SE438917B - OPTICAL FIBER CONNECTOR - Google Patents

Description

7800185-6 A pair of end connections, each comprising a pair of elongate channel elements with mating complementary surfaces and divided into spaced pins at one end, which pins are terminated in chlorine intended to contact and orient the peeled end of an optical fiber. , which otherwise extend through the duct elements, but are not in contact with them, the claws having tapered outer surfaces, with an end connection in each cable lug, and engaging locking means on the end connections and the body for holding the end connections in the cable lugs with the tapered surfaces in engagement with the seats.

Valuable advantages and objects of the connector according to this invention appear from the following description, with reference to the accompanying drawings, in which Fig. 1 is an enlarged perspective exploded view of the connector body and an end cap; Fig. 2 is a partial plan view of the connector shown in Fig. 1, with partial cut-out so that a section is obtained as showing construction details, Fig. Å is a partial cross-sectional view along the line 3-3 in Fig. 2, except that only one end connection is visible, which is shown in its entirety, Fig. 4 is a partial enlarged cross-sectional view of the connector, taken along line 3-3 of Fig. 2, showing the placement of optical fibers in the assembled connector, Figs. 5 and 6 are perspective and side views, respectively, of a channel member from the end connection of Figs. 1-4; Fig. 7 is a end view of the channel element with an optical fiber, shown in its position during assembly of an end connection.

The optical fiber connector selected for illustrative purposes includes a body 10 with opposite pairs of cable lugs 12, both intended to receive and contain an end connector 14.

The body 10 is assembled from adapted sections 16, 18 and wnje end connection 14 from a pair of identical channel elements 20.

The sections 16, 18 have integral pins 22 which have a press fit in the corresponding holes 23f. The section 18 has horizontal and vertical mounting flanges 24, 26. At each end of the body 10, three pairs of pins 28, 30 and opposite pairs of locking means define. 32, 34 rectangular inputs to the cable lugs.12.

The body 10 and the end connections 14 are formed from a polycarbonate and polyester, respectively. Other plastics are suitable, for example acrylic-nitrile-butadiene-styrene (ABS), phenylene oxide, polyether sulfones and mixtures of ABS with a polycarbonate. The plastic from which the end connections are formed can be reinforced, for example with glass fibers.

Referring to Fig. 3, each cable lug 12 includes an elongate passage 36 having a circular cross-section. The passage 36 extends to a ledge 38, from which the cable lug 12 continues inwardly through a conically tapered seat 40 and a recess 42 of circular cross-section to another recess or hole 44, which connects a pair of oppositely oriented cable lugs 12.

As shown in Figs. 5-7, each channel element 20 has a funnel-shaped channel 46 on its inside 48. Between its ends, at a lug 50, the outer geometry of the channel element changes from rectilinear surfaces to a rounded outside in a link 52. The link 52 is intended for insertion into a cable lug 12 and has its free end divided at 54 into flexible pins 56, 58. At the end of each pin a claw 60 is provided with a tapered outer surface 62 and a front end. large segment 64 with a cylindrical exterior. The surfaces 62, 64 are separated by a ledge 66. At the connection of an optical fiber, a channel element is placed in a fastening member. Thereafter, an optical fiber 68 with the polymer sheath 70 pulled from its end is placed on the channel member, as shown in Fig. 8, the peeled end extending beyond the square ends of the claws 60 and with the sheath 70 resting in the channel 46. Thereafter, eU: second channel element 20 together with and locked to the first. In this regard, each channel element 20 has a central lock 72 and an end lock 74. Each lock 72 engages in the corresponding recess 76 and each lock 74V has a corresponding recess 78 on the mated channel element 20. When the channel elements are locked in this way, it is gripped. the sheathed fiber is fixed in the channels 46. As best seen in Figures 7 and 8, the channels 46 are disc-shaped.

Their width adjacent to the heel 50 is greater than the diameter of a sheathed fiber and their depth slightly less than half the diameter of a sheathed fiber. This connection makes it easier to place and grip the jacket during assembly, 7800185-6 4 'When the channel elements are locked and held, the peeled end is cut off close, but slightly outside the square ends of the claws 60 (Fig. 4). The channels 46 can, of course, be dimensioned to grip the unsheathed end of a fiber.

