Hardened fiber optic connector

(54) Title: REINFORCED FIBER CONNECTOR (57) Summary: OPTICS (30) Unionist Priority: 24/01/2007 us 11 / 657,402 (73) Holder (s): adc telecommunications, inc.

(72) Inventor (s): Randy Reagan, Yu Lu (74) Attorney (s): DANNEMANN, SIEMSEN,

BIGLER & IPANEMA MOREIRA (86) International Order: pct US2008051782 de

23/01/2008 (87) International Publication: wo 2008 / 09i937de

31/07/2008

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222'

Descriptive Report of the Invention Patent for REINFORCED FIBER OPTICAL CONNECTOR.

This application is being filed on January 23, 2008, as an International PCT Patent Application in the name of ADC Telecommunications, Inc., a United States national corporation, applicant for designation in all countries except the United States, and Yu LU, a citizen of China, and Randy Reagan, a citizen of the United States, applicants for the designation of the United States only, and claims the priority of the US Utility Patent Application Serial No. 11 / 657,402, filed on January 24, 2007.

Technique Field

The present invention relates to optical fiber data transmission. Specifically, this order relates to fiber optic cable connection systems.

Background of the Invention

Fiber optic cables are widely used to transmit light signals for high speed data transmission. A fiber optic cable typically includes: (1) an optical fiber or optical fibers, (2) a sheath or coatings that surround (s) the fiber or fibers; (3) a layer of force surrounding the coating or coatings; and (4) an external dust jacket. Optical fibers work to carry optical signals. A typical optical fiber includes an inner core surrounded by a core cover that is covered by a coating. Coatings (for example, loose or tight coating tubes) typically work to surround and protect coated optical fibers. The reinforcement layers add mechanical resistance to the fiber optic cables to protect the internal optical fibers against the stresses applied to the cables during and after installation. Examples of the reinforcement layer include aramid wire, glass reinforced steel and epoxy preparation. External dust jackets provide protection against crushing, abrasion, and other physical damage. External dust jackets also provide protection against chemical damage (for example, ozone, alkali, acids).

Fiber optic cable connection systems are used to facilitate connecting and disconnecting fiber optic cables in the field without requiring a joint. A typical fiber optic cable connection system for interconnecting two fiber optic cables that includes fiber optic connectors mounted on the ends of fiber optic cables, and an adapter for mechanically and optically coupling the fiber optic connectors together. Fiber optic connectors generally include ferrules that support the ends of the optical fibers in fiber optic cables. The end faces of the bolts are typically polished and are often angled. The adapter includes coaxially aligned holes (ie, receptacles) to receive connectors for the fiber optic cables that are to be interconnected. The adapter includes an inner sleeve that receives and aligns the ferrules of the fiber optic connectors when the connectors are inserted into the holes in the adapter. With the bolts and their associated fibers aligned on the adapter sleeve, an optical fiber signal can pass from one fiber to the next. The adapter is also typically provided with a mechanical fixing arrangement (for example, a snap-fit ​​arrangement for mechanically retaining the fiber optic connectors on the adapter. An example of an existing fiber optic connection system is described in US Patent Nos. 6,579,014, 6,648,520 and 6,899,467.

Summary of the Invention

One aspect of the present description relates to a fiber optic connector being provided with a double fastening arrangement for attaching the fiber optic connector to a fiber optic adapter.

Another aspect of the present description relates to a fiber optic connector which is adapted to provide relatively high fiber optic circuit densities in a box.

A further aspect of the present description relates to a fiber optic connector being provided with a tapered interface adapted to complement a corresponding tapered interface of a fiber optic adapter.

A variety of additional inventive aspects will be shown in the description that follows. Inventive aspects can relate to individual characteristics and combinations of characteristics. It should be understood that both the foregoing general description and the detailed description that follow are only exemplary and explanatory and do not restrict the broad inventive concepts on which the modalities described here are based.

Brief Description of Drawings

Figure 1 is a perspective view of an example of a fiber optic connection system being provided with the characteristics that are examples of the inventive aspects according to the principles of the present description;

figure 2 is a perspective view of the fiber optic connection system of figure 1 with a connector of the fiber optic connection system terminating the end of a fiber optic cable;

figure 3 illustrates the fiber optic connection system of figure 1 with an adapter of the fiber optic connection system illustrated in hidden lines;

figure 4 illustrates the fiber optic connection system of figure 1 with an optical fiber connection system adapter mounted in a schematic box;

figure 5 is an exploded perspective view of the fiber optic connection system of figure 1;

figure 6 is a cross-sectional view taken along section line 6-6 of the figure of figure 5;

figure 7 is an exploded perspective view of the fiber optic connector of the fiber optic connection system of figure 1;

