Showing papers on "Bend radius published in 1989"

Splice case for optical fibre cable

Abstract: An enclosure capable of enclosing a butt splice between at least two optical fibre cables, which comprises: a base through which respective cables can pass; at least one optical fibre organizer capable of storing an optical fibre in a path from one of the outlets to another of the outlets, said path having a minimum radius of curvature no smaller than the minimum bend radius of said optical fibre; and a hollow cover which can surround the organizer and which can be fixed to the base to close the enclosure; the base being removable from the splice by sliding over the organizer.

円管の新しいフレキシブルな押通し曲げ : 第1報,mos曲げ加工法に関する研究

Abstract: A prototype flexible bending machine was made on the basis of a new method, idea which proposes to penetrate the tube into the die. Since the area of bending is limited and the cross section of the tube is restrained by the die, flattening, buckling and wrinkling at the inner wall of the tube can be prevented. The tube can be bent to any radius by using ths system. The effects of penetrated load flattening factor, variation factor of thickness, and bending radius are examined under various bending conditions. The results are concluded as follows: (1) In the beginning of bending, the penetrated load reaches the, maximum, and thereafter, the load decreases and remains constant as the bending continues smoothly. As the bending radius decreases the load increases. (2) The flattening factor increases as the bending radius decreases. The flattening nearly be prevented by the choice of bending conditions. (3) The reduce thickness of the inner wall of the tube is nearly prevented.

Small-diameter metallic conduit bending machine

Abstract: A small-diameter metallic conduit bending machine includes a stationary frame. The stationary frame made of bar stock or pipe stock is shaped so as to substantially conform to a finished metallic conduit. The stationary frame includes a bending section which has in its lengthwise direction a curvature smaller than the bend radius of the metallic conduit and in its widthwise direction a guide surface substantially orthogonal to the bend plane of the metallic conduit. A bending member whose outer peripheral surface faces the guide surface is disposed movably toward the stationary frame so that the metallic conduit can be bent so as to lie along the guide surface. The bending member is moved by an actuator when the actuator is in its pulling stroke.

All-Fiber Spectroscopic Probe Based On An Evanescent Wave Sensing Mechanism

Abstract: An all-fiber spectroscopic probe based on an evanescent wave sensing mechanism is described. the influences of refractive index, fiber length, fiber bend radius and the polymer cladding are evaluated.

Pipe on sheet type heat exchanger and manufacture thereof

Abstract: PURPOSE: To improve the thermal efficiency of the pipe on sheet type heat exchanger and to reduce its manufacturing cost by continuously bending the pipe of specific thickness ratio with the specific ratio and flatting the sheet part. CONSTITUTION: On the pipe on sheet type heat exchanger which consists of the continuously bent copper pipe 1 fixed to the sheet 2, the copper pipe 1 of D/t≥15 (D; outer diameter, t; thickness) is subjected to continuously bending work of R/D (R: bending radius of center line) and the contact part 1a of the copper pipe 1 with the sheet 2 is pressed flat and the copper pipe is fixed at the flat part 1a with adhesive agent 3 on the sheet 2. Therefore, the pipe on sheet for the heat exchanger of good heat conductivity is possible to be manufactured. COPYRIGHT: (C)1991,JPO&Japio

Small diameter metal conduit bending machine

Abstract: The machine includes a stationary frame 1, 1', made of bar stock or pipe stock, shaped so as to substantially conform to the bent conduit. The frame includes at least one bending section which has in its lengthwise direction a curvature smaller than the bend radius of the metallic conduit and in its width-wise direction a guide surface orthogonal to the bend plane or a section with a surface parallel to the bend plane and an orthogonal guide member of smaller curvature radius. A bending member 5 at each section whose outer peripheral surface faces the guide surface is disposed movably by pivoting or straight line motion toward the frame so that the conduit can be bent so as to lie along the guide surface. The bending member 5 is moved by an actuator 7 when the actuator is in its pulling stroke. … …

