Showing papers on "Bend radius published in 1997"

Fiber management system and method for routing optical fiber having a minimum bend radius

Abstract: A fiber management system (100) for routing a plurality of optical fibers having a minimum bend radius. The fiber management system (100) includes fibre guides (101, 102) and one or more fiber trays (111a-111g). The fiber guide (101) includes a plurality of inner fingers (102a-102e) and a plurality of outer fingers (104a-104e) for retaining the optical fiber. At least one of the fingers has a curved portion with a radius selected to insure that the optical fiber does not bend past its minimum bend radius when routed over the finger. The fiber tray, which routes the optical fiber to the fiber guide, has a curved lip with a radius at least as large as the minimum bend radius of the optical fiber. The fiber tray and fiber guide are positioned such that the curved lip of the fiber tray is adjacent to the curved portion of the finger. The optical fibers are routed over the curved lip of the fiber tray and the curved portion of the corresponding finger, thereby allowing the fibers to be routed without being bent past the minimum bend radius.

Measurement of mode field profiles and bending and transition losses in curved optical channel waveguides

Abstract: Curved, single-mode, silicon oxynitride optical ridge channel waveguides have been characterized by measuring mode field profile alteration, bending loss, and transition loss. The results were compared to theoretical calculations. Near field imaging of the channel mode field profiles showed the effect of bend radius on mode shape. Good agreement was obtained between the measurements and profiles obtained from two-dimensional (2-D) beam propagation method calculations. The exponential dependence of bending loss on bend radius and the variation of transition loss on the lateral offset between channels having different bend radius were successfully modeled by two simple theories.

Low profile communications outlet box

Abstract: A low profile communications outlet box is disclosed which can accommodate fiber optic cables in a compact housing without bending the fiber optic cables past their minimum bend radius. The outlet box has a base and a cover for forming a wiring space therebetween. A pair of winding rings or members are located between the base and cover to prevent the fiber optic cables from being bent beyond their minimum bend radius. The winding rings or members overlap each other to decrease the size of the outlet box. Moreover, the winding rings or members are offset from each other such that the upper winding member lies in a different plane from the lower winding member.

Optical fiber strain relief device

Abstract: A strain relief boot for attachment to an optical fiber or fiber containing cable has a mounting section and a tapered section extending therefrom with a smooth bore extending to the exit end of the tapered section. The exit or distal end of the tapered section has formed therein a curved funnel shaped portion, the curve of which is faired into the bore. The radius of curvature of the funnel is greater than the critical bend radius of the fiber or fiber cable and protects the fiber or cable exiting the boot from bending too sharply. The tapered section has a plurality of transverse slots which increase flexibility of the tapered section, but which limit the bend radius thereof under side loading to a value greater than the critical bend radius of the fiber or fiber cable. The mounting section is formed with a ridge or ridges for effectively attaching the boot to a connector.

Arrangement in a cable

Abstract: The present invention relates to an arrangement in a cable, especially a hydro electric control cable, which has a plurality of hydraulic tubes and electrical cables. In order to arrive at such an arrangement which allows for a required volume of service fluid while retaining an optimum minimum bending radius, the present invention suggests that the cable is designed as an umbilical (1, 101) with three centrally arranged tubes (2) in helical configuration which are surrounded by a ring of electrical cables and hydraulic tubes to allow for lower minimum bend radius (MBR).

Low loss optical fiber reel

Abstract: An optical fiber storage reel has a central axis of rotation and a plurality of arcuate surface members extending radially and spaced about the axis of rotation. Each arcuate surface has a radius of curvature that is equal to or greater than the critical bend radius of the optical fiber. The arcuate surfaces are spaced from the axis of rotation a distance such that a cable wound on the reel has a substantially straight line path between the arcuate surfaces, with the sum total of the straight line distances being sufficient to reduce the false loss readings on the cable which can occur when a cable is wound upon a circular drum or hub.

Articulated underwater cable riser system

Abstract: An articulated underwater cable riser system includes at least one articulated anchor section having a plurality of modular anchor segments and an articulated mid-span buoy having a plurality of modular buoy segments. The anchor segments and buoy segments encircle the cable and are secured adjacent one another in appropriate positions along the cable by cable clamps. The buoy segments and anchor segments are interfaced to the cable clamps by fairings which present smooth outlines for the anchor sections and mid-span buoy between the segments and the clamps to facilitate handling the anchor sections and mid-span buoy using conventional cable laying equipment. The anchor segments and buoy segments can be one-piece or, preferably, assembled by securing segment halves to one another. Bend limiters are coupled to at least some of the anchor segments to prevent an articulated anchor section from exceeding the minimum bend radius for the cable. The bend limiters can be one-piece collars or they can be formed as two pieces which are secured together to form a single bend limiter. The bend limiters are coupled to adjacent pairs of anchor segments by means of studs which extend from the out surfaces of the anchor segments with the studs extending into axially aligned oblong slots in the bend limiters.

