Abstract: A system for monitoring vibration or mechanical motion of equipment utilizing an optical waveguide sensor coupled to the equipment. The optical waveguide sensor is formed into a coil or a sinuous path which exceeds the bend radius or critical angle for internally reflected light directed through the waveguide. Vibration or mechanical force imparted to the waveguide from the equipment being monitored further alters the bending losses in the waveguide, and this change in bending losses is used to generate a signal as a function of the vibration or mechanical force.

Abstract: We report the successful demonstration of a new type of single‐mode semiconductor waveguide, an oxide‐confined optical waveguide, that has lower loss and should have a smaller allowable bend radius than previously reported structures. The waveguides are formed by a new technique of lateral epitaxial growth of single‐crystal GaAs over an SiO2 film. Rib waveguides formed on these epitaxial layers have SiO2 as the lower confining layer and thus have better confinement than comparable all‐semiconductor structures. Losses of only 2.3 dB/cm (0.54 cm−1) have been measured at 1.06 mm.

Abstract: It is shown that losses and phase constants in the general class of 2-D bent hollow waveguides are expressed by only one normalized parameter including the core width and the bending radius. Numerical analysis is made to obtain losses and phase constants, and simple approximate formulas are presented for several lower-order modes with reasonable accuracy.

Abstract: An operating arrangement for combined actuation of two movable control devices with the aid of a single operating lever has movement-translating means between an operating device with its associated operating lever and the control devices. The operating device includes a pivot plate (1) centrally mounted by a ball joint for adjustment in any desired inclination in any direction. Two pairs of Bowden operating cables (6, 11) are connected to the pivot plate in mutually right-angular planes. Each pair of cables is connected to a control device (16). In each cable pair one end of the casing (8) of a first cable (6) is connected to a fixed means (9) adjacent the pivot plate, and the wire (7) of said cable (16) is pivotably connected to the pivot plate, while the other end of the casing is connected to the control device, and the wire (7) of said cable (6) is connected to a fixed means adjacent the control device. One end of the casing (13) of the second cable (11) in the pair is connected to a fixed means adjacent the pivot plate and the wire (12) associated with said casing (13) is pivotably connected to the pivot plate while the other end of the casing is connected to a fixed means adjacent the control device and the wire (12) of the cable (11) is connected to the control device. Force transmission from the operating device (20) to the control device (16) always takes place during the development of tensional stress in the wire of the active cable. The arrangement enables the use of relatively light cables, since the wires do not transmit force by means of compression. The light cables enable smaller bending radii and reduced inner friction in the cable for a given bending radius. The light cables permit neater cable positioning to suit the structure on which the operating arrangement is used.

Abstract: An approximate and simple method for predicting the field profile in a curved dielectric waveguide of rectangular cross section is described. For a single-mode propagation, it is shown that the transverse field can be approximated inside the dielectric guide by the Airy function of the first kind and that the radial attenuation constant is a function of the bending radius outside the guide. Experimental verification of the theoretical results is included.

Abstract: PURPOSE:To contrive to reduce the working cost required at the place where the use of the elbow is inevitable, by applying the high frequency induction heating and bending, which are both freely adaptable to any bending radius, to the pipe possessing irregular wall thickness or to the round steel bar, in manufacturing the pipe with uniform wall thickness. CONSTITUTION:The inner surface of the pipe possessing the wall thickness to be specified by T=(designed minimum wall thickness) divided by (1- thickness reducting rate) (the round steel bar is also available) is mechanically machined to form the irregular wall thickness, and thus obtained thin wall thickness is specified as (the designed minimum wall thickness) divided by (1+ thickness increasing rate). This pipe 1-1 of irregular wall thickness is fixed by the guide support clamp 2 and the middle point clamping jig 3 so as to place the thick wall T on the outside and to place the thin wall C on the inside in respect of the bending neutral axis; and the tip of the pipe 1-1 is clamped by the arm point 6 being set at the specified radius R centering at the bending point 4. At the middle of the pipe 1-1, the guide roller 7 and the flattening preventive guide 8 are installed; then while the pipe 1-1 is being heated to the specified temperature by the work coil 11, the pipe 1-1 is pushed and bent by the hydraulic cylinder 10, the pipe feeder 9 and the jig 3; following to this, the bend zone Z is directly cooled. After, that the pipe 1-1 is cut at the planes X-X and Y-Y, and the elbow is obtained.

