Abstract: A method of forming fused quartz glass is provided. The method includes the steps of: (a) providing a starting body made of fused quartz glass; (b) positioning the fused quartz glass starting body on a base plate; (c) inserting a first insert device into an interior cavity of the starting body to form an assembled structure; (d) heating the assembled structure to a predetermined temperature at which the fused quartz glass has a viscosity in a range of 105 to 1013 poise; and (e) deforming the fused quartz glass of the starting body at the predetermined temperature or in the viscosity range of 105 to 1013 poise around the first insert device to change a shape of the starting body. A method for making a large fused quartz glass vessel and a forming assembly for forming fused quartz glass are also provided.

Abstract: Disclosed is a method for the production of a tube having, in sections, a non-circular profile by deforming, comprising: a) providing a tube, which has a circular initial profile; b) conveying the tube in a hot, malleable state through a nip, which is formed by squeezing rollers and has a first nip width, which is larger than or equal to an outer dimension of the initial profile; c) adjusting the squeezing rollers for setting a second nip width, which is smaller than the outer dimension of the initial profile, and deforming the initial profile in said hot, malleable state for obtaining said non-circular cross section; and d) adjusting the squeezing rollers for setting a third nip width, which is larger than or equal to the outer dimension of the initial profile, and severing said tube in a region having a circular cross section; so that respective end portions of said tube have a circular cross section According to the invention, the tubes can be connected reliably with connecting-members or other tube

Abstract: The invention relates to a method and apparatus for shaping an elongated glass body 81, which is a glass tube or glass rod and has an initial profile, to an elongated glass body having a different profile. In order to be properly shaped, an elongated glass body 81 passes through, in a hot malleable state, a nip, which is formed by squeezing rollers 1 and which has a nip width which is less than an outer dimension of the initial profile. In order to accomplish an enhanced precision of the shaping process, according to the invention the position of at least one of the squeezing rollers is varied continuously so that a contact area between the respective squeezing roller and the hot glass body is varied cyclic reciprocating movement. Disturbing effects such as local overheating of the squeezing rollers or an accumulation of dirt or glass particles on the surface of the squeezing rollers can thus be effectively prevented.

Abstract: A known method for producing a cylinder of quartz glass comprises a soot depositing process, in which SiO2 particles are deposited on an elongate carrier rotating about an axis of rotation with formation of a porous, hollow-cylindrical soot body, and a sintering process in which the soot body comprising an inner bore with inner wall, a longitudinal axis, an upper end and a lower end is held suspended in vertical orientation in a furnace, a holding element being provided for holding purposes, which projects from the upper end into the inner bore of the soot body and acts on a bearing provided in the inner bore.

Abstract: A tube bending apparatus for bending a straight lamp tube includes a horizontal heating chamber, a vertical heating chamber and a tube bending mold. The horizontal heating chamber includes a bending tube heating zone and two pre-heating zones. The bending tube heating zone has a working temperature higher than that of the two pre-heating zones. The vertical heating chamber communicates with the horizontal heating chamber and includes a mold heating zone. The mold heating zone has a working temperature higher than or equal to that of the bending tube heating zone. The tube bending mold is heated in the mold heating zone in a working temperature to bend the straight lamp tube held and heated in the horizontal heating chamber.

Abstract: A method and device for making high precision glass forms (110). A glass rod (1) is pushed into a melting tube (47) and the glass form is pulled from the chamber. Preferably, both the push rate and the pull rate are controlled. Fiber optic glass ferrules and other components manufactured by the use of this invention have precision dimensions that fall well within the tight dimensional tolerances required for ferrules and others.

Abstract: The invention is directed to a silver-containing polarizing boroaluminosilicate glass composition that has been doped with a noble metal selected from the group consisting of Pt, Pd, Os, Ir, Rh and Ru, including mixtures thereof, to nucleate and precipitate silver ions to silver metal without the need for a reducing atmosphere step. The invention is further directed to a method for making the glass composition of the invention. Using the composition and method of the invention, one can prepare a glass having a selected null transmission range.

Abstract: The manufacturing method comprises: a softening step of softening a straight glass tube in a heating furnace; a moving and placing step of moving the softened glass tube so that the glass tube is placed on the top of the mandrel; and a winding step of winding the glass tube placed on the top of the mandrel around the periphery of the mandrel. The mandrel is disposed beneath the glass tube starting to get soft, and the glass tube being soft is perpendicularly lowered in order to be placed on the top of the mandrel. In the winding step, the winding speed Vr at which the glass tube is wound around the mandrel is higher than the moving speed Vs at which chuck units holding the ends of the glass tube move toward the mandrel.

