Electrical connector connected to a cable end and having means for reducing a tension acting to the cable and through the cable

Abstract: For reducing a force acting through a cable (16) to a contact member (23) held in a connector housing (20), an electrical connector comprises a cable hook member (42) for restricting the cable in a condition extending along an outer surface of the connector housing. The cable hook member is mechanically coupled to the insulator housing and comprises a bar portion (43) extended along the outer surface with a predetermined gap left between the bar portion and the outer surface. The cable has a cable end (18) electrically connected with a terminal portion (31) of the contact member and a remaining portion (19) extended along the outer surface. The remaining portion is passed through the predetermined gap and is preferably turned to engage with the bar portion.

Description: This invention relates to an electrical connector for use in electrical connection of a cable with an electric circuit board. Such a conventional electrical connector comprises an insulator housing and a contact member held or supported in the insulator housing. The contact member is for making an electric contact with the electrical connecting object and comprises a terminal portion for electrically and mechanically connecting with a cable end of the cable. In order to tightly connect the cable with the terminal portion, a selected one of various manners, such as soldering, mechanical coupling, and others, is applied between the terminal portion and the cable end of the cable to thereby make a mechanical and electrical connection therebetween. When another end of the cable is pulled by an external force, a tensile force generates on the cable so that the cable end is also pulled by the external force through the cable. In case where the tensile force is strong, the terminal portion and/or the cable end may be broken by the tensile force. Therefore restriction means provided for taking up the tensile force. A connector which addresses this problem via the employment of a restriction means which acts upon the junctioning cable and which is mounted on the connector housing is disclosed in US-A-3 989 336. It is therefore an object of the present invention to provide an electrical connector for use in the electrical connection of a cable to a printed circuit board in which it is possible to reduce an external force transmitted through the cable to a cable end connected to a contact member. Other objects of this invention will become clear as the description proceeds. According to this invention, there is provided an electrical connector for use in electrical connection of a cable with an electrical connecting object with the features of claim 1. Preferred embodiments are given in the subclaims. Fig. 1 is a sectional perspective view of an electrical connector according to a first embodiment of this invention; Fig. 2 is a sectional view of the electrical connector shown in Fig. 1; Figs. 3 to 5 illustrate steps of assembling of the electrical connector shown in Fig. 1; Figs. 6 and 7 illustrate steps of connecting a cable with the electrical connector shown in Fig. 1; Fig. 8 is a perspective view of an electrical connector according to a second embodiment of this invention; Fig. 9 is a perspective view of a connector holder and the electrical connector shown in Fig. 1; and Fig. 10 is a side view of the connector holder, including the electrical connector of Fig. 9. Referring to Figs. 1 and 2, an electrical connector according to a first embodiment of this invention is for electrically connecting two flat cables 16 to an electric circuit board 17. Each of the cables 16 comprises a plurality of conductive wires arranged in parallel to one another and an insulating layer covering the conductive wires in the manner known in the art. Each of the cables 16 has a cable end 18 and a remaining portion 19 extended from the cable end 18. At the cable end 18, the insulating layer is removed or cut away from the conductive wires. In other words, the conductive wires are exposed at the cable end 18. The electric circuit board 17 comprises a central portion 17a and an edge portion 17b which is separated into two sections with a gap but is integral with the central portion 17a. The central portion 17a has an electrical circuit (not shown) thereon in the manner known in the art. The edge portion 17b has a plurality of conductive patterns (not shown) which are electrically connected to the electrical circuit in the manner known in the art. The electrical connector comprises first and second insulator members 21 and 22 and a plurality of conductive contact members 23. A combination of the first and the second insulator members 21 and 22 will be called an insulator housing as depicted at a reference numeral 20. The first insulator member 21 has, in a top surface 21a thereof, two central grooves 24 linearly extending in a first direction and a plurality of side recesses 26 recessed from side walls of each of the central groove 24 in a second direction which is perpendicular to the first direction. The central grooves 24 are for receiving the two sections of the edge portion 17b of the electric circuit board 17 therein, respectively. The side recesses 26 are preassigned to the contact members 23, respectively, as will later be described in detail. The second insulator member 22 is fitted on the first insulator member 21 and has inner surfaces 27 defining a predetermined space under a bottom surface 21b of the first insulator 21. The contact members 23 are