Small radius bends and large angle splitters in SOI waveguides

Abstract: The silicon/silicon dioxide (Si/SiO2) materials system provides a high index contrast waveguide platform compatible with existing monolithic microelectronic fabrication processes. The large index difference between the Si and SiO2 ((Delta) n approximately equals 2.0) allows the miniaturization of waveguide cross-sectional dimensions: single-mode strip waveguides with 0.2 X 0.5 micrometers cross-sections are possible. Additionally, right angle waveguide bends with radii of 2.0 micrometers can be fabricated with insertion loss of less than 1.0 dB. Bend radii of 250 micrometers or more are required to achieve the same performance in less confined waveguide systems such as GaAs/AlGaAs. The high confinement of the Si/SiO2 system also allows Y-branch power splitters with splitting angles greater than 20 degree(s) to operate with low loss. The combination of small cross- section, small bend radius, and large splitting angle provides a highly compact light guiding technology. Calculations of the loss due to 90 degree(s) bends in these waveguides and preliminary loss measurements for bends from 2.0 to 100.0 micrometers in radius are reported. Y-branch power splitters are analyzed and measurements of branches from 2 degree(s) to 40 degree(s) are presented.

Optical fibre organizer having through port extending between opposite faces thereof

Abstract: An optical fiber organizer which has at one face thereof: an inlet port and an outlet port through which fibers can pass substantially in the plane of that face; a through port that extends through that face to an opposite face of the organizer; and fiber storage means positioned with respect to the ports such that a fiber passing between the inlet and through ports or between the outlet and through ports is constrained by an outer surface of the storage means to a minimum bend radius at least equal to the critical bend radius of the fiber.

Telecommunications cable management

Abstract: A cable management apparatus includes a tray having a pair of arms for connections to a communications assembly and a body having a plurality of cable channels defined by arcuate guide walls. The channels have a relatively narrow exit and a relatively wide entrance and the curvature of the walls is chosen not to exceed a predetermined maximum cable bend radius. Further guides are arranged in the channel entrances as extensions of adjacent channel side walls.

Statistical analysis of fiber failures under bending-stress fatigue

Abstract: We have analyzed the failure data of a standard telecommunication optical fiber under static bending stress. Experimental data have been collected on a 468 day period, observing more than 7000 turns, with a bend radius ranging from 1.25 to 6 mm. The statistical analysis has been carried out by both the least-square and the maximum likelihood method. We have found that data are fitted by a Weibull distribution, as expected theoretically. Moreover, we have determined the scale and shape parameters and tested their dependence on the bend radius. According to our results, we conclude that in sensor applications silica fibers can be safely bent down to a radius less than 5 mm.

Reciprocal electric connector

Abstract: PROBLEM TO BE SOLVED: To prevent failure easily through a low cost structure by applying a resilient belt along a flat cable thereby preventing the flat cabled from being buckled at the time of reciprocal motion. SOLUTION: In the reciprocal electric connector, a U-shaped flat cable 2 is arranged with the breadthwise surface thereof directing vertically. A resilient belt 6 is applied to the inner surface of U-shaped flat cable 2 and secured at the opposite ends thereof, i.e., at the securing parts 7, 7, to the flat cable 2. The resilient belt 6 is bent arcuately in the breadthwise direction and each securing part 7 is provided with a resilient tongue 9 having a curled part 8a for ensuring the minimum bending radius of flat cable 2. Since the U-shaped flat cable 2 is reinforced by the resilient belt 6, the flat cable 2 can be protected against buckling.

Bend-radius reduction in planar waveguides using UV post-tuning

Abstract: The minimum radius for negligible loss in bent buried channel waveguides could be significantly reduced by increasing the core index through UV-tuning after fabrication. The potential reduction in bend loss is quantified and a simple adiabaticity criterion is presented for the permissible rate of increase and decrease of the core index on either side of the bend.

Nonperturbative calculation of bend loss for a pulse in a bent planar waveguide

Abstract: Conformally transforming the scalar Helmholtz equation for a step-index planar waveguide with a constant bend radius and assuming a bend radius large in comparison to the core half-width yields a differential equation whose solutions can be written in terms of Airy functions. A correct expansion of the leaky mode field in terms of these Airy functions and matching the field and its derivative across boundaries yields an eigenvalue equation whose complex roots give the leaky mode propagation constant and bend loss directly. This allows a second-order Taylor series expansion for the bend loss as a function of wavelength over the spectrum of a pulse to be determined. A comparison between bend loss for a cw wave and a pulse with the same carrier frequency is made.

