high density equipment usage so as to make small-sized and light-weight electrical equipment. Along with this increased use, since several electrical connectors need to be mounted in a printed circuit board in a high density fashion, it is required to provide a smaller-sized electrical connector. As an electrical connector for a resilient flat cable to be mounted to a printed circuit board, a known electrical connector comprises an insulating housing having a plurality of contact elements with contact arms contacting with the conductor parts within the opening so as to receive the conductor part of the flat cable and a plug member is hingedly connected to the housing and having a projection capable of being fitted into said opening. 
     In order to connect the flat cable by using this connector, the conductor part of the flat cable is inserted into the opening with the projection being fitted into the opening. Thus, the conductor part is pushed by the projection into contact with the contact arms so as to accomplish the electrical connection. However, in the case where flat cable is to be connected to a connector on a printed circuit board, other components mounted under high density conditions on the printed circuit board may hinder the flat cable, with the result that it sometimes is difficult to move the plug member relative to the housing and, further, it is hard to connect the flat cable or remove it from the connector. 
     In view of the foregoing, it is an object of the present invention to provide an electrical connector for a flat cable in which the flat cable can be connected or removed without being hindered by other components on the printed circuit board. 
     The present invention comprises an electrical connector comprising an insulating housing provided with an opening opened to face upward for use in receiving exposed conductors of a resilient flat cable, a plurality of contact elements having resilient contact arms arranged in said opening and contact legs passing through the bottom part of the insulating housing and projecting downwardly and fixed in a row in the insulating housing, and a plug member having a projection inserted into said opening to cause the exposed conductors of the flat cable received in said opening to be contacted with the resilient contact arms and is characterized in that guide grooves are formed at both sides of one of the insulating housing or plug member, guide projections are located at both sides of the other member, the guide grooves and the guide projections cooperate so as to cause the plug member to be slidable relative to the housing. The guide projections are slidably and forcedly mated with the guide grooves at the cable receiving position where the plug member is moved upwardly and the plug member is held stationary at this position and the exposed conductors of the flat cable can be received in the opening in the insulating housing whereby the projection of the plug member is inserted into the opening as the plug member is moved downwardly causing the exposed conductors to be electrically engaged with the resilient contact arms of the contact elements. 
    
    
     FIGS. 1 and 2 are perspective views showing the electrical connector of the present invention, respectively, wherein FIG. 1 shows a condition in which a plug member is located at a cable receiving position, and FIG. 2 shows a condition in which a plug member is located at the cable connecting position; 
     FIGS. 3 to 5 are perspective views showing a plug member, contact element and insulating housing having contact elements therein for forming an electrical connector of the present invention; 
     FIGS. 6 and 7 are a perspective view and a side elevational view when the electrical connector of the present invention is located at the cable receiving position; 
     FIG. 8 is a cross-sectional view taken along line 8--8 of FIG. 1; and 
     FIG. 9 is a cross-sectional view taken along line 9--9 of FIG. 2. 
    
    
     Referring now to the drawings, one preferred embodiment of the present invention will be described. 
     FIGS. 1 and 2 are perspective views for showing one example of an electrical connector of the present invention. FIG. 1 shows a condition in which the plug member 10 is moved upwardly in respect to the insulating housing 30 and placed at a cable receiving position. FIG. 2 shows a condition in which the plug member 10 is moved downwardly and placed at a cable connecting position. 
     This electrical connector is comprised of the insulating housing 30 having guide projections 31a and 31b at both ends thereof. A plurality of contact elements 50 are arranged in an opening 45 formed in insulating housing 30 while a plug member 10 has guide grooves 11a and 11b so as to be fitted to the guide projections 31a and 31b at both ends thereof. The plug member 10 is slidable upwardly and downwardly with respect to insulating housing 30 under the engagement of the guide projections 31a and 31b and the guide grooves 11a and 11b. Guide projections 31a, 31b can be on plug member 10 and guide grooves 11a, 11b can be on insulating housing 30 if desired. 
     FIG. 3 is a perspective view showing plug member 10, which is preferably made of a suitable insulating plastic material. Guide grooves 11a and 11b are formed at both side walls 12a and 12b, and a downwardly extending projection 14 is formed at the lower surface of the upper wall 13 connecting the upper ends of both side walls 12a and 12b. 
     FIG. 4 is a perspective view showing electrical contact 50 which is stamped from metal having resilient characteristics and it has a pair of resilient contact arms 52 extending upwardly from the ends of a base part 51 and they face slightly inwardly. A contact leg 53 extends downwardly and vertically from one side of base part 51, while the upper ends of resilient contact arms 52 are formed with inwardly projecting contact sections 52a. 
