Showing papers on "Bend radius published in 1988"

Optical fiber splice organizer

Abstract: An optical fiber organizer and splicing arrangement permits storage of variable lengths of surplus fiber. The organizer has a pair of separated cylinders extending from a first rectangular section of a base plate and a splice tray having opposite entrance sides for optical fiber in a second rectangular section. Each cylinder has a prescribed height permitting wrapping of multiple loops of fiber around the cylinder circumference and a diameter determined by the fiber bend radius restriction. The splicing tray is spaced from the base plate to permit passage of optical fiber underneath the splicing tray. The surplus fiber is directed around one or both cylinders and underneath the splicing tray through a plurality of different length passageways so that the varying lengths of optical fiber are stored. Clockwise, counter clockwise and figure eight loops are used so that each optical fiber end is directed to predetermined entrance side of the splicing tray without exceeding the fiber bend radius restriction.

Radiation of high-energy positrons channeled in bent crystals

Abstract: Computer calculations of radiation spectra of relativistic positrons planar channeled in a bent crystal were performed. It is observed that in the bent crystal, together with channeling radiation, additional quasi-synchrotron radiation occurs. The form of the total radiation spectra depends on the bending radius of the crystal. The intensity of the channeling radiation decreases with the increase of the crystal bend, while the intensity of quasi-synchrotron radiation increases. For a strong crystal bend the radiation intensities of the two types becomes comparable.

Magnetic head with constant area wear profile

Abstract: A particularized cross section for a magnetic recording head provides a constant area wear profile for cooperating magnetic tape. The constant area wear profile results from the "combined" use of a common radius of curvature for both the natural bending radius of the tape as well as the tape-contacting surface of the head, taken together with the requirement that the leading and trailing medium-contacting parts of the head form air-skiving edges which are essentially parallel to the force- (or pressure-) direction associated with the tape-contacting interface.

Tube curvature measuring probe and method

Abstract: The present invention is directed to a probe and method for measuring the radius of curvature of a bend in a section of tubing. The probe includes a member with a pair of guide means, one located at each end of the member. A strain gauge is operatively connected to the member for detecting bending stress exrted on the member as the probe is drawn through and in engagement with the inner surface of a section of tubing having a bend. The method of the present invention includes steps utilizing a probe, like the aforementioned probe, which can be made to detect bends only in a single plane when having a fixed orientation relative the section of tubing to determine the maximum radius of curvature of the bend.

A numerical study of laminar and turbulent flows in a two-dimensional bend with or without a guide vane

Abstract: A numerical study of the flow in a two-dimensional 90° circular-arc bend is presented. The study is based on the solution of the governing equations using a finite volume technique. Both laminar and turbulent flows are considered. Particular attention is given to the occurrence and size of the separation regions and, in this respect, the effects of Reynolds number and bend radius to height ratio are discussed. The study includes the effect of a guide vane, placed in the bend, on the flow characteristics. It is shown that the emerging velocity distribution is more uniform than that associated with flow in a bend without a guide vane. The presence of a guide vane is shown to suppress the formation of regions of flow separation. Comparisons are made between the effects on the flow of two different designs of guide vane.

GRP pipe bends subjected to out-of-plane flexure with and without pressure:

Abstract: Out-of-plane bending tests were carried out on eight E-glass reinforced polytester resin, 90 degree pipe bends of 250 mm diameter and 250 mm bend radius. Each bend specimen tested had 1175 mm long tangent pipes attached, and construction was by hand lay-up, the glass being in the form of chopped strand mat (either 2.4 kg/m2 or 3.6 kg/m2). In all cases low loads were applied so that deformations were sensibly linear. Strains and displacements were measured and distributions were compared with estimates calculated from pipe bend theory for isotropic materials under plane stress, but modified for composites by using separate moduli for direct and bending stress conditions. Further measurements were taken for internal pressure (only) loadings on five of the specimens, and finally for out-of-plane flexure loading combined with constant pressure. Again measured values were compared with theory. Results are discussed in relation to a typical design procedure for such pipe components.

