Showing papers on "Bend radius published in 1993"

Medical staple forming die and punch

Abstract: A medical staple forming die and pusher punch for use in a staple forming machine. The bend radius of the staple is formed either by the form punch pushing the wire past a set of rollers, or by movable forming dies in conjunction with a tapered or contoured pusher punch. Since the wire is not scrapping on a stationary rail, pulling thin or cracking in its corners is substantially eliminated and the possibility of metal slivers produced by the prior art scrapping methods is substantially reduced or eliminated.

A normalized approach to the design of low-loss optical waveguide bends

Abstract: A normalized approach for optimal design of abrupt junctions between straight and curved waveguides operating in the whispering gallery mode regime is presented. The optimization includes the widths of both the straight and the curved waveguides, the lateral offset between them, and the bending radius of the curved waveguide. With this approach, optimum bend design is possible from a simple set of formulas or normalized graphs. Predicted transmission losses for optimally designed junctions are well below 0.1 dB. >

Fiber optic cable connector with strain relief boot

Abstract: A strain relief system for the backside of a fiber optic connector has a controlled bend radius defined by the formula R=[(W+t) 2 /2(1-cos φ)] 1/2 , where W is the rib thickness, t is the width of spaces between the ribs, and φ is an angle defined by comers of the ribs which engage each other at the minimum bending radius and a pivot point about which the ribs pivot relative to each other.

Cable bend control device

Abstract: Disclosed is a device for bridging a cable over an edge of an exposed flange. An bridge has a first side containing one or more slots capable of receiving the edge of the flange, and a second side curved to allow a cable to pass over the device without kinking or allowing a bend radius less than that of the second side.

Triple-clad single-mode fibers for dispersion shifting

Abstract: A design procedure for triple-clad dispersion-shifted single-mode fibers is developed. Following this procedure, fibers are identified which have low dopant concentrations in the core compared to those of the previous dispersion-shifted fiber designs, a second-mode cutoff wavelength close to the operating wavelength, zero dispersion at 1550 nm, a small bending loss at 1550 nm (for a bend radius of 3.75 cm), and a spot size that is large enough not to compromise the splice loss. A significant advantage of these fibers is that low-dispersion is available over a wide wavelength band about the wavelength of zero dispersion. >

Swirling turbulent flow through a curved pipe

Abstract: An experimental study of swirling turbulent flow through a curved bend and its downstream tangent has been carried out. This study reports on the recovery from swirl and bend curvature and relies on measurements obtained in the downstream tangent and data reported in Part 1 to assess the recovery. Unlike the nonswirling flow case, the present measurements show that the cross-stream secondary flow is dominated by the decay of the solid-body rotation and the total wall shear stress measured at the inner and outer bend (furthest away from the bend center of curvature) is approximately equal. The shear distribution is fairly uniform, even at 1 D downstream of the bend exit. At 49D downstream of the bend exit, the mean axial velocity has recovered to its measured profile at 18D upstream of the bend entrance. Furthermore, the mean tangential velocity is close to zero everywhere and the turbulent shear and normal stresses take another 15D to approximately approach their stationary straight pipe values. Therefore, complete flow recovery from swirl and bend curvature takes a total length of about 85D from the bend entrance. This compares with a recovery length of about 78D for bend curvature alone. The recovery length is substantially shorter than that measured previously in swirling flow through straight pipes and is a consequence of the angular momentum decreasing by approximately 74% across the curved bend. Consequently, the effect of bend curvature is to accelerate swirl decay in a pipe flow.

Multichannel ballistic magnetotransport through quantum wires with double circular bends.

