Electrical connectors – Contact comprising cutter – Insulation cutter
Reexamination Certificate
1998-12-16
2001-06-26
Abrams, Neil (Department: 2839)
Electrical connectors
Contact comprising cutter
Insulation cutter
C439S344000
Reexamination Certificate
active
06250949
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to the field of cable connectors and more specifically to a modular plug for terminating round cables or cordage carrying conductor pairs.
BACKGROUND OF THE INVENTION
In the telecommunications industry, modular plug type connectors are commonly used to connect customer premise equipment (CPE), such as telephones or computers, to a jack in another piece of CPE, such as a modem, or in a wall terminal block. These modular plugs terminate essentially two types of cable or cordage: ribbon type cables and round cables.
In ribbon type cables, the conductors running therethrough are arranged substantially in a plane and run, substantially parallel, alongside each other throughout the length of the cable. The individual conductors may have their own insulation or may be isolated from one another by channels defined in the jacket of the ribbon cable itself, with the ribbon jacket providing the necessary insulation. Conversely, the conductors packaged in a standard round cable may take on a random or intended arrangement with conductors being twisted or wrapped around one another and changing relative positions throughout the cable length.
Traditional modular plugs are well suited for terminating ribbon type cables. Typically, these plugs are of a dielectric, such as plastic, structure in which a set of terminals are mounted side by side in a set of troughs or channels in the plug body such that the terminals match the configuration of the conductors in the cable connected thereto. When the plug is inserted into a jack, the terminals electrically engage jack springs inside the jack to complete the connection.
On the other hand, termination of standard round cables or cords poses unique assembly problems for the skilled technician. For example, termination of a round cable carrying, for example, four conductor pairs by means of an existing modular plug requires the following steps: First, the cable or cord jacket must be stripped to access the enclosed conductors. Next, because the conductors in a conductor pair are generally twisted around one another, the twist must be removed and the conductors oriented to align with the required interface. For some standardized plugs, aligning the conductors also involves separating the conductors in at least one of the pairs and routing these over or under conductors from other pairs while orienting all the conductors in a side-by-side plane, thus, the orientation process can result in various conductors of different pairs crossing over each other, thereby inducing crosstalk among the several conductor pairs.
Crosstalk is defined as the cross coupling of electromagnetic energy between adjacent conductor pairs in the same cable bundle or binder. Crosstalk can be categorized in one of two forms: Near End Crosstalk, commonly referred to as NEXT, is the most significant because the high energy signal from an adjacent conductor can induce relatively significant crosstalk into an attenuated receiver signal. The other form is Far End Crosstalk or FEXT. FEXT is typically less of an issue because the far end interfering signal is attenuated as it traverses the loop. Because the jack springs, conductors and the plug terminals or contacts near the jack springs are generally quite close to, and exposed to, one another in a communication plug, control of crosstalk is a paramount consideration in any plug design. Unfortunately, crosstalk in a communication plug cannot be merely eliminated. Jacks are engineered to generate a certain amount of compensating crosstalk to counter the crosstalk produced in the plug. Accordingly, a communication plug should be designed to optimize rather than to minimize crosstalk.
In modular plugs currently in use, when the conductors are untwisted and inserted into the front of the plug housing, it is difficult to control their lengths, which, in turn, causes variation in electrical performance. This lack of precise control also leads in variations in electrical performance from plug to plug, whereas reproducibility of performance is a desideratum. In addition, an anchor bar is generally used to hold the cord or cable in the housing, thereby provide strain relief. However, the anchor bar deforms the cable and introduces a random variable in performance which is caused by the conductors being forced together at different stages of their twist. As a consequence, it is difficult to predict a plug's electrical characteristics, and the high degree of variability can result in reduced signal carrying performance in at least some of the circuits. This problem is discussed fully in U.S. Pat. No. 6,056,586 of Lin, issued May 2, 2000, the disclosure of which is herein incorporated by reference.
Also, in some current high frequency communication plugs, the conductors are terminated in the middle of the plug by insulation displacement connectors. The materials cost of the plug is greatly increased due to the amount of material such as phosphor bronze required by this type of structure. Also, in such a plug, the overall dimensions of the plug are increased, which hinders or prevents use of the plug in a confined place, such as high-density network hubs.
In addition, the technician time involved in the prior art practice of separating out the twisted pairs of conductors and routing them to their proper terminals in the plug is considerable. Even if the technician, splicer, or other assembly person is accurate in the disposition of the conductors, the time consumed by him or her in achieving such accuracy is considerable. Thus, the time spent in properly routing the conductors can add considerable cost. When it is realized that thousands of such connections are made daily, involving at least hundreds of technicians, it can be appreciated that any reduction in time spent in assembling the plug can be of considerable economic importance.
Accordingly, there exists a need for a modular plug that can terminate a standard round cable and that provides a straightforward interface between the conductors in the cable and the plug terminals, involving less assembly time than heretofore, and which has substantially unvarying electrical characteristics from plug to plug.
SUMMARY OF THE INVENTION
The present application is a modular communication plug for terminating a cable having a plurality of conductors therein, wherein the plug has a unique “sled” for organizing and orienting the conductors of the cable prior to insertion of the sled into a housing having a conductor alignment region at one end.
The housing comprises a substantially hollow member forming a chamber for the sled, and having an opposite closed end having a conductor alignment region including a plurality of electrical contact members for establishing electrical contact with the jack spring contacts of a standard jack.
The sled for insertion into the housing comprises a first, or cable, end having a plurality of septa formed in a cruciform shape for insertion into the cable. The cruciform shape creates four separate conductor passages for the twisted pairs within the cable, and the cable jacket fits over the septa or partition walls. While the principles of the invention are herein illustrated as a structure for a cable having four twisted pairs, an industry standard, it is readily apparent that a cable having a different member of twisted pairs can be equally as expeditiously terminated, in which case, the septa would be oriented to create additional passages. Each twisted pair is assigned to one of the passages, and extends therethrough to a neck-down region in each passage. The neck-down region holds the conductors in a vertical position, i.e., one wire on top of the other, and prevents untwisting of each of the pairs. Beyond the neck-down region, is a straight tray region terminating in a planar array of grooves for holding each of the conductors in position for insertion into the housing and into the conductor alignment region thereof, and the ends of the conductors are trimmed to be flush with the end of the sled. Conduct
Abrams Neil
Lucent Technologies - Inc.
Zarroli Michael C.
LandOfFree
Communication cable terminating plug does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Communication cable terminating plug, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Communication cable terminating plug will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2506701