arranged in two rows, each row extending in the first direction. Each of the contact members 23 comprises supporting, contact, and terminal portions 28, 29, and 31 and is disposed so that the contact portions 29 are placed in the central groove 24 adjacent and opposite to the side recesses 26, respectively. In this event, the supporting portions 28 are supported or fixedly mounted to the first insulator member 21. The terminal portions 31 are placed in the predetermined space. Since the contact members 23 are arranged in two parallel rows as described above, the terminal portions 31 are also arranged in two rows which are apart from each other in the second direction. In other words, the terminal portions 31 are divided into two terminal portion groups corresponding to the two rows, respectively. When the edge portion 17b of the electric circuit board 17 is inserted into the central grooves 24 of the first insulator member 21, the contact portions 29 of the contact members 23 are forced into the adjacent recesses 26, respectively, by the edge portion 17b. Moreover, the contact portions 29 are elastically forced to come in contact with the conductive patterns of the edge portion 17b, respectively. As a result, the contact members 23 are electrically connected with the electrical circuit of the electric circuit board 17. The electrical connector further comprises a fastening member 33 made of insulator. The fastening member 33 is inserted between the terminal portion groups. More particularly, the fastening member 33 is placed in the predetermined space to leave two predetermined distances 34 in the second direction between the fastening member 33 and the inner surfaces 27, respectively. As a result, the terminal portion groups are disposed in the predetermined distances 34, respectively. Each of the cable ends 18 is placed between the fastening member 33 and each of the terminal portion groups and is tightly fastened therebetween. Each of the contact members 23 further comprises a spring portion 36 which is disposed in the corresponding one of the predetermined distances 34. The spring portion 36 is formed in a U-shape having ends which are integral with the supporting and the terminal portions 28 and 31, respectively. The spring portion 36 serves to elastically force the terminal portion 31 towards the fastening member 33. Therefore, each of the cable ends 18 is tightly fastened between the fastening member 33 and each of the terminal portion groups. Thus, the conductive wires are electrically and mechanically coupled to the terminal portions 31 at the cable ends 18, respectively. In this event, the inner surface 27 of the second insulator member 22 engages with a curved portion 36a of each of the spring portions 36 to back up the spring portions 36. Therefore, the inner surface 27 may be referred to as a back up arrangement. The insulator housing 20 has first and second side surfaces 37 and 38 which are adjacent each other. The first and the second side surfaces 37 and 38 are connected to form a corner 39 and are perpendicular to each other at the corner 39. In order to enable the cables 16 to be lead out from the predetermined distances 34, the first side surface 37 has a lead-out opening 41 connected to the predetermined space. The cables 16 are lead out as the remaining portion 19 from the predetermined distances 34 through the lead-out opening 41, respectively. Each of the remaining portions 19 is extended along the first and the second side surfaces 37 and 38. In this event, it is a matter of course that the remaining portion 19 is turned at the corner 39. The electrical connector further comprises a cable hook member 42 which is rendered integral with the first insulator member 21. The cable hook member 42 comprises a bar portion 43 and two coupling portions 46 which are for coupling both ends of the bar portion 43 to the first insulator member 21, respectively. The bar portion 43 is opposite to a specific outer surface of the second side surface 38 with a predetermined gap left between the second side surface 38 and the bar portion 43. Each of the cables 16 has a thickness which is slightly smaller than a half of the predetermined gap. In addition, the bar portion 43 extends along the second side surface 38 in parallel with the first direction so that the predetermined gap has a width which is slightly more than that of each of the cables 16. The cables 16 are passed through the predetermined gap with a superposed condition and are then turned perpendicular to the second side surface 38 to thereby engage with the bar portion 43. In this event, the cables 16 have a particular portion which is restricted or constrained by the bar portion 43 in a condition extending along the specific outer surface of the second side surface 38. Therefore, the bar portion 43 is referred to as a restriction arrangement. When it is assumed that an external force is applied to pull another end of at least one of the cables 16, the external force is transmitted to the cable end 18 through the cable 16 and a tensile force is generated on the cable 16. However, the external force is reduced during transmission through the cable 16, because the cables 16 are turned and constrained at the bar portion 43. Therefore, it is possible to reduce a tensile force which acts on the cable end 18 due to the external force. Referring to Figs. 3 to 7, description will be made as to steps of assembling of the electrical connector. In Fig. 3, the contact members 23 are held in the first insulator member 21. In this state, each of the contact members 23 comprises a straight