Small bending radius u form pipe bender

Abstract: The utility model belongs to the bent pipe mechanism device processed by pressure which is made up of upper and lower modules, pipe joint grip blocks and bathtub type sliders. The utility model can bend pipes in different formats such as simple steels, stainless steels and alloyed steels whose relative bending radius is 0.8<=R/D<=1.2, the relative thickness of the pipe is 0.8<=S/D<=0.25, and the angle of the bent pipe is between 90-180 DEG. The bent pipe joints have the advantages of small relative bending radius, simple bending processes, high output rate, and they are reliable, and two or more U form pipe joints can be bent on a same pipe joint continuously. The utility model overcomes the disadvantages of complicated processes, big relative bending radius of the prior art, and equipment and field limit of the bending of most pipe joints.

Optical fiber bending stress proof tester

Abstract: An optical fiber bending stress proof tester 40 which provides multiple mandrels or roller elements 22 and 24 for applying compression and tension stresses to multiple planes on the periphery of an optical fiber 10. In one embodiment, first and second roller elements 22 and 24 are incorporated in a roller block 50 which is stable in either of two angular orientations with respect to the longitudinal axis of the fiber 10. The fiber 10 is bent in an S curve around the two rollers 22 and 24. The rollers 22 and 24 control the bend radius and therefore the stress induced in the outer fibers of the filament. In a specific extension of this embodiment, multiple sets of first and second roller elements are provided in additional roller blocks. Each block is stable in a first loading position and a second test position. In the test position, discrete planes around the entire periphery of the fiber are exposed to bending stress in a single pass through the tester. A device constructed in accordance with the teachings of the invention would effectively bend the fiber in several planes with a controlled bend radius. More significantly, the device would subject the fiber to high stress levels for a very short period of time thereby minimizing the possibility of damaging the fiber.

Laminate bending device

Abstract: A laminate bending device includes a pair of parallel shafts extending outwardly through transverse slots in a front wall of a housing. A pair of clamping jaws on the shafts each include an elongated slot for the insertion of a narrow strip of a laminate material of the type sold under the trademark FORMICA. Each of the shafts are mounted within the housing for linear and rotary movement. A spring biases each of the clamping jaws toward a stop on the front wall of the housing. In use, a strip of laminate material is inserted into the slots of the clamping jaws, the spacing of which has been previously adjusted to determine the bending radius. A heating element is then activated to heat the strip and allow the spring biased force on the clamping jaws to bend the strip to the desired radius. A cooling mechanism is activated upon completion of the bending to cool the strip and set the deformed shape. A first timer allows adjustment of the duration of the heating period and is operative to initiate a second timer which is adjustable to control the duration of the cooling period.

Method and device for bending axial line of work

Abstract: PURPOSE: To efficiently execute a diameter axial line bending with a sall size device and simple process by clamping an end part of the long size work, applying the tension in the axial direction, pushing the work to the bending die while vibrating it and executing the axial line bending. CONSTITUTION: On the axial line bending of the work 2, there are two methods to vibrate the work 2, namely the method to vibrate in the axial direction of the work 2 with the vibrating device 9 connected to the clamp 14, and the method to vibrate in the crossing direction with the axial line, and the combination of both is preferable with respect to the portion of the small bending radius. And on the case of the bending radius equal to or larger than the specific value, the vibration is may be applied from one side or the both sides. Further, when the ultrasonic vibration is applied as the vibration, reduction of the bending deformation resistance is remarkable. COPYRIGHT: (C)1991,JPO&Japio

Method of inspecting bending radius of cable

Abstract: PURPOSE:To simply inspect whether the radius of carvature of a cable is the min. tolerant value or more, by passing the cable through a cylindrical body having definite relation between an inner diameter and a length. CONSTITUTION:When a cable 4 having an outer diameter dc bent in the min. tolerant bending radius rc is passed through a cylindrical body 3, the cylindrical body 3 is brought into contact with the cable 4 at both and parts and central part thereof. In this case, the relation represented by formula is present between the inner diameter D and length L of the cylindrical body 3. When the cylindrical body 3 is moved along the cable 4, in such a case that the radius of curvature of the cable 4 becomes the in tolerant bending radius or less, the cylindrical body 3 becomes impossible to move and a place where the bending radius of the cable 4 is abnormal can be discovered.

