Connector for Coupling Fiber Optic Transmission Means

The present invention refers to a multi channel connector for coupling-up the end portions of opposing transmission means, such as perferably optical fiber ends, provided with lenses, diodes or the like. The connector includes two connector parts, shaped for cooperation with a male and a female centering means for each of the transmission means for coaxial guiding and fixation of each transmission means regardless of the other transmission means.

Known multi channel connectors of above mentioned type require very high tolerances when manufacturing the closed parts, and then in particularly the case of the connector parts and linings, where the parallelism between the control hole for the transmission means to the optical fibers, the diode or the like, must be within 0.001 mm, as well as the control hole and guide-pin for centering of connector among themselves. Further, the right angle between the end-surfaces of the connector parts and the longitudinal axis of the guiding holes must lie within .+-.0.002 mm, as well as the partition between the control hole and the guide pin respectively.

In order not to let the transmission means be able to change position, these are fastened permanently in the case of the connector parts by means of, for example forced fit. This implies that if the transmission means should be defective, these can not be exchanged, but the whole multi channel connector must be discarded and replaced with a new one.

Through the German Patent Specification No. 2743626, it is known that a number of optical fibers can be coupled up by means of a connector device. A problem with this connector device is that the optical fibers consist of extremely thin fibres, with sizes of some micrometers. Because of this, it is extremely important that the centering is absolutely exact, since even very little deviations entails that the fiber ends lie side by, (ie., they are not coaxial). When a number of fibers are placed in one channel, as it is the case with the above-mentioned invention, a poor centering is obtained.

The purpose of the present invention is to provide a connector of the type mentioned by way of introduction, where the high demands for exact centering of the fiber end portions are fulfilled with appreciable simpler and cheaper means than earlier, where an exchange of the connector part closed components, such as transmission means, is easily accomplished, and which connector is formed so that standard components present on the market can be used. Further, it is possible to place the end portions of the optical fibers and one or more LEDs, for cooperation with optical fibers, in one and same connector, and on one hand attain an accurate centering for all optical fibers and in the other hand attain that the holders consist of two connector parts, in coupled up position, with their end surfaces come to bearing on each other, which further improves the coaxiality.

These problems are solved by placing the transmission means in the both connector parts in each belonging holder, which to a limited extent has radial mobility as, by means of a spring, and axial mobility in each of connector parts arranged channels, so that each holder is self-centering regardless of the other holders.

The invention is explained hereinafter with reference to the enclosed drawings, which show an embodiment of the invention.

FIG. 1 shows in enlarged scale section through two connector parts of a multi channel connector, according to the invention, whereby both of the connector parts are slightly pulled apart from each other.

FIG. 2 shows a bottom view of one of the connector parts shown in FIG. 1.

FIG. 3 shows a bottom view of a centering-cone, contained in the holder.

FIG. 4 shows a section along the line IV--IV in FIG. 3.

FIG. 5 shows, partly in section, a complete housing of a multi channel connector, but without a holder and a transmission means.

The connector according to the invention consists of two connector parts 11a and 11b, which in a way previously known are insertable in each other and by means of a nut 12 fixable in their coupled-up position. Each connector part 11 is provided with a number of axial channels 13, in which a holder 14, with some play, is inserted for each transmission device 15, via a centering cone 16. The transmission means 15 can have the shape of a plug, in which the end portion of a optical fiber is situated so that the end-surface of the fiber coincides with one front end-surface of the plug. The transmission means 15 can also be a transmitter or a receiver for a diode 17.

The holder 14 is provided with a shoulder 18, which bears on a corresponding ledge 19 in the channel 13. The holder 14 is kept in its inserted position by means of a spring 20, which rests against a pressable holder-on 21, which is screwed-on by the connector part's posterior end surface. Thus it is possible, by means of the spring 20, to axially displace the holder 14 within the channel 13. In addition, the play between the holder and the channel is enough that the holder can perform a limited radial motion.

The transmission mean 15 is centered in the holder 14 with the centering-cone 16, the conic form of which corresponds the conical outlet 30 of the socket formed holder 14. Even the centering-cone has the shape of a socket and is provided with elastic sectors 22, consisting of material-reduced axial portions 23, which is apparent from the FIGS. 3 and 4. The inner outlet 31 of the centering-cone is shaped in accordance to external form of the transmission means, ie., it has cylindrical form. Further, the transmission means 15 is provided with a peripheral flange 24, which forms the contact surface for a compression spring 25, the purpose of which is to press the forward end-surface of the transmission means to bear on an opening 26 in a seat 27, which is provided at the front end of the holder 14. The seat 27 takes up a lens 28, the center axis of which coincides with the central longitudinal axis of the transmission means 15.

In the joined position of the connector parts 11a, 11b, one of the connector parts 11a of the transmission means 15 will be positioned right opposite to a corresponding transmission means 15 in the other connector part 11b, and to accomplish an exact coaxial coupling-up between the transmission means 15 in the both connector parts 11a and 11b, in one of the connector parts, for example 11b, the holders 14 upper end portion is provided with a guide-sleeve 31, which by means of forced-fit is permanently attached to the holder. The other holder 14 of the connector part 11a does not have a similar guide-sleeve, but it is however formed with a guide 32, which working-fit can be inserted in the guide-sleeve 31, so that the both holders with their transmission means 15 will be situated in exact coaxial position. Each individual holder 14 with transmission means 15 can consequently independently of the other holders in same coupling part be centered relative the opposing transmission means in the other holder, which is possible by the holders being not rigidly fixed in each coupling part, but having a certain radial as well as axial mobility.