CH630731A5 - Connection device for flat cable optical fiber. - Google Patents

Description

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4. Connection device according to claim 3, characterized

1. A connecting device for a flat cable with a number shows that the abutting flanges are fitted into the hollow optical fibers stored in a flexible basic substance, space of the housing, by a slight radial and the first and second axially movable connections the flanges in the cavity and has a bare device, characterized in that the stress relief of the fibers is ensured in order to ensure optimum coupling (10, 139, 204).

a) a substantially flat housing (18, 20; 138, 140; 5. connection device in claim 1, characterized-205) with an inner holder (40, 142) which draws a passage that the engagement elements elastic fingers (68, 70), accordingly the shape and size of a cable to be accommodated therein and the elements (72, 74) at the free end of the fingers and cables (12, 144, 206) to be anchored are detents at one end.

forms the latter in such a way that the connection device accommodated in the housing can protrude beyond the holder, with channels, that the inner holder (40) of the housing has a single (6 , 48; 54, 56; 213, 214), which has a general orientation (42), which can be brought into engagement with an opening arranged in this way with the holder for receiving the fibers of the cable (44) in the cable, that without the ends, the ends of the fibers near an opening in which the optical fibers are exposed, the cable ends in the housing under an end part (58, 158 and 231) of the housing, in order to prevent stress on the fibers from being anchored, optical coupling of the fiber ends with the fibers in the in order to allow repeated insertion and pulling apart of the earth end part abutting second device. most and second device without weakening the optical b) to ensure a number of fiber retaining elements (22.24; 150.152; fibers and the pressure on the cable to mil-216.218), which in the channels (46.48; 54.56; 213.214) in the 20th

Housing in axial alignment with the fibers in position 7.

can be brought, each holding element being a smooth, in that the housing has two identical halves (18, 20)

has a substantially cylindrical circumference and a circular Boh-, which have interlocking surfaces, the tion, which extends along the cylindrical axis pins (30,32) and openings (34,36) such that and through which one end of an optical The fiber of the cable into the halves when inserting the pins into the corresponding opening

settable and essentially coplanar with one end of the bores in alignment.

tion can be anchored, the ends of the fibers and the fixed connection 8. 8. device according to claim 1, characterized

holding element essentially perpendicular to the axis of the drilling, that the second device (136) a set of

tion elements (176,178) and an essentially flat housing c) Alignment elements (26,28; 154,156; 224,226) with 30 (160,162) with an inner cable holder (164) in the vicinity of bores extending through the latter, essentially a passage for receiving and anchoring an end of the same size and shape as the cylindrical circumference of that of another flat cable (166) therein, which contains at least one pair of retaining elements for receiving one retaining optical fiber (172, 174) each such that the mentes in one end and protruding into the passageway for receiving retaining filament fibers and anchoring 35 elements (176,178) in the set of retaining struts (92,94; 176,178; 238,240) of the second device such that the housing (78,136,250) in the other end, the corresponding (160, 162) has an opening in a front part, through which the received elements can be butted against one another, and through which the second set of the holding elements nte (176, 178) for facilitating the fibers held therein, can be optically coupled and in axial alignment with the engagement with the retaining elements (22, 24; 150, direction are stable, and 152) can protrude from the first device, and that projections

40 ge (202) are provided, into which the engagement elements (194, 196,

d) engaging elements (68,70,76,77; 194,196; 225,254) 198,200 of the first device can be snapped into place.

contains, arranged in the vicinity of the side parts of the housing 9 connecting device according to claim 8, characterized and having elements (72, 74) which draws with corresponding that the one housing engages two identical halves (160, elements of the second device can be brought, 162), which have pins and openings in order to keep the retaining elements in alignment with the alignment device housing halves.

10. Alignable and receivable in the latter and held in a connection device according to claim 1, characterized by the abutting position in the alignment devices, indicates that the second device (78) is a set of fixed items. holding elements (92.94) and a housing (80.82.84.86) for

2. Connection device according to claim 1, characterized in receiving the latter, the retaining elements (92, drawing that the alignment devices have at least one 50 94) receiving and anchoring optical fibers (96,98) pair of sleeves (26,28) in the channels (46,48), and that an electronic circuit device housing is anchored, one end being provided in the vicinity of the end part device (90,250), which ends a light source (246) or the housing to enable that part of the fixed has a photodetector (248).

holding elements (22, 24) in a tight fit with the abutting holding elements (92, 94) of the second device in 55

the channels can be used.

