Showing papers on "Bend radius published in 1990"

Characterization of hollow fibers for the transmission of infrared radiation.

Abstract: Plastic hollow fibers were made from plastic tubes covered on the internal wall with a metal layer (a-type) or a metal layer and dielectric layer on top of it (b-type). The CO(2) laser energy transmission through the hollow fiber was measured as a function of the radius of curvature and the coupling lens (focal length at a constant fiber length). The yield of the transmission decreased in subtle curvatures (radius of curvature up to 100 cm) and remained almost constant as the curvature became sharper (down to radius of curvature of 13 cm). For the a-type fibers, the characteristics of attenuation depended on the focal length of the coupling lenses. The energy distribution at the output was measured and mapped. The experimental results showed that the maximum of the energy distribution is asymetrically positioned relative to the center and closer to the internal wall at a smaller bending radius. This was predicted in our previous theoretical calculation. The value of transmitted power attenuation was up to 1.4 dB/m. Maximum power at the output was 30 W, for a fiber of 50-cm length and a cross-sectional diameter of 1.9 mm. These types of hollow fiber have already been used in surgical experiments on dogs.

Hollow sapphire fibers for the delivery of CO(2) laser energy.

Abstract: Hollow sapphire tubing has been used to deliver nearly single-mode CO2 laser energy. The hollow single-crystal Al2O3 fiber has an n < 1 cladding at 10.6 μm. Measured losses at 10.6 μm are as low as 0.49 dB/m, and the minimum bend radius of the 580 μm × 380 μm fiber is 14 cm. Bending losses are shown to vary as 1/R, and essentially only the HE11 mode propagates in the bent guide.

Prosthetic anterior cruciate ligament design

Abstract: An artificial ligament device (36) is provided for joining the ends of two bones (12, 14) wherein at least one of the bones has a tunnel (32) extending therethrough. The device comprises a multilayered or tubular woven ligament (35) having an intra-articular region (38), at least one bend region (40), and at least one end region (46), each region being woven so as to possess qualities of flexibility and strength suitable to the particular types of stresses it receives during use. The end region and a portion of the bend region are encased within a polymer bone block (8); usually by thermomolding, and the bone block is inserted into the bone tunnel to attach the ligament. The bone block is molded to provide a fixed bend radius (60) for the ligament at the point of exit therefrom so as to control the amount of bending stress on the ligament during flexure and extension of the joint.

Face plate with seal and cover

Abstract: A face plate adaptor (10) includes spring driven doors (60) to seal apertures (42) and integral projections (46, 48) which latch connector halves (90, 100) to the plate. The adapter (10) precludes dust from collecting thereon and therein and provides an adequate bend radius for cable (90) extending within a wall box (16) to which the face plate is attached.

Kink-resistant, small bend radius hose with polyfluorocarbon liner

Abstract: A kink-resistant, small bend radius hose has a thin layer polyfluorocarbon liner tube with a thickness in the range of from about 0.005 inches to about 0.025 inches. The exterior of the liner tube is etched to allow silicone to be bonded thereto. A thin layer of silicone is bonded to the etched exterior of the liner tube. This layer of silicone serves as a bonding layer for a reinforcing layer of synthetic fabric, a helix strand and a cover layer. The reinforcing layer serves to strengthen the thin liner tube, the helix strand serves to support the hose against kinking and the cover layer adds additional strength and contains the helix strand with respect to the reinforcing fabric. Thus, a composite, integral, kink-resistant, small bend radius hose is achieved.

Turbulent boundary-layer development around a square-sectioned U-bend : measurements and computation

Abstract: A computational and experimental study is reported of turbulent flow around a square-sectioned U-bend with a mean bend radius equal to 3.375 times the hydraulic diameter (DH ): the duct Reynolds number is 58,000. The bend geometry is the same as that for which Chang et al. (1983) have reported extensive LDA data except that in the latter experiment the bend was preceded by some thirty hydraulic diameters of straight ducting (thus the boundary layers filled the duct). In the present case, with the inlet section shortened to only 6 DH , the boundary layer thickness at inlet to the bend was only about 0.15 DH . Despite the thinner boundary layers a strong secondary flow is generated which, by 135° around the bend, appears to have broken down into a chaotic pattern. Computations of the flow using a three-dimensional finite-volume solver employing an algebraic second-moment (ASM) turbulence model are in generally close agreement with the experimental data and suggest that the secondary flow, in fact, breaks down into a system of five eddies on either side of the mid-plane, in place of the classical single vortex structure.

Bend loss in large core multimode optical fiber beam-delivery systems

Abstract: We present results of an experimental investigation of the optical losses produced by bending large core optical fibres, typical of those used in power beam delivery systems. Experiments have been conducted over a range of core diameters for both plastic clad silica and all silica fibres, as a function of bend radius. A theoretical model has been developed for predicting the magnitude of the bend loss, and agreement was obtained with the experimental results. The study thus yields design information for fibre beam delivery systems.

