Connector apparatus for high density coaxial cables

Abstract: An apparatus for connecting a high density cable assembly (23) having a shield (23a) to corre­ sponding contact pins (10) provided on a substrate (1) having a grounding grid formed of conductive guides (11), each guide (11) having a predetermined number of contact pins (10) therein, includes a connector (20) to which the cable assembly (23) is connected and which is to be attached to the associated guide (11). The connector (20) has a connector body (21), a connector cover (22) surrounding the connector body (21), and a latching device (30) provided between the connector cover (22) and the connector body (21) for easily latching and unlatching the connector(20) to and from the associated guides (11).

Description: The present invention relates to a connector for a high density cable, more particularly, it relates to a mechanism for connecting a coaxial cable to a printed circuit board through an associated latch, the connectors being located on the printed circuit board in a matrix arrangement and at a high density. Due to a current requirement for an increased density of connectors mounted on a printed circuit board (referred to as PC board hereinafter), a matrix mounting system, in which a desired number of contact pins is grouped into a block and a plurality of connectors are located in a matrix arrangement corresponding to the desired number of contact pins, is used. In this matrix mounting system, however, because the number of connectors is increased the latch means must be improved to prevent interference between connectors located very close to each other, in order to increase the mounting density thereof, in a very small mounting space. In previously-proposed connector latch means, the connectors are individually secured to the PC board by set screws, or connectors in the same row of a matrix are latched together. The coaxial cables to be connected to the respective connectors are provided with grounding shields, and the shield connection is made by mating special grounding contacts and the contact pins by plugging them together. The previously-proposed latching method mentioned above has drawbacks in that it is very difficult to mount and dismount the connectors and that the latching means is large and complex. EP-A-0 202 916 discloses a connector apparatus according to the preamble of accompanying claim 1. A female connector has a single latching arm which co-operates with an abutment on a male connector (mounting means to a printed circuit board). According to the present invention there is provided an apparatus for connecting a high-density cable assembly to corresponding contact pins provided on a substrate, comprising a connector to which the cable assembly is connected, and substrate mounting means via which the connector is mounted on the substrate, said connector having a connector body and a connector cover surrounding the connector body, and a latching lever for engaging an abutment on the substrate mounting means so as to latch the connector; characterised in that:- said substrate mounting means is in the form of a plurality of guides extending perpendicularly from the substrate, each guide defining a connecting portion including a predetermined number of contact pins and a pair of oppositely-disposed side walls having abutments; and in that the latching lever is in the form of a gate with two opposing legs, said opposing legs having hooks which are engageable with said abutments of the guide side walls, said latching lever being pivotally mounted to the connector so as to pivot in a plane parallel to the guide side walls whereby said hooks can engage and disengage said abutments. Thus, an embodiment of the present invention can provide simple latching means for each connector, by which an effective utilization can be made of a very small mounting space. Note, the plug-in shield connection of the cable allows an increased number of contact pins and an increased number of patterns of the PC board to be used. Preferably, the shield of the cables is directly connected to a frame of a housing of the associated apparatus, to ground the same. In this case, preferably the connectors themselves are grounded to prevent generation of static electricity when an operator accidentally touches the connectors during the mounting and dismounting thereof. An embodiment of the present invention can provide connectors for high-density coaxial cables by which the shield connection of the cables is optimized, comprising one-touch-type latch means for each connector. With the above arrangement, a plurality of connectors each having the latching means can be easily and quickly latched and unlatched to and from the associated guides. The shields of the cables are grounded through the guides. Reference is made, by way of example, to the accompanying drawings, in which:- Fig. 1 is a partially sectioned side elevational view of a connector apparatus embodying the present invention; Fig. 2 is a plan view of a mother board having guides in a matrix arrangement shown in Fig. 1; Fig. 3 is a partially