figure 8 is a perspective view of a main body of the fiber optic connector housing of figure 7;

figure 9 is a plan view of the main body of figure 8; figure 10 is a perspective view of a cover of the fiber optic connector housing of figure 7;

figure 11 is a plan view of the cover of figure 10;

figure 12 is an exploded perspective view of a fiber optic adapter of the fiber optic connection system of figure 1;

figure 13 is a view taken along section line 13-13 of figure 12;

figure 14 is an enlarged view of part of figure 3; figure 15 is an enlarged view of a coupling provided on the fiber optic connector of the fiber optic connection system of figure 1;

figure 16 is a side view of the fiber optic connection system and a fiber optic cable of figure 2;

figure 17 is a cross-sectional view taken along section line 17-17 of figure 16;

figure 18 is a top view of the fiber optic connection system and the fiber optic cable of figure 2;

figure 19 is a cross-sectional view taken along the section line 19-19 of figure 18;

figure 20 is a perspective view of another fiber optic connection system having the characteristics that are examples of the inventive aspects according to the principles of the present description;

figure 21 is a top view of the fiber optic connection system of figure 20;

figure 22 is a cross-sectional view taken along the section line 22-22 of figure 23; and figure 23 is an end view of the fiber optic connection system of figure 20.

Detailed Description of the Invention

Figures 1 to 5 depict a fiber optic connection system 30 in accordance with the principles of the present description for optically connecting a first fiber optic cable 20 (see figure 4) to a second fiber optic cable 22 (see figure 4 ). The fiber optic connection system 30 includes a fiber optic adapter 34, a first fiber optic connector 32 terminating the first cable 20, and a second fiber optic connector 33 (illustrated in figure 3) terminating the second fiber optic cable 22. The adapter is described assembled in a box 19 (illustrated schematically in figure 4). Adapter 34 includes a first hole 35 for receiving the first connector 32 and a second hole 37 for receiving the second connector 33. The first cable 20 is optically coupled to the second cable 22 when the connectors 32, 33 are positioned within their respective holes 35, 37 of the adapter 34.

As shown in figure 4, the first cable 20 is an external cable (for example, an external installation cable located outside box 19) and the second cable 22 is located inside box 19. In such a way, the first cable 20 it is adapted to carry an optical signal to box 19 and the fiber optic connection system 30 allows the signal to be transferred from the first cable 20 to the second cable 22.

Cables 20 and 22 include one or more optical fibers capable of carrying optical signals. Optical fibers include a core surrounded by a core cover. The core is the central light-conducting part of an optical fiber. The core cover surrounds the core and is composed of a material with a lower refractive index than the core material. The light is reflected internally within the nucleus to transmit the optical signal throughout the nucleus. Optical fibers can be protected in the coating tubes. Fiber optic cables can also include power members in fiber optic cables to increase the tensile strength of fiber optic cables. Optical fibers, power members, sheath tubes and other cable components can be surrounded by an outer jacket or wire jacket that provides a protective cover for the cable components. As shown in figure 5, the first cable 20 includes a central sheath tube 220 containing at least one optical fiber 222. The power members 224 are positioned on opposite sides of the central sheath tube 220. The power members 224 and the tube sheaths are positioned within an outer layer 306 of the cable 20.

Box 19 may include a wide variety of boxes / housings (for example, drop terminals, pedestals, network interface devices, fiber distribution shafts, junction boxes, optical network terminals, etc.). In one embodiment, adapters 34 can be mounted on a drop terminal of the type described in US Patent Application Serial No. 11 / 075.847, entitled Fiber Access Terminal, filed on March 8, 2005, the description of which is fully incorporated into the present by way of reference. For such an embodiment, cable 20 can be a prorated drop cable to a subscriber location and cable 22 can be a connectorized fiber from an exposed wire tip cable that is prorated from the drop terminal to a fiber drill site of a fiber distribution cable. Examples of fiber perforation configurations are written in US Patent Application Serial No. 11 / 491,336, entitled Perforation of Fiber Optic Cable with Retention Block, filed on July 21, 2006, the description of which is entirely incorporated into the present by way of reference. In another embodiment, one or more of the adapters may be mounted on a network interface device of the type described in the US Patent Application Serial No. 11 / 607,676, entitled Network Interface Device, filed on December 1, 2006, the description of which is fully incorporated into the present by way of reference. In such an embodiment, the first cable 20 may include a drop cable and the cable 22 may include a cable / connectorized fiber positioned within the network interface device. Alternatively, the fiber optic connection system 30 can also be used without a box (for example, the adapter can be panel mounted).