Abstract: A preform manufacture apparatus is provided which can produce a preform at low cost. A preform manufacture apparatus 1 has a first mold 20 which receives molten glass, and a second mold 50 which receives a molten glass block moved from the first mold 20. The first mold 20 has a receiving surface 20A which receives molten glass, and is dividable into two or more of split dies 30 and 40 at the receiving surface 20A.

Abstract: The invention relates to apparatus for supporting a preform manufactured in an installation for manufacturing or building up preforms having supporting cores, said installation including at least rotation means having a horizontal axis of rotation and two mounting points between which the supporting core of the preform to be manufactured or built up is mounted, plasma-torch and material-supply means disposed radially relative to said supporting core and being mounted to move in axial translation relative to and parallel to the supporting core so as to make said preform around said supporting core, said apparatus being wherein it includes controlled support means constituting additional localized abutment points between said mounting points for said preform being manufactured or built up.

Abstract: A pair of upper die and lower die having forming surfaces corresponding to optical glass elements are prepared. A locating member having a plurality of locating holes for locating preforms is arranged on the lower die. A plurality of preforms are supplied to the locating holes, respectively, and the preforms are hot-press-molded between the paired upper die and lower die. According to this method, since a plurality of optical glass elements can be formed simultaneously, the high-precision optical glass elements can be manufactured at low cost.

Abstract: A system and method for forming infrared glass optical components are provided. The system includes first and second mold halves having first and second respective faces. The first and second mold halves are configured to be removably coupled such that the first face and the second face form an interface that defines a lens-shaped cavity. A tapered surface of the first face cooperates with a tapered surface of the second face to enhance centering of the first face with respect to the second face.

Abstract: In a known method of producing a quartz glass tube (22), a cylinder (21) of quartz glass which rotates about a rotational axis (27) is continuously fed to a heating zone (24), softened therein in portions starting from one end, and the softened portion (25) is drawn over a drill head (1) of a drill body arranged to be coaxial to the rotational axis and is thereby formed into the quartz glass tube (22). Starting therefrom, in order to indicate a method for forming a cylinder of quartz glass into a hollow cylinder of quartz glass having an inner bore that is as flawless as possible and straight and dimensionally stable, it is suggested according to the invention that a drill body should be used with a drill head (1) having a contact surface (2) of a convex curvature facing the cylinder (21), preferably a spherically shaped contact surface (2). The drill body according to the invention is characterized by a drill head (1) which has a contact surface (2) of a convex curvature (2).

Abstract: An extrusion system for producing a desired extrusion profile on a continuously moving work piece has a die containing two or more pressurized fluid extrusion cells therein, through which the work piece passes. Fluid under pressure id directed against the work piece to shape it without physical contact between the die and the work piece. The individual extrusion cells are configured to produce the desired profile, which is monitored by a non-contact metering member which applies signals to a processing unit which, in turn, applies correction signals to a pressured fluid supply module to control the pressurized fluid supply to each of the extrusion cells.

Abstract: A mold for shaping the end region and the opening at a selected end of a first, hollow, generally cylindrical, glass tube to enable a second tube, of smaller diameter than the first tube, to be inserted snuggly a first distance within the selected end of the first tube resulting in the two tubes nesting and being self-centered. The mold includes two complementary elongated side pieces having inner side surfaces for, when joined, encircling the periphery of the first tube along a given portion of its selected end region, and an end cap with a cylindrical stub for insertion within the opening of the first tube at its selected end.

Abstract: A method and apparatus are described for making an article such as the body of a needleless injector capsule, from a formable material, such as glass, the article having a cavity communicating with the exterior via an orifice. A blank having an open end is mounted on a first forming tool, and the open end is engaged by a second forming tool while an end region of the blank adjacent the open end is in a condition to permit it to be formed. One of the tools has a pin extending therefrom, and when the tools are brought together to form the end region into the desired shape the pin defines the orifice.

Abstract: A glass tube is positioned over a heater and stretched until drawn apart into two drawn portions. A controlled pulling force is applied to the tube by a powered driver such as a linear motor. After separation, one of the drawn glass portions is repositioned over the heater and reciprocated in a controlled fashion by the driver to refine the geometry of the fine tip formed on the resulting pipette.

