Patent Application
20090080849
1. Field
This invention generally relates to a blank plate for managing cables and, more particularly, for storing and protecting cables prepared in advance for future use in electronic and/or optical telecommunications equipment or the like.
2. Description of the Related Art
An electronics or optical equipment frame used by telcos and the like typically is subject to expansion during its useful life, i.e., additional circuit boards or cards will be installed. When a card is added to the frame, additional cables are required to connect the card to the appropriate external components. The additional cables need to be cut to the proper length, verified that they have been cut to the proper length, and routed and connected to the added card. It is often advantageous to cut, verify and route the additional cable in advance of the time at which an expansion card is added. It is important to store unused cables in a protective manner prior to installation of a new expansion card. For example, the present invention has particular utility with a Tellabs 8865 ServiceAware GPON Optical Line Terminal (OLT) system, which employs a chassis that supports up to 98 GPON ports for switching and routing, with 8 ports on each separate circuit board, or on each blank.
In this regard, fiber optic cables are more delicate than copper cables, and require increased vigilance and a secure and protective storage. Accordingly, it would be advantageous to provide a way to store and protect fiber optic cables that have cut, verified and routed in advance of the installation of expansion cards in a frame.
Optical fiber connectors permit connections either between two fibers, by physically aligning the cores of the fibers with one another, or to connect a optical fiber to a light source (e.g., a laser) or a receiver. Many commercially available connectors include four basic components: a ferrule; a connector body; a cable; and a coupling device. A ferrule is a long, thin cylinder in which the fiber is mounted. The end of the fiber typically is located at the end of a ferrule held in a connector body, typically of plastic with pieces to hold the fiber in place. The ferrule extends past the connector body to slip into a coupling device. A cable is attached to the connector body. Typically a strain-relief boot is added over the junction between the cable and the connector body, providing extra strength to cable that location.
Examples of commercially available optical fiber connectors include SMA 906 connectors (Amphenol Corp.), ST connectors (introduced by AT&T), FC connectors (introduced by NTT), D4 connectors (designed by NEC), HMS-10 (by Diamond, Inc.), and SC connectors (from NTT). A Singlemode application, type SC connector is illustrated in the drawings in an example embodiment of the invention. Such a configuration commonly is used in long-haul network connections by telcos when fiber optical cabling is used for connections between switching offices. Examples of a single cable connector system are illustrated within Akins et al. (U.S. Pat. No. 5,828,804) and examples of duplex cable connector system are illustrated within Connelly et al. (U.S. Pat. No. 6,511,230).
An example of a prior, elongated card that simply replaces an active circuit with clamps and a stop for engaging an unused single fiber optic cable end inside of a chassis is illustrated at FIG. 2 of Gehrke et al. (U.S. Pat. No. 6,487,358). Further examples of prior optical fiber cable management structures are illustrated within Musetti (U.S. Pat. No. 6,459,841); Griffiths et al. (U.S. Pat. No. 6,810,194) and Tirrell et al. (U.S. Pat. No. 6,791,841).
The present invention addresses the challenges discussed above.
According to an example aspect of the present invention, there is provided a blank plate for managing cables, including a planar base that is removably securable to a chassis, with at least one resilient holder being removably secured simply within the planar base, for securing a cable end. The blank plate does not extend at all within the chassis, and the resilient holders do not extend substantially within the chassis, leaving a large open space behind each holder.
According to a another example aspect of the present invention, there is provided a blank plate for managing cables, including a base, that is removably securable to a chassis, with at least one resilient holder, removably secured to the base, for securing a cable end at a position that is not substantially within the chassis but instead substantially at the same position of the cable when secured to a circuit board, instead of the blank plate.
According to still a further example aspect of the present invention, there is provided a device for managing unused cables, including a base for attaching to a chassis surface that is a blank plate with at least one holder of molded rubber being removably held within an aperture of that blank plate by a grommet configuration proximate the middle of that holder. The holder has a front opening to an enclosed space that is adapted to accept a cable end. The back of the holder is closed and does not extend substantially within the chassis. The rubber holder can be easily pulled into the base plate aperture by an optional handle, formed on the back of the holder.