In the described embodiment, the first connector 32 and the adapter 34 are hardened or strengthened. Hardened or strengthened, it is understood that the first connector 32 and the adapter 34 are adapted for use outdoors. For example, first connector 32 and adapter 34 may include environmental seals to prevent moisture / water from entering. In addition, it is preferable that the first connector 32 is able to withstand an axial pull-out force of 45.36 kilograms (100 pounds) when coupled to adapter 34. The second connector 33 can be a conventional fiber optic connector such as a connector

Subscription Channel (SC). An example of a SC connector is illustrated and described in US Patent No. 5,317,663, the description of which is fully incorporated herein by way of reference.

With reference to figures 5 and 7, the first connector 32 includes a connector housing 39 including a main body 36 and a cover 41. The connector housing 39 extends from a distal end 52 to a proximal end 54 (distal and proximal are defined with respect to connection with fiber optic cable 20 to connector 32). A bolt assembly 43 mounts adjacent to the distal end 52 of the connector housing 39 and a strain relief sleeve 42 mounts adjacent to the proximal end 54 of the connector housing 39. A sealing member 49 (for example, a seal) rim) mounts around a periphery / outside of the connector housing 39. The sealing member 49 is adapted to provide a seal between the connector housing 39 and the adapter 34 when the first connector 32 is plugged into the first hole 35 of the adapter 34. The first connector 32 also includes a wave strip 38 that mounts over the main body 36 and the cover 41, and a sealing tube 106 that seals the interface between the cable 20 and the connector housing 39. The ripple strip 38 helps to retain the cover 41 on the main body and also helps to hold the power members 224 of the cable 20 in place between the cover 41 and the main body 36. The first connector 32 also includes first and second protection structures. fixation to retain (i.e., connect, secure, etc.) the first connector 32 within the first hole 35 of the adapter 34. For example, the first connector 32 can include a coupling 50 (see figures 3, 7, 14 and 15) to mechanically interconnect with adapter 34 when the first connector 32 is inserted into the first hole 35. The first connector 32 also includes a coupling nut 40 adapted to thread on adapter 34 to retain the first connector 32 within the first hole 35 of adapter 34.

The connector housing 39 of the connector 32 extends from the distal end 52 to the proximal end 54. A plug part 56 is defined at the distal end 52 and two flaps 58 are provided on the proximal end 54. One of the flaps 58 is provided by the body 36 of the housing and the other flap 58 is provided by the cover 41 of the housing 39. The body 36 is described as a unitary molded part (for example, a molded plastic part as shown in figures 7 to 9) and the cover 41 is described as a separate unitary molded part (for example, a molded plastic part as illustrated in figures 7, 10 and 11). A central passage 118 is defined through the inside of the connector housing 39 from the proximal end 54 to the distal end 52. The central passage 118 is provided with a distal part 118a defined through the plug part 56 of the connector housing 39 and the proximal part 118b defined between the body 36 and the cover 41. The proximal part 118b of the central passage 118 is defined in part through the body 36 and partly through the cover 41. Removing the cover 41 from the body 36 provides lateral access to the proximal part 118b of the central passage 118. The distal part 118a of the passage 118 is defined entirely by the body 36 and extends through the plug part 56. The distal part 118a of the passage 118 is provided with a distal end at the distal end 52 of the housing 39 and a proximal end adjacent to the proximal part 118b of passage 118.

The plug part 56 of the first connector 32 is sized and shaped to fit with the first hole 35 of the adapter 34, as shown in figures 3, 17 and 19. The distal end of the plug part 56 is preferably provided with a conical configuration that unite or equip (for example, embed, complement) with a conical part of a first receptacle of plug 59 accessed from the first hole 35 (see figure 17). As shown in figure 17, the conical configuration is defined by the opposing surfaces (for example, the left and right surfaces 61, 63) that converge as the surfaces extend along a central geometric axis A1 of connector 32 in one direction distant. The end of the plug part 56 is truncated. When the plug part 56 is positioned within the first plug receptacle 59, the surfaces 61, 63 engage and are parallel to or generally parallel to the guided surfaces 67, 69 that define the first plug receptacle 59.

As shown in figures 14 and 15, the coupling 50 of the first connector 32 is provided in an upper part of the plug part 56. The coupling 50 is provided with a cantilevered arm 90 with a base end 81 which is integrally molded with the plug part 56. The arm 90 extends in a direction distal from the base end 81 to a free end 83. A retaining tab 51 is provided adjacent the free end 83 of the arm 90. The retaining tab 51 includes an inclined region 92 and an inclined region 94. The arm 90 is configured to flex as the plug portion 56 is inserted into the first hole 35 of the adapter 34, and to provide a snap connection between the first connector 32 and adapter 34 when plug part 56 is fully inserted into first hole 35. For example, as shown in figure 14, the retaining tab 51 closes on the engagement notch 82 defined by the adapter 34 when the plug part 56 is fully inserted into the first hole 35. The engagement notch 82 is defined in part by a surface retention 96.