Abstract: A method and apparatus for controlling the shape and position of a deformable object are described. At least a portion of an object is heated to a temperature sufficient to render the heated portion deformable by a force. An image profile of the heated portion of the object is obtained. A controller compares the image profile to a reference profile and produces an error image signal. Based on the error image signal, an instruction signal is generated. A force applicator responsive to the instruction signal applies a radial force to at least one distinct predetermined location on the heated portion of the object in response to the instruction signal to cause the heated portion of the object to conform to the reference profile. The invention is particularly useful in controlling the shape of an optical fiber preform.

Abstract: An apparatus and method for manufacturing an optical fiber preform from a tube of vitreous material. A holding device holds the tube during manufacture of the preform and a heater supplies the necessary heat energy for preform manufacturing. A diffuser is disposed adjacently to an end of the tube of vitreous material to trap and diffuse light radiation generated in the tube by the heater. The invention can be used in an apparatus for drawing an optical fiber from a preform. The diffuser traps and diffuses light radiation generated in the optical fiber preform by a fiber drawing oven.

Abstract: A method and apparatus are described for making an article such as the body of a needleless injector capsule, from a formable material, such as glass, the article having a cavity communicating with the exterior via an orifice. A blank (1a) having an open end is mounted on a first forming tool, and the open end is engaged by a second forming tool (22) while an end region of the blank (1a) adjacent the open end is in a condition to permit it to be formed. One of the tools (7a) has a pin (21) extending therefrom, and when the tools are brought together to form the end region into the desired shape of the pin (21) defines the orifice.

Abstract: A known method for producing an object having a flanged tubular portion at the outer periphery, comprises supplying a continuously extended, cylindrical body made of the flange material to a welding zone at the tubular portion of the object and welding the flange material to the welding zone by heating and winding the cylindrical body around the object.

Abstract: A method of preparing a high purity massive synthetic silica glass article. The method includes a homogenizing step, wherein a rod shaped synthetic silica glass material has a greater optical homogeneity in a plane perpendicular to its rotational axis than a plane parallel thereto, a step of forming the homogeneous synthetic silica glass and a step of cutting the formed synthetic silica glass.

Abstract: The apparatus for preparing quartz micropipettes includes a pair of carriers mounted on a linear ball bearing guide which grasp opposite ends of a quartz glass capillary tube. A pair of miniature torches fueled by a mixture of oxygen and propane simultaneously heat a portion of the center of the capillary tube and an inverted U-shaped bar disposed between the torches in propinquity to the capillary tube. A cable having one end attached to one of the carriers and the other end attached to the core of a solenoid, the intermediate portion of the cable being wound around a pulley and attached to the second carrier, is used to pull the capillary tube in opposite directions as the tube softens. The cable is also wound around the axle of an optical encoder assembly which sends an electrical signal to a computer based upon either the distance or velocity at which the tubing is pulled apart.

Abstract: A method of preparing a ball-shaped synthetic silica glass optical article. The method includes a step of providing a rod-shaped synthetic silica glass having end faces at both sides thereof and having fewer cords per unit volume viewed in a direction perpendicular to a line connecting the end faces relative to the number of cords per unit volume viewed in a direction along the line connecting the end faces. The synthetic silica glass being optically homogeneous in the direction perpendicular to the line connecting the end faces. The method includes the further step of establishing support portions at the end faces of the synthetic silica glass. The rod-shaped synthetic silica glass is thereupon heated while being rotated around an axis connecting the support portions wherein a molten zone is formed.

Abstract: During the fire-polishing of a lengthwise extended glass body (3), for example a preform for drawing optical fibers, the glass body (3) is held by a holding device (5, 7), and is heated by a burner (23) moving at a variable advancing speed parallel to the lengthwise axis (19). The surface temperature of the glass body (3) is determined with a temperature measuring device (25). The mechanical stress condition of the glass body (3) is detected with an optical device (29) and can be controlled by varying the burner temperature and/or the advancing speed of the burner. The invention makes it possible to counteract the occurrence of high mechanical stresses in the glass body (3).

Abstract: A device for manufacturing a spiral fluorescent tube is disclosed. The device includes a rod aerially supported in a first predetermined direction; a first clamp supporting a straight fluorescent tube in a second direction which is at right angles to the first predetermined direction; heating device for heating a part of the straight fluorescent tube, which is not facing the rod, to a glass softening temperature; two second clamps disposed in a direction parallel to the rod for clamping ends of the straight fluorescent tube; and device for winding the straight fluorescent tube around the rod by rotating the two second clamps in opposite directions to each other around an axis of the rod while shifting the two second clamps away from each other in a direction parallel to the first predetermined direction.