Further example aspects of the present invention include the following features. The holder may be removably securable directly to the base, without an intermediary member between the holder and the base. The holder may secure a portion of the cable in a straight position within the holder, so the end of the cable is constrained an angle greater than 0° and less than or equal to 90° with respect to the base. The base may be removably secured to a carrier, with that carrier then being removably secured to the chassis. Such a carrier may be capable of having at least two bases removably secured thereto. The cable end may be removably engaged inside the holder by means of resilient contact against a cable end connector. The cable may be an optical fiber. The blank plate may include no electronic or optical parts. While a single cable and connector application of the SingleMode type, with common SC type connectors, is illustrated in the following embodiments, the invention is equally applicable to a duplex cable and connector system.
A better understanding of these and other aspects, features, and advantages of the invention may be had by reference to the drawings and to the accompanying description, in which example embodiments of the invention are illustrated and described.
Throughout the figures, like or corresponding reference numerals are used to identify like or corresponding parts.
An example embodiment of the present invention comprises a blank plate 100, which stores and protects cables 110 that are cut, verified and routed in advance of the installation of expansion cards in a frame. Blank plate 100 may be thought of functionally as a dummy or “parking” card which is substantially flat, with structure that differs significantly from that of an elongated, active or functional card. The structure and function of blank plate 100 according to example embodiments of the invention are described below.
Blank plate 100 comprises a base surface 102 into which resilient holders 104 are inserted. Two such blank plates 100 commonly would be held in a carrier 106, as shown in
The term “chassis” is to be understood in the broadest possible sense. As an example, the term may refer to a cabinet, frame or the like for housing equipment such as electronics equipment, telecommunications equipment, etc. Such a chassis commonly, though not necessarily, has multiple shelves and slots for accommodating circuit boards or cards having, e.g., optical or electrical components mounted thereon. Such components may typically, but need not, be connected to a communications network via, e.g., fiber optic or other cables. The example embodiments of the invention discussed herein have particular, although not exclusive, application to optical telecommunications equipment.
The term “cable” is also to be understood in the broadest possible sense, and contemplates single and duplex cable configurations. The term subsumes any conduit, e.g., electrical, optical or other such media used to transmit and/or receive data or information. The example embodiments of the invention discussed herein have particular, although not exclusive, application to fiber optic cables, which may also be referred to herein as optical fibers. Suitable modifications to the example embodiments discussed below for the purpose of adapting those example embodiments for use with electrical cables, to the extent that such modifications would be necessary or desirable, would be known to those of skill in the art in view of the descriptions herein.
The term “carrier” is also to be understood in the broadest possible sense. As an example, the term refers to a member that accommodates one or more circuit boards or cards, or blank plates, dummy cards or the like, and that may be accommodated in a chassis.
Each cable 110 may be provided with a connector 112 at one or both ends of cable 110. For example, a fiber optic cable end may have a secured connector 112 that frictionally engages into the rectangle opening 113 of a rubber holder 104
The illustrated SC type connector 112 male portion is plastic and includes a key 111 (
It is further noted that it is possible to fasten a cable 110 to a holder at a position other than the absolute end of that cable. It is further noted that use of a connector 112 on the end of a cable is not required.
The term “secure” as used herein means to hold in place in the broadest sense, not necessarily involving a physical connection of the two items secured to one another and not necessarily requiring that the secured items cannot move. For example, a wire running through a channel may be deemed secured in the channel insofar as the range of motion of the wire, or the range of positions the wire can occupy, is limited. In contrast, the terms “attach,” “connect,” “join,” and “fasten” as used herein are all taken as requiring a physical connection between two items.
In this regard, it is possible for cable 110 to be merely secured against, but not firmly attached to holder 104. Ways of securing cable 110 to holder 104 will be known to those of skill in the art in view of this description.
Holder 104 is illustrated to be of a molded rubber or like resilient material, and a simulation of an SC type female connector, with a rectangular inner spacel 13 behind an SC type opening or inlet 115 at a front end thereof adapted to distend if needed to engage against both an SC type male portion connector 112 and possibly also an exterior sheath of a Singlemode fiber optic cable 110. Opening 115 thus serves as an inlet for either the sheath of a cable 110 or just a connector 112. Holder 104 may be formed so that, aside from the inlet 115, the inner space 113 constitutes a closed space. Forming holder 104 as closed space may help protect cable 110 from physical damage, dust, and the like.
It is not necessary to form holder 104 as such an enclosing structure. For example, the rear end of holder 104 could be open. Holder 104 alternatively could have an inner space 113 that is ring-like or semi-cylindrical, to engage resiliently against an exterior sheath surface of a cable 110.