When inserting the plug part 56 in the first hole 35 of the adapter 34, the arm 90 of the coupling 50 is flexed towards the geometric axis A1 by the adapter 34 as the inclined region 92 contacts the adapter 34. The arm 90 it is designed from a material capable of flexing when compressed, such as a plastic. The insertion of the plug part 56 into the hole 35 continues until the sloped region 92 passes through the retaining surface 96 of the slot 82. After the sloped region 92 has passed entirely from the retention surface 96, the declined region 94 comes into contact with the surface 96. A force generated by the flexion of the arm 90 causes the retention flap 51 to lift as the declined region 94 continues passing in front of surface 96. The insertion continues until the declined region 94 has completely, or almost completely, passed in front of the retention surface 96 of the slot 82. At that point, the compression of the arm 90 by the adapter 34 is released, so that the arm 90 returns to its uncompressed state. Alternatively, if desired, adapter 34 can be designed to retain part of the compression of the arm 90.

One of the benefits of the engagement mechanism is that it provides a force that inhibits the removal of the first connector 32 from the first hole 35, in order to resist unintentional disengagement from the first connector 32 from the first hole 35. For example, if the first connector 32 beginning to move in a direction away from the first hole 35, the declined region 94 comes into contact with the retaining surface 96 of the coupling notch 82. At that point, in order for the first connector 32 to be removed from the first hole 35, a force must be applied in a direction away from the first hole 35 sufficient to cause the arm 90 to compress as the declined region 94 is recessed along the surface. 96. The required force can be configured to be greater or less by adjusting the arm strength 90, and also by adjusting the slope of the declined region 94. The engagement configuration of the coupling 50 also provides a physical and audible indication that the first connector 32 has been fully inserted into the first hole 35.

The inclined region 92 of the retention flap 51 is provided with an inclination angle illustrated as A2 and the declined region 94 of the retention flap 51 is provided with an angle of decline illustrated as A3. In the illustrated embodiment, angle A2 is less than angle A3. The benefit of this is that the hitch 50 will be easier to insert than it will be to remove, because the decreased tilt angle (A2) will not show as much resistance to insertion as the increased decline angle (A3) will present for removal. In one example, the angle A3 is around twice the angle A2. In another example, angle A2 is more or less equal to angle A3. It is recognized, however, that any angles A2 and A3 can be formed. In one example, the angles A2 and A3 are in a range of about 0 degrees to about 90 degrees, and preferably 15 degrees to about 85 degrees. In another example, angle A2 is in the range of about 15 degrees to about 45 degrees and angle A3 is in the range of about 30 degrees to about 90 degrees.

The sloping and declining regions 92 and 94 are at a peak, having a height H1. The arm 90 extends at a height H2 over an adjacent part of the plug part 56. In one example, the height H1 approaches the height H2. Alternatively, the height H2 is greater than the height H1 to ensure that the engagement 50 is not impeded from movement by the adjacent part of the plug part 56. Alternatively, height H2 may be less than height H1, as long as adequate space is provided to enable latch 50 to be properly inserted into slot 82.

In another example, the angle A3 can be around 90 degrees, so that the declined region 94 generally extends perpendicular to the arm 90. In this example, the declined region 94 will not allow the hitch 50 to be removed by simply applying a force in a direction away from the orifice 35. In contrast, the latch 50 can be released manually, such as by manually compressing the latch 50, such as through the notch 82. The latch 50 can be compressed, for example, by inserting a release tool through the notch 82 to compress the latch 50. Alternatively, a button can be formed on the notch 82. The button can include an arm that extends through the notch 82, so that the button is compressed, the arm compresses the engagement 50, allowing the first connector 32 to be removed from the first hole 35.

The coupling nut 40 of the first connector 32 is adapted to provide a second connection mechanism for attaching the first connector 32 to the adapter 34. After the coupling 50 is interconnected with the adapter 34, the coupling nut 40 can be threaded on the corresponding threads provided within the first orifice 35 to provide a second connection to the adapter 34. The coupling nut 40 provides a connection to the adapter 34 which is substantially provided with a greater pull-out resistance from the pull-out resistance provided by the coupling 50. In an example of an embodiment, the coupling nut 40 retains the first connector 32 in the first hole 35 even if a pullout force of at least 45.36 kilograms (100 pounds) is applied to the first connector 32.