Method and apparatus for bending plate material

Abstract: PURPOSE:To automatically perform bending a plate material with a smaller radius of curvature, by transferring a linear motor along an upper frame of a bending machine for the plate material, grooving by a provided laser nozzle, then immediately by lowering the upper die of the upper frame. CONSTITUTION:A traveler 17B is sent along a stator 17A of the linear motor 17 provided along the upper frame 11 of a plate material bending machine 1. By projecting from a laser nozzle 23 on the top of a 1st arm member 19 capable of freely lifting up and down attached on the traveler 17B and a 2nd arm member 21 capable of freely rotting, the plate material W positioned on a lower die 7 is grooved, then the nozzle 23 is rotated to raise. Then, immediately the upper frame 11 is lowered to bend the plate material W by an upper die 13. As the plate material W is grooved on the lower die 7 and immediately the bending is performed, so the plate material W is bent automatically and easily with the minimum bending radius.

Bending radius transmission cable with controlled and limited torsion variation

Abstract: A transmission cable for coaxial microwave cables has a limited capability to bend, and to twist under torque, the cable comprising a coaxial microwave transmission line (8) covered by a helically-wound armor sheath (1) having a hard wire (2) located in the grooved joint of the sheath, a hard wire or braid insulation (3) covering the sheath, a jacket (4) and at the ends of the cable, strain relief boots (5) and connector ends (6) to which connector bodies (7) are attached.

Bending device for optical fiber

Abstract: PURPOSE:To accurately bend an optical fiber at a prescribed state and to improve the mechanical strength including a bent part by fitting an optical fiber holding means for holding an optical fiber with a prescribed refraction angle and a refraction radius to a base. CONSTITUTION:A groove 3 with a uniform depth is formed on the upper part of the base 1 consisting of an acryl resin material and constituting an optical fiber bending device and the optical fiber 2 is held by the groove 3. In the groove 3, straight part A-A' is formed on the light indicent side of the fiber 2, a straight part B-B' is formed on he light projection part and a bent part of connecting both the straight parts A-A', B-B' with a prescribed bending angle theta and a bending radius R is formed. The face forming the bent part is positioned in parallel with the upper face of the base 1 and the depth of the groove 3 on the bent part is made uniform. The fiber 2 is accurately bent like a prescribed shape and the mechanical strength of the fiber 2 including the bent part is improve.

Lap bending machine

Abstract: PURPOSE:To execute a bending with an optional and desired bending radius without changing a press die by forming the press die bending a work with plural press pieces and making the mutual arrangement position of these press pieces movable according to the bending radius of the work CONSTITUTION:The both end parts of the work W to be worked are held with the tension extendably to the clamp C of a clamp holding device 1 and the parallel press jig device composed of plural jig devices 4-12 provided with the press pieces 4a-12a arranged in the right angles direction with the longitudinal direction of the work W is provided along the direction thereof With the operation of a control device 3 the supporting arm 13 to support the clamp C is rotated to the right and left symmetrically via gears 17-15 by the preinputted program, the position of the press piece is arranged by moving to the position corresponding to the prescribed bending radius and the work W is automatically worked in the prescribed bending radius

Cold forming method for tapered coil spring

Abstract: PURPOSE:To easily form a tapered coil spring of a normal shape dimension by rewinding successively a tapered wire bar from a coil-shaped tapered wire body in which a larger bending habit than that of a thin diameter part is given to a thick diameter part, allowing it to pass through a straightening roller, and bringing it to coil forming. CONSTITUTION:A bend radius R1 of a thick diameter part 4 is smaller than a bend R2 of a thin diameter part 5, and a large bending habit is formed. When this wire bar is fed into a straightening roller 26 of a spring forming machine, the wire body becomes roughly linear by only giving such straightening as making the thick diameter part 4 linear. It is because according to the straightening roller 26, the thick diameter part 4 is straightened effectively, and the thin diameter part 5 is straightened weakly, but as for the thin diameter part, only a smaller bending habit then that of the thick diameter part 5 is given before it is straightened. In such a way, at the time of coil forming after straightening, a tapered coil spring of a satisfactory shape dimension is obtained continuously with high efficiency.