Abstract: In forming a piano-convex lens from a column-like lens blank by heating the blank to a temperature higher than the transition temperature thereof and by pressurizing an upper die with a closed space formed between the blank and the upper die, there are alternately repeated operations of pressurizing the upper die and stopping the application of pressure thereto. Through the control of the amount of displacement of the upper die, the maximum pressure of gas in the closed space at each pressurizing step is so controlled: as to be low according to the surface viscosity of the blank to the extent that no local concave deformation in the surface of the blank is produced; and as to be high to the extent that gas caught in the closed space is discharged at each step of stopping the application of pressure.

Abstract: In a device for shaping glass tubes (32), the shaping tools (3, 4), which are designed as shaping rollers, are mounted on a rotary table (2) that encloses the glass tube (32) and that rotates at a speed that is several times higher than the speed of rotation of the glass tube (32). The shaping tools (3,4) are moved in a perpendicular direction to the longitudinal axis (40) of the glass tube (32) in order to shape it. The relatively high speed of rotation of the rotary table (2) allows the advance of the shaping tools per rotation of the rotary table (2) and at the same time the forces that act on the softened part of the glass tube (32) to be kept small.

Abstract: A method and an apparatus for producing an optical element capable of performing a molding temperature control required for a plurality of independent molding blocks in a short period of time, and continuously and simultaneously producing a plurality of different optical elements having a high degree of accuracy at a low cost is provided.

Abstract: An apparatus for heating an elongated glass body, which, for example, may be used as a pre-form for the drawing of glass fibers, includes a rotatable first chuck wherein the first end of the elongated glass body may be rotatably secured. In addition the apparatus includes a second rotatable chuck whereat the second end of the elongated glass body is introduced into a quartz tube and this quartz tube is clamped into the rotatable second chuck. A burner, which is adapted to slide parallel to the longitudinal axis of the elongated glass tube, heats the elongated glass body in such a manner, that a so called fire polish of the elongated glass body for the improvement of its surface quality occurs. A method for heating the elongated glass body is also disclosed.

Abstract: In order to shape the necks of glass tubes (1) on glass processing machines, use is made of a device with two shaping tools, one of which takes the form of a ring (3) surrounding the glass tube (1) and the other shaping tool consisting of a roller (2).

Abstract: The present invention provides large, high-purity quartz glass plate with a high degree of smoothness and flatness, its manufacturing method and equipment. The invention is characterized by the procedure in which a quartz glass tube with an opening over a specific width, in the direction of the tube shaft, that is preferably band-shaped, is heated and softened in a band-shaped area over the entire width, in the direction of the tube shaft, progressing sequentially along the direction of tube circumference from a specific position on the glass tube. While softening and heating, the quartz glass tube is pulled in a line approximately tangential to the specific position to flatten the glass tube.

Abstract: A spout forming assembly for glassware and a method therefor in which the assembly includes a spout forming device for forming a pour spout on the edge of a piece of glassware, an actuation device for actuating the forming device, and a control device for controlling the actuation device. The method generally includes the steps of: (a) moving a piece of glassware having an edge along a predetermined path; (b) heating the edge; and (c) engaging the edge with forming means to form a spout on the edge of the glassware.

Abstract: In forming a plano-convex lens from a column-like lens blank by heating the blank to a temperature higher than the transition temperature thereof and by pressurizing an upper die with a closed space formed between the blank and the upper die, there are alternately repeated operations of pressurizing the upper die and stopping the application of pressure thereto. Through the control of the amount of displacement of the upper die, the maximum pressure of gas in the closed space at each pressurizing step is so controlled: as to be low according to the surface viscosity of the blank to the extent that no local concave deformation in the surface of the blank is produced; and as to be high to the extent that gas caught in the closed space is discharged at each step of stopping the application of pressure.

Abstract: A pipette puller has a heater coil X-Y position controlled by two knobs. The coil can be vertically positioned along a pipette by moving a third knob for the Z positioning. A dual-heat heat control provides two pre-set temperatures. A movable shield covers the coils when they are heated, eliminating accidental burnings. Sensors run the status panel. The panel tells when to start a pull, the position of the movable chuck, the position of the shield, and when to reposition the coil and indicates a primary stop between two burns of a patch electrode pull. A vertical rail supports all of the major mechanical moving parts, with the exception of the adjustable stop which swings in and out of operative position.