Multi-role tube-curving machine

Abstract: The utility model discloses a multi-role tube-curving machine which is a universal machine. The multi-role tube-curving machine is composed of a base, a driving arm of a speed reducer gearing device, a slip cap, a fixing bracket, an eccentric fixture, a stationary fixture and an angle board, etc. The utility model can curve and process pipe materials of various specifications into different angles and different bending radius without using molds. The applicable maximal bending tube angle is about 120 DEG, the scope of the pipe diameter is phi 15-phi 40, the bending radius is 5-10 times. The utility model has the advantages of small size, light weight, labor saving, high work efficiency, and because wheels and rotatable legs are arranged, the utility model is convenient to move. Moreover, compared with traditional hydraulic and mechanical pipe bending machines, the multi-role tube-curving machine saves molds and is applied to bending tubes in the laying and arranging work of tubes in water supply, air supply for heating, electrical wires and cable protection.

Process for producing a pipe bend from thermoplastic material and a pipe bend produced by this process

Abstract: Process for producing a pipe bend from thermoplastic material by heating and bending a pipe, characterised in that the bending is carried out section by section in such a way that the bending line runs substantially along the outer contour of the pipe bend, and a pipe bend, produced by this process. Pipe bends produced in this way have the same pressure resistance as the pipes used for the bending.

Subterranean heat insulated pipe system with a bending, and a method of establishing such a system

Abstract: In a subterranean heat insulated pipe system as laid with angellike bendings between straight pipe lengths, i.e. a district heating pipe underneath a street angle, the conventional bending elements are substituted by pipe elements joined so as to form a bending run of a relatively large bending radius, which, depending of the pipe size, has a minimum value, by which the pipe bending by itself and by interaction with the earth is able to take up the expansion and contraction forces, which are created in the pipe in response to temperature changes therein. The said minimum value has been found to be so low that in many instances it is hereby possible to avoid the sharp bending elements with their associated heavy problems due to expansion effects.

Breakdown roll for steel pipe manufacturing line

Abstract: PURPOSE:To eliminate the reduction of wall thickness and the shortage of bending in time of forming a steel pipe by making the difference between the bending radius of an upper roll and the bending radius of a lower roll in a breakdown roll larger at the ends than in the center CONSTITUTION:Regarding the bending radii of the forming rolls 1, 2, the bending radium difference rb-rt between the upper 1 and the lower roller 2 is designed based on the maximum wall thickness Besides, regarding the inner bent part, the bending radius difference Rb-Rt between the upper 1 and the lower roll 2 is designed based on the maximum wall thickness and the difference between the upper and the lower bending radius is made larger in the inner side Accordingly, when the plate thickness is thick, the difference between the upper and the lower bending radius is large in the plate edge parts, therefore, a satisfactory interval between the rolls can be maintained and the plate thickness can be prevented from reducing When the plate thickness is thin, the difference between the upper and the lower bending radius is small in the central part of the plate, therefore, the bending operation can be executed over the large area to eliminate shortage of bending