broken perspective view of a connector apparatus shown in Fig. 1; Figs. 4A and 4B are a front elevational view and a partially sectioned side elevational view of a connector cover shown in Fig. 1; Fig. 5 is a perspective view of a latching lever used in the connector apparatus of Fig. 1; Fig. 6 is a view showing consecutive steps of connecting the connector of Fig. 1 to a substrate; Fig. 7 is a partially sectional side elevational view of contact assemblies which can be employed in the present invention; Figs. 8 and 9 are front and side elevational views of a contact assembly shown in Fig. 7, respectively; Fig. 10 is a perspective view of a jig which can be used to mount and dismount a connector to and from a substrate; Fig. 11 is a perspective view of the jig shown in Fig. 10, in which the jig is disconnected from a connector; Fig. 12 is a side elevational view showing how to operate clamping levers of the jig; and Fig. 13 is a side elevational view of Fig. 12 showing how to operate an unlocking lever of the jig. Referring to Figs. 1, 2 and 3, a printed circuit board (PC board) 2 has LSI's 100 mounted thereon on one surface (lower surface in the illustrated embodiment) of a motherboard (substrate) 1 by connectors 8, and on the surface of the motherboard 1 opposite to the PC board 2 (which can be a substrate in the absence of the mother board) a grounded frame 3 is provided in parallel with the plane of the motherboard. The mother board 1 is attached to a housing frame 6 by mounting frames 4 and L-shaped mountings 5. The grounded frame 3 is connected to the frame 6 by a connecting means 7, to form an electrical shielding circuit. A number of contact pins 10 corresponding to the LSI's 100 are provided on the side of the motherboard 1 close to the grounded frame 3. The contact pins 10 are divided into groups of a predetermined number of the contact pins 10, in a grid-like arrangement, by guides 11. The guides 11 are made by metal die casting and are taller than the contact pins 10. The guides 11 are held by the mounting frame 4 in such a manner that a clearance exists between the guides 11 and the mother board 1; and so that the guides 11 per se are grounded. Connecting portions 12, defined by the guides 11 to form a matrix, are connected by a plurality of connectors 20 which extend through corresponding openings 13 of the grounded frame 3. As the connectors 20 are identical, the following description is directed to only one of the connectors 20, with reference to Figs. 3 and 4A and 4B. The connector 20 has a generally rectangular box-like connector body 21 containing contacts to be connected to associated contact pins 10 in a plug-in manner. The connector body 21 can be loosely inserted in the associated guide 11 before the final connection with the contact pins 10. The connector body 21 is provided with a rectangular box-like metal cover 22, which preferably consists of two parts 22A and 22B secured to each other by set screws 73, surrounding the periphery of an upper part of the connector 20. Namely, the lower part of the connector body 21 is not covered by the cover 22, as can be seen from Fig. 4A. The height of the uncovered area of the connector body 21 depends on the height of the guides 11. The front cover part 22A is provided at the upper end thereof with a cable mounting portion 22a integral therewith, so that a shield 23a of an associated coaxial cable assembly 23 having a plurality of coaxial cables is held by a clamp 24 secured to the cable mounting portion 22a by screws 25 and connected to the cover 22. The cover 22 is provided at the upper end thereof with an opening 22c located below the cable mounting portion 22a and having a stepped stop 22b. A latching means 30, described hereinafter, is provided in the opening 22c. The latching means 30 includes a generally inverted U-shaped (gate-like) latch lever 31 made of metal, as shown in Fig. 4. The latch lever 31 has right and left legs 31a having tapered hooks 31b, which are bent outward, at the lower ends thereof. The legs 31a are also provided with pin holes 31c at an intermediate portion thereof. The upper ends of the legs 31a are interconnected to form an abutment surface 31d having a bent grip 31e. The latch lever 31 is also provided with a bridging portion 31g connecting the leg portions 31a and having spring arms 31f. The latch lever 31 is located in the cover 22 in such a way that the grip 31e is protruded outside thereof through the opening 22c, the abutment surface 31d bears against the stop 22b, the legs 31a extend downward in side recesses 21a formed on opposite right and left side faces of the connector body 21, and the hooks 31b are located outside the cover 22. The latch lever 31 is rotatably supported on the cover 22 by associated pins (shafts or projections) 22d provided on the inner side faces of the cover 22 and rotatably fitting in the associated pin holes 31c, to enable the legs 31a to rotate about the respective pins 22d. The free ends of the spring arms 31f bear against an inner projection 22e provided on the cover 22 (rear cover part 22B) to elastically bias the latch