The coupling nut 40 of the first connector 32 includes a first region 180 and a second region 182. The first region 180 includes a plurality of grooves 184 to facilitate compression of the first region 180, such as by a person skilled in the art or another user during connecting or disconnecting connector 32 with adapter 34. The grooves 184 are, for example, a plurality of longitudinally oriented grooves that enable a user to more easily rotate the coupling nut 10 to 40. The rotation of the coupling nut 40 makes it possible to engage or disengage a connection device of the second region 182 with adapter 34. In the illustrated embodiment, the second region 182 includes an external screw thread connection device 75 adapted to mate with the internal threads 76 provided within the first hole 35 of the adapter 34.

In another embodiment, another connection device can also be used.

The bolt assembly 43 of the first connector 32 includes a bolt 100 (for example, a ceramic bolt), a drum 101 mounted on bolt 100, a spring 102 and a spring support 104. Bolt assembly 43 is loaded on the first connector 32 at the same time as cover 41 is removed from main body 36. To load the bolt assembly 43 into the connector housing 39, the bolt 100 is positioned at the distal part 118a of the central passage 118 by inserting the bolt 100 through the proximal end of the distal part 118a. Inserted in this way, the drum 101 leans against a shoulder 103 located within the plug part 56 (see figures 17 and 19). The spring 102 is then inserted in the distal part 118a behind the bolt 100. Thereafter, the spring support 104 is loaded into a pocket 114 (see figures 8 to 11) of the main body 36 at a location behind the spring 102 so that the spring 102 is captured within the distal part 118a between the drum 101 and the spring support 104. In this way, the bolt 100 is spring loaded in a distal direction.

The proximal part of the connector housing 39 is configured to facilitate the provision of a firm connection between the first cable 20 and the first connector 32. For example, the proximal part 118b of the central passage 118 is sized to receive the casing tube 220 of the first cable 20. Reinforcement member receivers 120 (e.g., channels, passages, grooves, etc.) are provided on opposite sides of the proximal part 118b of the central passage 118 to receive the force members 224 of the first cable 20. The body 36 includes the alignment openings 116 which receive the corresponding alignment pins 117 of the cover 41 to ensure that the cover 41 aligns properly with the body 36 when being mounted thereon. The connector housing 39 also includes the slit openings 122 to allow the adhesive to drain from the inside of the housing 39 when the cover 41 is mounted on the body 36. The inside of the housing 39 also includes structure to provide adhesion between the adhesive and the inner part of the housing. For example, the interior of the housing includes a plurality of slots 123 to improve the adhesion characteristics of the internal surface of the housing 39. Other adhesion structures include knurling, surface roughness, or other structures.

The outside of the connector housing 39 includes a circular groove 112 for mounting the sealing member 49. The outside of the housing 39 also includes the circular shoulders 124 and 125 (see figure 7), in which the waving strip 38 can be touch after mounting the connector and a circular shoulder 113 (shown in figures 8 and 9). A circular recessed part 128 is defined outside the flaps 58. The retaining teeth 130 are located inside the flaps 58.

We will now describe the installation of the connector 32 at the end of a fiber optic cable 20 with reference to figure 5. To begin the installation, the end of the fiber optic cable 20 is prepared using a process of removing the cover. In the process of removing the cover, the outer jacket 226 is torn to expose the reinforcement members 224 and the casing tube 220. After the cover removal process, a portion of the sheath tube 220 is cut to expose the optical fiber 222.

After the end of the cable 20 has been prepared as described above, the sleeve 42 is slid to the end of the fiber optic cable 20, followed by the sealing tube 106 (for example, a thermal shrink tube or thermal shrink tape / wrap) ), the coupling nut 40, and the ripple strip 38. The exposed optical fiber 222 is then fed through the spring support 104 and spring 102, and is mounted within the bolt 100. The bolt assembly 43 is then loaded into the plug portion 56 of the connector housing 39.

Once the ferrule assembly has been loaded into connector housing 39, the first cable 20 is secured in connector housing 39 so that cable 20 extends longitudinally from a proximal end 54 of housing 39. Figures 5 and 7 they are seen in perspective of the body 36 being provided with the cover 41 separated from it, as well as in position for installation with a fiber optic cable. To make the connection, the power members 224 of the fiber optic cable 20 are inserted into the reinforcement member receivers 120 and the sheath tube 220 is inserted in the proximal part 118b of the central passage 118, so that the optical fiber 222 is generally extend along the geometric axis A1. Adhesive is then applied to the liner tube 220, the members 224, the central passage 118, and the reinforcement member receivers 120, including those on the body 36 and the cover 41. The adhesive can be an epoxy or other type of adhesive. Alternatively, the fasteners can also be used to connect the cover 41 with the body 36. The body 36 and the cover 41 are properly aligned by the pins 117 located on the inner side of the cover 41 which are inserted into the alignment openings 116 of the body 36. The cover 41 is then pressed against the body 36 to encircle the force members 224, the sheath tube 220 and the optical fiber 222 within the connector housing 39. The adhesive draining apertures 122 provided in the body 36 and the cover 41 they enable the excess adhesive to be discharged from the housing 39. When the cover 41 is compressed on the body 36, the excess adhesive flows out of the drainage openings 122 and can then be cleaned.