portion 51 straightly and downwardly extending from the bottom surface 21b. As shown in Fig. 4, the straight portion 51 is bent inwardly and upwardly to form the terminal and the spring portions 31 and 36. Turning to Fig. 5, the second insulator member 22 is fitted on the first insulator member 21 to make the predetermined space containing the terminal and the spring portions 31 and 36. The second insulator member 22 has a plurality of partitioning walls 52 which are parallel with one another with an additional distance left therebetween for containing the terminal and the spring portions 31 and 36. The partitioning walls 52 serve as an enclosure for protecting the terminal and the spring portions 31 and 36. As shown in Fig. 6, the cable ends 18 of the cables 16 are inserted through the lead-out opening 41 into the predetermined space. As a result, the cable ends 18 are placed between the terminal portion groups in the predetermined space. In this condition, the remaining portions 19 of the cables 16 are separated from each other. Next, the fastening member 33 is inserted between the cable ends 18 as shown in Fig. 7. As a result, the conductive wires of the cable ends 18 are brought in press contact with the terminal portions 31 of the contact members 23, respectively. Then, the remaining portions 19 of the cables 16 are collectively extended along the first and the second side surfaces 37 and 38 and are passed through the above-mentioned predetermined gap, as shown in Figs. 1 and 2. As a result, the remaining portions 19 are formed in a crank shape as shown in Figs. 1 and 2. Referring to Fig. 8, description will be made as regards an electrical connector according to a second embodiment of the present invention. The electrical connector comprises similar parts designated by the same reference numerals as in Figs.1-7. In Fig. 8, the spring portion 36 is simpler than that in Figs. 1 and 2. More particularly, the spring portion 36 is merely formed in an arch shape apart from the cable end 18. Each of the contact members 23 further comprises a guide portion 56 extending from the terminal portion 31 outwardly. The guide portion 56 is for guiding the fastening member 33 to be inserted between the terminal portion groups. Referring to Figs. 9 and 10, description will be made as to the electrical connector 61 and a connector holder 62 which is for mounting the electrical connector 61 on an electrical device, such as an electrical printer. The electrical connector 61 comprises two positioning and two engaging projections 63 and 64. The positioning projections 63 are formed on opposite end surfaces 66 of the first insulator member 21, respectively. Similarly, the engaging projections 64 are formed on the opposite end surfaces 66, respectively. The positioning and the engaging projections 63 and 64 are rendered integral with the first insulator member 21 and are displaced from each other in the second direction. The connector holder 62 is included in the electrical device and comprises a pair of side walls 67, a front wall 68, a rear wall 69, and a bottom wall 71 collectively defining a receiving chamber which is for receiving the electrical connector 61. When being mounted on the electrical device, the electrical connector 61 is inserted into the receiving chamber. For positioning the electrical connector 61 in the second direction, the connector holder 62 comprises two positioning grooves 73 made in the side walls 67, respectively. The positioning grooves 73 are for slidably receiving the positioning projections 63 to thereby restrict the electrical connector 61 from moving in the second direction. The connector holder 62 further comprises two hooking elements 74 placed between the front wall 68 and the side walls 67, respectively. Each of the hooking elements 74 comprises neck and jaw parts 76 and 77. The neck part 76 has a bottom end connected integral with the bottom wall 71 and is elastically deflectable in the second direction. The jaw part 77 is connected integral with another or top end of the neck part 76 and is protruded rearwardly with a slant top surface 78. The jaw part 77 has an original position which slightly projects into the receiving chamber. When the electrical connector 61 is moved into the receiving chamber of the connector holder 62 downwardly, a bottom corner 79 of the electrical connector 61 engages with the slant top surfaces 78 and pushes the jaw parts 77 frontwardly. As a result, the jaw parts 77 are moved frontwardly with the neck parts 77 elastically deflected. Therefore, the electrical connector 61 is smoothly inserted into the receiving chamber of the connector holder 62. When the electrical connector 61 is inserted into the receiving chamber, the positioning grooves 73 receive the respective positioning projections 63 therein. In addition, each of the jaw parts 77 returns to the original position thereof due to elasticity of each of the neck parts 76 and resultantly engages a top end of each of the engaging projections 64. Therefore, the electrical connector 61 is reliably held in the receiving chamber. Each of the cables 16 has another end electrically connected to an electric element, for example, a printer head (not shown) which is mounted to the connector holder 62. In order to remove the electrical connector 61 from the connector holder 62, each of the hook parts 77 is frontwardly moved at first to deflect each of the neck parts 76. As a result, it becomes possible to move the electrical connector 61 upwardly. Therefore, the electrical connector 61 can readily be removed from the connector holder 62.