Leak light fiber cable

Abstract: PURPOSE:To decrease the number of optical fibers and to allow arbitrary setting of light emitting parts without being limited by changing the doubling and twisting pitch of the optical fibers so that light emission and display are selectively executed. CONSTITUTION:A piece or plural pieces of the optical fibers 1 are doubled and twisted around a tension member 2 at the center and the doubling and twisting pitches P1, P2 are changed longitudinally, by which the bending radius of the optical fibers 1 is changed and the quantity of the visible light transmitting in cores 11 and leaking to the outside is controlled. Namely, the bending radius increases and the leak light decreases if the doubling and twisting pitch is increased to P2. The bending radius decreases and the leak light increases if the pitch is decreased to P1. Bending is eventually imparted to the optical fibers 1 by doubling and twisting the optical fibers around the central tension member in such a manner and the quantity of the visible light transmitting in the core 11 and leaking to the outside is controlled by changing the doubling and twisting pitch.

Optical fiber splice organizer

Abstract: A splice organiser comprises a tray having a plurality of formers (14, 15) which control the minimum bend radius of the fibres, a groove for retaining a splice, an enclosure into which coiled fibre loops are introduced and permitted to expand so that they are retained by the resilience of the fibre itself, and a plurality of guide tracks (23, 24, 25) which enable fibres to enter and exit the organiser at any corner of the tray.

Low-loss Ti:LiNbO/sub 3/-waveguide bends prepared by MgO indiffusion

Abstract: A significant bend loss reduction for z-cut Ti:LiNbO/sub 3/ waveguides was achieved with a single and very efficient technique. The refractive index on the outer sides of an S bend was decreased through indiffusion of a double-MgO layer for reducing the radiation losses, and a broadening of the bent waveguide sections was used for further decreasing of the radiation losses and additionally reducing the transition losses. The acceptable bend radius for an allowed excess loss of 1 dB could thus be reduced from 24 mm down to 5 mm for TM polarization and from 26 mm down to 10 mm for TE polarization. >

Optical fiber tape assembly and canister

Abstract: An optical fiber is joined, preferably with an ultraviolet curable adhesive, to a strip of a flexible support material such as a plastic tape to form an optical fiber assembly. The assembly is wound onto a bobbin to form an optical fiber canister, which is then paid out upon demand. The optical fiber assembly requires little or no adhesive to hold it in place on the bobbin, as the support material of each turn aids in holding the adjacent turns in place, with the result that the bend radius during payout is increased.

Transmission losses and mode-selection characteristics of a curved hollow dielectric waveguide with a rough surface

Abstract: The effects of surface roughness and axial bends of a hollow dielectric waveguide on transmission of 10.6-μm CO2 waveguide laser radiation are measured. An analytical expression for various waveguide modes has been obtained in the beam approximation for calculating the value of the transmission of a real waveguide. This expression takes into account both Fresnel losses and radiation scattering due to the roughness. It is shown that the efficiency of selecting transverse modes from the waveguide laser is diminished with an increase in the bending radius and the waveguide diameter and also with a decrease in the radiation wavelength.

Method for bending complex shapes on a glass sheet

Abstract: The invention relates to a method and a mould assembly for bending complex shapes on a glass sheet. The invention relates also to a bending mould and its manufacturing method. A heated glass sheet placed upon a ring mould is bent to its final shape by means of an over-head non-contacting mould (6) whose curved lower surface (7, 8) is provided with blasting orifices (10) and suction orifices (11). Blasting orifices (10) are used to blow hot air for heating a glass sheet at least locally while building an air cushion between shaping surface and glass sheet. The hot air blown from blasting orifices (10) is used to apply a greater heat volume to those sections of the glass sheet surface in which the bending radius of a glass sheet is the smallest or deformation (elongation, bending) is the greatest.

Cable type remove control device and remote control system employing the same device

Abstract: PURPOSE:To reduce a control force, to reduce the size of a cable, to decrease a bending radius, and to enhance the degree of freedom of cable wiring by a method wherein a servo assist mechanism is mounted on the driven side or in the middle of a force transmission route formed by using a cable. CONSTITUTION:When a control lever 6 of an input mechanism 1 is operated in a direction A, torque in the direction A is exerted on an input pulley 7 of a servo assist unit through an input cable 18. The torque is transmitted to an output pulley 9 through the one strain absorber 8, but simultaneously a pressure-sensitive sensor incorporated in the strain absorber 8 is worked. When an electromagnetic clutch 10 is engaged through a controller C and a motor M is also run in the direction A. Thus, solely by exerting a force, being low enough to allow working of the pressure-sensitive sensor, on the control lever 6, an object 3 to be controlled is controlled by means of a high power generated through a standard cable. Since, when the control lever 6 is stopped, the pressure-sensitive sensor does not detect a pressure, the electromagnetic clutch 10 is immediately disengaged, and the motor M is stopped.

