Abstract: A new criterion for the optimum design of curved dielectric waveguides is proposed. The bends designed according to this model are named matched bends. In the matched bend, the suitable choice of both bending radius and bending angle reduces the total losses of the bend and avoids the leaky-mode excitation at the end of the bend. For a given angle, a discrete number of bending radii that satisfy the matched bend criterion can be analytically determined. With respect to the lateral offset, matched bends are more robust to both fabrication tolerances and wavelength and can be realized in every technology. The reduction of the leaky-mode excitation at the output of the bend is a fundamental property when two or more components are cascaded. Ghost images in the spectral response, cross talk, and asymmetries of the transfer function are successfully reduced. Some examples that use buried, rib, ridge, and diffused waveguides are presented and discussed.

Abstract: The present invention relates to a fiber optic cable assembly (100) comprising (a) a connector subassembly comprising a fiber optic (300) cable terminated in a connector, the fiber optic cable having a minimum bend radius; and (b) a strain relief boot attached to the connector subassembly, the strain relief boot comprising a core portion, a flexible extension having a proximal end and a distal end, the proximal end extending from the core portion, and a means (26) for retaining at least a portion of the fiber optic cable which is disposed along the flexible extension. The flexible extension does not have a predetermined bend.

Abstract: A rotating radius limiter for an optical fiber cable management panel is provided. The radius limiter includes a radius limiter structure and a bracket that permit relative motion between the structure and the bracket. The structure and bracket are mounted to a sliding cable management panel. The radius limiter structure includes a curved wall, an opening for receiving cables and a trough section for retaining cables about a radius portion.

Abstract: Ge-doped silica-on-silicon waveguides with index steps of 0.01 and 0.02 were fabricated by a combination of plasma enhanced chemical vapour deposition (PECVD) and reactive ion etching (RIE) techniques, and their characteristics, including propagation loss, coupling loss with standard singlemode fibres, minimal bend radius, and birefringence, were investigated. The waveguides have good propagation properties and small birefringence, compared to using flame hydrolysis deposition (FHD).

Abstract: An apparatus and method for retaining a length of fiber optic cable to a circuit board includes a body portion. The body portion of the apparatus includes at least a pair of spaced legs extending from the body portion, each of the legs is adapted to be received in a mounting opening formed in the PC board. Each of the spaced legs includes a foot portion adapted for securing the body to the circuit board and at least a pair of spaced arms extend from the body portion defining a slot between the arm and the body portion for receiving and retaining a portion of the length of fiber optic cable. The arms are spaced a distance from each other for retaining the fiber optic cable in an arc having a radius greater than a minimum bend radius of the fiber optic cable.

Abstract: A cable management system is disclosed including a frame that can be attached to an equipment rack. Cable guides can be mounted on the frame to align a plurality of cables adjacent to each other. A cable tray is positioned adjacent the cable guides. The combination of the frame, the cable guides, and the cable tray can be positioned alongside a component in the equipment rack to route the cables around an outer edge of the component.

Abstract: A high density integrated optical chip (20). The optical chip features an optical function (26) connected to a low minimum bending radius dielectric waveguide (24), and a large mode field size dielectric waveguide (22) to interface with an external optical device (28), such as an optical fiber. The large mode field size dielectric waveguide is optically connected to the low minimum bending radius dielectric waveguide on the optical chip.

Abstract: The heating effect in highly bent singlemode optical fibres under high power conditions was studied. It was found that heating of the coating depends on the bend radius and the type of telecommunication fibre used. The detected heating only occurred at bend diameters much smaller than that recommended for normal deployment.

Abstract: A communication cable having a communication wire and an armor including at least two synthetic resin layers, and protects the communication wire in a loose state. The communication wire protecting tube includes at least two synthetic resin layers, and inserts the communication wire in a loose state. The most hard resin layer of the armor has a crosswise or spiral annular groove or cut portion continuous in the longitudinal direction to reach the radially inner face, and the outermost layer of the armor is formed of a protective layer made of a softer resin than the hard resin layer. The adjoining edge portions of the annular groove or the cut portion come, when the communication wire is to be bent, into contact with each other so that it may be prevented from being bent to a predetermined or smaller bend radius.