Abstract: A theoretical study of magnetotransport through two-dimensional quantum wires with double circular bends is made within the ballistic approximation. By means of the mode-matching method, the S matrix of the single bend with a hard-wall confining potential is calculated as a function of the magnetic field or the Fermi energy for the bending radius and the bending angle as parameters. The combination of S matrices is performed for bends in series. The technique is applied to systems consisting of double bends. The symmetry properties of the S matrix are clarified for the two-terminal systems with rotational symmetry or mirror-plane symmetry. The transmission matrix is evaluated in detail for the case of three propagating channels. The strong dependence of the interchannel scattering on the magnetic field is found. The structure of dips (antiresonances) appearing in the conductance is studied as a function of the distance between bends.

Piezoelectric energy generator

Abstract: A ballistic fuse, which converts mechanical energy derived from the initial firing to stored electrical energy used to energize a later detonation, having piezoelectric polymer film strip with oppositely polarized layers on opposite surfaces, is pre-folded end to end before pleating and stacking in order to place both halves of a surface layer of one polarity into mutually contacting relationship, thereby reducing the risk of short circuits, and furthermore to double the bend radius required for pleating, thereby decreasing the risk of hinge failure due to bending stress at the pleated folds, and the continuous pattern of circles joined side by side in each layer is printed with conductive silver ink on the polymer film to eliminate the necessity of joining surfaces of like polarity with individual leads.

High energy flexible coaxial cable and connections

Abstract: A high energy coaxial cable is disclosed which is flexible to the extent of allowing a bend radius as short as 11 1/2 inches. The cable will conduct up to 500 kiloamperes and is reinforced to resist the high magnetic forces within the cable caused by the high current conducted. The cable is therefore useful in coupling high current between parts which experience relative movement such as a stationary power supply and a recoiling gun breech.

Method for bending tubes using split die

Abstract: Method and apparatus for bending metal tubes such as for furnace heat exchangers After the bend die is rotated 180° to make a bend, an upper section of the bend die is split from a lower section, and the upper section is then rotated approximately 90° In such manner, a portion of the upper section is displaced laterally to vacate a region directly above the lower section Therefore, in moving the tube forwardly to a new location for a subsequent bend operation, a portion of a previous bend passes through the vacated region thereby enabling sequential bend angles that are less restricted than without rotating the upper section of the split die

Limited bend crush-resistant cable

Abstract: A limited bend crush-resistant cable, adaptable to either electrical signal cable, microwave transmitting dielectric waveguide, or optical signal fiber cores to provide high air content, low dielectric constant, crush-resistance, and bend limitation by spiralling insulation around the core which has an air gap between spirals of insulation. The air gap closes on bending the cable to contact an adjacent spiral of insulation to provide resistance to further bending of the cable.

Monitoring and protection device for optical-fibre cables (fibre-optic cables)

Abstract: The subject-matter of the invention is a monitoring and protection device for optical-fibre cables which detects energy leakage from an optical-fibre cable or from an optical fibre as a result of an interference. Damage to the optical-fibre cable occurs by uncontrolled coupling-out (detection) of the laser beams at interference points of the optical fibres, for example due to the bending radius dropping slightly below the permissible value. In the device according to the invention, the optical-fibre cable is designed in such a manner that it has one or more optical fibres with in each case one or more fibre coatings (layers), in the case of which device at least one fibre coating is provided for transmitting radiation power (radiant power), and that the lost radiation leaking from the fibre coating or coatings transmitting the radiation power is coupled into a second fibre coating by means of elastic or inelastic diffusion (conversion) and is guided to a detector. The conversion of the lost radiation is in this case performed by a suitable preparation of the secondary coatings, for example by enriching it with diffusers, dyes or scintillators. In the simplest case the optical-fibre cable is surrounded by a protective sheath which is filled with a liquid or a gel-like dye or scintillator carrier. The device according to the invention has the advantage that an interference of the optical-fibre cable is recognised at an early stage, so that severe damage or total destruction of the optical waveguides by power reduction or switching off of ... Original abstract incomplete.

