Abstract: Disclosed is a method of minimizing re-wetting of a preform upon removal of the preform from the consolidation furnace and producing core cane and/or optical fiber therefrom. During removal, the consolidated preform and, in particular, the centerline aperture is exposed to a heavy inert gas, such as Argon, Krypton or Xenon. This reduces the amount of re-wetting thereby concomitantly improving attenuation of the optical fiber produced therefrom. This method produces beneficial attenuation reductions in the 1383 nm wavelength region.

Abstract: A method for threading a lead end of a fiber through the drawing apparatus of a fiber draw process. A prethread filament is fed through the apparatus of a draw process. One end of the prethread filament is then attached to the lead end of the fiber and used to pull the fiber through the apparatus of the draw process.

Abstract: Helium recycling for optical fiber manufacturing in which consolidation process helium is recycled either directly for use in consolidation at high purity or recycled at lower purity adequate for usage in draw or other processes having a lower helium parity. Integrated processes for recycling helium from two or more helium using processes in the optical manufacturing process are also described. Substantial helium and cost savings are recognized.

Abstract: A double crucible fiber fabrication system employing a rod to control flow of the core material to produce a core of desired diameter. The rod fits closely within the inner crucible and moves at a speed necessary to produce a core material flow rate which will produce a desired core diameter. Control of the rod speed produces good control of core diameter for a wide variety of different core materials. It is also possible to control the rod speed in order to compensate for capillary effects and leakage of core material. Furthermore, control of the rod speed allows fabrication of a fiber having a core diameter which varies as desired throughout a single fiber.

Abstract: An elastomer damper (20) for damping movement between two relatively moveable members, such as shimmy motion between components in an aircraft landing gear assembly (10). The damper (20) includes a housing (24) having an internal cavity (36) with a cylindrical interior surface (34) and an opening (41), and a member assembly (28) moveable relative to the housing (24) having an elongated shaft (30) received through the opening (41) with a piston head assembly (32) mounted thereon. The piston head assembly (32) has a annular support element (46) received over the shaft (30) with a sleeve-like elastomer member (48) received over it. The elastomer member (48) engages the interior surface (34) in an interference fit relationship thereby radially precompressing the elastomer element (48) in the range of between about 5% and 15%. Low friction washers (50a, 50b) are preferably positioned adjacent to the ends of the elastomer ember (48) and the support member (46).

Abstract: A controllable pneumatic actuator and motion control apparatus including a field responsive medium and control method therefor. The apparatus has a pneumatic actuator coupled to a rotary-acting brake such that a motion (e.g., a displacement, velocity or acceleration) of an output member may be precisely controlled. The pneumatic actuator has a housing with a piston moveable responsive to a pressure differentials and an output member coupled to the piston. The rotary-acting controllable brake includes a field responsive medium and a brake shaft coupled to the output member. Preferably, the apparatus includes a control system having a sensor for deriving motion signal and a motion control for processing the motion signal and providing a control signal to the brake.

Abstract: An elastomer coupling (20) including an outer member (40) including a leading contact face (38), and an elastomer component (30) including a driving elastomer contact face (41) opposing and adapted for operable unbonded contact with said leading contact face (38), the driving elastomer contact face (41) including a thin polyurethane coating (50). In another aspect, the elastomer coupling (20) has an elastomer member (30) preferably having a plurality of parallel-sided bonded lugs (47) having thin elastomer driving and following skins (46, 46′) received in preferable line fit relationship in a plurality of parallel-sided recesses (44) formed in a preferably plastic outer member (40) for transmitting torques, accommodating slight parallel and angular misaligninents, and isolating vibrations thereof.

Abstract: An elastomeric bearing. The bearing which may be used to support a railway car body includes first and second members and an elastomeric member interposed in a cavity defined between the first and second members. The second member has a recess formed therein which communicates with the cavity. The elastomeric member includes a working section positioned in the cavity and a non-working section integral with the working section and disposed in the recess. The non-working section serves as a sprue location site during the molding process to avoid locating surface defects associated with the sprue in the working section.

Abstract: A leaf spring suspension assembly includes a leaf spring assembly having a plurality of vertically stacked leaf springs and a bearing assembly positioned adjacent an end thereof. The bearing assembly includes an upper insulator cup having an upper recess and a lower bracket cap having a lower recess and upper and lower bonded bearings. The upper bonded bearing is received in the upper recess and includes a rigid lower member having an upper elastomer element bonded thereto; the bearing being received adjacent the upper side of the leaf spring assembly. The lower bonded bearing is received in the lower recess and includes a rigid upper member having a lower elastomer element bonded thereto; the lower bearing being received adjacent the lower side of the leaf spring assembly. At least one of the upper and lower elastomer elements includes a spherical elastomer element.

Abstract: A coupling (20) having a driving member (22) with an inner surface (24), a driven member (26) having an outer surface (28), a flexible member (27) intervening between the surfaces (24, 28) exhibiting an elastic center (EC), and a pivot (32) cooperating between the members (22, 26) wherein an axial location of the pivot substantially coincides with the axial location of the elastic center (EC). In another aspect, a bonded Subassembly (34) is provided which, together with the driving member (22), forms the coupling (20). The subassembly (34) has a driven member (26) with first (40) and second (50) projecting portions extending from a main body portion (38). The first portion (40) has an outer surface (28) and the second portion (50) includes a bearing member. The flexible member (27) is bonded to the outer surface (28) and a third projection (42) extends from the main body portion (38). The axial location of the bearing member is substantially aligned axially with the position of the elastic center (EC).