lever 31 in a counterclockwise direction (in Fig. 4B), whereby the legs 31 are held in a vertically extended position by the stop 22b. Furthermore, each guide 11 is provided with abutments 33 defining recesses 32 and having tapered upper edges 33a on the right and left side walls 11a of the guide 11. Note that, in the illustrated embodiment, since one abutment 33 is common to the two adjacent hooks 31b of the two adjacent latch levers 30, the amount p (Fig. 4A) of outward projection of the hooks 31b is substantially equal to or less than half the width w (Fig. 3) of the abutment 33. Figure 6 shows the consecutive steps (a) to (d) for connecting the connector 20 to the guide 11 by the associated latch means 30. In Fig. 6, before the connection, the latch lever 31 of the latching means 30 bears against the stop 22b, so that the leg 31a and the hooks 31b are vertically extended. From this position, when the connector 20 is inserted into the associated guide 11 the plug-in connection begins, and the hooks 31b of the latch lever 31 come into contact with the tapered edges of the associated right and left abutments 33 of the guide 11, as shown in Fig. 6 (b). A further insertion of the connector 20 causes the hooks 31b of the latch lever 31 to slide down on the tapered edges of the abutments 33, thus resulting in an elastic deformation of the latch lever 31, as shown in Fig. 6 (c). Namely, the latch lever 31 rotates about the pins 22d in a clockwise direction in Fig. 4B. Note that the rotation, i.e. the elastic deformation of the legs 31a of the latch lever 31, occurs in a plane substantially parallel with the opposite side faces of the connector body 21. The hooks 31b lie in a plane parallel with the plane of the legs 31a, as can be seen from Fig. 4A, and accordingly, the displacement (deformation) of the hooks 31b also occurs in a plane substantially parallel with the side faces of the connector body 21. When the plug-in connection is completed, i.e. when the hooks 31b pass the associated abutments 33, the latch lever 31 is elastically returned to the initial position thereof shown in Fig. 6 (a), due to the elastic bias applied thereto, as shown in Fig. 6 (d), so that the hooks 31b are snap-engaged by the associated abutments 33 to lock the latch lever 31 in position, and accordingly the connector 20, in the guide 11. In the locked or latched position shown in Fig. 6 (d), the lower end of the cover 22 comes into contact with the upper peripheral surface of the guide 11. Note, when the connector 20 is in the latched position, the shield 23a of the cable assembly 23 is connected to the grounded frame 3 through the cover 22, the latch lever 31, and the guide 11, and therefore, the shield 23a of the cable, the cover 22, etc., of the connector 20, and the guide 11 are directly grounded and electrically shielded. Figure 6 (e) shows the latched (or locked) position shown in Fig. 6 (d), as viewed from the left side of Fig. 6 (d). When the connector 20 is to be disconnected from the associated guide 11, the latch lever 31 is rotated in the counterclockwise direction in Fig. 4B by manual pressure exerted on the grip 31e by the operator's finger, to disengage the hooks 31b from the associated abutments 33. The connector 20 can be then easily pulled up, to separate the connector body 21 from the contact pins 10. Note that, when pressure is applied to the grip 31e, the grip 31e is brought into contact with an end surface (stop surface) 22f of the cable mounting portion 22a of the cover 22 to hold the latch lever 31 at an elastically deformed position and thus enable the disconnection of the connector 20 from the contact pins 10. As can be understood from the above description,according to an embodiment of the present invention, since each connector is provided with a latching means able to be operated by a one-touch operation, the connectors can be easily and firmly connected to the P.C. board. Further, since the latching means 30 which ensure this connection in cooperation with the associated guides 11 provided on the mother board 1 are accommodated between the connector bodies 21 and the connector covers 22, the connector mechanism can be made compact and small. Also, since the elastic latching means are in the form of a gate having right and left legs 31a by which the opposite sides of the associated connectors are latched, a strong latching effect is obtained. Note, the latching means also contributes to a prevention of connection failures among a plurality of the connectors and the contact pins, since the latching levers 31 are engaged in the corresponding recesses 21a formed on opposite sides of the connector body 21. Further, since the shields of the cables are effectively grounded by the connector covers, etc., the number of contact pins and patterns for the PC board can be reduced, as there is no need to provide specific contact pins for grounding. Also static electricity is not generated, since the connector cover, the latch lever and the guides form a shield circuit which is integrally grounded. Figures 7 to 9 show the internal construction of the connector