Western Electric Company, Inc.

At&t Technologies, Inc.

At&t Bell Laboratories

American Telephone and Telegraph Company, At&t Technologies, Inc.

Brian Lynch

Fred P Partus

William D O'Brien, Jr

Gary L Baltzer

James G Wright, Jr

John Burnette MacChesney

Jay R Simpson

Pundi L Narasimham

In order to provide a substrate such as an optical preform rod (24) which is suitable for insertion into a tube and which has a transverse cross section that is substantially circular and disposed concentrically about a longitudinal axis of the substrate substantially along its entire length, a force-applying means such as a graphite roller (52) is adapted to be moved incrementally toward an axis of rotation (35) about which the preform rod is turned rototably. Movement is discontinued when there is an indication that the force-applying means has been in continuous engagement with the preform rod for at least a predetermined portion of the periphery of the rod. In a preferred embodiment, the engagement of the force-applying means and the preform rod is discontinued after a predetermined time, whereafter the force-applying means again is moved toward the axis of rotation. Cycles of engagement and disengagement are continued as relative motion is caused between the force-applying means and the preform rod in a direction along the axis of rotation.

Apparatus for contacting a preform rod to cause the preform rod to have

In order to provide a substrate such as an optical preform rod (24) which is suitable for insertion into a tube and which has a transverse cross section that is substantially circular and disposed concentrically about a longitudinal axis of the substrate substantially along its entire length, a force-applying member such as a graphite roller (52) is moved incrementally toward an axis of rotation (35) about which the preform rod is turned rotatably. Movement is discontinued when there is an indication that the force-applying member has been in continuous engagement with the preform rod for at least a predetermined portion of the periphery of the rod. In a preferred embodiment, the engagement of the force-applying member and the preform rod is discontinued after a predetermined time whereafter the force-applying member again is moved toward the axis of rotation. Cycles of engagement and disengagement are continued as relative motion is caused between the force-applying member and the preform rod in a direction along the axis of rotation.

Apparatus for adjusting the configuration of optical substrates

In order to provide a substrate such as an optical preform rod (24) which suitable for insertion into a tube and which has a transverse cross section that is substantially circular and disposed concentrically about a longitudinal axis of the substrate substantially along its entire length, a force-applying means such as a graphite roller (52) is adapted to be moved incrementally toward an axis of rotation (35) about which the preform rod is turned rotatably. Movement is discontinued when there is an indication that the force-applying means has been in continuous engagement with the preform rod for at least a predetermined portion of the periphery of the rod. In a preferred embodiment, the engagement of the force-applying means and the preform rod is discontinued after a predetermined time whereafter the force-applying means again is moved toward the axis of rotation. Cycles of engagement and disengagement are continued as relative motion is caused between the force-applying means and the preform rod in a direction along the axis of rotation.

Methods of adjusting the configuration of optical substrates

A preform from which lightguide fiber is drawn is made by depositing optically suitable layers of doped silicon dioxide on an inner wall of a rotating glass tube (31) which is exposed to a moving zone of heat (56) which is provided by a torch assembly (50) during a deposition mode and during a collapse mode. After the deposition mode and generally prior to the collapse mode, one end portion of the tube is at least partially closed in order to allow pressurizing of the tube during collapse. This is accomplished with a pivotally mounted tool (70) which straddles the torch assembly to cause an internally water cooled contact device (92) to be disposed within the confines of the torch. Further, the contact device is configured to provide a curved lead-in from the tube to the at least partially closed portion. The use of separate apparatus for initially closing the tube provides control of the sealed-off portion and prevents an irregular cross-section from being propagated along the length of the tube.

Methods of and apparatus for at least partially closing an end portion

A vapor delivery system for the manufacture of an optical preform includes a deposition bubbler (60) and another bubbler (40) referred to as a supply bubbler which is interposed between a reservoir (24) of a liquid and the deposition bubbler. Heat energy is applied to the supply bubbler and to the deposition bubbler to vaporize liquid therein. A carrier gas is introduced into the liquid in the supply bubbler at a location below the free surface and into the deposition bubbler to cause vapor of the liquid to become entrained in the carrier gas and to flow from the supply bubbler into the deposition bubbler and from the deposition bubbler to a substrate tube from which an optical preform is made. Facilities are provided for maintaining sufficient liquid in the supply bubbler and suitable temperatures of the liquid in the supply and deposition bubblers to control the vapor flow into and out of the deposition bubbler to prevent unintended perturbations in the deposition bubbler. As a result, the concentration level of the vapor which is entrained in the carrier gas and delivered to the substrate tube is maintained at a substantially constant value.