Claims: An electrical connector for electrical connection of a cable (16) to an electric circuit board (17), the circuit board (17) comprising a central portion (17a) and an edge portion (17b) integral with said central portion (17a), said central portion (17a) having disposed upon it an electrical circuit, said edge portion (17b) having a first surface and a second surface opposite to said first surface, said edge portion (17b) including on both of said first and second surfaces a plurality of conductive patterns electrically connected to said electrical circuit, said electrical connector comprising: an insulator housing (20) with a specific outer surface (37, 38, 39) and a pair of contact members (23) held in said insulator housing (20) and electrically insulated from one another, said cable (16) including a first cable and a second cable, each having a cable end (18) and a remaining portion (19) extended from said cable end (18), said contact members (23) being for making an electric contact with said conductive patterns on said opposite first and said second surfaces of said edge portion (17b), respectively, when the said circuit board (17) is pushed into the said connector, each contact member (23) comprising a terminal portion (31) for electrically and mechanically connecting with a corresponding cable end (18), each remaining portion (19) of said first and second cables (16) having a particular portion outside of said insulator housing (20), restriction means (43) opposite the said specific outer surface (37, 38, 39) of said insulator housing (20) for restricting said particular portions in a condition extending along said specific outer surface (37, 38, 39): means (46) mechanically coupling said restriction means (43) to said insulator housing (20). An electrical connector as claimed in Claim 1, wherein said restriction means (43) is opposite to said specific outer surface with a single predetermined gap left between said restriction means (43) and said specific outer surface, said gap being for permitting said cable to extend therethrough to thereby make said particular portion in said condition extending along said specific outer surface. An electrical connector as claimed in Claim 1, which further comprises fastening means (33) made of insulator and coupled to said insulator housing (20) between said first and second terminal portions (31) for tightly fastening said cable ends (18) in cooperation with said terminal portions (31). An electrical connector as claimed in Claim 3, wherein said fastening means (33) is removable from said insulator housing (20). An electrical connector as claimed in Claim 3, wherein each contact member (23) further comprises a spring portion (36) coupled to said terminal portion (31) for elastically forcing said terminal portion (31) onto said respective cable end (18). An electrical connector as claimed in Claim 5, wherein said insulator housing (20) comprises back up means operatively coupled to each spring portion (36) for backing up said spring portion (36) to reliably force said terminal portion (31) onto said cable end (18). An electrical connector as claimed in Claim 5, wherein said insulator housing (20) comprises a first and a second insulator member (21, 22) removably coupled to each other, said contact members (23) being supported in said first insulator member (21), said second insulator member (22) having said back up means. An electrical connector as claimed in Claim 7, wherein said mechanically coupling means (46) is mounted on said first insulator means (21). An electrical connector as claimed in Claim 7, wherein said second insulator member (22) has an inner surface defining a predetermined space, said fastening means (33) being placed in said predetermined space with a predetermined distance (34) left between said inner surface and said fastening means (33), said terminal portions (31) being disposed within said predetermined distance (34). An electrical connector as claimed in Claim 9, said cable ends (18) being placed between said fastening means (33) and said terminal portions (31), wherein said spring portions (36) elastically force said terminal portions (31) towards said fastening means (33) to make said cable ends (18) be tightly held between a corresponding terminal portion (31) and said fastening means (33). An electrical connector as claimed in Claim 9, wherein said second insulator member (22) has a particular surface portion (27) in said inner surface adjacent to said spring portion (36) for functioning as said back up means. An electrical connector as claimed in Claim 1, wherein said insulator housing (20) has a first and a second side surface (37, 38) adjacent each other and a lead-out opening (41) in said first side surface (37) for leading out said cable therethrough, said second side surface (38) comprising said specific outer surface. An electrical connector as claimed in Claim 11, wherein said first and said second side surfaces (37, 38) are connected to form a corner (39) and perpendicular to each other at said corner (39). A combination of an electrical connector as claimed in Claim 1 and a connector holder removably supporting said electrical connector for use in mounting said electrical connector on another electrical device, said electrical connector further comprising a pair of positioning projections (63) projecting from opposite end surfaces of said insulator housing (20), and another pair of engaging projections (64) projecting from said opposite end surfaces of said insulator housing (20), said connector housing comprising a front wall (68), a rear wall (69), and opposite side walls (67) to thereby define a chamber for receiving said electrical connector, said side walls (67) being provided with grooves (73) in inner surfaces thereof for slidably receiving said positioning projections (63), respectively, when said electrical connector is disposed in said chamber, said connector holder further comprising a pair of hooking means (74) for engaging said engaging projections (64), respectively, to thereby hold said electrical connector in said chamber.

Inventors: MATSUYAMA YUKIO, TAKAHASHI HIROJI, TATEBE YU C O JAPAN AVIATION, YASUI HIROSHI C O JAPAN AVIATI, MATSUYAMA, YUKIO, TAKAHASHI, HIROJI, TATEBE, YU C/O JAPAN AVIATION, YASUI, HIROSHI C/O JAPAN AVIATION
Applicants: JAPAN AVIATION ELECTRON, NIPPON ELECTRIC CO, JAPAN AVIATION ELECTRONICS INDUSTRY, LIMITED, NEC CORPORATION
Application year: 1988
Main classification: H01R9
IPC codes: H01R12, H01R13