Patent Application
20100199447
The present invention relates generally to optical networks. More particularly, this invention relates to a cleaner guide for cleaning backplane optical connectors.
Fiber optic systems have been getting more popular recently. With the advent of light-wave technology, a large amount of information is capable of being transmitted, routed and disseminated across great distances at a high rate over communication lines made of optical fibers which are coupled with each other through optical connectors.
Dust, dirt and other contaminants are a problem in such optical connections because they interfere with the passage of light from one fiber to another. Fiber optic connectors must be kept clean to ensure long life and to minimize transmission loss and optical return loss at the connection point. A single dust particle caught between two connectors will cause significant signal loss.
Optical connectors on a backplane are difficult to clean for several reasons. One reason is because the equipment housing the backplane and optical connectors is generally placed against a wall making access to the rear of the optical connectors difficult. Also, the optical connectors are small and difficult to handle when removed for cleaning so it is advantageous to be able to leave them in the system and clean the optical connectors via front access to the shelf. Another reason is that cleaning the optical connectors via front creates the possibility of contact with other system components causing catastrophic failure of the system.
Conventional methods require the removal of adjacent circuit pack modules to create space for the operator to reach the optical connectors on the backplane. However, removal of adjacent circuit pack modules may prevent the system node from operating partially or even completely. In addition, removing, rotating, and replacing the cleaning adapters individually could be a cumbersome process if the backplane has many optical connectors.
There has been a lack of simple and reliable solutions for cleaning and inspecting optical connectors inside a backplane chassis where the connectors are not easily accessible, while allowing other components to continue operating.
An apparatus for cleaning backplane optical connectors is described herein. According to one embodiment, an apparatus includes a cleaner guide having a frontend and a backend, where the cleaner guide has a cleaning channel extended from the frontend to the backend and the backend includes a mounting bracket for removably mounting a connector adapter. When the cleaner guide is inserted into a slot of the chassis, the connector adapter is aligned and engaged with an optical connector disposed on a backplane of the network chassis, such that a cleaner tool can be inserted from the frontend of the cleaner guide, through the cleaning channel, to reach the connector adapter of the backend for cleaning the optical connector, without having to remove an adjacent circuit pack of the network chassis.
Other features of the present invention will be apparent from the accompanying drawings and from the detailed description which follows.
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar elements.
A cleaner guide for cleaning backplane optical connectors is described herein. In the following description, numerous details are set forth to provide a more thorough explanation of embodiments of the present invention. It will be apparent, however, to one skilled in the art, that embodiments of the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring embodiments of the present invention.
Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification do not necessarily all refer to the same embodiment.
In most fiber systems, dust and other contaminants are not a major problem as long as the “light”, that is the optical signal, remains within the optical fiber. However, problems arise when the optical signal must pass from one fiber to another or where the optical signal must leave the fiber and enter a receiver or piece of test equipment, such as an optical power meter. The most common mechanical arrangement to allow light to travel from one fiber to another is an optical connector. Fiber optic connector systems are designed to align two fiber ends so that the light signal will pass between them.
Most connector systems restrain the two fibers to be coupled within precision ferrules, which in turn are held in place by a housing. Within the housing, a precision alignment sleeve aligns the two ferrules and thus the two fibers. The fiber ends are flush with the ferrule ends and are polished to reduce loss of light. All modern connector designs involve physical contact between the two fiber ends.
As mentioned above, dust, dirt and other contaminants are a problem in such optical connections because they interfere with the passage of light from one fiber to another. Fiber optic connectors must be kept clean to ensure long life and to minimize transmission loss and optical return loss at the connection point. A single dust particle caught between two connectors will cause significant signal loss.
In order to avoid problems and to keep fiber ends in peak condition, connector cleaning must be undertaken frequently. Inspection of the fiber end quality also needs to be undertaken to determine if cleaning is required or if the connector is seriously damaged.
The two basic approaches to cleaning are wet and dry cleaning. Wet cleaning utilizes a solvent such as Isopropyl Alcohol and fiber optic swabs. The swabs have a head made of a soft nonabrasive material that has low particle and fiber generation. Dry cleaning takes a number of forms, but the most common approach involves a special alcohol-free cloth or textile cleaning tape or film on a reel inside a cartridge. The cartridge stores the tape reel and provides a window onto a short portion of the cloth tape for cleaning the fiber ends of connectors. Also, a fiber optical swab with a sticky or tacky head may be used. Dynamic cleaning devices are also available which “spin” a cleaning cloth across the end of the fiber.
Microscopic inspection must be conducted to confirm that cleaning is successful. On some occasions, even after repeated cleaning, inspection will show that the fiber end is damaged beyond recovery and the connector must be replaced.
As mentioned above, optical connectors on a backplane are difficult to clean for several reasons. A backplane is an electronic circuit board containing circuitry and sockets into which additional electronic devices on other circuit boards or cards can be plugged. One reason is because the equipment housing the backplane and optical connectors is generally placed against a wall making access to the rear of the optical connectors difficult. Also, the optical connectors are small and difficult to handle when removed for cleaning so it is advantageous to be able to leave them in the system and clean the optical connectors via front access to the shelf. Another reason is that cleaning the optical connectors via front creates the possibility of contact with other system components causing catastrophic failure of the system. Another reason is that once the cleaning process is complete, all the fiber ends in the bundle must be clean. Furthermore, due to the small scale of the optical connector, finding the correct position for the cleaning swab or inspection scope while viewing the backplane from the front is very difficult.