3. Connection device according to claim 2, characterized in that the holding elements and the alignment sleeve. The invention relates to a connection device for opti-sen each flanges (60,62,64,66) with essentially the same fibers and in particular a connection device for rather Size and same manners, with a 60 flat cable with a number of optical fibers, as is arranged in particular flange along each retaining element in such a way, which are used in data transmission systems, so that if one end of the retaining element approximately to the preamble of the UPA1.

Half is inserted into the bore of the alignment sleeve, when flanges to be used are used in optical transmission systems, and that the channels of the housing are known, e.g. from the publication "Fiber Optics Cavities (46,48) of approximately the same size and shape 65 Developments Spark Worldwide Interest", R. Grundlach, Elec-like the flanges, so that the assembled electronics, from August 5, 1976, emerges . Despite the requirement, elements are anchored in the housing when they are inserted into the cavities for trouble-free and wide bandwidth. Transfers is the commercial use of data

3rd

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Transmission links due to the problem of making reliable, cost-saving and low loss connections between fibers or a given fiber and an associated optical element, e.g. a light source or a photo detector, has been prevented so far. The connection devices mentioned must take into account at least three problems, namely the axial alignment, the alignment in the longitudinal direction or the gap between associated elements and an angular alignment.

The axial alignment is generally achieved through the use of precision sleeves which are precisely adapted to the outside diameter of the fiber, as a result of which the fibers used can be guided into an axial position in such a way that they can be fixed in their position. From US Pat. Nos. 3,972,585, 4,005,522 and 4,008,948, various connection devices with sleeves emerge into which exposed fiber ends are inserted directly.

U.S. Patent Nos. 3,809,908 and 4,019,048 disclose e.g. different systems with fiber optic receiver-transmitter components that are complex, use non-standard components and are not suitable for data transmission connections in which a plurality of separate optical fibers are used to connect a given light source to a photodetector.

A fiber optic cable system has been developed by Quadri Corporation, Tempe, Arizona (model 2403), which comprises a cable with a single optical fiber that connects a transmitter unit to a receiver unit. The system is designed for use with 12.5mm centered circuit board assemblies, requires separate intermediate receiver and transmitter assemblies, and provides a one-way signal flow alone.

The aim of the invention is to provide a connection device with which the flat nose can be connected or connected easily and reliably with a number of optical fibers.

This aim is achieved according to the invention with the characterizing features of patent claim 1.

The connection device according to the invention will now be explained in detail with reference to the drawings. In the latter are

1 is an exploded view of a connection arrangement, in which a connection device according to the invention for coupling a flat cable with optical fibers is shown with a cable end closure;

2 shows a similar exploded view of connection devices according to the invention for coupling or splicing flat cables and optical fibers

Fig. 3 is a view of a cross section of the connection arrangement shown in Fig. 1.

A preferred embodiment of the connecting device according to the invention is shown in an exploded manner in Fig. 1. The connector 10 is suitable for connecting a flat fiber optic cable 12 having a pair of optical fibers 14 and 16, two identical housing parts 18 and 20 with a pair of fiber retention members 22 and 24, and a mating pair of alignment sleeves 26 and 28, respectively. The housing parts 18 and 20 are preferably injection molded from a thermoplastic, such as Polycarbonate or the like. Each housing part has protruding pins, e.g. the pins 30 and 32 of the housing part 20, which are fitted into corresponding openings 34 and 36 in the opposite housing part 18 when the housing parts 18 and 20 are pressed together, whereby the halves of the connecting device are held together in a suitable orientation. The interior of the housing parts 18 and 20 is shaped in such a way that a rear opening 38 is provided in a section 40 which carries the cable and which defines a passage corresponding to the size and shape of the cable 12 to be received and anchored in the housing. The section 40 has an extended flat part on which the flexible basic substance of the cable 12 can be applied. The flat part 40 has a projecting pin 42 which engages with a similar pin in the housing part 18. If a cable 12 is to be mounted with the connection device 10, a hole 44 is compressed between the fibers 14 and 16 through the flexible basic substance of the cable 12. Through this hole, the cable is anchored to the pin 42 in the housing and a load on the optical fibers is absorbed if pressure is exerted on the cable independently of the housing. Furthermore, locating hole 44 at the end of the cable facilitates subsequent drilling operations to bring the ends of the fiber into the appropriate position in the associated connector elements. Channels through which the fibers can extend and which have a pair of larger cavities 46 and 48 extend forward of the passageway, generally in alignment with the axis of the 20 optical fibers in the cable 12. The channels have a pair of small openings which lead from the passage at 40 into the larger cavities 46 and 48 and larger, axial openings 54 and 56, 25 which open at an end part 58 of the housing of the connection device. Each cavity 46 and 48 is adapted to receive a retention element 22 or 24 which is inserted into one of the alignment elements 26 and 28, respectively.