Abstract: The invention can be defined in its most general form as a method for production of sandwich panels with zigzag corrugated core (2) from sheet material used in aircraft construction, shipbuilding, and other branches of industry.With the aim to improve the quality and ease of sheet blank folding into the 3-D relief structure in the sheet blank at locations of crimp zigzag lines (4) protrusions and recesses the holes are punched with the diameter not less than the sheet blank bending radius.

Abstract: A layered optical circuit including a multi-substrate optical circuit. The multi-substrate optical circuit includes a plurality of optical fibers, a first substrate supporting a first portion the optical fibers to form a first optical subcircuit, and a second substrate supporting a second portion of the optical fibers to form a second optical subcircuit. A third portion of the optical fibers between the first and second portions extends between the first and second substrates. Free fibers in the third portion are elongated to permit repositioning of the first and second optical subcircuits in an overlapping arrangement without exceeding a minimum bend radius of each of the optical fibers. The overlapping arrangement of the first and second optical subcircuits forms a layered optical circuit. Accordingly, a layered optical circuit having a large number of fibers and/or a complex circuit pattern may be affixed on a relatively small footprint of a backplane, etc.

Abstract: Optical ribbon cable fan-out device includes a top cover portion, a fan-out portion and a bottom portion formed as a unitary body. The fan-out portion has an array of guides housing individual fibers of the optical ribbon cable. The top cover portion and bottom cover portion are connected respectively to the fan-out portion by first and second hinges. The top cover portion and the bottom cover portion each have a plate projecting respectively therefrom to secure a ribbon cable in an axis extending longitudinally through the fan-out apparatus. The fan-out portion is so configured that a first portion of the arrayed guides is co-linear with the axis, a second portion of the arrayed guides is above the axis and a third of the arrayed guides is below the axis. The fan-out apparatus defines pathways for individual optical fibers having a bend radius of at least approximately 1.5 inches.

Abstract: PROBLEM TO BE SOLVED: To provide a method for manufacturing a hollow stabilizer superior in fatigue resistance. SOLUTION: The manufacturing method comprises: heating a mother steel pipe; draw-rolling it at a rolling temperature of 600 to 850°C and with a cumulative diameter reducing rate of 40% or higher into a stock steel pipe; forming the stock steel pipe into such a shape of the stabilizer as to include a portion having a bend radius R of 2D or less when D is defined as an outside diameter of the stock steel pipe, by cold bending; then heating it to a predetermined heating temperature for quenching by electrification; quenching it; and subsequently tempering it. Thereby, the hollow stabilizer acquires less reduced wall thickness and superior fatigue resistance. COPYRIGHT: (C)2005,JPO&NCIPI

Abstract: The authors propose a new strategy to increase or decrease bend loss in single-mode buried channel waveguides in a predictable manner. This strategy is based on the presence in the cladding of additional layers with different refractive indices on either or both sides of the core in the plane of the bend. It is demonstrated that this approach can lead to significant bend loss reduction when compared to other strategies, and, conversely, can be used to enhance bend loss for a fixed bend radius for application to devices such as optical attenuators.

Abstract: Disclosed is a loose tube optical cable having an unstranded structure, which includes a tensile strength member longitudinally elongated and having a central axis deviated from the center of the optical cable, a loose tube optical fiber unit longitudinally elongated without intended twist against the tensile strength wire, and a cable coating for wrapping an aggregation in which the tensile strength member and the loose tube optical fiber unit are straightly aggregated. By suitably selecting geometric parameters of the tensile strength member and the loose tube optical fiber unit, the center of mass of the aggregation is positioned within the tensile strength member and the maximum modulus of elongation of the optical fiber is restricted within a predetermined range in a predetermined bending radius.