Bulge forming method and apparatus

Abstract: According to a hydraulic bulge forming method, a bend pipe (1) is inserted in a cavity (20), and when the bend pipe is subjected to bulge forming, the bend pipe is deformed by supplying a pressure medium to an interior of the bend pipe so that an inside and/or outside of the bent portion is bulged along a bulging region (4) formed at a portion of the cavity (20) corresponding to the inside and/or outside of the bent portion of the bend pipe.A reduction in wall thickness of the outside portion of the bent portion is suppressed by a movable support die, so that breaking can be prevented.

Electrode for medium- or high-voltage apparatus

Abstract: An electrode is made from wire mesh and has a curved surface with edge zones rounded off in the radial direction. The wires of the mesh are slanting relative to the axis (11) and the radius in the edge zone is a multiple of the wire diameter. All the wires have the same slant angle, approximately 45 degrees. The bending radius of the edge zone lies between 1 and 3 mm. The edge zone has a bend of about 180 degrees, this being an outwards bend. The procedure for making this electrode has the mesh curved first to the required shape and then the end zone is bent around.

Portable multifunctional pipe bender

Abstract: The utility model relates to a portable multifunctional pipe bender which belongs to the bending apparatus for holding the shape of the pipe. The utility model comprises a square support frame and a hydraulic cylinder, wherein, the left end of the square support frame is hinged with a bending mould with the outer side surface forming a circular arc-shaped groove, and the other end of the bending mould is hinged with a pipe clip. The outer end of a piston rod of the hydraulic cylinder is provided with a top wheel frame, and the front end of the top wheel frame is provided with a top wheel. A straight mould with the side surface forming a circular arc-shaped groove is arranged between the top wheel and the bending mould. The device has the advantages of high precision of processed bending pipe, wide bending radius, large bending angle, light structure, convenient operation, convenient use on site, etc. and ensures the roundness of the bending part of the bending pipe. The bending part is difficult to generate gauffer.

Two-part curvilinear guide for optical cable into termination plug

Abstract: The cable (LWL) is terminated in a plug (ST) to which the cable guide (KF) is fitted and secured with screws, snap connections or rivets (B) holding together the two rigid curved half-shells. The cable duct formed between the half-shells is matched to the contour of the cable. A groove may be made in the duct to accommodate a protrusion extending along the cable sheath. The curvature of the half-shells corresponds to the necessary minimum bending radius prescribed for the cable.

Cover for sunroof of motor vehicle

Abstract: The cover comprises an inner plate (5) with an outer edge which is surrounded by the cover outer plate (4). The cover inner plate has a bending radius (r), around which the cover outer plate is bent with an all-round unified bending radius (R). The edge of the cover outer plate faces approximately horizontally inwards and the edge of the cover inner plate is looped, forming an upwardly open channel (9). It suffices for the bending radius (R) of the cover outer plate to amount to 2.5 mm. The bending radius (r) of the cover inner plate is smaller than that (R) of the cover outer plate.

Cable tray bend

Abstract: A bend 18 which can serve as an internal or external bend when joining cable trays or ladders, comprises two parallel side elements 20 which are connected by at least one transverse member 40 connected to the elements 20 by means of bolts 30, 32, 34 The member 40 can be fixed so that its flat portion is near the outer (longer) edge 36 of the bend thus providing an internal bend, or near the inner (shorter) edge 38 so providing an external bend (Figure 4) The member 40 may be moved from one position to another by loosening the securing bolts and rotating it about 180{; the bolts slide in an elongate hole (44 Figures 1 and 2) in the elements 20 to bring the flat portion near the edge of the elements In another embodiment (Figures 5 and 6) three transverse members (40') are used

Arrangement of heat exchanger

Abstract: The exchanger has a radial fan (10) which is surrounded by a burner (12). It also has a pipe (14) which is formed in at least one section to a freely cantilevered bend (16). Preferably the bend has an enlarged cross-section and the pipe sections which form the bend meet at an acute angle, the bend including a change of direction of 180 degrees . The preferred cross-section of the pipe in the region of the bend is an oval shape.

Optical waveguide adhesive ribbon cable system for installing in interior cavities and rooms

Abstract: The system is based on a ribbon cable (1) which can be glued (7) to a wall (5) and contains the optical waveguides (4) attached in an undulatory manner for equalisation of length to an elastic supporting film (3). The waveguides are secured to the film by adhesive (6) and are protected by one or more layers (8) of greased paper or film. The cable is unwound from a reel (2) for laying along the walls. It can be routed around corners with the aid of suitably shaped mouldings to ensure conformance with minimum bending radius requirements.

Pneumatic radial tyre

Abstract: A pneumatic radial tyre has a tread profile comprising a curved crown part (TW1) having a radius of curvature R1, a pair of curved middle parts (TW2) having a radius of curvature R2 and a pair of curved shoulder parts (TW3) having a radius of curvature R3 which extend continuously without forming any inflection point, wherein the radius R1 is in the range of from 2.0 to 3.5 times the tread width TW and is less than the radius R2 and more than the radius R3, and the camber quantity T1 which is the radially distance of the tread edges from the tyre equator is 0.038 to 0.050 times the tread width TW, whereby noise generated from the tyre when going down a difference in road level is reduced.

