Distribution frames are widely utilized, for example in a building communications network, to interconnect optical fibers. Such distribution frames are sometimes also referred to as “termination” or “cross-connect” frames because they include connector modules having adapters and jumper cables or “jumpers” that extend between two connector modules to interconnect optical fibers terminated at adapters within the connector modules. The increasing demand for communications services, particularly within office buildings and technology centers, requires that new distribution frames be able to interconnect a greater number of optical fibers. This requirement is commonly referred to as “termination density” and frames meeting the requirement are commonly referred to as “high density” distribution frames. Numerous high density fiber optic distribution frames are known including the Advanced Distribution Frame (ADF) available from Telect, Inc. of Liberty Lake, Wash., USA and the Fiber Main Distributing Frame (FMDF) available from ADC Telecommunications, Inc. of Eden Prairie, Minn., USA. Such distribution frames are shown and described in many prior United Sates patents, including for example, U.S. Pat. No. 6,360,050 assigned to Telect, Inc., and U.S. Pat. Nos. 5,758,003, 5,717,810 and 5,497,444 assigned to ADC Telecommunications, Inc.
Each of the known high density fiber optic distribution frames, however, has certain deficiencies and none provides a combination of features necessary to address all of the deficiencies. For example, the known distribution frames are typically not compatible with existing fiber optic hardware, commonly referred to as “legacy” hardware. In particular, the existing distribution frames are not compatible with legacy connector housings, such as LGX® connector housings available from American Telephone and Telegraph Corporation (AT&T Corp.) of New York, N.Y. or LDC™ connector housings available from Coming Cable Systems LLC of Hickory, N.C.
In addition, the known distribution frames do not include a frame assembly that adequately controls the bend radius of the optical fiber as the jumpers transition on the frame between connector modules. Control of the bend radius of the optical fiber is essential to prevent damage that degrades the transmission characteristics of the optical signal being transmitted over the optical fiber. Stated differently, the known distribution frames include a frame assembly that exceeds the minimum bend radius of the optical fiber at some point along the path of travel of the jumpers between connector modules.
Further, the known distribution frames do not include an Interbay Fiber Manager (IFM) that can be readily configured with the distribution frame for convenient storage and routing of optical fiber, while maintaining the minimum bend radius of the optical fiber. Still further, the known distribution frames typically employ a single length jumper for convenience and ease of manufacture. The length of the single length jumper must be long enough to extend between the connector modules that are positioned farthest apart on the distribution frame. As a result, the majority of the jumpers are longer than necessary and the slack lengths of the jumpers must be stored on the distribution frame. The slack lengths of the jumpers tend to accumulate, or “pile-up,” adjacent the base of the distribution frame, thereby unnecessarily increasing the lateral and depth dimensions of the frame.
The present invention addresses each of the aforementioned deficiencies, as well as others. Accordingly, the invention provides an improved high density fiber optic distribution frame for interconnecting optical fibers in a communications network.