The retention members 22 and 24 have a short section of a stainless tube that is press fit into brass flanges 60 and 62 such that a short end extends beyond one side of the flanges, thereby aligning the members in the small openings of FIG the passage at 40 is facilitated. Such a tube is commercially available with 35 diverse inside and outside diameters, so that it is easy to choose a tube with an inside diameter that is slightly larger than the diameter of the optical fibers to be used. Correspondingly, an optical fiber 14 or 16 can be inserted into the holding elements 22 or 24 in such a way that the end of the fiber is essentially coplanar with the end of the holding element 22 or 24. The fiber is then permanently e.g. fixed in the retaining element by means of an epoxy resin. The outside diameter of the elements 22 and 24 is selected in a similar manner so that 45 the latter can be accommodated in the alignment elements 26 and 28 in a tight fit. The radial flanges 60 and 62 are of a suitable size, which are fitted into the larger cavities 46 and 48 to create a tensile load for the fibers, but with a limited freedom of movement of the flanges to ensure an optimal optical appearance To ensure coupling of the fibers. The alignment elements 26 and 28 are preferably made of brass and have an inner diameter which is slightly larger than the outer diameter of the retaining sleeves 22 and 24. The 55 alignment elements 26 and 28 have radial flanges 64 and 66 of similar size and shape as the flanges 60 and 62, so that when the retention elements 22 and 24 are inserted into the alignment elements 26 and 28, the flanges abut and bond together in one of the cavities 46 60 or 48 can be accommodated. The front part of each alignment element 26 or 28 is adapted to be fitted into the front parts of the channels 54 and 56 in axial alignment with the cable 12 so that the front opening parts thereof are accessible through the front part 58 of the housing. When the device is assembled, the retention members 22 and 24, which permanently anchor the ends of the fibers 14 and 16 coplanar therewith, are approximately halfway into the alignment members 26 and 28. This too

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4th

Assembled elements are received in the cavity such that the front end of each alignment element 26 and 28 projects a short distance forward over the front portion 58 of the housing. Each alignment member 26 and 28 is preferably flared at both ends to facilitate the insertion of a retention member 22 or 24 into the rear opening and the insertion of a similar retention member of a coupled connector into the front opening.

The connector further includes locking means such as a pair of elastic fingers 68 and 70 for engagement of the connectors, the elastic fingers 68 and 70 having pawl teeth 72 and 74 at the front ends. The fingers are suitable for engagement with corresponding elements on a coupled connection device.

The housing halves 18 and 20 are preferably made of a plastic by injection molding and have an identical structure. The upper half 18 therefore has the same cavities as the lower half 20. When the halves are joined together, the parts form complete internal cavities. In a similar manner, the corresponding fingers 76 and 77 in the other housing half 18 are assigned to the elastic fingers 68 and 70 on the lower half 20.

In the embodiment shown in FIG. 1, the connection device 10 for a fiber-optic flat cable 12 is provided with a pair of optical fibers which have a diameter of approximately 0.25 mm and in an extruded vinyl base substance with an outer width of 12.5 mm and embedded about 1.5 mm thick. The optical fibers are spaced approximately 7 mm apart. In such an embodiment, the housing halves 18 and 20 have approximately a thickness of 3 mm, approximately a total width of 25 mm and approximately a total length of 32 mm. The platform-like section 40 is shaped to contain the cable 12 from 12.5 mm to 1.5 mm. Correspondingly, each platform-like section of the housing halves 18 and 20 has a cutout of approximately 0.75 mm to 12.5 mm. The protrusions 42 are similarly shaped to abut one another when the housing halves are assembled so that they engage a hole 44 that is dipped into the cable 12.