Methods of and apparatus for vapor delivery control in optical preform

A lightguide fiber preform is made by depositing optically suitable layers of doped silicon dioxide on an inner wall of a rotating glass substrate tube (31) which is exposed to a moving zone of heat during a deposition mode and during a mode when the tube is collapsed. During each of a plurality of passes of a torch assembly (50) in the collapse mode following deposition, a contact device (101) is in continuous engagement with the tube and is caused to apply forces to each successive increment of its length following exposure to at least an initial portion of the zone of heat to collapse incrementally the tube. Between successive ones of the plurality of passes, the contact device is moved inwardly of the tube so that each increment of length is exposed to forces which as between the successive passes are applied at points incrementally closer to the longitudinal axis (36) of the tube.

Methods of and apparatus for collapsing a preform tube into a preform

A preform from which lightguide fiber is drawn is made by depositing optically suitable layers of doped silicon dioxide on an inner wall of a rotating glass substrate tube which is exposed to a moving zone of heat during a deposition mode and during a collapse mode. During at least a first pass following the deposition mode, a contact device is caused to engage each successive increment of length of the tube during exposure to the zone of heat. The contact device causes any sagged or offset portions of the tube to be reconfigured and causes the tube to have a central longitudinal axis which is a straight line which extends between stocks of a lathe by which ends of the tube are supported. The contact device may also be used to cause the tube to have a predetermined configuration along its length. The position of the contact device relative to the maximum temperature within the moving zone of heat for each increment of length of the glass tube allows the shape of the tube to be changed and allows that shape to be retained.

Method of and apparatus for straightening and configuring a preform tube

A closure which is particularly useful to seal a container of material that is used in a process for the manufacture of preforms from which fiber lightguides are drawn includes an annular seal having a tapered opening therethrough. The annular seal is supported in engagement with an outwardly facing surface of a flared neck of a container by a shelf of an annular retainer which is held about the neck by an adjustable clamp which is disposed about the retainer. The neck opens to an external surface of the container which is covered by a stepped cap made of plastic material that is clamped in engagement with a ring seal positioned in a groove formed in the external surface by an outer clamp plate. A smaller diameter portion of the cap is received in a centrally disposed opening of the outer clamp plate which is connected to the retainer by a plurality of circumferentially disposed fasteners. Advantageously, the outer clamp plate, cap and ring seal can be removed from the container to provide access for cleaning, for example, without removing the annular seal, retainer and adjustable clamp.

Closure for container

In order to react gases and/or vapors to deposit optically suitable layers of doped silicon dioxide on an inner wall of a glass substrate tube to produce a preform from which optical fibers are drawn, the glass tube is heated by a mixture of combustible gases. The combustible gases are directed along passageways in a housing of a torch assembly which confines a portion of the length of the tube and then out of the passageways to produce a flame that engages the confined portion of the length of the tube. The housing and walls that define ends of the passageways adjacent the tube are cooled to an extent which substantially eliminates oxidation of the material from which the housing and the walls of the passageways are constructed. The torch assembly provides a variable confinement of the tube, radially and longitudinally, which is effective to control the temperature profile produced at the surface of the tube as it is rotated about its longitudinal axis, and as the torch assembly is moved to heat successive portions of the length of the tube.

Methods of and apparatus for heating a glass tube

Paper pulp insulation of uniform weight per unit length is formed simultaneously on each of a plurality of advancing electrical conductors (21--21) by the use of a dual zone headbox (23) which cooperates with a forming cylinder (24). In one zone of the headbox, the average velocity of a pulpous mixture flowing in a channel (54) is controlled by a first velocity control member (58) after which the pulpous mixture is split into a plurality of streams to form a pulp ribbon (29) below each of the conductors on the periphery of the forming cylinder. In the other zone, the pulpous mixture is passed through a channel (57) prior to being split into individual streams that are deposited as ribbons (31--31) above the conductors. The average velocity of the pulpous mixture in the channel (57) in the other zone is controlled by a second velocity control member (66) having a plurality of discrete individually adjustable sections which are aligned with the streams. Selected sections of the second velocity control member (66) are adjusted to insure that the combined weight of each increment of the ribbon (31) of the pulpous mixture which is deposited above each conductor together with each associated increment of the underlying ribbon (29) is substantially constant.

Growing community of inventors

Norcross, GA, United States of America

Brian Lynch