Shaped glass sheet and a process for the preparation thereof

Abstract: A shaped glass sheet having a sharp bend is provided, wherein a radius of curvature of an outer circumference of the bend transverse to the bend is at most 4 times a thickness of the glass sheet and the straight sections of the shaped glass sheet are substantially flat. A process for the preparation of the shaped glass sheet comprises applying an electrically conductive material on a surface of a glass sheet to form a bend line, generating a graded temperature profile transverse the bend line, and then applying an electrical potential to the bend line. In another process, a width or thickness of a bend line is not uniform or a bend line is discontinuous in the longitudinal direction of the bend line, no particular temperature profile is required and, upon applying an electrical potential, arc discharge occurs along the bend line to melt the glass rapidly.

Waveguide type optical device with monitor

Abstract: PURPOSE:To prevent a monitor output from varying with wavelength, polarized light, temperature, etc., and improve the reliability of the monitor, and to reduce the size and cost of the optical device by providing a monitor circuit in a waveguide substrate. CONSTITUTION:The output-side optical waveguide 4 of the waveguide type optical device 1 is provided with an S-shaped optical waveguide 20 and a photodetecting element 30 is installed having its photodetection surface opposite the substrate flank 2A of the optical device 1 so that the emitted light of the 2nd bent part 22 is photodetected. The bent part 22 is formed closely to the substrate flank 2A; and the bending radius of the 1st bent part 21 of the optical waveguide 20 is made sufficiently large and the bending radius of the bent part 22 is made desirably small. Part of the light is emitted horizontally at the bent part 22 toward the substrate flank 2A to become monitor light. The quantity of the emitted light is determined depending upon whether the bending radius of the bent part 22 is large or small and there is not any variation with wavelength, polarized light, temperature, etc., so the quantity of monitor light does not vary and the reliability of the monitor is improved.

Bending structure of optical waveguide

Abstract: PURPOSE:To attain bending structure for obtaining an optical waveguide with a low loss even in the case of a small radius of curvature. CONSTITUTION:Plural triangular high refractive index areas 20, 21 are formed in the optical waveguide 11 so that the distribution of electromagnetic fields does not run off to the outside in a bending direction by defracting propagated light in the bent waveguide or equivalently improving the refractive index of a bent part. Consequently the low loss optical waveguide 11 with a small bending radius can be obtained and a compact optical waveguide device can be attained.

Manufacture of laser beam welded member

Abstract: PURPOSE:To enhance strength of the welded member by making arrangement so that the bend outside of a work is superposed on the bend inside of a mating work and irradiating superposed bends with a laser beam to perform welding. CONSTITUTION:In the radius R1 of curvature of a bend 13b and the radius R2 of curvature of a bend 14b of a side frame outer 13 and a reinforcement 14, R1<=R2 is formulated. When arrangement is made so that the bend 13b outside is superposed on the bend 14b inside, a close adhesion part 16 where both are completely adhered is generated. A laser beam torch is arranged on the position in opposition to the outside of the bend 14b and the close adhesion part 16 is irradiated with the laser beam. Since the side frame outer 13 and the reinforcement 14 are welded together at the bends 13b and 14b which are inward parts than flange parts 13a and 14a of both side ends, strength can be enhanced. In addition, the width of the flange parts 13a and 14a can be narrowed.

method for manufacturing square pipe with sharp corners

Abstract: By use of direct cold-bending shaping method featuring fixed bending radius and inward moved bending centre and based on the high-frequency current's skin-effect, attraction, proximity and strong mutual-inductance principle, a steel plate may be welded into a square pipe which has only one welded seam and a sharp corner at 90 deg. with radius R is less than or equal to 7 mm. Said method has the advantages of easy operation, no need of straightening process, smooth surface of product and saving raw material.

Compound radius guide post

Abstract: The invention is a tape guiding post including a tape engaging surface having a longitudinal contour with a compound radius of curvature. In the preferred embodiment, the longitudinal contour has a smoothly varying radius of curvature. The outer portions of the contour have a relatively large radius of curvature and blend smoothly into a central portion which is of a relatively small radius of curvature to allow for any desired bending of the tape in its easy direction. The combination minimizes both friction and stiction between the tape and the guide. The guide is also laterally contoured to accommodate droop at the edges of the tape, caused by low air pressure at the edges.