Abstract: A heat exchanger comprising at least one row of flattened tubes through which a heat exchange medium may pass. A serpentine fin 10 disposed between adjacent flattened tubes has relatively straight segments that are connected by bend radii 20. The fin 50 defines a plurality of louvers 32 therein. Each louver 32 forms an elongated slit that extends at least partially into the bend radii 20, through which a fluid to be heated or cooled by the medium may pass. The fin 50 is formed by a tool with fin blades that have tips that are configured to form the extended length louver that protracts into the bend radius that separates adjacent convolutions.

Abstract: In order to reduce pressure loss and asymmetry, a flow control device was applied to the complex flow field in a 90-degree bend pipe : a trip wire was attached on the inside wall of the curve at appropriate upstream position to the 90-degree bend. The trip device spans half circumferential length, that is, it is called as "half-trip" in the present experiment. To see ability of the device to control the complex flow, pressure loss, axial mean velocity profile and secondary current were measured for Reynolds number range Re=50000-82000. The experiment was made with relatively small rate of curvature to pipe radius 2R/D=1.43. Wall static pressure measurements certainly show that the half-trip is effective to reduce pressure loss as well as asymmetry of the axial mean velocity at exit of the bend pipe. The maximum reduction rates of pressure loss coefficient is 23% for trip device height k=3.0mm and 5.0mm. A possible mechanism is discussed with available experimental evidences of axial velocity, secondary velocity vectors and oil film pattern observations.

Abstract: A 10 T racetrack magnet (HFDB-03) wound with pre-reacted Nb{sub 3}Sn Rutherford cable has been fabricated and tested at Fermilab. This magnet is the third one in a proof-of-principle series for the use of the React-and-Wind technology in common-coil dipole magnets for future accelerators. It consists of two flat racetrack coils (28 turns each) separated by 5 mm. The maximum field on the coil, at the short sample limit of 16530 A, is 10 tesla. The cable has 41 strands with 0.7 mm diameter and the minimum bend radius in the magnet ends is 90 mm. The predecessor of this magnet (HFDB-02) reached 78% of the short sample limit at 7.7 T. The mechanical design was improved and the fabrication procedure was slightly modified in order to address possible causes of limitation. In this paper we present the mechanical design and analysis of HFDB-03, the modifications to the fabrication procedure and the test results.

Abstract: The inventive method and apparatus relate to fiber optic ribbon cable capable of being bent and curved through a very small bend radius The method involves an improvement to the direct-melt ribbon-cable manufacturing process, creating ribbon cables with adhered ends, and un-adhered fiber centers Such ribbon cable overcomes typical sideways bend radius limitations This ribbon cable is a second aspect of the invention A reformatter is further contemplated by this invention, wherein at least two of the inventive ribbon cables are arranged to form a rectangular array of optical fibers at one end and a linear array at the other, provding a compact optical fiber reformattor for use in space limited locations

Abstract: PROBLEM TO BE SOLVED: To accurately calculate a movable range of a filamentary material such as a wire harness. SOLUTION: A table based on actually measured values is stored for the minimum bending radius, maximum amplitude, etc., (S11), Conditions for an actual target wire harness (W/H) are entered (S12). The minimum bending radius and the maximum amplitude of the target W/H are calculated based on the actually measured values (S13). The movable range of the W/H is mathematically calculated (S14). The calculated movable range is corrected based on the maximum amplitude in S13 (S15). Based on the corrected movable range, the movable range plane is defined and outputted (S16, S17). COPYRIGHT: (C)2004,JPO

Abstract: The NC thinwalled tube bending process is multiplefactorcoupled and wrinkling often occur in the process. A numerical method is put forward to predict the wrinkling onset based on the energy method and FEM. At the same time, the influences of forming parameters, such as bending radius, relative tube radius, material properties, forming speed and so on, on the wrinkling initiation are also researched. The results indicate that the bending radius, the relative tube diameter, the extension of mandrel, the hardening factor of material and friction are the main factors determining the wrinkling onset in the process, while the strength coefficient of material and forming speed only have little effect. These results provide guidance for the optimization of the forming parameters in tube bending. 