The fiber optic cable 20 is preferably torn in the previous steps so that the outer jacket 226 ends at a shoulder 136 (see figures 8 to 11) of housing 39. Shoulder 136 is located at the distal ends of the flaps 58 at the proximal ends the reinforcement member receivers 120 and the central passage 118. Therefore, the flaps 58 cover the end of the outer jacket 226 when the cover 41 and the body 36 are connected. When the cover 41 and the body 36 are pressed together, the teeth 130 of the flaps 58 are pressed on or against the outer jacket 226. The teeth 130 are oriented to resist movement of the outer jacket 226 in the proximal direction away from the body 36. Therefore , the teeth 130 provide an additional connection device for securing the fiber optic cable 20 securely engaged with the connector housing 39.

After the cover 41 has been connected with the body 36 and the fiber optic cable 20, the ripple strip 38 is slid over a part of the connector housing 39 and folded in place to secure the cover 41 securely to the body 36. The tube sealing strip 106 is then slid over a portion of the ripple strip 38 so as to cover the end of the cable 20, the proximal end of the connector housing 39 and at least a portion of the ripple strip 38. Heating is then applied to the sealing tube 106 to cause the sealing tube 106 to contract and form tightly around adjacent parts of the connector housing 39, the ripple strip 38, and the fiber optic cable 20 to seal the foreign matter connector. The coupling nut 40 is then slid over the corrugation strip 38, the sealing tube 106 and the connector housing 39. The cover 42 is then slid into the first connector 32 and over the sealing tube 106. The cover 42 is, for example, a flexible rubber / polymeric material. At the distal end of the cover 42, the cover 42 can include a structure (e.g., a flange or flange projecting inward) that provides mechanical intercommunication with the recessed part 128 of the flaps 58. Although the flaps 58 are spaced from the cover 42 by the sealing tube 106, the sealing tube 106 fits tightly around the flaps 58, so that the recessed part 128 of the flaps 58 can be engaged by the cover 42. The sealing member 49 is then mounted with the groove 112 around the connector housing 39 to complete the installation of the connector 32 on the fiber optic cable 20. The cover 42 retains the coupling nut 40 in the connector housing 39.

Referring to figures 1, 2, 5 and 12, the adapter 34 of the fiber optic connection system 30 includes an external housing 44 being provided with a first housing 45 which interconnects with a second housing 47. The first housing part 45 defines a first end 70 of outer housing 44 in which the first hole 35 is located. The second housing part 47 defines a second end 72 of the outer housing 44 in which the second hole 37 is located. An adapter assembly 140 mounts within the outer housing 44. Adapter 44 also includes a mounting ring or nut 46 that mounts to the around the outer part 44 external housing.

The first housing part 45 of the adapter 34 includes a first region 60 separated from a second region 62 by a shoulder 64. The first and second regions 60, 62 are generally provided with cylindrical outer shapes and the shoulder 64 provides a reduction in diameter from the first region 60 to the second region 62. The second region 62 defines the ^k 20 external threads 66 located adjacent to shoulder 64. The external threads 66 are dimensioned to join with the corresponding internal threads 68 of the mounting nut 46 so that the mounting nut 46 can be threaded in the second region 62 of the first housing piece 45 The second region 62 also includes a pair of opposing couplings 167 for securing the first housing piece 45 to the second housing piece 47. Each latch 167 includes a flexible cantilever arm 170 being provided with a base end integrally formed with the second region 62. Each cantilever arm 170 defines an opening 172 adapted to receive a corresponding retaining tab 174 of the second housing piece 47 when the first and second housing parts 45, 47 are connected together.

Referring to figure 12, the first region 60 defines the first hole 35 of the adapter 34. The internal threads 76 are provided within the first region 60 adjacent to the first end 70 of the housing 44. The internal threads 76 inside the first hole 35 are dimensioned to receive the external screw threads 75 of the coupling nut 40 when the coupling nut is threaded in the first hole 35 to provide a secure connection between the first connector 32 and the adapter 34.

Referring now to Figures 17 and 19, the first housing piece 45 defines an annular sealing surface 78 positioned within the first housing piece 45 at a location adjacent to the internal threads 76. An angled diameter transition 79 decreases the internal diameter from the first hole 35 of the internal threads 76 to the annular sealing surface 78. The annular sealing surface 78 is preferably generally cinector 32 when the first connector 32 is fully inserted into the first hole 35. The interface between the sealing surface 78 and the sealing member 49 provides an internal environmental seal between the first connector 32 and the adapter 34.

