JPH0651549B2 - Device that pulls filaments out at high speed - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to the field of machines for treating filament or optical fiber cables, and more particularly to a device for drawing filaments at high speed.

[Prior Art and Problems] When optically testing a filament, that is, an optical fiber cable for various types of applications, it is necessary to pay out the cable at a high speed in a laboratory or a test environment. The problem is to apply sufficient force to the fiber optic cable to withdraw it from a supply reel or other source and move it at high speed to or through the test site. Such forces must be applied to the filament so that the cable is not damaged or distorted, and there is no permanent deformation to the cable, abrasion to the optical surface of the optical fiber, damage or impact on its optical properties. .

Therefore, what is needed is a method and apparatus in which the force is applied to the filament in a gentle and uniform and sufficient amount, and sufficient tensile force is applied to prevent damage, cracking, kinking, abrasion or strain, and filament quality. It is applied to the filament to pull it at a high speed without any decreasing force.

[Means for Solving the Problems] A device for pulling out filaments at high speed according to the present invention is
A capstan having a pressure gas source, a side surface, and a peripheral surface in which an exhaust groove for receiving the filament is formed, and the capstan is frictionally engaged with the filament to draw out the filament at high speed, and the capstan is arranged to cover the capstan. A shoe having a pressure chamber that communicates with the pressure gas source, the shoe including a side surface and a peripheral surface of the capstan, and a circumferential gap that communicates with the pressure chamber and the atmosphere between them. The pressure chamber supplies pressure gas to the filament from the pressure chamber so that the filament is frictionally engaged with the exhaust groove.

As a result, a uniform stress is applied to the filament, causing a frictional engagement between the cable and the capstan, and rapid rotation of the capstan causing rapid unwinding of the cable.

Further, a device for drawing out filament of another aspect according to the present invention at high speed is provided rotatably about a long axis,
A capstan having a groove having a pair of side surfaces that extend along the outer peripheral surface and are spaced apart from each other, and a capstan that is provided near the outer peripheral surface of the capstan and that extends in a predetermined region through which the capstan rotates. A shoe assembly having a gas discharge means for discharging a gas having a pressure higher than the atmospheric pressure to temporarily frictionally contact the optical filament with the groove when the outer peripheral surface of the capstan is in the predetermined region; And a gap provided in the capstan for direct fluid communication between both portions of the groove located inside and outside the predetermined area. Means for applying and maintaining a pressure higher than atmospheric pressure on the other side of the optical filament facing the shoe assembly while the gap is provided and one side of the optical filament is maintained at approximately atmospheric pressure. , Without giving unnecessary stress to the optical filament between the drawer fast optical filament to maintain frictional contact of the optical filament to inclined side surface of the groove.

EXAMPLE A device and method for uniformly applying a compressive force to a filament, i.e., a fiber optic cable, so as to frictionally engage the filament with a capstan, without stress concentrating at any point on the filament. Is done by pressing the filament with air pressure into the V groove along the center of the peripheral surface formed on the capstan. Pneumatic pressure is supplied to a predetermined portion of the capstan by a pneumatic shoe having a shoe pressure chamber inside. The pressurized gas, for example, compressed air, is supplied from a chamber inside the shoe toward a predetermined portion in the vicinity of the V-shaped groove at the center of the peripheral surface of the disk-shaped capstan. The V-shaped groove is open towards the atmosphere, so that the cable is laid or blown into the V-shaped groove. The side and end mutual clearances between the rotating capstan and the shoe are dimensioned to take into account the viscosity of the pressure gas and prevent this gas from escaping immediately into the atmosphere from the V-shaped groove. And operating to prevent the pressurized gas from escaping immediately from a predetermined portion of the capstan. Also, annular baffles are provided on the central surface of the capstan's peripheral surface and the corresponding surface of the shoe, respectively, to provide frictional engagement between the pressurized gas and a predetermined portion of the capstan. By using such a device, a filament of about 10 km or more can be fed out in about 32 seconds or less.