The stainless retention sleeves 22 and 24 have an inner diameter of approximately 0.33 mm so that they can accommodate the fibers 14 and 16. The fibers are contained therein by a suitable resin, e.g. Epoxy resin type 96-083 from Dow Corning Corporation. In the preferred embodiment according to FIG. 1, the flanges 60, 62, 64 and 66 have an outer diameter of approximately 4.5 mm and an inner diameter, which enable their press-fit arrangement in the steel tube.

The paired connection device 78, which is shown in the left part of FIG. 1, forms an end closure interface between optical signals on a fiber cable, such as the cable 12, and corresponding electrical signals. The connecting device 78 has a housing which is formed from two identical, molded plastic support elements 80 and 82, which in turn are sandwiched between a base element 84 and a cover plate 86. The connection device also has a printed circuit board 88 on which electronic circuit components 90 are provided depending on the desired application. The connector device 78 further includes a pair of fiber retention members 92 and 94 in which short optical fibers 96 and 98 can be anchored to provide optical coupling of associated optical elements in the electrical circuit unit 90 and optical fibers in the first connector device 10. The housing halves 80 and 82 are made of a suitable one

Plastic, e.g. a polycarbonate resin or the like, moldable. Each half has at least one protruding pin 100 and a corresponding opening 102, so that when the halves are assembled, the pin 100 of one housing half is received in a corresponding opening 104 in the opposite housing half. The cover plate 86 can also be produced by injection molding from a suitable plastic and has a number of protruding pins 106, 108 and 110. The pins can be inserted into suitable openings 112, 114 and 116 in the lateral legs of the elements 80 and 82. The base element 84 is similarly provided with a number of openings through which pins corresponding to pins 106, 108 and 110 can be used when the connecting device is assembled. Following assembly, the protruding pins can be pegged for permanent locking of the device. A rear end part 118 on the cover plate 86 closes the rear part of the end closure 78, wherein access to electrical connections 120 for connecting the electronic assembly 90 is possible. The 20 retaining elements 92 and 94 are essentially identical to the retaining elements 22 and 24 of the first connection device 10 and are made of a stainless tube which is arranged in a press fit-like manner in brass flanges 124 and 126. These elements are fitted into suitably shaped recesses 128 and 25130 in the housing halves 80 and 82, so that the front end projects beyond an end part 131 of the housing halves 80 and 82.

The optical fibers 96 and 98 may be permanently anchored in the retainer 92 and 94 with the front end of the fibers 30 substantially coplanar with the ends of the members 92 and 94. The rear end of the fibers can be optically associated with elements, not shown, in an electronic assembly 90, e.g. be coupled by means of a transparent adhesive, mechanical clips and the like. 35 The housing halves 80 and 82 are also fitted with interlocking locking devices, e.g. notched parts, which are arranged on the opposite sides of the elements. A locking device 132 is shown. The notched portions may suitably 40 receive the ends of resilient fingers 72, 74, 76 and 77 of the first connector to lock the connector together and hold the corresponding retention members abutting and in axial alignment in the alignment members 26 and 28.

45 While the elements shown in FIG. 1 can all be produced from plastic using the injection molding process, in a particularly preferred embodiment the base element 84 can be produced from a heat-conducting metal or the like and provided with a corrugated outer surface in order to provide additional heat dissipation . In such a case, the circuit board 88 can be suitably made of an insulating material, such as an electronically insulating quality ceramic.