Still with respect to figures 17 and 19, the first housing piece 45 defines an inner pocket 80 within the second region 62 to receive an end part of the second housing piece 47 when the housing pieces 45, 47 are interconnected. The pocket 80 is separated from the annular sealing surface 78 by a shoulder 84 which provides an increase in the diameter of the annular sealing surface 78 for the pocket 80. As shown in figure 13, a keying member 150 (for example, a flap or rail) is provided in pocket 80 to ensure proper pivoting alignment between the first housing piece 45 and the second housing piece 47. The keying member 150 is received in a corresponding keyway 151 defined by the second housing piece 47 when the first and second housing pieces 45, 47 are interconnected together.

The second housing part 47 of the adapter 34 includes a first region 86 separated from a second region 88 by a shoulder 89. The first and second regions 86 and 88 are generally cylindrical in shape. Shoulder 89 provides a reduction in the outside diameter of the first region 86 for the second region 88. The retaining tabs 174 for interconnecting the first housing piece 45 with the second housing piece 47 are provided in the second region 88.

The first region 86 of the second housing part 47 includes a pair of couplings in opposite positions 160 to secure the adapter assembly 140 within the second housing part 47. As shown in figures 12 and 17, each coupling 160 includes a flexible cantilevered arm 161 being provided with a base end 162 integrally formed with the second housing piece 47, and a free end 163 positioned opposite the base end 162. The retaining tabs 164 are provided on the free ends 163. The retaining tabs 164 include the angled surfaces 166 that angled towards the central geometric axis of the adapter 34, and the retaining surfaces 168 that are generally aligned transversely with respect to the geometric axis adapter center 34. The first region 86 of the second housing part 47 may also include a keyway 169 (see figure 3) to receive a corresponding rail 165 from the second connector 33 to ensure that the second connector 33 is inserted into the second hole 37 in the appropriate rotational orientation .

The second region 88 of the second housing piece 47 defines the first plug receptacle 59 for receiving the plug portion 56 of the first connector 32 when the first connector is inserted into the first adapter hole 35. As previously described, the first plug receptacle 59 it is provided with a conical part defined by the opposing surfaces 67, 69 that converge towards each other as the surfaces extend towards the second end 72 of the adapter 34. The conical configuration of the first plug receptacle 59 and the plug part 56 of the first connector 32 facilitates maintaining the precise alignment of the first connector 32 within the adapter 34. The first region 86 of the second housing part 47 also defines a second receptacle of plug 97 corresponding to the second adapter hole 37. The second plug receptacle 97 is adapted to receive the second connector 33.

Adapter assembly 140 of adapter 34 includes a connector retaining clip 201, a split sleeve 202, and a support piece 204. The split sleeve 202 is adapted to receive the bolts of the first and second connectors 32, 33 when the connectors are inserted in adapter 34 to maintain the alignment between fibers 222 of connectors 32, 33. The connector retaining clip 201 includes a pair of latch arms 206 that interconnect with the second connector 33 when the second connector is inserted into the second hole 37 of adapter 34. In this way, the latch arms 206 retain the second connector 33 inside the second hole 37. The connector retaining clip 201 also includes a cylindrical receptacle 208 for receiving an end of the slotted sleeve 202. The other end of the split sleeve is received inside a cylindrical receptacle 209 of the support piece 204. In this way, the split sleeve 202 is captured between the retaining clip 201 and the support piece 204. The flanges 211, 212 of the support clip retainer 201 and support piece 204 are fastened together to retain the split sleeve 202 between retainer clip 201 and support piece 204. When the split sleeve 202 is mounted on the retaining clip 201 and the support piece 204, the split sleeve 202 is provided with a limited amount of space available to slide axially into the cylindrical receptacles 208, 209. However, this limited space does not allow that the split sleeve 202 floats within the cylindrical receptacles 208, 209 to provide proper alignment between the bolts 100 of the connectors 32, 33.