Optical cable provided with bending mechanism

Abstract: PURPOSE:To optionally change the bending radius of a bending type optical fiber sensor by inserting the bending type optical fiber sensor previously bent with a required bending radius into a tube with high bending flexibility, filling the inside of the tube with liquid or gas and compressing the liquid or gas. CONSTITUTION:The optical fiber sensor body 1 is inserted into the tube 3 consisting of plastic such as polyethylene or rubber such as silicone rubber and having high bending flexibility. Since the tip of the optical fiber sensor 1 is previously bent with a required radius of curvature, the tube 1 is shaped as shown by a solid line in a drawing. When the gap 2 is filled with liquid or gas, the inner pressure of the gap is increased because the tip part is closed by a stopper 4 and the tube 3 and the stopper 4 are bent in the direction (a) in accordance with the rise of the inner pressure. Thus, the bending degree of the optical fiber sensor 1 can be changed by using the mechanism and controlling the inner pressure of the gap.

Water-cooling flame pipe bender

Abstract: The utility model relates to a bending device for pipes, which is composed of a platform, a clamping device arranged on the platform, a heating device, a force-exerting device and a cooling device. The heating device is composed of a hollow circular ring, and a hose, wherein, flame nozzles are uniformly distributed on the circumference of the hollow ring, and the hose is communicated with a flammable gas source and the hollow circular ring. The device solves the defects of complicated processes, low efficiency, high cost, unqualified quality existing in the existing various heating and bending methods and devices. The utility model can heat and bend various steel pipes, such as the pipes with bending radius within 2.5-7 times of outer diameter and the heating and bending ellipticity not exceeding 8%.

Clinical Options In The Delivery Of The CO 2 Laser In The Tracheobronchial Tree

Abstract: The clinician interested in using the CO2 laser endoscopically in the tracheobronchial tree presently has limited options due to problems in fiberoptic transmission. Three delivery systems have been used in a laboratory setting in a canine model: a CO2 laser coupler with a specially modified rigid bronchoscope (Cooper LaserSonics), a metallic waveguide (Laakmann Electro-Optics) and a polycrystalline fiber (Cooper LaserSonics). The most efficient laser delivery system for clinical application occurred with the wave-guide requiring 32 joules to create a standard 5 mm2 lesion, as compared to 54 and 184 joules for the coupler and fiber respectively. Limited bend radius with both the fiber and the waveguide limited clinical usefullness even through rigid bronchoscopes. In addition, only 60% power transmission was possible with the waveguide (bend radius of 6 cm). This loss of power was not associated with the fiber use. Waveguide and fiber transmission of the CO2 laser have the advantages of open bronchoscope systems with excellent telescopic optics. Unfortunately, due to the awkward, semi-flexible nature of the current waveguide and fiber deliver systems flexible bronchoscopes can not be utilized and the clinician is still obliged to use the laser coupler for most clinical applications.

Coil shaped tapered filamentous body

Abstract: PURPOSE:To improve productivity through reducing maximum bending stress and making correction unnecessary at a time of coil formation by taking up the large diameter parallel portion of a tapered filamentous body in the state of elastic deformation and making its bending radius larger than that of a small diameter parallel portion. CONSTITUTION:A large diameter parallel portion 4 is taken up in the state of elastic deformation by an adequate back tension, and its bending radius R1 is made to be larger than the bending radius R2 of a small diameter parallel portion 5, and a filamentous body thus subjected to the above is formed by means of a cold rolled coil spring forming machine. Accordingly, the reduction of maximum bending stress is attempted at the whole of the filamentous body, and the old take-up equipment can be used as it is, and a correction into a linear state at a time of coil formation is unnecessary, thus resulting in projectivity improvement.

Device for small curvature winding pipe forming

Abstract: The utility model relates to a device for forming small curvature winding pipes, which is composed of a traction wheel, a driven wheel, a quick heating device, a clamping block, etc. The utility model is suitable for the pipe of which the external diameter is not more than 60 millimeters, the thickness is not less than 3.5 millimeters, and the scope of the small curvature is 1.3 (R is bend radius; DW is external diameter of the pipe) The utility model adopts non-pistil bending system; the ellipticity of the elbow is not more than 10%; reducing ratio of wall thickness of the pipe is not more than 15%; the inner side of the pipe can not be wrinkled.