Method for laying optical cable

Abstract: PURPOSE:To protect an optical cable by affixing lengthwise or winding spirally a reinforcing wire to a contact part, of the optical cable, with obstacles covering the outside periphery of the optical cable of a part to which the reinforcing wire has been installed, with a thermal contraction tube and reinforcing the optical cable. CONSTITUTION:To a part which comes into contact with a obstacle 12, of an optical cable 11, at least one piece of reinforcing wire 3 is affixed lengthwise, and the outside periphery of the optical cable 11 of the part to which this reinforcing wire 3 has been installed is covered with a thermal contraction tube. Also, when the reinforced part of the optical cable 11 is linear, the optical cable is bent at both end parts of the reinforced part, therefore, it is necessary that the reinforcing wire 3 is worked in advance to the allowable bend radius or above of the optical cable 11 for fitting an angle of bending. Accordingly, even if tension or vibration is applied to the optical cable, the optical cable 11 is not bent and the transmission loss is not increased, nor a protective covering 2 is damaged due to friction. In such a way, even in case of the optical cable whose mechanical strength after laying is small, it can be fully protected from various obstruction due to contact with an obstacle.

High modulus-of elasticity polyethylene wire material

Abstract: PURPOSE: To provide the subject high-elasticity polyethylene wire material that has a very small value of allowable bending radius despite of its large diameter and its extremely high tensile elasticity, shows outstanding flexibility and pliability and is useful as a variety of supporting wires with easiness to handle. CONSTITUTION: The objective wire materials satisfies the following formulas: (1) R [minimum allowable bending radius (the minimal bending radius at which a circle can be retained without development of crimping) in mm )]/100; (2) D>=0.3; (3) E =50 mm and untwisting the twists given formerly.

Pipe bender for making v-shape glass pipe

Abstract: The utility model relates to a pipe bender for making a U-shaped glass pipe, in particular to for making a U-shaped glass pipe whose inner bending radius is quite small. Comprising three machine heads, an optical disc programmed control instrument, drive chains A, B, C and D, a machine body and an annealing furnace, wherein, the optical disc programmed control instrument gives forth instructions to the four drive chains a, b, c and d according to the given programs; the drive chains achieve respective processes through respective control mechanisms. To realize the complicated technology of the bend pipe, the utility model specially designs a synchronous rotating pipe system of bevel gear, a rectangular multi-core oxidizing flame torch, an inner diameter frictional clamp, an automatic inflating mouth, a loop tunnel annealing furnace and a hyperbolic arm bend pipe mechanism. The whole technological cycle is 50 seconds, three U-shaped glass pipes are produced in each cycle, the productivity is that the annual output is 500, 000 glass pipes, and the qualified rate is 90%. The space occupation of the apparatus is 1.05*1.4*1.4 meters + [3].

Optical fiber splice tray

Abstract: An optical fiber splice tray (40a, 40b) capable of permitting the close packing of a plurality of optical fibers while fitting within a substantially standard pedestal closure (10) is described. The splice tray (40a, 40b) further provides installer-ready access to the optical fibers while maintaining the optical fiber cables at a radius greater than the minimum bend radius of the optical fibers so as to minimize optical losses.

Thermal stresses in u-tubes of heat exchangers

Abstract: A comprehensive procedure for development of the design charts for determination of thermal stresses due to interleg differential thermal expansion in U-tubes of heat exchangers is presented. A computer program, based on the classical method is employed for generation of the charts. A parametric study covering the practical range of heat exchanger geometrical parameters is carried out to identify the critical parameters. Each geometric parameter is expressed as a scalar multiple of tube outer diameter. A typical chart showing the variation of (MAX.STRESS/E) as a function of tube overhang, bend radius, baffle spacing, tube thickness, tube diameter and interleg differential thermal expansion is presented. The usage of the chart is demonstrated with an example. The charts are intended for the designers to quickly determine thermal stresses while optimising the design of U-tube heat exchangers.

Effect of link geometry on properties of chains

Abstract: The present work has arisen from a continuing need to improve the performance of round-steel lifting (hoist) and mining chains, and the hypothesis that this might be done by modification of the link geometry. The finite element (FE) method has been used to analyse the stresses in the chain links. The effects of link length and the bend radius in the crown were considered. The effect of maintaining link length constant and departing from the conventional straight sided (standard) geometry by changing the link shape from eight shape (pinched), through straight sided, to elliptical has been examined. Mining chains made from non-circular section rod have also been investigated. The finite element work has been supported by practical investigations using through-yield strain gauges. [Continues.]

