Optical waveguides – With disengagable mechanical connector – Structure surrounding optical fiber-to-fiber connection
Reexamination Certificate
1998-09-04
2001-03-06
Lee, John D. (Department: 2874)
Optical waveguides
With disengagable mechanical connector
Structure surrounding optical fiber-to-fiber connection
C385S140000
Reexamination Certificate
active
06196729
ABSTRACT:
FIELD OF THE INVENTION
The invention relates generally to apparatus for retaining a signal attenuator element. More particularly, the invention relates to apparatus for retaining an attenuator element within an optical fiber buildout.
BACKGROUND OF THE INVENTION
Often times it becomes necessary to arrange a plurality of optical fiber connectors in a connection panel to facilitate multifiber connections. Typically, devices for holding connectors are mounted in the panel, but the connectors themselves are not connected to incoming or outgoing fiber paths until needed to provide service. Commonly used devices which are used to accommodate interconnections are generally referred to as couplings. One type of coupling which is mounted in a connection panel is known as a buildout system.
Coupling components of buildout systems such as buildout bases and caps can be received in the connection panels to accommodate the optical fiber connectors to be installed at a future time. This permits the installer to connect a first connector, which terminates an incoming or outgoing fiber path, to a buildout base and await future connection of a second connector which terminates another outgoing or incoming fiber path.
One frequently used optical fiber connector is the ST® connector, ST being a registered trademark of the AT&T Corporation. The ST connector is disclosed, for example, in U.S. Pat. No. 4,934,785, which was issued on Jun. 19, 1990, in the names of Mathis and Miller. Other popular optical fiber connectors include the SC connector and the FC connector.
One known buildout system capable of accommodating ST, SC, and FC connectors is disclosed in U.S. Pat. No. 5,274,729, which issued on Dec. 28, 1993, in the names of King et al. The King et al. system includes a plurality of buildout bases, identified in the patent as “blocks,” that are adapted for mounting to a panel through a plurality of openings provided therein. Further disclosed is a plurality of buildout caps, identified in the patent as “buildouts,” that are adapted to be removably attached to the buildout bases mounted to the connection panel. The bases are provided with front apertures that each form a keyway that is adapted to align and receive a cylindrical sleeve housing of the caps. Both the bases and caps are open-ended such that they can receive the optical fiber connectors to be coupled within the buildout. Inside the cylindrical barrel of each cap is an attenuator element which is used to attenuate the signal traveling from one fiber to the next.
Although the King et al. system described above functions adequately well, demand for increasing numbers of optical fiber connections has prompted the design of smaller optical fiber coupling systems that occupy less space. For instance, one recently developed optical fiber connector is the LC® connector, LC being a registered trademark of Lucent Technologies, Inc. This connector is disclosed, for example, in U.S. Pat. No. 5,481,634, which was issued on Jan. 2, 1996, in the names of Anderson et al. The design of the LC connector is advantageous because the connector has a smaller footprint than each of its predecessor connectors and therefore requires less panel space.
Although development of the LC connector has shown that optical fiber connectors can be successfully reduced in size, similar size reduction of buildout systems is more problematic. In particular, reducing the size of the buildout creates a number of difficulties that do not exist or that are not as significant in the larger buildout systems currently used with the ST, SC, and FC connectors. One problem is that buildout manufacture processes become much more difficult as the buildout components and the structural features of these components become smaller. For example, the molding of extremely small structural details can be difficult.
Another problem with buildout size reduction relates to buildout strength and durability. Again, if the size of the buildout is substantially decreased, the strength and durability of the buildout likewise decreases and the likelihood of buildout failure increases. For instance, the design of the cylindrical sleeve housing of the buildout cap must be such that it can flex sufficiently to permit insertion of the attenuator and attenuator retention means, but must not permanently deform to the point at which the attenuator element could dislodge or be damaged. Furthermore, despite its reduced size, the buildout must withstand a certain degree of side loading applied to the buildout caps via the fiber cables to protect the fragile optical fibers contained therein.
A further complication created by reduced size occurs in the buildout assembly process. Specifically, assembly of the buildout cap and the attenuation means can be difficult when the constituent components of the buildout system are small, especially when such assembly is conducted out in the field. Therefore, provision must be made for structural features that permit the technician to manipulate more easily the components of the system to avoid structural damage to the buildout and optical fibers and to prevent delays in servicing.
Accordingly, it can be appreciated that it would be desirable to have a buildout system that can accommodate ST, SC, and FC connectors as well as LC connectors, which has a relatively narrow footprint such that connection panel space may be optimized. Furthermore, it would be desirable to have such a buildout system that can be relatively easily manufactured and assembled. Moreover, it would be desirable to have such a buildout system which is adequately strong and durable. The present disclosure discloses one such buildout system.
SUMMARY OF THE INVENTION
The present invention relates to apparatus for retaining an attenuator element between two optical fiber connector ferrules. The apparatus comprises a sleeve housing including front and rear ends, and a passage that extends from a first opening formed in the front end of the housing to a second opening formed in the rear end of the housing. Inside the passage are inner flanges formed adjacent each of the housing openings. Formed at the front end of the housing is a top notch and an opposed bottom notch. The top notch joins an attenuator element travel slot that extends from the top notch to an end point adjacent the rear end of the sleeve housing.
Typically, the apparatus includes a ferrule sleeve adapted to receive and support the attenuator element within said sleeve housing. The ferrule sleeve has first and second ends that are positioned adjacent the front and rear ends of the sleeve housing when the sleeve is disposed within the housing.
In practice, the sleeve housing normally is supported by the front side of a buildout cap and is formed as a substantially cylindrical tube having a continuous inner flange at the rear end of the housing and a pair of partial inner flanges at the front end of the housing. To retain the attenuator element, the attenuator element is first placed within the ferrule sleeve. Once the attenuator element has been disposed within the sleeve, the sleeve is inserted into position within the sleeve housing. Because the cap is made of a resilient material, the sleeve housing flexes to accommodate the ferrule sleeve until the entire sleeve snaps into place within the sleeve housing.
The insertion of the ferrule sleeve is facilitated by the notches and slots provided in the sleeve housing. In particular, the top notch and the elongated travel slot in combination with the bottom notch provides the resilience needed to permit insertion of the ferrule sleeve and the strength needed to avoid breakage of the sleeve housing. Furthermore, the configuration of the partial inner flanges minimizes the shearing of polymeric material from the sleeve housing during installation of the ferrule sleeve.
REFERENCES:
patent: 5067783 (1991-11-01), Lampert
patent: 5082345 (1992-01-01), Cammons et al.
patent: 5212752 (1993-05-01), Stephenson et al.
patent: 5274729 (1993-12-01), King et al.
patent: 5481634 (1996-01-01), Anderson et al.
p
Connelly-Cushwa Michelle R.
Lee John D.
Lucent Technologies - Inc.
LandOfFree
Apparatus for retaining an attenuator element does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for retaining an attenuator element, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for retaining an attenuator element will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2533504