An optical waveguide bend with enhanced curvature and the optimization of its structure

Abstract: We have investigated a waveguide bend having enhanced curvature with reduced loss. The waveguide width is made wider toward the inner side of the bend. The numerical analysis, by means of the beam propagation method, showed that the loss of the proposed bend is lower than that of an abrupt bend or a smooth bend of constant curvature. For a typical waveguide, we have optimized the structure of the bend and achieved one order of loss reduction in comparison with an abrupt bend of the same angle.

Neutron flux detector distribution system with improved drivability

Abstract: A flux mapping system for a nuclear reactor uses a detector having an outer diameter approximately fifteen percent smaller than the inner diameter of distribution tubing through which it passes and a length less than eight percent of the minimum bend radius of the tubing. Frictionless limit switches are used in the flux mapping system to further reduce friction against cables which drive the detectors through the distribution tubing. In combination, these dimensions and switch changes result in a fifty percent improvement in driving force at the thimbles into the core of the nuclear reactor.

Universal holder for tubes of wiper arms - has elastically deformable section to adapt to bend in arm

Abstract: The holder for a tube (24) extending along at least one wiper arm (10) which has a bend encloses the tube in the area of the bend. The section (28) enclosing the bend is elastically deformable and length adjustable to conform to the outer shape of the bend. The inside outline of the holder can correspond in the area of the bend to the outer outline of the bend. The holder is preferably an injection moulded plastics part with compensating recesses (30-44) of adjustable width measured in the direction of the wiper arm. ADVANTAGE - The holder can be used for practically any type of wiper arm of any shape.

One-way clutch

Abstract: PURPOSE:To improve the raising strength of a cam part without any increase in weight and prevent clutch slippage by extending both edges of the cam part provided at the peripheral edge of a base part to form a reinforcing portion, and making the bend radius of the reinforcing portion larger than that of the cam part CONSTITUTION:In a one-way clutch, a roller 22 is pressed against a cam part 27 by large force through a starting gear 21, so the cam part 27 is deformed outwards in a radial direction depending upon strength, and torque transmission becomes insufficient due to the roller 22, thus facilitating clutch slippage Therefore, the fore and aft edges of the cam part 27 are extended further to form a reinforcing portion 29 and a relief groove 27a is made for only the cam part 27, and the bend radius R of the reinforcing portion 29 is made larger than the bend radius (r) of the cam part 27 As a result, the raising strength of the cam part 27 can be improved largely with a simple structure without any increase in plate thickness It is thus possible to bear the load by the roller 22 sufficiently and prevent clutch slippage completely without the cam part 27 being deformed outwards

Method for bending plate stock to acute angle

Abstract: PURPOSE:To bend a plate stock to an acute angle of a bend radius <= a plate thickness by working a groove of a prescribed thickness at a bending site near a bending place of a desired thickness, then, putting the groove part inside and carrying out an acute angled bending. CONSTITUTION:When the plate thickness T near the bending place of the plate material W exceeds a desired plate thickness (t), a suitable range L near the bending place is worked by grinding to obtain a desired thickness (t). At a bending site in this working area L, a V- or U-shaped groove G is worked into a prescribed thickness S thinner than this (t). Then, bending is carried out by a die D and a punch P at a position excepting this working area L of the plate material W so that the other side of the plate material W comes inside. Thereafter, an acute angled bending is carried out at the position of the groove G so that the groove G comes inside. In this way, a projecting edge E' is formed on the plate material W. When the thickness of the plate material W is thinner than the desired thickness (t), the plate material W can be bent to an acute angle at a bending site near the bending place having a prescribed thickness S thinner than the desired thickness (t) over a suitable range.

Hot bending method for steel tube

Abstract: PURPOSE:To perform high frequency bending and to accurately bend a steel tube without leaving a sensitization area by heating not only a bending part of the steel tube but also the straight tube part of an unbending part at a temperature higher than the solid solution temperature. CONSTITUTION:In a push roll system, a high frequency induction heating is performed by heating coil 7 to a stainless steel tube 2 over the solid solution temperature. When a drive device 4 is advanced under this state, the heating area of the stainless steel tube 2 is moved continuously and heated. Further, since cooling nozzles are equipped on the heating coils 7, the heating area moves to the cooling area with the advance of the tube and is quenches. Then, the tube in the bending is sent under the same heating and cooling conditions as under the straight heating and is bent by giving the bending moment at right angles to the advancing direction through a push roller 3 laid before the heating coils. The bending angle and bending radius are determined by controlling the position of the push roller 3 by a detected device set.