Manufacture of copper or copper alloy foil for circuit board

Abstract: PURPOSE:To prevent the generation of contraction, and to secure an excellent flatness by giving the bending of a specific radius to a band-like copper or copper alloy foil, along an edge line of a pressurized fluid which has been jetted linearly from a hole, and also, executing the tension leveling of a specific elongation. CONSTITUTION:From one or plural holes 3 of a header 2, a prescribed fluid such as water or a rolling oil emulsion, etc., is jetted in the width direction of a band-like copper or copper alloy foil 1. By adjusting a bend radius of this copper or copper alloy foil 1 between 1.5R-2.5Rmm, leveling of a foil of 10mum-60mum is executed moderately. As for an elongation of the copper or copper alloy foil by tension leveling, 0.2-1.5% is suitable. In such a way, no wrinkle is generated in the plating process, the generation of contraction is prevented, and an excellent flatness by which uniform etching can be executed is obtained.

Optical-loss change characteristics of fiber organizers for optical-fiber cable joints

Abstract: This paper discusses and evaluates optical-loss change characteristics which occur in the process of installing the optical-fiber splicing points and slack fibers into an optical-fiber organizer. First, as the optical-loss change factors, bend lateral force and twisting were discussed. Their effects on the loss characteristics have been studied theoretically and experimentally so that the main factor for degrading the transmission characteristics is the bending process of the slack fiber. Next, the evaluation method for the optical-loss change characteristics is studied at the fiber joint for the analog baseband video signal transmission. It is found that the allowable optical output vs. optical-loss change ratio SNRC is 37.1 dB, and the bend radius is satisfying the present allowable SNRC at all frequency components of the optical loss change is more than 18 mm. Also, the relationship was studied between the bending radius of the fiber satisfying this SNRC and the changing frequency. It is found that the allowable bend radius can be relaxed by about 20 percent by doubling the fiber organizing time. Further, the optical-loss change characteristics have been evaluated for the individual organization and the simultaneous organization. It is pointed out that the individual organization is suited for subscriber optical cables.

High reliability FRP strength member for nonmetallic optical fiber cable

Abstract: It is possible to employ nonmetallic optical cables in regions with strong electromagnetic disturbances such as the vicinity of railroads, etc. However, the method to evaluate the reliability of the strength members of FRP in these cables is not yet known. In this paper, experimental investigations are carried out on bending strain characteristics, which is the main problem in reliability of FRPs. The method to estimate the lifetime of FRP with known temperature and humidity conditions and under fixed bending radius is described. Next, using this method, experiments on evaluation of FRPs with different comprising materials are carried out. It is indicated that there is a remarkable improvement in reliability by using glass fibers of high strength which are very suitable to be used as highly reliable FRPs in optical cables. As the result, it is shown that by using these FRPs in optical cables, the allowable bending radius of the optical cable is reduced by the factor of one-half and the modulus of elasticity of the optical cable is increased by a factor of 1.4, compared to the optical cables with previous FRPs.

Fixing method of accelerometer cable

Abstract: PURPOSE:To stabilize the performance of an accelerometer, by turning round an introducing portion of a cable from above to below said accelerometer with a minimum bending radius not affecting the capability of said accelerometer. CONSTITUTION:A cable 3 of an accelerometer 1 fixed to a measuring surface 2 is bent with a minimum radius so that no kinds are generated at an introducing portion thereof. The cable 3 is turned from above the accelerometer therebelow. Then, a lower portion of the cable 3 is fixed to a rear portion of the accelerometer 1. The vibrations of the cable 3 in a vertical and a horizontal directions are restricted by the turn of the cable 3. Therefore, the irregularity in the sensitivity of the acceleration of the accelerometer due to the vibrations of the cable 3 can be removed, thereby stabilizing the performance of the accelerometer.