In the connection 55 device 10 shown in the right part of FIG. 1, the alignment elements 26 and 28 are provided in the housing halves 18 and 20 and the retaining elements 22 and 24 are inserted into one end of the alignment elements 26 and 28. When the connectors 10 and 78 are assembled, a second set of retainers 92 6c and 94, which are retained in the housing halves 80 and 82 of the paired connector 78, are inserted into the alignment members 26 and 28 such that the end portions of both sets of the retainers abut each other , whereby an optical coupling of the fibers anchored therein is achieved. 6; The alignment elements 26 and 28 can also be arranged in one of the two matching alignment elements, it only being important that the retaining elements of each connection device are inserted into the alignment

5

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demente be used that the latter in axial alignment. Fig. 3 is the view of a cross section of an arrangement

butt each other in a suitable manner in order to highlight the fixation contained therein, the details of the connected connection

coupling fibers with each other. directions for coupling a fiber optic flat cable with

In a second embodiment shown in FIG. 2, shows an end closure, the connecting devices of the invention being suitable for connecting a pair of flat fiber optic cables to one another, shown at a short distance from one another for simplification. According to this, a connection device 204 is to be spliced in a manner similar to that in FIG. In such an embodiment, FIG. 1 is attached to a flat cable 206 that is a pair of optical

Housing of the connection device 134 has fibers 208 and 210 embedded in the injection molding process. The cable is anchored in the housing 205 made of plastic with identical elements 138 and 140 by means of a projecting pin 212,

poses. The same applies to the housing of the connection device through a similar shaped opening in the cable 206

tion 136, which also protrudes from the fibers 208 and 210 in the plastic injection molding process. The fibers 208 and is and has two identical elements 160 and 162. 210 thus protrude axially with the cable

The connection device 134 essentially coincides with that of the channels 213 and 214 and penetrates into a corresponding one

1 and has a retaining element 216 or 218, in which the fiber ends

Opening in a platform 142 with a projection for permanent opening by means of a suitable adhesive, e.g. take and anchor a flat cable 144 with a pair of epoxy resin type 96-083 from Dow Corning Corporation,

optical fibers 146 and 148. The corresponding housings are anchored.

halves 138 and 140 have a pair of channels in which a during assembly of the connector and

Pair of fiber retaining elements 150 and 152 are receivable, that of the fiber optic cable becomes the opening into which the pre-

to be inserted abutting in corresponding alignment pin 212 into which cable 206 is

ten 154 and 156 are inserted, and elastic fingers 194, 196, compresses, so that a suitable length of the cable over the location

198 and 200 protrude near the side parts of the corresponding Ge of the hole. The flexible base substance of the cable halves, as described in connection with FIG. 1, is then removed so that a suitable length of the fibers 208

is. An end part 158 of the housing halves 138 and 140 points and 210 extends beyond the end of the flexible basic substance.

openings through which the front end of the alignment 25 extends. The cable is then placed in a suitable

can protrude dementia 154 and 156, whereby access to a tensioning device, not shown, is used, which

the retaining elements 150 and 152 for an optical coupling pin and cavities in which the cable and lung with the fibers 146 and 148 anchored therein guarantee the retaining elements 216 and 218 are arranged, so that it is continuous. Location of the retaining elements exactly in relation to the opening in