Mounted adapter assembly 140 is loaded onto second housing 47 by inserting adapter assembly 149 into second plug receptacle 97 through second adapter hole 37. As adapter assembly 140 is inserted into second plug receptacle 97, the flanges 211, 212 of the adapter assembly engage the angled surfaces 166 of the cantilever arms 161 causing the cantilever arms to flex outward. After the flanges 211, 212 have been pressed in front of the angled surfaces 166, the cantilever arms 161 fit radially internally and the retaining surfaces 168 of the retaining flaps 164 capture and retain adapter assembly 140 in the second housing 47 (see figure 17). Thus positioned, the retaining clip end of adapter assembly 140 is accessible from second hole 37 of adapter 34 and the end of support piece of adapter assembly 140 is accessible from first hole 35 of adapter 34. Flanges 211, 212 are captured between the retaining surfaces 168 of the retaining tabs 164 and a shoulder 213 of the second housing piece 47. The cylindrical receptacle 208 of the retaining clip 201 is positioned within the second plug receptacle 97 and the cylindrical receptacle 209 of the support piece 204 is located within the first plug receptacle 59. The split sleeve 202 is generally aligned along the geometry axis adapter center 34. In the described embodiment, the adapter does not include a frame (for example, a spring or other resilient or polarizing structure) to facilitate adapter assembly 140 to float within outer housing 44. Instead, retaining tabs 164 prevent assembly adapter 140 floats or otherwise moves within the outer housing 44. However, as indicated above, there is a limited amount of space between the split sleeve 202, which is arranged in the adapter assembly 140, and the cylindrical receptacles 208, 209 which allows the split sleeve to float within the cylindrical receptacles 208, 209.

After the adapter assembly 140 has been fitted to the second housing part 47 of the outer housing 44, the first and second housing parts 45, 47 are connected together. For example, the second region 88 of the second housing piece 47 is inserted into the pocket 80 defined within the second region 62 of the first housing piece 45. During insertion, rotational alignment is ensured by inserting the keying member 150 of the first piece housing 45 in the keyway

151 of the second housing 47. As the second housing 47 is inserted into the first housing 45, the cantilever arms 170 engage the retaining tabs 174 causing the can21 arms 170 to flex outward. When the openings 172 of the cantilever arms 170 align with the retention flaps 174, the cantilever arms fit radially inward to a locked position in which the retention flaps 174 project through the openings 172.

The adapter 34 is adapted to be mounted inside an opening defined by a wall of the housing 19. To mount the adapter 34 in the opening, the mounting nut 46 is first removed. The second end of the outer housing 44 is then inserted from the outside of the box through the mounting opening until the shoulder 64 touches the outer surface of the box wall. Thereafter, the mounting nut 46 is threaded on threads 66 until the nuts touch the inner surface of the housing wall. With the box wall captured between the shoulder 64 and the mounting nut 46, the adapter 34 is mounted securely in the box.

As indicated above, adapter 34 is configured to provide an optical connection between the first connector 32 and the second connector 33. To provide this connection, the first connector 32 is mounted in the first hole 35 and the second connector 33 is mounted in the second hole adapter 37. To mount the first connector 32 in the first adapter hole 35, the first connector 32 is inserted axially into the hole 35 until the plug part 56 fits into the first plug receptacle 59 and the latch 50 fits into the slot 82. Thus positioned , the bolt 100 fits within one end of the split sleeve 202 and the sealing member 49 engages the annular sealing surface 78. The connection is terminated by screwing the coupling nut 40 onto the internal threads 76 of the adapter 34 until an end surface 115 (shown in figures 7 and 17) of the coupling nut 40 touches the circular shoulder 113 of the connector housing 39, retaining thereby the connector housing 39 against the second region 88 of the second housing piece 47 of the adapter 34, as shown in figure 17. The second connector 33 is mounted in the second adapter hole 37 by inserting the connector axially into the hole 37 until the connector 33 is seated between the arms 206 of the connector retaining clip 201. Thus positioned, the bolt

230 of the connector 33 is received inside the other end of the split sleeve 202 so that the bolts 230, 100 are secured in axial alignment with each other.

The fiber optic connection system 30 is preferably provided with a compact configuration adapted to provide relatively high circuit densities. In one embodiment, the diameter D1 of the sealing member 49 and the diameter D2 of the annular sealing surface are less than or equal to 15 mm. In an alternative embodiment, the diameter D1 of the sealing member 49 and the diameter D2 of the annular sealing surface are less than or equal to 12.5 mm. In another embodiment, the diameter D1 of the sealing member 49 and the diameter D2 of the annular sealing surface are less than or equal to 10 mm.

Figures 20 to 23 describe another fiber optic connection system 330 having the characteristics that are examples of the inventive aspects according to the principles of the present description. The system includes a first connector 332 and an adapter 334 to optically connect the first connector 332 to another connector. The structure of the fiber optic connection system is provided with the same general configuration as the system 30 in figures 1 to 22, except that connector 332 includes a multi-terminated bolt 301 (for example, a bolt with more than one fiber assembled) in it) and adapter 334 to connect the first multi-termination connector to a second multiple-termination connector. The multiple termination bolt 301 is generally provided with a rectangular configuration, and the adapter 34 generally includes multiple termination bolt receptacles to accommodate the multiple termination bolts.

From the detailed description above, it will be evident that changes and variations in the devices of the description can be made without departing from the spirit or scope of the invention.