Bending manufacture of half divided pipe

Abstract: PURPOSE:To exactly and efficiently execute bending of a half divided pipe by pressing the inside surface of the half divided pipe, and bending the half divided pipe by a projecting metallic die provided with a clearance groove in the corner, and a recessed metallic die for pressing the outside surface of the half divided pipe. CONSTITUTION:In a projecting metallic die 1, a clearance groove 4 is provided on a corner part (R part) 3. A half divided pipe is inserted between the projecting metallic die 1 and a recessed metallic die 2 which have been set to a bender machine. Subsequently, each metallic die 1, 2 is rotated, and by a push-in force of the recessed metallic die 2, the half pipe is finished to a prescribed bend radius. As for a shape of the clearance groove 4, its width is set to 1-1.4 times of plate thickness of the half divided pipe, and its depth is set to 1.2-1.6 times. In such a way, the half divided pipe can be bent and manufactured to a prescribed shape.

Water absorption type waterproof cable

Abstract: PURPOSE:To sufficiently reduce the residual strain of the titled cable at the time of bending the titled cable by directly disposing an optical tape core on the base of the groove of a rod-like spacer. CONSTITUTION:The optical cable (a) is composed of the optical cable unit in which the plural numbers of the optical tape cores 2 and water absorbing taps 6 are accommodated, laminating them in plural grooves E provided on the outer circumferential surface of the rod-like spacer 1, and then, a press winding 3 is subjected on said surface of the spacer 1. The optical cable (a) has the structure of directly disposing the optical tape core 2 on the base of the groove E of the rod-like spacer 1. Thus, the titled cable having the water proofing characteristics which does not present the practical trouble is obtd. by using said structure and the water absorbing tape composed of a sodium acrylate polymer, and the bending strain of the optical fiber at the bend radius of the cable of about 300mm, is controlled to <=0.3%.

Member for treating surplus part of optical fiber cord

Abstract: PURPOSE:To prevent the titled cord from the damage and the application of the sharp bend to the titled cord by providing with a fixture in which one end of a leg thereof is vertically fixed to the lower divided part of a hollow ring, and the another end of the leg thereof is fixed to a printed board. CONSTITUTION:The hollow ring 1 is constituted by combining pair of the upper divided hollow ring and the lower divided hollow ring 1a, 1b having the inlet 4 and the outlet 5 of the optical fiber cord 3 respectively. The inside radius R of the hollow ring 1 is established so as to be larger than the allowable bend radius of the titled cord 3. The prescribed numbers of the fixture legs made of metal are vertically fixed on the bottom surface of the lower divided hollow ring 1b, and the tops of the fixture legs 2 are inserted in holes 7 provided to the board 6 respectively and fixed to the printed board 6 with a solder. Thus, the surplus part of the optical fiber cord is treated without injuring said part.

Coil-shaped tapered wire bar

Abstract: PURPOSE:To easily form a tapered coil spring of a normal shape dimension by giving a larger bending habit than a thin diameter part, to a thick diameter part, so that radius of the thick diameter part in a non-restraint state become smaller than a bend radius of the thin diameter part. CONSTITUTION:A tapered wire bar 3 passes through in a bending shape extending from the lower part of a front fixing roller 12a to the upper part of a moving roller 12b, and also, passes through the lower part of a rear fixing roller 12a, drawn by a winding drum 11 and wound. In this case, when it is passing through a habit forming roller 12, a bending habit having a prescribed bend radius is given to a thick diameter part 4 by an interval of the moving roller 12b and the fixing roller 12. A habit forming state of a thin diameter part 5 becomes weaker than the thick diameter part 4. In such a way, by supplying a tapered wire bar which has been straightened, to coil forming, a tapered coil spring of a normal shape dimension is easily formed.

正方形断面を有する90°ベンド内の乱流 : 第1報,平均速度の測定

Abstract: Three components of mean velocity have been measured in a square-sectioned 90 degree bend of 2.0 radius ratio with upstream and downstream straight ducts attached using rotable hot wires. Measurements were made for a Reynolds number of 40, 000 and in various cross-section planes. The contours of the longitudinal velocity and the velocity vector diagrams of the secondary flow were obtained at successive streamwise stations. The main conclusions derived from the experimental results are as follows : (1) The flow is biased towards the inner-radius wall of the bend over the range from the entry of the bend to the streamwise coordinate θ≒80°, θ being an angle measured from the entry of the bend in the streamwise direction ; (2) On the contrary, the flow is biased towards the outer-radius wall at θ 80° and the bias is the most remarkable just behind the exit of the bend ; (3) The intensity of the secondary flow induced in the cross-section is maximum near the exit of the bend.