Abstract: Optical fiber bend limiter that prevents contaminates from entering an optical fiber closure is described. The optical fiber bend limiter has an arcuate portion having a bend radius for limiting a minimum bend of an optical fiber. The bend limiter has a central recess for inserting a wall of an optical closure therein and limiting the minimum bend radius of an optical fiber. The bend limiter also includes peripheral recesses. When desired, the bend limiter is secured to a wall of the optical fiber closure via the peripheral recesses thereby closing the aperture and protecting the optical fibers from contaminants.

Abstract: A protective tube for communication cables and communication wires in which anti-bending effect is enhanced such that the communication cables can be bent easily up to a specified bending radius with a small force but a large force is required for bending them furthermore. The protective tube is passed over communication cables (10, 10A) where communication wires (11, 11A) are protected in loose state by sheaths (13, 13A) composed of two or more synthetic resin layers or is passed over communication wires. The hardest resin layers (13a, 13aA) of the sheaths (13, 13A) are provided with sliced or spiral annular grooves (14) or cuts (14A) made continuously in the longitudinal direction to reach the inside diameter face. The outermost layers of the sheaths (13, 13A) are formed of protective layers (13b, 13bA) of resin softer than that of the hard resin layers (13a, 13a). When the communication wires (11, 11A) are bent, adjacent edge parts (14a, 14aA) of the annular grooves (14) or the cuts (14A) touch each other to block bending of the communication wires to below a specified bending radius.

Abstract: The device has a curved sheet strip of x-ray absorbent material with closely adjacent stop slits and attached to a correspondingly shaped holding body positionable via detector evaluation electronics and movable by motor with linear guides between a working position and an axially offset non-operating position. The holding body consists of two mutually clampable half-shells (1a,1b) with guide grooves (2) accommodating the edges (3) of the slotted, elastically deformable sheet strip (5) and determining the bend radius.

Abstract: A suspension load beam for an actuator assembly of a disk drive includes a bend radius portion with a spring rate that is less than 18 Newtons per meter, a first bending mode that is greater than 3,500 Hertz, and a first torsion mode that is greater than 5,300 Hertz. The method of making this suspension load beam includes cutting a sheet of material to form a flat suspension load beam including a bend radius portion, removing material in the bend radius portion from full thickness, inspecting the bend radius portion to determine its thickness, and removing material from the bend radius portion and/or from the main body of the suspension load beam to compromise the performance difference due to thickness variation in bend radius portion.

Abstract: A method for bending a rigid pipe to accomplish a centerline radius less than or equal to the outside diameter of the pipe. Moreover, the method accomplishes such a bend whereby the wall thickness of the pipe on the outermost portion of the wall of the pipe is substantially maintained, as is the inside diameter throughout the bend of the pipe. The pipe bend is accomplished by first determining the desired angle of bend and the desired centerline radius. The arc length of the outermost portion of the pipe is then determined. The height and width of each corrugation is then selected in order to determine the length of the outer surface of each corrugation. The arc length is then divided by the corrugation length to determine the number of corrugations required to accomplish the desired bend. The pipe is then deformed to define the required number of corrugations having the determined height and width. After forming the corrugations, the pipe is bent through the selected degree of the bend.

Abstract: The need for very low noise, low RF loss dynamic rotating electrical connections exist, in particular for pointing mechanisms requiring very high stability. Four basic designs are presented: • the cable-wrap (clock-spring shaped flat cable) • the vertical goose-neck (flat cable squeezed between two rotating cylinders) • the horizontal goose-neck (flat cable squeezed between two parallel disks) • the twist cable (twisted cable bundle in a cylindrical housing). The choice of the appropriate design is highly dependent on the following parameters: available space and shape, torque, angular range, current, signal type to be transferred. A discussion of the design selection parameters, and typical achievable performances will be presented. The cable wrap design is favourable when the Housing diameter (outer diameter O.D.) to Drum diameter (inner diameter I.D.) ratio is large. When this ratio tends to unity, the gooseneck design is preferable and is essentially limited by the bending radius of the cable sheet that is directly related to the life of the mechanism.