body 21. In the connectors for the coaxial cable assembly 23 according to the prior art, each of the coaxial cables (123A, 123B, etc.) in the cable assembly 23 has at least one signal line and a grounded shield. Accordingly, when the number of the coaxial cables in one cable assembly is increased, the number of corresponding contacts of the connector body to be connected to the signal lines and the grounded shield must be increased. Furthermore, in the prior art, the coaxial cables in the cable assembly are separate from each other, and accordingly, the assembly thereof is cumbersome. With a view to solving these problems, according to another aspect of the present invention, two coaxial cables are paired and have a common ground, to reduce the number of the contacts in the connector body, and thus make it possible to reduce the space (pitch) between the contacts. Namely, in any one pair of coaxial cables, one contact for grounding is provided commonly to the two coaxial cables of the pair. Preferably, the contacts for the signal lines are located on opposite sides to the grounding contact. As shown in Figs. 7, 8 and 9, the bottom part of the connector body 21, the upper part of which is covered by the cover 22 as mentioned before, is provided with a plurality of pin insertion holes 103, arranged in three rows in the illustrated embodiment, and a contact assembly 110 is located above each pin insertion hole 103. The contact assembly 110 will be described below in detail with reference to Figs. 8 and 9. Each contact assembly 110 is provided with a center elongated connecting piece 111 for grounding (referred to hereinafter as a ground connecting piece) and right and left short connecting pieces 112 and 113 for signal lines (referred to hereinafter as signal connecting pieces). The signal connecting pieces 112 and 113 are located on opposite sides of and in parallel with the center ground connecting piece 111, with a space therebetween. The pieces 111, 112, and 113 are provided at intermediate portions thereof with recessed portions 111b, 112b and 113b, and are made integral with each other at the recessed portions 111b, 112b and 113b by a holder 114, preferably made of plastic. The lower ends of the pieces 111, 112, and 113 are provided with forked or bifurcated contacts 111a, 112a, and 113a lying in a plane, i.e. in a row, and two coaxial cables (e.g., 123A and 123B) are located above and substantially in line with the signal connecting pieces 112 and 113. The signal lines 115A and 115B of the cables 123A and 123B are fixed to upper ends 112c and 113c of the connecting pieces 112 and 113 by heat-shrinkable tubings 117. The upper end of the ground connecting piece 111 extends upward beyond the upper ends 112c and 113c of the signal connecting pieces 111 and 112 and is bifurcated to form terminal ends 111c and 111d which are soldered directly to the shields 115b and 116b of the cables 123A and 123B. The holder 114 is provided with clamp pin holes 129 located between the recessed portions 111b and 112b and between the recessed portions 112b and 113b thereof. Note, the holder 114 is also provided with a projection 118 on one side face thereof, to enable the operator to differentiate the front and rear sides of the holder 114. The connector body 21 is provided with contact holes 104 directly above the pin inserting holes 103, stepped portions 105 for accommodating the projections 118 of the holders 114 pin holes 106, and a chamber 107 for receiving the contact assembly 110. When the contact assembly 110 is inserted in the receiving chamber 107, the projections 118 of the holders 114 are engaged in the stepped portions 105, and the contacts 111a, 112a, and 113a are inserted in the associated contact holes 104. The other contact assemblies 110 are similarly inserted in the connector body 21 in a side by side arrangement, so that the holders 114 are brought into contact with each other at the longitudinal opposite sides thereof. Thus, when all of the contact assemblies 110 have been inserted in the connector body 21, clamp pins 119 are inserted in the pin holes 117 through the pin holes 106 to prevent an accidental removal of the contact assemblies 110 from the connector body 21. In this arrangement, when the connector body 21 is fitted onto contact pins provided on the mother board 1, the contact pins of the mother board 1 are inserted in the associated pin insertion holes 103 and the associated contacts 111a, 112a, and 113a and connected thereto in a plug-in manner. In the arrangement shown in Figs. 7 to 9, two coaxial cables 123A and 123B are paired and provided with a common ground, and accordingly, theoretically the number of ground contacts can be cut by half, and thus a small and compact connector mechanism having a reduced pitch of the contacts can be obtained. Note, the arrangement of the signal lines on opposite sides of the ground line contributes to a reduction of noise, and since the cables are soldered to the corresponding signal connecting pieces substantially in a straight line, damage to the cables can be reduced. Figures 10 to 13 show a special