Showing papers on "Bend radius published in 1983"

Phase Diagrams for Microemulsions

Abstract: A phenomenological mean-field model of globules for a three-component microemulsion is presented and typical phase diagrams are obtained. Two types of two-phase coexistence are found as well as a three-phase equilibrium. The topology of the phase diagram is determined by the ratio of the critical globule radius to the natural bending radius and by the radius dependence of the attractive interactions.

Bend behaviour of polarising optical fibres

Abstract: Experimental results are presented which show how both bend radius and the orientation of the fibre in the bend considerably affect the single-polarisation operation of bow-tie fibres.

Optical fiber cable and method of jointing two cable elements

Abstract: The strength members of the optical fibre cables to be jointed comprise inner and outer layers of high-tensile wires (9, 10; 9', 10') arranged on respective pressure-resistant tubes (5; 5'), each containing an optical fibre package (not shown). The strength members are jointed by trapping the wires between a quill (15) and a ferrule (16) pressed towards the quill. The quill (15) is of a relatively hard steel and serves to partially reinstate the pressure tube between the ends of the cables, whereas the ferrule (16) is of a relatively soft steel. For jointing of two dielectric covered elements the ferrule is subsequently encapsulated in a dielectric moulding (27). A thin-walled reinstatement tube (17) is arranged between the quill (15) and one tube (5'). The cavity in the reinstatement tube (17) is larger in diameter than the cavity in the tubes (5 and 5'). Thus, when the optical fibres are arranged to lie helically in the reinstatement tube without exceeding their minimum allowable bending radius, optical fibre slack can be absorbed in a minimum distance, and any diameter increase over optical fibre joints can be readily accommodated. Pressure tube repairs can be made with such a reinstatement tube (7- FIG. 2) arranged directly between two tubes in cases where there are no wires to join.

Bending machine with bend angle stop

Abstract: The bending machine for bending tubes or other stock in bar form operates by the three-point pressure method and is equipped with a new type of bend angle stop. The bend angle stop is arranged on the workpiece counterholder (3) and, by virtue of its special construction, is capable of precisely detecting the swivel angle of both workpiece counterholders (3) together. Presetting of the desired bend angle and precise achievement of it in the bending operation is thereby guaranteed. In addition, high repeatability of the bend angle is achieved, irrespective of workpiece tolerances.

Buried conductor cable energy distribution system with conductor loop enclosure

Abstract: An energy conducting cable loop enclosure which receives and retains an above-ground loop of a flexible conductor cable in an underground energy distribution system, particularly in a system for the supplying of electrical energy. The main body structure, which is upright in normal placement, is of elongate rectangular shape with an above-ground and a below-ground portion and having an open bottom and a closed top. At the junction of these two portions, supporting feet are located which bridge a hole in the ground, in which the below-ground portion is inserted, to rest on the surrounding ground. A removable front plate provides access to the interior of the above-ground portion. The above-ground portion contains a cable hoop having a radius at least as great as the minimum allowable bending radius of the cable on which a loop of cable is trained after being led through the open bottom and out through the open above-ground front. The depth of the hoop is substantially equal to the depth of the body structure so that the cable loop is captured on the hoop when the front plate is secured in place. The structure is held in place by the anchoring effect of the buried cable by way of the captured cable loop. The dimensional interaction of the structural elements combine for the provision of cable loops of desired size for interfacing with system components. Means are provided to prevent unauthorized removal of the plate.

Manufacture of steel pipe by uoe-system

Abstract: PURPOSE:To manufacture an UOE-system steel pipe by a small press duty by U- forming a blank plate having properly bent ends and further, O-forming it by regulating an acting angle of forming force within a range of giving no circumferential compression, before welding, expanding, and straightening a formed plate. CONSTITUTION:A blank plate 10 is U-formed after subjecting the ends of plate 10 to an end bending by regulating a bending radius (rc) at the end parts within an allowable range of peaking between the end parts of plate 10 at the time of O-forming, or regulating it preferably to the degree of (rc)/R=0.62-0.75 with respect to the radius R of a desired steel pipe. Next, a welding is performed by restricting the O-forming within a range, where an acting angle of forming force with respect to the plate 10 is >=-45 deg. and gives no circumferential compression. Next, the out of roundness of a welded pipe is straightened while expanding it with a small expanding rate to obtain a steel pipe having a desired radius, thus a duty of forming press necessary for performing the O-forming in a UOE-system steel-pipe manufacturing is remarkably reduced.