Thus, the purpose of embodiments of the invention is to create an efficient solution for cleaning optical connectors mounted on a backplane of a chassis. The optical connectors are cleaned from the front of the chassis without having to remove adjacent circuit pack modules. Thus, it allows cleaning of the backplane optical connectors, one slot at a time, without having to completely shut down the corresponding system node (e.g., the chassis).
According to certain embodiments, to dry clean optical connectors in a backplane from the front of the chassis, a cleaner adapter needs to be installed into each optical connector. A cleaning ward of a cleaning tool is then inserted through the cleaning adapter and into the optical connector to clean the first set of ferrules (e.g., fibers) of the optical connectors. To clean the second set of ferrules of the optical connector, the cleaning adapter needs to be removed from the optical connector, then rotated in 180 degrees, and finally reinserted into the optical connector. The cleaning ward is then reinserted through the cleaning adapter and into the optical connector to clean the second set of ferrules.
Embodiments of the invention allow for a safe and efficient process for cleaning optical connectors. One advantage of embodiments of the invention is that cleaning could be performed without the removal of adjacent circuit packs. Another advantage is that it eases the process of installing the cleaning adapters. Such a design also provides safety to adjacent circuit packs during the cleaning process, such that the adjacent circuit packs would not be damaged during the cleaning process.
Referring back to
In addition, dry cleaning of HBMT connectors requires the attachment of the HBMT cleaning adapter in two positions to clean both sets of optical fibers (e.g., ferrules of a connector). The two positions require a user to rotate the HBMT cleaning adapter 180 degrees around an axis of the HBMT connector. According to one embodiment, the design described throughout this application allows the HBMT cleaning adapter to be rotated 180 degrees to fulfill the required positions for multiple HBMT connectors per circuit pack slot as shown in
Once cleaning module 100 is inserted into chassis 108 with appropriate HBMT cleaning adapter 106 mounted via alignment bracket 104 in an appropriate orientation, a dry cleaner wand of a dry cleaner 110 can be inserted from a front panel of chassis 108, through cleaning module 100, to reach the HBMT connectors (not shown) mounted on a backplane of chassis 108 for cleaning, where ferrules of the HBMT connectors are maintained opened by HBMT adapters 106 which are aligned by alignment bracket 104, as shown in
According to another embodiment, cleaning module 100 can also be used for wet cleaner and optical inspection probes. In such situation, cleaning module 100 can simply inserted without the HBMT adapters and/or the alignment bracket mounted thereon. A wet cleaner and an optical inspection probe can be inserted through the cleaner module to reach the HBMT connectors mounted on the backplane.
Further, according to one embodiment, cleaner module 100 further includes side panels to form a tunnel or channel to allow a cleaner or inspection probe to be inserted therein. The side panels also serve a protection purpose such that during the cleaning or inspection process, adjacent circuit packs would not be accidentally contacted (e.g., short circuit).
Before cleaning the HBMT connectors of a particular circuit slot of a chassis, the corresponding circuit pack of the particular circuit slot is removed from the chassis. An HBMT adapter 106 is attached to an alignment bracket 104 and the alignment bracket 104 having HBMT adapter 106 attached thereon is then inserted into cleaner guide module 102, forming a cleaning module 100, as shown in
Once the first set of ferrules of an HBMT connector has been clean, cleaning module 100 is removed from the slot as shown in
According to one embodiment, cleaner guide 102 includes a front panel 112, a first side panel 114, and a second side panel 116, which are mounted onto the front panel 112 via a pair of mounting brackets. Side panel 114 is a relatively flat panel while side panel 116 is in a U-shape form, which when attached onto side panel 114, forms a tunnel, in this example, a relatively rectangular tubular tunnel 118 which connects with an opening of front panel 112 with a back of cleaner guide 102. As described above, tunnel 118 may be used to insert a cleaning tool from a front panel 118 of cleaner guide to the backend of the cleaner guide in order to reach and clean the HBMT connectors of the backplane for the inspection and/or cleaning purpose.
Front panel 112 includes one or more handles 120A-120B to allow a user to pull the cleaner guide 102 out from a slot of a backplane chassis. Front panel 112 further includes one or more stop brackets 122A-122B to stop the cleaner guide 102 from being overly pushed into a slot of the backplane chassis. An enlarged version of front panel 112 is shown in
Referring back to
In one embodiment, cleaner guide 102 further includes one or more alignment slots 124A-124B mounted on a backend of cleaner guide 102. In this embodiment, alignment slots 124A-124B are mounted on a backend of side panel 114. When cleaner guide 102 is inserted to a circuit slot of a backplane chassis, the alignment slots 124A-124B are aligned with corresponding alignment pins (not shown) mounted on a backplane of the chassis. In this way, the HBMT adapters along with the alignment bracket can be precisely aligned with the corresponding HBMT connectors mounted on the backplane of the chassis.
In this embodiment, side panel 114 is formed in a relatively U-shape having a center piece and two wing pieces as shown in
In addition, according to one embodiment, a portion of a backend of side panel 116 is bent or folded inwardly to form a mounting fixture or mounting bracket 140 for mounting an alignment bracket with one or more HBMT adapters such as one shown in
Thus, a cleaner guide for cleaning backplane optical connectors has been described herein. In the foregoing specification, embodiments of the invention have been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of the invention as set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.