Abstract: PURPOSE:To produce a uniform branched bent pipe easily with high efficiency at low cost by pressing and curving the central part of a straight pipe from the side opposite to a pair of turnable receiving means while supporting both ends of the straight pipe by means of said receiving means. CONSTITUTION:A long-sized steel pipe P is cut with a cutter C to manufacture a straight pipe SP. The straight pipe SP is set to split dies DI1 and is subjected bulging to be formed to a branched straight pipe SP'. Next, while both ends of the branched straight pipe SP' is being supported to the receiving means 2, 2 of a press- bending device B1, a push-down roll 3 is lowered to hot-bent the straight pipe SP' to a required bending radius. At this time, the receiving means 2, 2 turn around the respective fulcrum axes along with the descending of the roll 3. The thus formed branched bent pipe BP' is set as it is or after reheating, to a press-bending device B2, by which it is further bent to a required bending radius. Next, both ends of the bent pipe BP' are cut in the positions (a), (b) and the blank branch pipe T' is cut in the position C. The pipe is then put into split dies DI2, by which the reduction of the outside and inside diameters thereof and the sizing of the outside diameter are accomplished. At this time, the branch part T is also sized by using a plug PG.

Abstract: PURPOSE:To obtain a correct bending angle and bending radius by giving a pipe the initial bending moment in the same direction as the bending moment at bending time prior to the bending. CONSTITUTION:Both ends of a pipe 1 is held by a fixing device 2 and revolving arm 4 and the pipe 1 is heated by a heater 6, but in this case the temp. rises slightly lower than the temp. necessary for bending. An axis 3 is moved from the position O to O' with the action of the bending moment in the same direction as the bending moment at the bending time via the revolving arm 4 on the pipe 1 when the load in the right direction is acted on the revolving axis 3 by a driving mechanism 5 in parallel to the preheating of the pipe 1 or prior to the preheating. In this case the bend is not caused due to the pipe 1 being not heated upto the bending temp. The pipe 1 is raised to the bending temp. after making it in the state of causing a cold deflection and the load given to the axis 3 is made the load necessary for causing the generation of the bending moment necessary for the bending. When the heater 6 is moved to the right direction simultaneously, a continuous bending is performed on the pipe 1.

Abstract: PURPOSE:To eliminate the deterioration of electric properties and the reflection of a high frequency signal and furthermore hold such condition stably and for a long period of time, by bending a flexible coaxial cable and then fixing the state of bend with a hardening material. CONSTITUTION:The outer coat 4 at the area to be bent of the flexible coaxial cable is exfoliated by a desired length to expose the outer circumferential surface of the outer conductor 3. The coaxial cable is bent evenly at the part 5 where the outer coat is exfoliated with the prescribed bending radius and bending angle and so as not to lose the concentricity with the roundness of an insulator as well as the conductor at the bent part 5'. The state of bend is held temporarily with a tool such as a clamp or the like. Thereafter, the hardening fixing material 6 of the solder or the hardening adhesive is coated over the entire circumferential surface of the exposed outer conductor 3 at the part 5' of such coaxial cable.

Abstract: PURPOSE:To form the plural metallic materials into the desired bends with one machine, by holding and forcibly feeding the metallic material to the bend former waiting on a circular arc of a radius equal to the desired bending radius. CONSTITUTION:Plural metallic materials like as the reinforcing iron bar 3, etc., are piled up one upon another to form a flat wall, and their tips are held by pinching with the pinch rollers 6. Meanwhile, the bend forming part 12a of the bend forming roller 12 is located on the circular arc of radius equal to the desired bending radius of the reinforcing iron bar 3. Next, by forcibly feeding the iron bars 3 in the direction C by the pinch rollers 6, the length of the iron bar 3 from the tip to the desired position can be bent into the desired radius by the bend forming part 12a of the bend forming roller 12 waiting ahead. The present method is also suitable for bending various metallic materials other than the bending work for the concrete reinforcing steel bar of various bending shapes and various bending angles.

Abstract: Properties of a relatively new type of waveguide structure of potential use for confining infrared radiation to a small mode volume over long path lengths are reviewed. A single guiding surface with curvature radius p and bend radius R allows propagation of a near-grazing incidence "whispering mode" of transverse width ≈ (λρR/π)1/2 and radial width ≈ 1/2 (λ2R)1/3. For sufficiently large p, the loss per revolution for TE-mode propagation is π AN, where AN is the normal-incidence reflection loss. Results on a number of prototype structures in general agreement with these considerations are described.© (1981) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Abstract: PURPOSE:To easily perform the bending work for the thin-walled pipe into a small bending radius, the pipe of high rigidity, etc., by applying the ultrasonic vibration to the mandrel or the bending die, at bending the pipe. CONSTITUTION:At the stretch bending, etc., in which the pipe 5 is clamped by the bending form 1 and the clamp die 2, and is bent successively by the pressure die 3, the mandrel 4 and the bending form 1 while the pipe 5 is being turned round, the ultrasonic vibrator 6 is attached to the rear end of the mandrel 4 or the bending die. Hereby, the pipe 5 is bent while the ultrasonic vibration is being applied to the mandrel 4 or the bending die. According to the present method, the bending resistance is weakened so that the generation of cracks in the pipe can be prevented. Moreover, the use of the lubricant can be excluded.