Abstract: An isolation system includes a housing that contains an electromagnet, a sensor and a controller. The housing is mounted underneath a table top of an isolation table (or other structure requiring isolation from a second body), and target elements, such as permanent magnets, are associated with the frame of the table in proximity to the housing. The sensor provides an input signal representative of motion of the table to the controller, which generates a control signal for the electromagnet to produce a force acting on the target element. The housing can be attached to the table top with magnets, which facilitate installation. The housing provides a unit that is simple to install, is unobtrusive, and advantageous for retrofitting existing isolation tables.

Abstract: A method, apparatus and controller for machining non-circular work pieces. The apparatus, method and controller are preferably used in combination with rotating, equipment, such as a turning center having an x-y table capable of gross movements. The apparatus includes at least one position sensor for deriving an angular position signal of the work piece, a preferably longitudinally-disposed, flexible tool holder attached to a rigid tool block which holds the machine tool, a preferably solid state vibration actuator imparting active vibrational forces to the end of the tool holder, thus vibrating the machine tool at high frequency to impart the desired ovality to the work piece, and a control system for generating the output signal to the vibration actuator. Preferably, the control system includes manually adjusted magnitude and phase thereby providing a non-circular work piece profile with the desired ovality and positioning thereof.

Abstract: A controllable damper for resisting movement between two relatively moveable members includes a first member and a second member coupled for relative movement having a working space between them, and a controllable medium retaining structure, for example, an absorbent matrix, to hold a controllable medium only in the working space. A cage preferably supports the matrix. A field generating coil is mounted to one of the first and second members to generate a field acting on the first and second members and the controllable medium in the working space. The rheology change in the medium produced by the field results in resistance to relative movement of the first and second members. A device according to the invention may be used in apparatus, such as washing machines, exercise equipment, air supported tables, and a range of other apparatuses that would benefit from controlled damping or braking. Devices including a two-piece outer housing are described.

Abstract: A method of making a segmented core optical waveguide preform for making fiber that is resistant to attenuation increases due to hydrogen and heat aging. A first core region comprising a silica glass rod containing at least a first dopant is inserted into a central opening of a second core region comprising silica soot containing a second dopant. The first core region and second core region are consolidated together to form a segmented core region and cladding is deposited on the outer surface of the segmented core region.

Abstract: Gas-assisted atomizing devices are provided that include liquid orifices, which release liquid, and gas orifices, which release gas to atomize the liquid into droplets. The atomizing devices are formed by at least a first layer and a second layer. The atomizing devices can include a gas supply network and a liquid supply network that supply gas and liquid to the gas and liquid orifices.

Abstract: A mount for isolating a vibrating member from its support. In several embodiments an elastomeric element is made up of four components that are preferably bonded to the inclined outer surface of an inner member and the inclined inner surface of an outer member. One of the inner and outer members is bifurcated and drawing the two halves into mating engagement results in the elastomeric components being preloaded simultaneously in compression and shear. The elastomeric element is preferably formed with portions which snub movement in each of three orthogonal directions. The dimensions of the pair of elastomeric components above or below the vibrating member may be different than the other pair since the greater compression strain on one pair of components to maintain maximum design stress levels.

Abstract: A magnetorheological brake includes an outer, rotating flywheel member having a hollow interior space, and an inner fixed member disposed in the hollow interior space. The inner fixed member is sized so that a working space is provide between the surfaces of the fixed member and the inner wall of the rotating member. A controllable medium of magnetically permeable metal particles is disposed in the working space. A field generator is mounted in the interior space to the fixed member to selectably generate a field acting on the outer and inner members and the controllable medium in the working space. The rheology change in the medium produced by the field generates resistance to rotation of the outer member about the inner member. A device according to the invention may be used as a flywheel/brake or resistance-generating device in exercise equipment, rotating equipment, such as conveyors, and vehicles.

Abstract: A resistance device (20) useful as a thumb or hand exerciser. The device (20) includes an outer member (32) including an axial through bore (34); an inner member (22) received within the through bore (34) and extending out of both its ends; and a friction member (36), such as an elastomer sleeve, immovably mounted on said inner member (22); said friction member (36) being in operable contact with the through bore (34) to provide resistance to relative axial movement between said inner (22) and outer (32) members. The level of resistance may be adjusted by rotating ends (24, 24′)of the inner member (22) relative to one another such that the friction member (36) is axially compressed. Stops (30, 30′) limit axial travel.

Abstract: An optical fiber having optical characteristics that vary along its length is made by assembling a plurality of cylindrical glass or soot tablets into or along a glass tablet alignment device, then fused into monolithic assembly. If desired, additional glass may be applied to the assembly before or after the fusing step. A vacuum is preferably applied during the fusing step. Each tablet preferably contains a core region, and it optionally contains a layer of cladding glass. Adjacent tablets are capable of forming optical fiber sections having different optical properties. Prior to consolidating the glass particles, chlorine preferably flows through or around the tablets and alignment device. The resultant draw blank can be drawn into a low loss optical fiber having short transition regions between adjacent areas of fiber. This method is particularly useful for making dispersion managed single-mode optical fibers.

Abstract: A controllable valve assembly (18) applicable in Magnetorheological (MR) fluid devices (20), such as MR mounts and MR dampers. The valve assembly (18) includes a valve body (32) having a magnetic circuit (40) contained therein which carries magnetic flux .phi., a controllable passageway (42) within the magnetic circuit (40), a MR (magnetically controlled) fluid (44) including soft-magnetic particles in a liquid carrier contained in the controllable passageway (42), a magnetic flux generator, such as a wound wire coil (46), generating magnetic flux .phi. which is directed through the MR fluid (44) in the controllable passageway (42) thereby generating "rheology" changes causing restriction in flow of MR fluid (44) therethrough.