The degree of flexibility in the pins 56, 58 is a structural detail that can be varied to obtain a loose fit or a light pressure on a fiber 60 when the channel elements 20 are locked. With the divided end connections according to the invention, the peeled ends of optical fibers can thus be connected exactly without threading through small passages or otherwise be subjected to abrasive contacts, which often lead to scratches or ruptures. The possibility of scratches and stretch marks is further reduced by not having to cut off the end of the fiber until after its connection and by cutting the relatively stiff length close to the claws.

When an end connection is inserted, rotational orientation is maintained by fitting the rectilinear length to the rear of lugs 50 in the rectangular inputs defined by pins 28, 30 and locks 32, 34 of sections 16, 18 of the body 10. Referring to Fig. 3, and 6, each lock 72 has a gradually sloping leading edge and a strongly sloping trailing edge. Upon insertion, the leading edges of the lock 72 engage in locks 32, 34 and the latter engage the trailing edges. As shown in Fig. 3, the gripping surfaces of the locks 32, 34 are arranged to engage the trailing edges of the lock 72. In case axial forces are applied to a cable, the cooperating edges of the locks allow an end connection to release itself before the applied force reaches the breaking limit of the cable. . The cable can be moved with respect to inserted end connections without breaking due to the funnel-shaped ends in the channels 46. In this respect, the maximum degree of expansion in the channels is less than the bending angle at which the fibers are broken off.

When the end connection is inserted, the interrupted cylindrical surface obtained by segment 64 orients the end connection with respect to the cable lug 12 and the hole 44; The tapered surfaces 62 of the claws 60 engage the seat 40 and are moved together to orient the fiber 68 with the hole 44. The hole 44 should be constructed to have a slightly larger diameter than the fiber 68. When the end connection is already oriented with cable lug 12 and the hole 44, engagement between the surfaces 62 and the seat 40 ensures orientation of the fiber end in the claws 60 and thus with the hole 44. Thus, the projecting ends of the fibers do not come into contact with the body 10 and are thus damaged. non. Once another end connection 14 has been inserted into the opposite cable lug 12, the separate ends are oriented on two fibers and light can be transmitted efficiently from one to the other through the hole 44.

The gap between the two fibers should not exceed the diameter of an exposed fiber end. As a minimum, the projecting ends of the fibers should not come into contact with each other. If the fiber ends are placed close to each other, an acceptable level of light loss can be achieved with the parts as they are formed. As the gap increases, the rate at which light loss increases is reduced by enhancing the reflectivity of the hole, for example by polishing the shaped hole or by depositing aluminum on the surface of the hole by sputtering. Other coating materials, such as gold and dielectric multilayer films are suitable. Other precipitation techniques, including vacuum precipitation and chemical vapor precipitation, can be used.

The connecting piece shown in Fig. 1 has two pairs of oriented cable lugs 12. As such, this is particularly suitable for use when connecting reinforced and sheathed cables with two sheathed fibers. Such a cable is available from EI du Pont and is called PFX-P24OR. The cable contains two plastic optical fibers, each of which consists of a polymethyl methacrylate core in a polymer sheath with a lower refractive index. Sheaths on the individual fibers and on the cable consist of flame resistant polyester elastomer. The connection cable is of course adapted to connect non-wired fibers / of other compositions, such as pure silica, doped silica, glass or a polystyrene core, coated with an acrylic plastic.

Claims (3)

7800185-6 6 Patent claims Connecting piece for optical fibers, characterized in that it comprises a body (10) with oppositely oriented cable lugs (12), which leads to a connecting hole (44), each cable liner having a tapered seat (40). ) adjacent to the hole, a pair of end connections (14), each comprising a pair of elongate channel elements (20) with mating complementary surfaces and divided into spaced pins (56, 58) at one end, which pins are terminated in claws (60). ) intended to contact and orient the peeled end of an optical fiber (68), which otherwise extends through the channel elements (20), but is not in contact therewith, the claws (60) having tapered outer surfaces (60). 62), there being an end connection (14) in each cable lug (12), and engaging locking means (32, 34) on the end connections (14) and the body (10) for holding the end connections in the cable lugs with the tapered surfaces (62) in engagement with the seats (40). Connection piece according to claim 1 ,. characterized in that each cable lug (12) has a recess (42) between its conical seat (40) and the hole (44), the pins (56, 58) on each end connection (14) having square ends inside a recess. Connection piece according to Claim 1, characterized in that the claws (60) have segments (64) with an increased radial extent adjacent to the tapered outer surfaces (62), which segments (64) have an interrupted cylindrical surface, adapted to provide slidable engagement with the body within a cable lug as each end connection is inserted.