Filter device comprising pleated material

Abstract: A high efficiency air filter is described which comprises a depth filter sheet that has been formed with micropleats stabilized by application of a strip of a thermoplastic adhesive across the peaks of the micropleats and then formed into a macropleated structure with the axes of the micropleats and the macropleats being essentially parallel. The micropleats preferably have a bending radius no greater than the critical radius.

Push-through bending method and bending device by this method

Abstract: PURPOSE:To enable bending with an arbitrary bend radius by bending tube, etc. by pushing through in the state that the central axis of a guide cylinder and the center of the bearing part of die are shifted and using the die of bearing part with the sectional shape of tube. CONSTITUTION:In the state that the center axis of the guide cylinder 2 and the center of the bearing part 3a of the die 3 are relatively shifted, that is, the state that a offset (u) is provided, bending is executed by pushing the pipe through the guide cylinder 2 and the die 3. By using only one die with the bearing part which is formed corresponding to the cross sectional shape of tube, etc., continuous bending with the arbitrary bend radius is possible only by controlling the offset. The highly exact position control becomes possible, because securing the offset is enough only by the straight movement of the die or guide cylinder. And the deformation of sectional shape is restrained by performing bending while the outer peripheral part of tube, etc. is constrained with the die and compressive force is loaded. Thereby, the exact bending corresponding to the specifications can be realized.

Bent metal pipe and molding method thereof

Abstract: PURPOSE:To make such a pipe that is small in a radius of curvature and high in reliability possible for bending in a simple manner by setting a bending radius of a bending part or a slip type insert hole to specific times over each pipe diameter, and increasing wall thickness of the bending part or at time of being hard to secure the wall thickness, push through it with progressive backward load and with no load at time of being possible, respectively. CONSTITUTION:A bend radius of a bending part in an insert hole is set down to 1 to two times over a pipe outer diameter, and a rectilinear metal pipe 10A is inserted into this insert hole 24 from the upside of a split mold 20, and a push rod 38 is lowered as far as the specified value. If so, this rod 38 is engaged with a pipe rear end 10b, pressing the pipe 10A into the insert hole 24. At this time, the pipe 10A is passed through the bending part 25 of the insert hole 24 in order from a tip end, and bent in a form after the bending part 25. Then, a pipe tip end face 10a is engaged with a slider tip end 34a of a pipe end reverse back pressure adding mechanism 30, receiving load in a pipe progressive reverse direction. Consequently, there is produced a thickness increasing action at the inside of a pipe bending part, and since the promotion of thinness due to expansion is checked at the bending part outside, a certain degree of wall thickness is secured at the bending part outside as well.

Hot plastic working method

Abstract: PURPOSE:To reduce the transformation stress and to prevent the generation of a crack on the outside surface of a tube by bringing a tube to be worked to hot bending, and thereafter, reheating locally the outside surface of the tube at the time of cooling CONSTITUTION:While feeding a tube to be worked 1 by a feed truck 4, the whole periphery of the outside surface of the tube 1 is heated locally by a heating ring 2, and thereafter, said tube is bent to a prescribed bend radius by pressing force of a push roller 5 A postheating ring 3 is provided right before a position in which the outside surface of the pipe 1 which passes through the heating ring 2 starts a transformation, and by a gas flame 6, the outside surface of the pipe 1 is reheated to an appropriate temperature In such a way, the time for a start and a completion of the transformation on the outside surface of the pipe and the inside surface of the pipe of the pipe to be worked 1 is allowed to coincide roughly As a result, the residual transformation stress of the tube to be worked 1 is reduced, and the generation of a crack on the outside surface of the tube 1 is prevented, by which a homogeneous product can be obtained

Calculation of closed orbit errors due to misalignment of combined function magnets with large bend angle

Abstract: The effects of different misalignments of bending magnets with very small bending radius ({rho} < lm) and very large bending angle ({Phi}{sub b} = 180, in some cases 360{degree}) are discussed These magnets are represented by n segments A method is given to calculate misalignments of a segment at any {alpha} < {Phi}{sub b} bend angle from the misalignments of the whole (rigid) magnet This method is then used to calculate distorted closed orbits for the SXLS ring 6 refs, 10 figs, 1 tab

Reliable raney catalyst composition and vessel for containing same

Abstract: A Raney catalyst composition which has ice as a solid carrier. The reaction involving the Raney catalyst of the invention is carried out by portionwise adding a Raney catalyst containing ice as solid carrier to the reaction mixture. The operation-safe cylindrical or angular vessel used for the storage and/or handling of the Raney catalyst has a conical casing or side walls joining to the bottom through a bend radius of greater than 0.5 mm. The vessel is covered by a tightly closing cap.