     FIG. 5 is a perspective view showing a plurality of contact elements 50 secured within insulating housing 30. Insulating housing 30 is made of a suitable resilient plastic material and formed as a box-like shape having side walls 32a, 32b, a front wall 33, a rear wall 34 and a bottom wall 35, and further has an opening 45 enclosed by these walls and opened to face upward. A plurality of grooves 36 are located on the inner surfaces of walls 33, 34, 35 for receiving and holding contact elements 50. Contact elements 50 are arranged in grooves 36 in an alternating reverse pattern such that contact legs 53 pass through the bottom wall 35 and project downwardly in a zig-zag form. The outer surfaces of both side walls 32a and 32b are formed with guide projections 31a and 31b and mate with guide grooves 11a and 11b of plug member 10. 
     The assembled unit of plug member 10, insulating housing 30, and a plurality of contact elements 50 corresponds to the connector shown in FIGS. 1 and 2. The rear side of the connector shown in FIG. 1 corresponds to one shown in FIG. 6 and, as apparent from FIGS. 8 and 9, an engagement groove 16 is formed on the inner surface of a central rear wall section 15a of rear wall 15 of the plug member 10 intersected by two slits 15b, 15b, and an engaging projection 37 formed on the outer surface of rear wall 34 of insulating housing 30. 
     The connector is fixed to a printed circuit board so that the contact legs 53 that pass through lower wall 35 of insulating housing 30 and extend downwardly are fitted in holes in the printed circuit board. Under this condition, in order to connect flat cable 1, plug member 10 is first moved upwardly with respect to insulating housing 30 and cable 1 is then located at the cable receiving position shown in FIG. 1. FIG. 7 illustrates a left side elevational view of the connector, wherein the width of guide groove 11a formed in plug member 10 is made such that the width &#34;B&#34; and the lower end is slightly smaller than the width &#34;A&#34; of the other portion, and the width &#34;C&#34; of guide projection 31a to be fitted in guide groove 11a is smaller than width &#34;A&#34; and slightly larger than width &#34;B&#34;. Due to this fact, when plug member 10 is moved upwardly and located at the cable receiving position, guide projection 31a is press fitted in the portion of width &#34;B&#34; at the lower end of guide groove 11a and plug member 10 is kept stationary at that position. The amount of press fitting of plug member 10 is slight and can be moved by a slight external force, that is, the plug is slidably press fitted. 
     FIG. 8 illustrates clearance 3 formed between the upper edge of insulating housing 30 and the lower edge of projection 14 of plug member 10 such that it is possible to insert end part 1a of flat cable 1 into opening 45 of insulating housing 30 through clearance 3. Flat cable 1 is a flexible cable provided with a plurality of parallel conductors 2 (see FIG. 2) therein. End part 1a of flat cable 1 to be inserted into opening 45 has conductors 2 exposed by the desired amount. 
     When the exposed conductor end part 1a of flat cable 1 is received in opening 45, plug member 10 is pressed downwardly. This pressing force causes press fitting between guide groove 11a and guide projection 31a to be released, while plug member 10 is moved downwardly along guide groove 11a and, as shown in FIG. 2, is positioned at the cable connecting position. An engaged condition between the plug member 10 and the insulating housing 30 at this cable connecting position is shown in FIG. 9. 
     When plug member 10 is moved downwardly from the cable receiving position to the cable connecting position, projection 14 of plug member 10 is fitted between pairs of resilient contact arms 52 of contact elements 50 within opening 45 of insulating housing 30. With this arrangement, projection 14 pushes exposed conductors 2 of flat cable 1 against contact parts 52a whereby flat cable 1 is electrically connected to contact elements 50. During the downward movement of projection 14, exposed conductors 2 are wipingly engaged with contact parts 52a so that a complete and optimum electrical connection can be attained. 
     At the cable connecting position, engaging projection 37 on the rear wall 34 of the insulating housing 30 is engaged with engaging groove 16 on central rear wall section 15a of plug member 10 and maintained at this position under a resilient force generated by rear wall section 15a. 
     As described above, according to the present invention, the plug member is slidable with respect to the insulating housing. The end part of the flat cable is inserted between the insulating housing and the plug member at the cable receiving position when the plug member is in an upper position. The plug member is then moved downwardly to the cable connecting position to enable an electrical connection between the exposed conductors of the flat cable and the contact elements within the insulating housing to be made. In order to insert or remove the flat cable, the plug member may merely be moved up and down and the flat cable can easily be connected or removed without being hindered by other components on the printed circuit board on which the present connector is mounted. 
     Additionally, many variations of the present invention may be practiced without departing from the spirit and scope of the present invention. For example, the contact legs of the contact elements may be modified so as to accommodate surface mounting. Additionally, different types of guide projections and guide grooves may be utilized and slightly different contact parts contained on the contact elements may be used. Further, the engagement grooves and engagement projections may be moved or different types of locking arrangements may be utilized.