jig 150 for mounting and dismounting the connector to and from the contact pins on the mother board 1 (or the PC board). This jig is particularly useful when the connectors are mounted in a high density matrix arrangement. The jig 150 is provided with a shank 151 to serve as a grip for the operator, and a connector unlocking lever 153 rotatably supported by the lower end of the shank 151 at a point close to the connector 20, through a pivot pin 155 extending perpendicular to the length of the shank 151. The connector unlocking lever 153 rotates in the clockwise direction A₁ in Fig. 13. After the jig 150 is attached to the associated connector 20, as described hereinafter, the upper end thereof is manually pushed close to the shank 151 and the connector unlocking lever 153 is rotated in the clockwise direction A₁ in Fig. 13, so that the lower end 153a of the lever 153 is pressed against the grip 31e (Figs. 4A, 4B, and 5) of the latching lever 31 to exert pressure on the grip 31e to unlock the hooks 31b of the latching lever 31 from the associated abutments 33 of the guide 11. Note, the hooks 31b can be manually disengaged or unlocked from the associated abutments 33 without using the jig 150, i.e., the grip 31e can be directly moved by the operator's finger to unlock the hooks 31b from the associated abutments 33. The lever 153 is continuously biased in an open position by a spring 154 provided around the pivot pin 155, in which the lower end 153a of the lever 153 is held apart from the associated lower ends 157a of the clamping levers 157, as can be seen in Fig. 13. The jig 150 is also provided with a pair of clamping levers 157 rotatably supported at the lower end of the shank 150 by respective pivot pins 159 extending perpendicular to the pivot pin 155 and to the length of the shank 151. The clamping levers 157 are continuously biased to a closed position by springs 161 provided between the shank 151 and the levers 157, in which the lower ends of the levers 157 adjacent to the connector 20 are brought close to each other. The clamping levers 157 are opened in the directions A₂ (Fig. 12) at the lower end thereof, against the force of the springs 161, by pressing the upper ends of the clamping levers 157 toward each other in the directions A₃ in Fig. 12. The lower ends 157a of the clamping levers 157 are provided with claws 165 which can be engaged in corresponding clamping recesses or openings 167 (Fig. 3) formed in opposite sides of the cable mounting portion 22a of the cable cover 22, when the clamping levers 157 are in the closed position. When the clamping levers 157 are brought to the open position in which the lower ends 157a of the levers 157 are separated from each other, the claws 165 of the clamping levers 157 are engaged in the associated clamping openings 167. When the external force applied to the upper ends of the clamping levers 157 in the direction A₃ is released, the clamping levers 157 are automatically returned to the closed position, so that the claws 165 are engaged in the corresponding opposed clamping openings 167 from the opposite sides of the connector 20, and as a result, the connector 20 is firmly held by the jig 150, as shown in Fig. 10. Since the jig 150 substantially has no part projecting outward from the width of the connector, the jig can be easily and firmly connected to the associated connector without interfering with an adjacent connector. When the connector 20 is to be disconnected from the mother board 1, the jig 150 is first attached to the connector 20 by engaging the claws 165 in the corresponding clamping openings 167 of the connector, and then the unlocking lever 153 is pressed toward the shank 151 of the jig 150 at the upper end of the lever 153 to disengage the hooks 31b from the associated abutments 33 of the guide 11 of the mother board 1, as mentioned before, and as a result, the connector 20 is unlocked from the mother board (guide 11). Then, the jig 150 is pulled up with a force sufficient to overcome the contact pressure between the contacts (111a, 112a, etc., in Fig. 8) of the connector 20 and the contact pins 10 (Fig. 3) on the mother board 1, to separate the connector 20 from the mother board 1. When the connector 20 is completely disconnected from the mother board, the clamping levers 157 are opened to disengage the claws 165 from the corresponding openings 167 of the connector, and the jig 150 is removed from the connector 20. As shown above, when the connector 20 is mounted to the mother board 1 with the help of the jig 150, the jig is first attached to the connector and then the connector is inserted onto the mother board 1. When the connector is inserted, however, it is not necessary for the operator to operate the unlocking lever 153, since the hooks 31b can be automatically displaced to be engaged in the associated abutments 33 by the tapered upper faces 33a of the abutments 33. Namely, the hooks 31b slide over the tapered upper faces 33a of the abutments 33, while elastically deforming, when the connector is forced into the associated guide 11 of the mother board 1, as mentioned before.