High-frequency coaxial cable and manufacture thereof

Abstract: PROBLEM TO BE SOLVED: To provide a high-frequency coaxial cable having its better attenuation characteristics as a high-frequency signal transmission line of 0.5GHz or more and having it minimum bending radius which can be used as an internal wiring of high-frequency equipment. SOLUTION: Insulation body 2 of polytetrafluoroethylene resin(PTFE) is formed on the outer circumference of a center conductor 1 of a silver plating copper clad steel wire, on the outer circumference of which an external conductor 3 is formed. When a top skin depth is δ(μm) and the external conductor thickness is x (μm), 2.75δ.<=x<=70. Thereby, a high-frequency coaxial cable having its better attenuation characteristics and small minimum bending radius is obtained. An elongated high-frequency coaxial cable can be manufactured. Thermal history processing is unnecessary, the manufacturing time can be reduced, and the manufacturing cost can be reduced. A sheath can be provided on the outer circumference of the external conductor by means of continuous extrusion method.

Laminated optical device assembly

Abstract: Disclosed is a laminated optical device assembly having a template which both restrains an optical device and provides a safe bending radius about which to mount fiber optic cables emanating from the device. The assembly is adapted for field assembly to assist a craftsperson with the placement and protection of fragile fiber optic cables. The template is adhesivey bonded between a bottom and a top to provide a robust assembly which is further incorporated into an optical device housing.

Optical fiber cable and tension member for optical fiber cable

Abstract: PROBLEM TO BE SOLVED: To provide an optical fiber cable which is easily bendable and hardly has the permanent set in bending even if a bending radius is reduced and to obtain sufficient tension without using metallic materials by using tension members composed of tension member bodies which are solidified and integrated as to be made easily bendable and to hardly have the permanent set in bending and tensile fibers. SOLUTION: This optical fiber cable 1 is composed of a coated optical fiber 2, the tension members 3 for the optical fiber cable of the diameter larger than the diameter of the coated optical fiber 2 arranged apart a prescribed spacing on both side parts of the coated optical fiber 2 and a coating 4 which covers the outer peripheral parts of the tension members 3 and the coated optical fiber 2. The tension member 3 for the optical fiber cable are composed of the tension member bodies 7 formed by solidifying and integrating reinforcing fibers 5, such as glass fibers, by synthetic resin materials 6, such as polyester resins, so as to be made easily bendable and to hardly have the permanent set in bending and the tensile fibers 8, such as aramid fibers, arranged to be placed along the outer peripheral parts of the tension member bodies 7.

Connecting socket insert for light conducting cable for surface and under plaster mounting

Abstract: The socket insert (1) has a cylindrical holder part (4) for the light conducting cable (7) on its underside matched to the socket mounting space and protruding into it and elements for relieving cable strain. The upper side of the insert has a circular guide element (12) matching the defined minimum bending radius and mounted and designed so that the individual cables (6) are fed round the circular guide element to form a cable reserve. At least one other guide element (13) forms a guide chamber for the individual cables.

Bending method by pushing through

Abstract: PROBLEM TO BE SOLVED: To improve machining accuracy and productivity by correcting the correction factor of springback for each material to be worked to difference in characteristic and variation of each material to be worked in bending by pushing through which is applied to the bending work of a three-dimensional solid shape. SOLUTION: In the bending work which is controlled by calculating the moving amount of a movable die based on the numerical value of a three- dimensional coodinate system of the three-dimensional solid shape as an object and correcting the moving amount of the movable die by the correction factor of springback which is preliminarily determined as a function of the 0.2% yield strength (σ 0.2 ), work hardening index (n-value), bend radius (R), section modulus (Z) and cross-sectional area (A) of a shape by experimentation, plastic deformation such as bending work is executed in the tip part at the time of starting the bending work, the σ 0.2 is calculated from the relationship between the load and deformation and the correction factor of springback to the individual material to be worked is corrected. COPYRIGHT: (C)1999,JPO

Pipe bend for pipes feeding liquids or gases

Abstract: The bend consists of three straights welded together. The centre section (2) has a centreline (a) which makes an angle ( gamma ) with the centreline (b) of the inlet section (1). This angle is smaller than half the total angle ( delta ) of the pipe bend. Taking a cross section along the central plane of the bend, a line drawn along the inside of the outer wall of the centre section will intersect a similar line on the outlet section (3) at a point (S). This point (S) also lies on the intersection point of a line (V) drawn from the inside of the bore (Di) of the inlet section (along the inside of the bend) with the wall of the outlet section.