Abstract: A glass vessel edge chamfering method and apparatus wherein heat energy can be controlled readily and chamfering of a glass vessel having a deformed profile, local chamfering and simultaneous processing of the opposite inner and outer sides of a lip of a vessel can be performed readily and besides the efficiency in consumption of energy necessary for chamfering for one glass vessel is improved so that a glass vessel can be processed efficiently in a short time. A pair of positive and negative electrodes are opposed in a predetermined spaced relationship to an edge of a glass vessel, and flame is blown from a pair of burners into gaps between the edge of the glass vessel and the electrodes while a high voltage is applied between the electrodes. Thereupon, electric current flows between the electrodes and the glass vessel by way of the flame and heats the glass vessel by Joule heat when the electric current flows through the glass vessel.

Abstract: An apparatus is provided for coiling fluorescent tubes, so that the tubes may be placed within a bulb. The apparatus includes a rotatable turntable having a plurality of ovens thereon. Each oven has a lever to enable the oven to be opened for placement of a fluorescent tube therein. A piston/cylinder assembly is mounted in proximity to the rotatable turntable and can selectively engage one of the levers for opening the corresponding oven. A ratchet assembly is provided for selectively rotating the turntable into positions where the piston/cylinder assembly in contact one of the levers and open the respective oven. A tube coiling screw is disposed in proximity to the turntable to enable coiling of a fluorescent tube thereabout after sufficient heating in one of the ovens.

Abstract: The transverse cross section of a body is modified by the steps of: a) determining the extent to which the body has material in excess of a desired shape at a plurality of points, b) exposing the body to a local heat source having a temperature sufficiently high to remove material from the surface of the body, and c) moving the surface of the body in relation to the source at a speed which decreases in regions where the body has material in excess of the desired shape so as to remove more material from such regions than from other regions. In a preferred embodiment, the body is an optical fiber preform, the local heat source is the fireball of a plasma torch, and the body is moved relative to the torch by rotating the preform at a controllable angular velocity while the torch is translated along the length of the preform.

Abstract: A preform tube (31) is caused to be collapsed into a preform rod by causing a heat zone (54) provided by a torch assembly (50) to traverse the tube longitudinally in a plurality of passes. During this so-called collapse mode, a muffle tube (100) encloses that portion of the tube which extends through the torch assembly. Advantageously, the muffle tube projects a predetermined distance beyond one major face of the torch assembly. The torch assembly comprises annular semi-circular end plates and an annular semi-circular center portion having a plurality of exit ports through which gases are directed into engagement with the tube. The center portion is caused to be recessed between the end plates thereby causing the heat zone generated by the gases to be narrowed.

Abstract: A preform tube (31) is caused to be collpased into a preform rod by causing a heat zone (54) provided by a torch assembly (50) to traverse the tube longitudinally in a plurality of passes. During this so-called collapse mode, a muffle tube (100) encloses that portion of the tube which extends through the torch assembly. Advantageously, the muffle tube projects a predetermined distance beyond one major face of the torch assembly. The torch assembly comprises annular semi-circular end plates and as annular semi-circular center portion having a plurality of exit ports through which gases are directed into engagement with the tube. The center portion is caused to be recessed between the end plates thereby causing the heat zone generated by the gases to be narrowed.

Abstract: A capillary flow cell in which a capillary (9) partially extends along the optical path of the cell and has its two end portions (12, 13) bent to achieve an essentially Z-shaped configuration. A template (1) has a central bore (2) in which the middle part (11) of the capillary (9) is positioned. A method of manufacture of this capillary flow cell including inserting a capillary in a central bore of a template, heating the capillary immediately outside the bore to soften the capillary material, and bending the two ends to achieve an essentially Z-shaped or U-shaped configuration.

Abstract: A preform tube (31) is caused to be collapsed into a preform rod by causing a heat zone (54) provided by a torch assembly (50) to traverse the tube longitudinally in a plurality of passes. During this collapse mode, a muffle tube (100) encloses that portion of the tube which extends through the torch assembly. The muffle tube projects a predetermined distance beyond one major face of the torch assembly. The torch assembly comprises annular semi-circular end plates and an annular semi-circular center portion having a plurality of exit ports through which gases are directed into engagement with the tube. The center portion is caused to be recessed between the end plates thereby causing the heat zone generated by the gases to be narrowed. The narrowing of the heat zone and the substantial confinement of the heat energy within the muffle tube cooperate with increased gas flow rates to cause the tube to be collapsed in a time period which is substantially less than that achieved by prior art methods.