In this embodiment, the paired connector 30 can be assigned to the cable. The optical fibers locking device 136 has an opening in a platform 164 for insertion into the retaining elements and then slightly accommodates and anchors a cable 166. The plate is cut off over the front ends. The fiber shape has a protrusion 168 which extends into a hole between the then befe-optical fibers 172 and 174 of the cable 166 which are then permanently compressed in the manner described above. The ends of the fibers can thus be fitted into the ends of the 170, so that the cable anchored in the housing 35 has corresponding holding elements, which makes it more fitting if the housing halves 160 and 162 prevent insertion and later breaking out of the fiber ends when inserted Projections 188 and 190 will be in corresponding. If the fibers and the corresponding holding element openings in the elements lying opposite one another are assembled in this way, they are to be put together. The connection device 136 has an alignment element 224 and 226 inserted, so that the pair of flanges has retaining elements 176 and 178, in which the fibers 40 see each other on both sets of the elements. 172 and 174 of cable 166 can be anchored so that abutting ridges are then inserted into the cavities, the ends of the fibers are substantially parallel to the front end 228 and 230 of the assembled housing and the retention members 176 and 178 are. When these elements pressed together the corresponding housing halves. inserted into corresponding cavities 184 and 186 and which in a similar manner have the end closure connecting device elements 160 and 162 pressed together, the mount 234 can have a housing which is pressed together with the housing of an outer end of the two cables 144 and 166 - Closing device 204 can be assembled. The ge of the two connecting device halves with one another housing 234 has an end part 236 which is coupled to the end part, so that the ends of corresponding sets of the 231 of the first connection device 204 are joined together — retaining elements 150 and 152 or 176 and 178 in the end can. The connection device 234 also has a pair of directional elements 154 and 156 abutting one another. After 50 holding elements 238 and 240, in which short sections of the following insertion, the elastic fingers 194, 196, 198 and optical fibers 242 and 244 are anchored. The fibers 242, 200 of the right hand connector 134 in and 244 are permanently attached to the notched parts 202 of the attached connector 238 and 240 in appropriate retention elements by a suitable adhesive so that 136 is received so that corresponding elements are in close proximity to the fiber ends of the end part of the retaining elements are locked and locked in axial alignment. 55 are located. The elements are then fastened in corresponding hollow-die connection device spaces shown in FIGS. 1 and 2 in the housing 234, so that the optical fibers are suitable for use for revenge cables, each with a pair in axial alignment with the end part 236 of the housing 234 optical fibers. The anes can be similar. After coupling the connection device 234 to the connection devices of any number of optical fibers connection device 204, the retaining elements 238 will be laid out in flat cables. Instead of the mechanical 60 and 240 used in the alignment elements 224 and 226 of the elements for aligning and maintaining the alignment locking device 204, in order to optically couple the two connection devices, the latter can also effect the optical fibers therein. The end parts of the Fa are thermally welded or by a suitable adhesive sera 242 and 244 are optically connected to one another with a light source 246 or material and are coupled as a function of a photodetector 248 which is unequal in terms of their specific electrical use Have shape. The 65 African unit 250 is stored. In the case of a preferred anchoring of the optical fibers in the housing, the light source 246 can also be provided by a mechanical holding device other than the outside, e.g. by the diode type FPX-2000 from Fairchild Semiconductor a rail shaped transverse to the platform 142 or 164. Corporation formed. In a similar preferred embodiment

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For example, the photodetector 248 can be of a photodiode type of light-emitting diode as the light source 246.

C-30807 from RCA Corporation. Electrical order is particularly optimal insofar as such diodes frequently see inputs and outputs from and to the light source 246 and uneven light across the light-emitting surface.

the photodetector 248 can radiate in a conventional manner. Accordingly, the optimal position of the fiber can be formed in lines, not shown. s Relation to the light-emitting surfaces of the light source 246

Preferably, the alignment members 224 and 226 are tapered at both ends by monitoring the light output at the front end to facilitate their entry into the corresponding fiber 242 and by permanently anchoring the fiber in the retainers 216,218 and 238,240. Proximity of a particular part of the light emitting surface, the

Furthermore, the front part 236 of the housing 234 is determined according to the maximum light output, is shaped so that when the retaining elements 238 and 240 are inserted, if the fibers are permanently formed by means of a suitable light-covering, corresponding cavities are formed, whereby the forward adhesive is anchored, the corresponding ends of the retaining element can be connected and protrude beyond the plane of the front part of the housing halves in the manner described, so that the end of the retaining elements and the optical fiber fully corresponding to the assembly of the connecting device arrangement are ground and polished therein will be ends.

can. The front part 236 is ground as desired so that 15 instead of the elastic fingers that correspond to the engagement

the corresponding forehead part 236 in the relief-ground part of the connecting devices can also be used for locking

236 can occur to ensure a firm connection, gel devices such as countersunk screws and corresponding

while the elastic fingers 252 and 254 fit into the corresponding threaded parts in the attachable connection

notched parts 256 and 258 of housing 234 can be used. Additional seals or external

adds. 20 sere reinforcement flanges and the like can be used for external protection

The first time the optical fibers 242 and 12 are used. The cavity in which the electronic

244 is arranged in the corresponding retaining elements 238 and 240 unit 250, can also be connected to electrical

the other ends of the fibers can be provided with the appropriate shielding to minimize electrical interference.

associated optical element to be connected to the op.

maximize table coupling. In case of use 25

C.

2 sheets of drawings