Method for drawing and bending round pipe

Abstract: PURPOSE:To provide a method for drawing and bending a round pipe which can reduce the thickness reduction ratio of the pipe thickness of the outside to be bent drastically, therefore, use a pipe stock comparatively small in thickness from the beginning to keep the strength of the bent pipe large, to secure the minimum thickness on the outside of the bent part of the round pipe and reduce the cost when the round pipe is bent by the so-called minimum bending of bending radius/external diameter of the pipe <=1. CONSTITUTION:When a part 1a to be bent of the round pipe 1 is bent along a bending die 3, a projecting part 7 for hooking the rear end of the pipe is mounted on a moving press die 2, the rear end 1d of the pipe 1 is hooked at this projecting part 7 and when the part 1a to be bent of the round pipe 1 is bent along the bending die 3, the moving press die 2 is pushed forward at the same time and the rear end 1d of the pipe 1 hooked at this projecting part 7 is pushed out forward together with the moving press die 2 by a prescribed length L, for example, 2-5mm.

Bended metal pipe and forming method therefor

Abstract: PURPOSE:To form bended metal pipes having small bending radius and larger diameters than the diameters of the bended parts at least at one end without buckling bended parts; moreover. CONSTITUTION:A segmental die 5 has an inserting hole 6 in which the metal pipe is inserted for bending, and the corved part 8 with a small diameter that is continued to the straight part 7 having an inlet with a large diameter and formed with the inserting hole 6. when a metal pipe that fits in the diameter of the straight part 7 is inserted from the inlet and extruded with a pressing mandrel, the metal pipe is pushed into the bended part 8, drawing is performed for a contracted diameter and simultaneously bending is performed. The top end of the metal pipe is then expanded with an enlarging mandrel 11.

Design of a 90° Overmoded Waveguide Bend

Abstract: A design for a 90” bend for the TEsr mode in overmoded circular waveguide is presented. A pair of sept,a, symmetrically placed perpendicular to the plane of the bend, are adiabatically introduced into the waveguide bcfore the bend and removed after it. Introduction of the curvature excites five propagating modes in the curved section. The finite element field solver YAP is used to calculate the propagation constants of these modes in the bend, and the guide diameter, septum depth, septum thickness, and bend radius are set so that the phase advances of all five modes through the bend are equal modulo 2a. To a good approximation these modes are expected to recombine to form a pure mode at the end of the bend.

Squeezing coating device for steel pipe inner coating

Abstract: The utility model relates to a squeezing coating device for a steel pipe inner coating, which is mainly composed of a hollow cylinder, a circular head, a helical blade, a scraping plate, a sealing bell mouth and a sealing head. The main parts of the squeezing coating device for a steel pipe inner coating are stamped into an entirety by elastic materials. Compared with the prior art, the squeezing coating device for a steel pipe inner coating has powerful elbowpassing ability, and can pass through a 90 DEG elbowed pipeline whose bend radius is smaller than 1.5 D; the pipe diameter can be smaller than 25 mm. The squeezing coating device for a steel pipe inner coating has no holiday and has high spreading quality. The squeezing coating device for a steel pipe inner coating can satisfy the requirement of the construction with multiple elbows and long distance. In addition, the head of the squeezing coating device for a steel pipe inner coating can be provided with a scaling brush so that the squeezing coating device for a steel pipe inner coating can be served as a scale breaker or a pipeline cleaner.