Using Bends in a Single­ Mode Optical Fiber

Abstract: A new method of wavelength demultiplexing is identified which makes use of the wavelength and bend radius dependence of the pure bend loss at single radius bends in a single-mode fiber. The light leaving the fiber at a bend forms one output of the demultiplexer. Equations are derived which predict the bend radii for the most effi­ cient operation of the demultiplexer and the power extracted from the fiber at each wavelength. Tbe demultiplexer operates over the wave­ length range corresponding to V numbers from 2.4 to 1.6. A two waVe­ length demultiplexer formed from 90° bends is constructed and tested. Collection eftlelencies of 70 percent and insertion losses of less than 2 dB are sbown to be possible. Crosstalk isolation in excess of 40 dB can be achieved with tbe aid of optical wavelength filters. The performance of a thee wavelength demultipleer 'is also considered.

Bristles straightening machine

Abstract: The utility model discloses a bristles straightening machine. The bristles with definite numbers have small bend radius and are tied on a wooden plate; then the bristles are shaped via the drying of the kitchen range. The utility model comprises rotary drums (15), conveyer belts (25), seven rotating rollers, semicircular heating plates (10), semicircular heated boards (20), and machine frames (30). The conveyer belt (25) is tensioned via the rotating roller (2), and the rotary drum (15) and the semicircular heating plate (10) are respectively provided with the heat source. The bristles are processed by the ironing press between the rotary drum (15) and the conveyer belts (25) via the rotating roller (5) for making the bend radius minimize and become the radius of the rotary drum (15); the purpose of straightening the bristles can be implemented. The natural color of the bristles can be ensured.

Numerical analysis of steady flow in a 90° circular section bend

Abstract: Laminar‐viscous flow around a bend of radius twice the conduit diameter, preceded and succeeded by a straight conduit, is calculated via primitive variables for a Reynolds number of 100. The nature of the finite‐difference equations and the solution approach used are indicated. In the solution, pressure is evaluated via the Poisson equation involving velocity components. Initially, axial velocities are found to shift toward inside of bend; later they shift toward outer wall. Secondary flows initiate upstream of the bend proper and continue in the downstream conduit. They maximize and level off about one‐third the way around the bend and decrease after another third. Detailed information on pressure field indicates appreciable modification in the bend proper together with significant modification in the upstream and downstream straight conduit. Wall shear stresses are found to vary greatly in the bend. Axial components are largest and vary most in the junction region between the bend and the straight conduit.

Bending device for flat bar material

Abstract: PURPOSE:To perform the bending in a larger bending radius with a simple control and short bending arm by the composition of moving the bending arm fitted with the clamp to hold the tip of a flat bar material by holding it rotatably on a truck. CONSTITUTION:The pivot 34 of the arm 33 having the clamp 35 to hold the tip of the flat bar material 21 is placed at the position PO in the Y axial direction of a heating device 26 and the bar material is advanced in X axial direction with continuing the heat cooling of the flat bar material 21 with the heating device 26. An arm 33 is rotated with the pivot 34 as the center and the flat bar material is bent at a radius R but when a truck 28 is moved in X axial direction and a truck 30 in Y axial direction by controlling motors 29B, 31B, the pivot 34 is moved on X-Y face, so the flat bar material 21 can be subjected to a bending in the necessary radial or curved shape.

Verfahren und vorrichtung zum biegen von rohren

Abstract: By rotating a bending roll (10) in the pipe bending direction, a pipe bend portion (11a) held in a sandwiched state by a pressure die (13) and a block member (14) is bent around a circular section of the bending roll (10) as it emerges from between these members. The outer bend periphery section of the pipe (11) is under the axially compressive force of a pressurizing means (16), which by a top (16a) abuts an outer edge of the pipe, and undergoes a change in such a manner that the elongation ratio thereof is restrained. Further, the inner bend periphery section of the pipe (11) undergoes a change in such a manner that wrinkle generation on the surface thereof is prevented by the elongating tensile force exerted by the block member (14) and the core bar (17), such prevention being aided by a wrinkle checker (18) on the core bar (17). The pipe has a bend radius of down to its diameter.

The Effects of Frictional Forces in Bending Cables

Abstract: In this work the effects of the frictional forces involved in a steel cable subjected to axial and bending loads are studied. The results show that the cable bending-stiffness is affected more strongly by the frictional forces when values of the helical angle of outer wire and the ratios of cable radius to bending radius are getting larger.