Method and device for rolling and bending channel material

Abstract: PURPOSE:To execute easily a small outside circumference bending radius working in a thin channel material which has been difficult up to the present, by rolling and bending one rib and web of the material, when bending horizontally the material by a small outside circumference bending radius. CONSTITUTION:When bending a channel material 1 to an outside circumference bending radius (r), the tip of the material 1 fed onto a table 18 is inserted between projecting and recessed rolls 5, 6. Subsequently, a hydraulic pump 12 is driven, and one rib 24 and web 26 of the material 1 are subjected to rolling reduction by a prescribed rolling reduction force between the rolls 5, 6 by a hydraulic cylinder 11. Subsequently, when a rolling and bending device is turned on, the rolls 5, 6 are rotated in the direction opposite to each other by hydraulic motors 7, 8 and the material 1 is rolled under a set pressure. Next, a ring material 2 of the radius (r) in which the rib 24 becomes the outside circumference is bent horizontally. According to this method, even in case when a thickness of the material 1 is less than about 1/10 of a web width H, it can be bent horizontally easily to the radius (r) which is less than about 10 times of the width H.

Fibre=optic communication cable termination box - uses drums inside box to carry cable and has edge connected pull-out termination boards

Abstract: The fibre-optic cable terminal box is intended for use in telecommunications distribution systems and comprises a box (11) with a cable (21) entry hole (12), two parallel cylindrical drums (18,20) mounted inside the box. Several pull out modules (13-16) edge-wise in the face of the box. The multi-conductor cable is stripped inside the box and the optical conductors (13) wound over the cylndircal drums, which have a radius exceeding the minimum bending radius of the optical fibre, to provide anchorage for the optical conductors. Each optical conductor is then brought out to the edge of one of the pull-out modules where it is stripped and the individual fibres in the conductor terminated onto the edge of the pull-out module. Electrical connections are then taken from the pull-out module.

Field Experience with Fiber-Optic Cable Installation, Splicing, Reliability, and Maintenance

Abstract: The experience obtained during the installation of more than 700 sheath km of fiber-optic cable is summarized. These include in-building, underground (duct), aerial, buried, and underwater installations. In general, no special precautions are required except to maintain the specified pull tension and cable bend radius. Field splicing is discussed and results are given on splice losses with and without splice loss monitoring with the optical time domain reflectometer. A 28 percent learning curve for fusion splicing is derived. Reliability data on 312 sheath km of installed cable and field splices are presented. Most of the cable failures were in the "uncontrollable extrinsic category," and most of these were due to complete cable cuts. Finally, restoration is reviewed with emphasis on troubleshooting, repair, emergency restoration, and offset breaks.

Light transmission of bent multimode optical fibers

Abstract: An analysis is made of the dependence of the transmission of light on the bending radius of a waveguide from the point of view of mode–ray equivalence. A study is made of the influence of directional properties of a radiation source exciting a waveguide and of the parameters of the waveguide itself on the sensitivity to bending. The dependences of light transmission on the bending radius are derived for various waveguides and angular distributions of the radiation emitted by a source.

Variable radius lead former

Abstract: A variable radius lead former operates an axial lead electronic component wherein the bend radius may be adjusted to any desired radius within specifications.

U press tool for uoe steel tube manufacturing process

Abstract: PURPOSE:To smoothen preprocessing for O press forming and regular welding that follow U forming and to improve the quality of a steel tube by specifying a tool used for U press bending in manufacturing UOE steel tubes. CONSTITUTION:A tool 1 used for U press forming is so made so that the range of angle theta on the bottom 1a is 100-150 deg., and the radius of U-shaped steel plate sprung back after U press has a radius of curvature R that becomes the bending radius nearly corresponding to succeeding O press, and the radius of curvature on both sides 1b, 1b of the tool 1 that continue from the bottom 1a is made to a radius R1 which is smaller than the radius of curvature R of the bottom 1a by at least 30%.

Forming method of heat exchange tube

Abstract: PURPOSE:To suppress the local reduction of outer wall thickness at a bent part and consequently uniformize the thickness by a structure wherein the bent part of the heat exchange pipe in zigzag is bent by connecting curves, which have at least two kinds of radii of curvature or variable curvatures. CONSTITUTION:The thickness reduction value epsilono of the outer wall to the locus of the center of the tube bent with a single bending radius of curvature r0 of a half of the pitch P between straight tube parts lS adjoining to each other becomes maximum near the middle of the bent part. On the other hand, the thickness reduction value epsilonn, which does not exceed the maximum value of the thickness reduction value epsilono produced in case of the bending with said single bending radius of curvature r0, can be obtained by bending the bending range in such a way that firstly said range is divided into five parts and the divided five parts are smoothly connected by curves with a radius of curvature r1, which is same as the single bending radius of curvature r0 with a radius of curvature r2, which is 0.8 times the single bending radius of curvature r0, and with a radius of curvature r3, which is twice the single bending radius of curvature r0. In such a way as mentioned above, the local thinning is prevented and consequently the pressure and erosion resistance are improved and furthermore spring-back force is suppressed due to the thinner parts epsilonp being separated into two positions and consequently the proper gaps requested for mounting fins are easily obtained and, in addition, because the height of the arcuate part is small than the single bending radius of curvature r0, the straight tube parts lS can be made longer and more fin equipments can be installed, resulting in enabling to improve the heat exchange performance.