Design of a 90/spl deg/ overmoded waveguide bend

Abstract: A design for a 90/spl deg/ bend for the TE/sub 01/ mode in over-moded circular waveguide is presented. A pair of septa, symmetrically placed perpendicular to the plane of the bend, are adiabatically introduced into the waveguide before the bend and removed after it. Introduction of the curvature excites five propagating modes in the curved section. The finite element field solver YAP is used to calculate the propagation constants of these modes in the bend, and the guide diameter, septum depth, septum thickness, and bend radius are set so that the phase advances of all five modes through the bend are equal module 2/spl pi/. To a good approximation these modes are expected to recombine to form a pure mode at the end of the bend. >

Rotary draw bending apparatus and method

Abstract: A rotary die pipe bending apparatus comprising a bend die mounted for rotation about a bending axis and a clamp die for clamping a pipe to the bend die. The clamp die holds the pipe to be bent as the bend die and the clamp die rotate about the bending axis. A pressure die directed against an outer surface of the pipe for restraining a portion of the pipe spaced away from the bend to be formed in the pipe. A reverse die engaged with an inner surface of the pipe at a location spaced away from the clamp and bend dies and near the pressure die for resisting the bowing of the pipe in back of the bend die and for avoiding the formation of an indentation at the end of the bend.

Wavelength filter for optical waveguides.

Abstract: In a wavelength filter for optical waveguides, it is provided for the optical waveguide (10) to be curved in the shape of a coil to form a fibre coil, the bending radius, which is the minimum permissible radius per se, being undershot and being smaller than 15 mm, for example.

An examination of the effect of polarization on the radiation losses of bent optical fibres

Abstract: It has long been recognized that the bending losses in weakly guiding optical fibres are independent of the polarization for large bend radius. Here, we show this fact using the volume equivalent current method. The procedure is then applied to a helically bent fibre and it is shown that the radiation from the helical fibre is also independent of the polarization as long as the fibre is weakly guiding.

Device for digging line pressure small-radius mid-frequency elbow

Abstract: The utility model discloses a device for digging line pressure small-radius mid-frequency elbow pipe. A hydraulic cylinder (1) used for applying pressing is arranged in a pushing force box (2) and is connected with the pushing force box (2) through a hinged supplementary (3). A pipe sleeve (5) is arranged in the center hole of the cover (4) of the pushing force box. Both ends of a bracing cable (6) can respectively be connected with the piston rod of the hydraulic cylinder (1) and an end cover (7). The utility model has the advantages of simple structure, easy fabrication, reliable use, etc. The device for digging line pressure small-radius mid-frequency elbow pipe can be matched with various conventional mid-frequency elbow pipe machines. A small-radius elbow pipe whose bend radius R is equal to 1.5-3D (D stands for the outer diameter of the pipe) can be bent and made.

Design of a 90-degrees over moded waveguide bend

Abstract: A design for a 90{degree} bend for the TE{sub 01} mode in over-moded circular waveguide is presented. A pair of septa, symmetrically placed perpendicular to the plane of the bend, are adiabatically introduced into the waveguide before the bend and removed after it. Introduction of the curvature excites five propagating modes in the curved section. The finite element field solver YAP is used to calculate the propagation constants of these modes in the bend, and the guide diameter, septum depth, septum thickness, and bend radius are set so that the phase advances of all five modes through the bend are equal modulo 2{pi}. To a good approximation these modes are expected to recombine to form a pure mode at the end of the bend.

Investigation of the Bending Effect and the Critical Current Density on a Bi-Based Superconducting Tape

Abstract: Flexible sintered Bi-based superconducting tapes with textured structure and high critical current density Jc have been fabricated by powder-intube technique. The sintered tape for a given thickness can be bent into a limited radius of curvature R O without deteriorating the transport properties at 77K. The transport J c decreased for bending radius R < R O. It was believed that the predominant factor for result of the superconducting current flowing through the fractured grain boundaries. The transport property of the granular superconductors was assumed to be the collective behavior of the random weak-link network. The Josephson tunning model was proposed to explain the transport J c vs bending radius R and found a good agreement with our experimental results. The decay length y of the wave function at grain boundary was determined to be about 1.2 A.