Abstract: PURPOSE:To reduce the number of times of the interchanging works for the roll, and to improve the working efficiency, by employing the segment type roll whose both end segments are provided with three kinds of curved surfaces and the middle segment is provided with the flat profile. CONSTITUTION:The upper roll 1 and the lower roll 2 are respectively divided into three segments; hereupon, the left and the right end segments 3, 4, are provided with the profile of curved surface, and the middle segment 5 is provided with the flat profile. The left and the right end segments of the rolls 1, 2, are provided with the profile comprising three kinds of curved surfaces as follows; the description of three curved surfaces are made from outside to inside successively; the outermost curved surface has a bend radius R3 and the arc angle theta3 of 15-45 degrees re- quired for rough shaping the edge of the pipe of the maximum diameter; the middle curved surface has the bend radius R1 and the arc angle theta1 of 40-55 degrees required for rough shaping the edge of the pipe of minimum diameter; and the innermost curved surface has the bend radius R2 and the arc angle theta2 of 5-45 degrees required for rough shaping the inner curved surface connecting to the edge of the pipe of minimum diameter; hereupon, the sum of three arc angles are specified to be 60-130 degrees for the segment on one side.

Abstract: A pneumatic tire made of polyurethane elastomers or other moldable material which can be made into an elastic, plastic material by means of a chemical reaction is provided. The tire includes a belt which is mounted beneath the tread surface which essentially consists of threads of a stress carrier, which threads run in the circumferential direction of the stress carrier. Alternatively, the belt is made of a moldable material which can be hardened into an elastic, plastic material having an E-modulus larger than 20,000 N/cm2. The tire is characterized by the provision of an increasing bending radius of the neutral axis of the tire sidewall from the tire bead to the edge of the belt.

Abstract: A crucial parameter in the design of compact dielectric waveguide integrated circuits is the minimum bend radius below which radiation losses become prohibitive. It is shown that, for waveguides with a relative permittivity of 10, values of bend radii down to four guide wavelengths are acceptable.

Abstract: In the upright type of resistor, both connecting wires being led out of the bottom of the outer protective coating (5) The connecting wires (3,4) are connected to the resistor (1) end caps (2) off-centre (7) so that a greater bending radius (6) is achieved for the 180 degree bent connecting wire (3) from the top of the resistor, and less bending is required for the bottom wire (4) for it to come out of the side of the outer moulding (5)

Abstract: PURPOSE:To prevent a generation of the crack in folded portions of a hose, by interposing a belt-shaped spacer with its width narrower than that of the hose between turns of the hose when reeling said hose. CONSTITUTION:When a hose 1, to which a strong tension is applied, is rolled in to a hose reel 2, a belt-shaped spacer 4 is fed out from a spacer reel 5 and interposed between the hose reel 2 and the hose 1 and between winding turns of the hose 1 to reel said hose. A width of the spacer 4 is determined to a dimension enough for the allowable bending radius of the hose 1 to be left by (r) at its both sides, and its thickness is arranged to such a dimension that both upper and lower inflated end parts of the hose are not interfered with each other.

Abstract: PURPOSE:To enable an optical fiber cable to be drawn out to the outside without giving any undue bending radius by drawing out the optical fiber cable through the draw-out port provided on the slope of the end copper pipe of an OF-cable pipe. CONSTITUTION:In order to connect an OF-optical fiber cable 12 and an OF-cable 13, an optical fiber cable 3 is drawn out about 3 m, and an end copper pipe 10 provided with a cable draw-out port 15 at the slope, an end copper pipe 9 and an intermediate pipe 8 are inserted thereon. After a power cable is connected, the optical fiber cable 3 is passed through the draw-out port of the end copper pipe from the end of said cable and the end copper pipe is slided and is assembled at the center part, whereby the fiber cables are connected without being given any undue bending radius.

Abstract: PURPOSE:To reduce the number of facilities and jig, tools for fabrication and improve the efficiency of fabrication and assembly work by fixing the bending radius of a semicircular barrel plate for an oval tank and adjusting the length of a side plate on a straight-line part. CONSTITUTION:The width W of a tank is decided by the content of winding 6, etc. The bending radius Ro of semicircular barrel plate 1B is fixed and the length l of a side plate 1A on a straight-line part is adjusted so that a tank is fabricated. The fixed bending radius Ro of the barrel plate is caused to coincide with the maximum shape of an oval tank. The radius of the mounting part of various parts such as bushing pockets 4, 5, etc. to be installed on the semicircular barrel plate 1B is fixed at Ro. Thus standardization for fabrication is feasibe and the efficiency of part fabrication and assembly work can be improved significantly.

Abstract: Wavelength-dependent effects are discussed for a single-mode optical fibre. A specific case is analysed quantitatively to point out the limitations imposed by external factors, like bending & splicing, on the choice of operating wavelength. It is shown that at the wavelength considered optimum from the point of view of minimum intrinsic loss and zero total dispersion, the operation for a graded-index fibre is significantly affected by the loss due to small bending radius in layout and angular misalignment at the splice.