Claims: An apparatus for connecting a high-density cable assembly (23) to corresponding contact pins (10) provided on a substrate (1), comprising a connector (20) to which the cable assembly (23) is connected, and substrate mounting means (11) via which the connector (20) is mounted on the substrate (1), said connector (20) having a connector body (21) and a connector cover (22) surrounding the connector body (27), and a latching lever (31) for engaging an abutment on the substrate mounting means (11) so as to latch the connector (20); characterised in that:- said substrate mounting means (11) is in the form of a plurality of guides extending perpendicularly from the substrate (1), each guide defining a connecting portion (12) including a predetermined number of contact pins (10) and a pair of oppositely-disposed side walls (11a) having abutments (33); and in that the latching lever (31) is in the form of a gate with two opposing legs (31a), said opposing legs having hooks (31b) which are engageable with said abutments (33) of the guide side walls (11a), said latching lever (31) being pivotally mounted to the connector (20) so as to pivot in a plane parallel to the guide side walls (11a) whereby said hooks (31b) can engage and disengage said abutments (33). A connector apparatus according to claim 1, wherein said hooks (31b) are provided on the lower ends of the latching lever legs (31a) adjacent to the guides (11). A connector apparatus according to claim 2, wherein said hooks (31b) lie in a plane substantially parallel to the plane of movement of the latching lever (31). A connector apparatus according to claim 3, further comprising means (31f) for biasing the latching lever (31) to an initial position. A connector apparatus according to claim 4, wherein an upper end of said latching lever (31) is provided with a grip (31e) which can be manually pressed to bring the latching lever (31) into an unlocked position in which the hooks (31b) are disengaged from the corresponding abutments (33) of the guides (11). A connector apparatus according to claim 5, wherein said latching lever legs (31a) are located on opposite sides of the connector body (21) between the connector body (21) and the connector cover (22). A connector apparatus according to claim 6, wherein said cable assembly (23) comprises a plurality of coaxial cables (123A, 123B) each having a shield and signal lines. A connector apparatus according to claim 7, wherein said coaxial cables are paired. A connector apparatus according to claim 8, wherein said connector (20) comprises one contact assembly (110) for each pair of coaxial cables (123A, 123B). A connector apparatus according to claim 9, wherein each of said contact assemblies (110) comprises a ground connecting piece (111) commonly connected to the shields of the associated pair of coaxial cables (123A, 123B) and two signal connecting pieces (112, 113) connected to the signal lines of the associated pair of coaxial cables. A connector apparatus according to claim 10, wherein each of said contact assemblies (110) comprises a holder (114) which joins the ground connecting piece (111) and the signal connecting pieces (112, 113) of the associated pair of coaxial cables (123A, 123B). A connector apparatus according to claim 11, wherein the lower ends of the ground connecting piece (111) and the signal connecting pieces (112, 113) are formed as bifurcated contacts. A connector apparatus according to claim 12, wherein said signal connecting pieces (112, 113) in each pair of coaxial cables are located on opposite sides of the ground connecting piece (111). A connector apparatus according to claim 13, wherein said abutments (33) of the guide side walls (11a) have tapered abutting surfaces (33a) over which the hooks (31b) of the latching lever (31) can slide when the hooks are pressed thereon. A connector apparatus according to any preceding claim, wherein the guides (11) are arranged in a grid-like pattern, each guide (11) having a second pair of oppositely-disposed side walls perpendicular to said pair of side walls (11a) having abutments (33).

Inventors: ISHIKAWA KOUJI, KAWANO KYOICHIRO, MURASE TERUO, NORMAN C TIMOTHY, SOCHOR JERZY R, ISHIKAWA, KOUJI, KAWANO, KYOICHIRO, MURASE, TERUO, NORMAN, C. TIMOTHY, SOCHOR, JERZY R.
Applicants: AMDAHL CORP, FUJITSU LTD, AMDAHL CORPORATION, FUJITSU LIMITED
Application year: 1989
Main classification: H01R13
IPC codes: H01R13, H01R43