Abstract: A glass tube bending apparatus according to the present invention includes a drum for bending a heated/softened glass tube into a circular shape, a first driving device, coupled to the drum, for moving the drum straight, and a second driving device, coupled to the drum, for rotating the drum in a direction, and a control for independently controlling the rotating speed and the moving speed of the drum. According to this apparatus, the operation speeds of rotating and moving of the drum can be controlled independently. Therefore, distortion of glass tubes can be decreased, and thermal bending of tubes can be performed with high precision. Further, various sorts of glass tubes can be treated. Still further, since the first driving device and the second driving device are operated in synchronism, the precision of the thermal bending of glass tubes is enhanced.

Abstract: 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.

Abstract: The invention is a machine for processing tubes. Preferably the machine is adapted to create glass flares by flaring an end of each tube and then cutting a length off the flared end. The machine includes several holding devices, each of which is adapted to hold a tube, preferably in a generally horizontal position. Each holding device is pivotally connected to two adjacent holding devices to thereby form an endless loop. The endless loop of holding devices is adapted to travel in a first endless path, preferably obround. The machine includes devices for continuously moving the endless loop of holding devices in the first endless path. The machine also includes a plurality of tube processing devices, such as flaring heads, which are also adapted to travel in a smaller endless path, preferably circular.

Abstract: A method for heating thick-walled glass tubes, particularly quartz tubes, in the manufacture of optical fibres while using microwave energy. According to the invention, the tube (5) is pre-heated to a temperature of about 1000.degree. C.-1500.degree. C., preferably in a known manner with the aid of a gas flame, whereafter the tube is further heated by means of microwave energy, generated by a microwave generator, by inserting the tube (5) axially into a microwave cavity (2) incorporating in both end walls (6,7) or end surfaces openings (3,4) for the tube (5), the electrical field strength being given a field image which includes only one tangential component, according to TE-01n-mode, preferably according to the mode TE-011, whereby the electrical field is so formed as to be tangential to the surfaces of the tube (5), and so formed that the electrical field strength is zero adjacent the surfaces of the cavity (2). The invention also relates to apparatus for carrying out the method.

Abstract: In a holding chuck (3) for tubes of glass-working machines, clamping jaws (7) which are guided in a basic body (5) and have, at their ends, plates (9) provided with a bore for receiving a ball (12) are used. Each ball is guided in a bore (14) in a thrust ring (13), whilst the plates (9) are additionally guided in slots (15) of the thrust ring (13).

Abstract: An apparatus and method are disclosed for fabricating an expanded beam cylindrical terminated optical fiber taper from a reduced diameter preform rod. The present invention comprises uniformly heating the circumference of a predetermined portion at an intermediate point of the preform rod to a predetermined temperature and then uniformly pulling the preform rod while continuing to heat additional material of the preform rod to produce a pair of expanded beam cylindrically terminated optical fiber tapers connected by a predetermined length cylindrical central section of standard optical fiber having a uniform diameter less than that of the original preform rod.

Abstract: An apparatus for producing bends in optical bends in optical fibers comprising a pair of plates hingedly connected along one edge of each of the plates so that the plates may lie in face-to-face contact and may be hingedly separated, means defining a cavity between the plates when in face-to-face contact, the cavity having two portions for receiving lengths of a fiber on opposite sides of a bend to be formed, the portions being joined at an apex section, means defining an opening into the cavity at the apex section, a fiber channel in each of the portions, the fiber channels being mounted in the portions for relative movement in the cavity to a desired bend angle while the apex of the desired angle is positioned at the opening in the apex section, and pulling means for acting on an optical fiber in the channels when the plates are in face-to-face contact and thereby positioning a fiber at the desired angle whereby the apex of the bend of the fiber is accessible through the opening; several variations of the a

Abstract: An apparatus for manufacturing a fluorescent lamp envelope comprises means for holding the envelope, a plurality of heat sources, means for providing relative rotation between the envelope and the plurality of heat sources with the heat therefrom acting on substantially narrow axially spaced regions on the envelope, means for engaging the envelope and for forming a plurality of constricting portions at axially spaced regions on the envelope, means for moving the forming means to engage the envelope and means for applying a positive pressure within the envelope while the forming means is engaged with the envelope.