Infrared Optical Fiber for Energy Transmission

Abstract: An infrared optical fiber using Tl Br-Tl I applicable to CO2laser has been newly developed.The most preferable composition for the fiber has been investigated to be 43 weight% Tl Br, and under this composition the fiber with 0.5 mm diameter and 1.5 m length has following excellent characteristics. (1) High output power of 70 watts, (2) high transmissibility of 96%/m, (3) minimum bend radius of 10 cm, (4) transmission spectra from 4μm to 22μm. This fiber has been put into practical use for a new CO2laser scalpel, and is expected to be used for many promising applications such as laser processing machines, infrared measuring instruments, etc..

Transportable measuring device for the optical measurement of pipe bends

Abstract: The invention relates to a transportable measuring device for the optical measurement of pipe bends, covering structural dimensions such as angle, bending radius and limb lengths. In order also to be able to measure relatively large pipe bends with high accuracy independently of position, the invention proposes a transportable measuring instrument which is characterised by two measuring rails (2, 3), which are to be arranged at a right angle on an arbitrary horizontal plane (1) on which the measurement object (6) rests, and of which each supports a direction-finding measuring head (4) that can be displaced on said measuring rails and can be rotated or pivoted horizontally and vertically, with the aid of which measuring head it is possible to lock onto measuring points (9) marked on the neutral line or over the core of the pipe bend (6) to be measured.

Fibre optic splice organiser

Abstract: A device and method for organizing a bight in an optical fiber at a splice (18) or slack point, so as to both minimize the size of a container necessary to enclose that bight and maximize the radius through which such fiber is bent, is provided. The method comprises laying the bight on a sheet (26) in such a way that, when the sheet is wrapped about a cylindrical core (20) the radius of any bend in the fiber is greater than the minimum bending radius, and wrapping the sheet about the core. The method is suitable for both in-line and butt splices, and provides ready means of fiber identification and encapsulation.

Fabrication and testing of the flexible transmission line to the TFTR neutral beam ion sources

Abstract: The four Neutral Beam Injectors (NBI) on the TFTR Tokamak Test Cell (TTC) floor require twelve transmission lines to carry arc and filament power to the twelve ion sources from the basement. Also, the Neutral Beam Test Cell (NBTC) requires three lines but on the same floor through a wall. The same basic specifications apply: (1) center bundle operates at 120 kV with respect to the outer cables, (2) filament circuits at 6000 A, (3) arc circuits at 3000 A, (4) gradient grid, (5) accel grids in a quadrupole configuration, (6) multi wire control cable, (7) SF/sub 6/ environment, (7) flexible, (8) 36'' centerline bend radius and (9) hi-pot to 200 kV.

Pipe bend formation method

Abstract: The method forms a pipe bend from a straight pipe with several successive bend sections and straight sections between them The bend is defined by the radius and angle, while it can have straight ends beyond the curved portion All the bend sections (1a,1b) run in the same direction and of the same radius (R), which is smaller than the overall radius of the bend The sections are each bent through the same angle, which is a fraction of the overall angle The overall radius of the bend is determined by the length of the straight sections (2) The sections can be bent through an angle of between 1 and 30 deg

Bend losses in drop inlet spillways

Abstract: The drop inlet spillway consists of a vertical riser open at the top and connected to a horizontal conduit or tunnel at the bottom. A 90° change in direction is required at the connection between the riser and the conduit. In the interests of simplicity a square bend, sometimes called a miter bend, is often used for small unimportant structures. This type of bend produces separation zones and large eddy losses (bend loss). At the other extreme is the fully curved bend, commonly used for large shaft spillways. A properly designed curved bend will eliminate separation and minimize head loss. However, layout and forming for construction of a curved bend for a tunnel is complicated and expensive because the elbow surface is of double curvature.In this paper the results of hydraulic tests on five bend designs are presented. It was found that a simplified design with only an inside curve performed almost as well as the fully curved bend. It is suggested that the proposed design will meet the requirement for man...

Extraction of Single-Mode Fiber ESI Parameters by Using a Simple Technique for the Measurement of Bend Loss

Abstract: It has been shown by a number of authors /1-3/ that for a practical range of V values, the field profile of the fundamental mode can be closely approximated by a Gaussian function more or less independent of the exact shape of the fiber’s refractive-index profile. This property has naturally led to the idea of replacing (for calculations) the complex profiles typical to MCVD fibers, by equivalent-step-index (ESI) models /2–4/ that yield reasonably accurate estimates of parameters such as constant bend, transition (microbend), and coupling losses /3/. The prediction of dispersion behaviour from ESI parameters is presently somewhat uncertain /5/.