The term “enclosure” as used herein is not to be taken as necessarily so fully enclosing as are the holders 104 illustrated in the figures. Rather, the term is intended to subsume a structure that to some degree encloses the enclosed item from its surroundings.
Holder 104 may be of rubber and include an outer grommet-like portion 116, as shown in
Base 102 of blank plate 100 may be a planar member fastened to a chassis 108 through a carrier 106 by means of a screw or screw assembly 120. Screw assembly 120 may, but need not, be a captive fastener, such that the screw remains fastened to the screw assembly 120 or base 102 even when fully loosened and when blank plate 100 is removed from carrier 106. One of ordinary skill in the art will appreciate in view of this description that any other type of suitable fastener may be used to fix blank plate 100 to chassis 108. Active card 101 typically will be fastened to carrier 106 by means of an identical or similar screw or screw assembly 120, or by such other suitable fastener as may be used to join blank plate 100 to carrier 106.
As shown in
Carrier 106 may be thought of as a convenient intermediary between a blank plate 100 and a chassis 108. It is not required to employ carrier 106 or any other intermediary or the like. It is possible to suitably modify chassis 108 so that blank plate 100 can be fastened directly to, or mounted or fitted directly in, chassis 108. Ways to accomplish this will be understood by one of ordinary skill in the art in view of this description.
A conventional carrier 106 typically will have slots (not shown) for holding either blank plates 100 or cards 101. As shown in
A chassis 108 typically will have slots for accommodating carriers 106, and may include rails (not shown) similar to card rails 126 for helping secure carriers 106. As shown in
As will be appreciated by one of ordinary skill in the art in view of this description, it will generally be advantageous and convenient for all of the connections, mountings, and the like described herein to be capable of being easily released, undone or the like, although this is not an absolute requirement.
A typical carrier 106 will hold two blank plates 100. In
It will be appreciated by one of ordinary skill in the art in view of this description that the design of the various components described above may be modified to vary the number of holders that may be accommodated on a single blank plate, the number of blank plates and/or cards that may be accommodated in a single carrier, and the number of carriers (or, in other example embodiments, blank plates and/or cards) that may be accommodated in a single chassis. Similarly, the spacing between, or location of, holders on a blank plate may be modified, as will be appreciated by one of ordinary skill in the art in view of this description. As an example, a blank plate could be made having a double width, thus accommodating two rows of holders, side by side.
Operation of an example blank plate 100 will be further described below. Blank plates 100 may be provided in sufficient number to fill some or all of the unpopulated slots of a chassis 108, while not intruding any substantial distance into the chassis space. Unused cables 110 may be provided in sufficient number to connect to some or all holders 104 of blank plates 100, so as to accommodate quick and efficient future installation of expansion cards. Hence, unused fiber optic cables 110 with functional male connectors may be temporarily and safely parked inside holders 104 on a blank until an active card is required to replace that blank.
Whenever it is desired to install an expansion card 101, i.e., a dummy card or blank plate 100 can be replaced with a new, active circuit board 101, which does substantially extend inside the chassis, using the following steps. Ends of unused cables 110 are disconnected from holders 104 of a blank plate 100 to be replaced, which then is disconnected from carrier 106 by means of screw assembly 120 and slid out of its slot in carrier 106. An expansion card 101 is slid into the empty slot in carrier 106 along card rails 126 and connected to carrier 106 by means of its screw assembly 120. Cables 110 which had been disconnected from inactive holders 104 then are connected to active holders 130 (
As seen from the above description of example embodiments of the invention, blank plate 100 serves to store and protect unused cables 110 that are cut, verified and routed in advance of the installation of an expansion card 101. In particular, blank plate 100 retains cables 110 in such a manner as to minimize handling of cables 110 and contact of delicate end portions of unused cables 110 with foreign objects, without requiring an elongated metal dummy circuit board and interior holding clamps and end stops, for example, which must be located substantially inside the chassis space. Further details in this regard, as well as additional advantages provided by example embodiments of the invention, are discussed below.
In the example embodiments illustrated in the figures, blank plate 100 is formed as a faceplate-like flat structure, which does not extend substantially within carrier 106 or chassis 108. In contrast, an active expansion card 101 extends substantially the length of card rails 126. A blank plate 100 requires only a relatively small amount of material for manufacture thereof, as compared to card 101, and does not require use of card rails 126 for mounting on carrier 106 (or, in other example embodiments, similar rails for mounting directly in chassis 108), thus reducing the load on the rails. In addition, as shown in the figures, blank plate 100 is relatively simple in configuration (shape, etc. of base 102, holders 104, etc.), which simplify design and manufacture thereof.
A blank plate 100 does not provide any elongated surface extending into the chassis, since no manner of active, functioning electronic or optical components are associated with the enclosure inside the rubber holder, 104. A holder 104 made of molded rubber is easily secured or attached to simple apertures formed in the planar base 102 directly, without need for any intermediate member, to achieve the connection. In that regard, a resilient grommet outer surface configuration molded on the holder, proximate its midsection, particularly allows inserting the holder in a simple fashion, and greatly simplifies manufacture. All of these aspects of blank plate 100, while not required, may reduce costs of manufacture and increase durability and reliability.
In the example embodiments illustrated in the figures, holders 104 are mounted at an angled orientation relative to the face or front surface of base 102 in which they are mounted. Holders 104 are also mounted in the same position and orientation in base 102 as holders 130 are mounted in card 101. These features of holders 104, while not required, may serve to protect cables 110 by ensuring a minimum bend radius of cables 110, so as not to overly strain cables 110.
In
For purposes of describing the angle at which the holders 104 are mounted in base 102, 0° will be taken as referring to the case in which holder 104 lies parallel to base 102 in an upward direction, 90° will be taken as referring to the case in which holder 104 lies normal to base 102, extending outward from the face or front surface of base 102 (i.e., outward from the plane of the paper in
In the example embodiments described and illustrated herein, holders 104 have been described as being mounted at an angle between 0° and 90° (i.e., mounted at an upward angle) or at an angle between 90° and 180° (i.e., mounted at a downward angle), with respect to base 102. Such upward and downward angles are suitable for the purpose of ensuring a minimum bend radius and thus avoiding undue strain on cables 110, in some common configurations of a system including a chassis 108 from which cables 110 are routed to other components. The angle of a mounting holder 104 may be varied as appropriate in view of a system configuration, for the purpose of avoiding excessive strain on cables 110 as will be understood by those of ordinary skill in the art. In addition to avoiding excessive strain on cables 110, another purpose achieved by mounting resilient holders at an angle other than 90°, is to reduce the amount of space required for a system. By mounting holders 104 at an angle other than 90°, the amount of space required in front of chassis 108 is reduced as compared with holders 104 mounted at an angle of 90°. In view of the above discussion, the term “orientation” may be used to refer to the angle at which holders 104 are mounted or, similarly, at which cables 110 are secured in holders 104.
The base 102 configuration is illustrated with holders 104 to be mounted at only a single given angle. Alternatively, base 102 could be formed in for permitting holders 104 to be mounted at different angles. For example, base 102 could be formed in a configuration permitting holders 104 to be rotatable between one or more upward angled positions and one or more downward angled positions, at each of which holders 104 could be releasably held in place. Other example configurations of base 102 in this regard are possible.
The example embodiments illustrated in the figures, holders 104 hold cables 110 having a male connector 112 at the end of each cable. In
Either a blank plate 100 or an active card 101 optionally may have an electromagnetic shield 134 provided along the length of the side of base 102, as shown in
As for the materials of composition of blank plate 100, base 102 may be made of metal, plastic, fiberglass, or other materials. One example of metal for this purpose is steel. For the purpose of electromagnetic shielding, metal may be more advantageous than plastic.
Holders 104 may be made of natural rubber or a blend thereof, a synthetic vinyl or nylon, or other materials. Examples of such resilient materials for this purpose include EPDM (ethylene propylene diene monomer), silicone or any soft thermoplastic material.
Electromagnetic shield 134 may be made of, e.g., copper, or other suitable materials. The range of such materials is understood to be known to one of ordinary skill in the art.
The details of the present invention as described above and illustrated in the accompanying figures are to be taken as examples and not as limiting. It is understood that to the extent any details pertinent to the invention are omitted herein, they are known to those of skill in the art.
One of ordinary skill in the art will realize that modifications and variations, including but not limited to those discussed above, are possible within the spirit and scope of the present invention. The invention is intended to be limited in scope only by the accompanying claims, which should be accorded the broadest interpretation so as to encompass all such modifications, equivalent structures and functions.