FIG. 1 shows that the pneumatic pinch shoe 18 has a filament 12
Figure 3 is a schematic side view of the device shown for driving or paying out. In FIG. 1, the dimensions of the various elements of the device are not to scale and are unrelated to the essential details of the invention, so that various details of certain elements have been omitted.
For example, the capstan 16 is driven by the shaft 14,
The shaft 14 is driven by a conventional motor shown as the motor 13, typically an electric air turbine motor. The motor 13 is driven and controlled by various conventional electronic circuits that are not critical to the invention. The pinch shoe 18 is driven by the shaft 14 and surrounds a part of a thin disk-shaped capstan 16 having a V-shaped groove formed on the outer periphery thereof. The shoes 18 are arranged along a part of the periphery of the capstan 16 as shown in the side view of FIG. 1, and are adjacent to each other, as best seen in the end view of FIG. Siege. The shoe 18 and the capstan 16 are separated from each other and do not come into contact with each other at any point. Shoe 18
Is the internal shoe pressure chamber 2 whose outline is shown by the dotted line in FIG.
Has 0. The pressure chamber 20 includes a duct 22 and a pipe 24.
Through the pressure reducing valve 26. On the other hand, the pressure reducing valve 26 is connected to a compressed air tank 30 via a pipe 28.
The air tank 30 is also connected to a dryer 34 that removes water vapor and other contaminants from the air compressed in the tank 30 via a supply pipe 32. Compressed air is passed through a pipe 36 from a conventional air compressor 38 to a dryer 3
It is divided into four. Removal of water vapor is necessary because the outlet temperature of the gas from pressure chamber 20 is low enough to cause freezing or condensation.

FIG. 3 better illustrates and understands the operation within the pneumatic pinch shoe associated with the filament 12. Third
The figure is a schematic cross-sectional view taken along the line 3-3 of FIG. 1 and enlarged. As shown in FIG. 3, the capstan 16 is composed of a pair of thin disk portions 16a and 16b arranged along the center plane and symmetrically with respect to the center plane. The disk portions 16a and 16b are integrally bonded to each other by a disk-shaped spacer (separating means) 40 arranged in the axial direction. The spacer 40 only extends outward from the center to a predetermined point 42 in the radial direction between the disc portions (first and second discs) 16a and 16b. As a result, the spacer 40 is not present,
An annular gap 44 is formed near the peripheral surface between the circular portions 16a and 16b. A portion of the gap 44 outside the shoe 18, that is, a portion not covered by the shoe 18 communicates with the atmosphere. The disk portions 16a and 16b are chamfered so that when they are combined, a V-shaped groove (exhaust groove) 46 extending along the center of the outer peripheral surface of the capstan 16 is formed. The V-shaped groove 46 extends in the outer peripheral direction, serves as an orifice of the gap 44, and extends over the entire circumference of the capstan 16.

The action of the pinch shoe 18 is to provide a sufficient frictional engagement force between the capstan 16 and the filament 12 to press the filament 12 into the V-shaped groove 46 so as to produce a predetermined tension on the filament 12. .

The filament 12 is pressed into the V-shaped groove 46 by air pressure. The compressed dry air is supplied to the shoe pressure chamber through the compressor, dryer, tank and pressure reducing valve 26 shown in FIG. A narrow uniform width gap 50 (the width of which is indicated by reference numeral 48) is defined between the outer peripheral surface of the capstan 16 and the shoe 18. The gap 50 forms a minimum or narrow region into which high pressure air is injected from inside the pneumatic shoe 18. The high-pressure air is guided from the shoe pressure chamber 20 into the gap 50 by the plurality of ducts 52. One of the ducts 52 is shown schematically in the sectional view of FIG.

The air flow in the gap 50 is equalized as an isentropy, becomes a sonic state, and is generated in the gap 50 and the gap 54 between the inner surface of the shoe 18 and the outer surface of the capstan 16. Given the total pressure and temperature conditions, the amount of air flow required to be introduced into the shoe 18 is estimated.

Air is supplied to the pneumatic shoe 18 from the high pressure tank 30 via the pressure reducing valve 26, so that the total pressure in the pneumatic shoe 18 is maintained at a desired constant value. In the illustrated embodiment, the total pressure is 150 psia. The required operation time is roughly estimated from the length of the filament 12 to be fed and the feeding speed. The dimensions of the tank 30 are determined by considering the amount of air supplied from the tank 30 at the estimated speed.

However, these estimates only determine the upper limit, since the viscous effect of the air flow is important in practice. In order to obtain a more realistic calculation, it is necessary to consider the air flow in the gaps 50 and 54. In the analysis of the present invention, the air flow in the gap was discussed as a Fano flow characterized by a constant cross-sectional area in an adiabatic flow with friction, for example. The rotational effect of the capstan 16 due to viscous loading is very small and almost negligible. Because of its viscosity
The consequence of the reduced flow through the gap 50 is significant from the standpoint of reducing the required tank volume for a given transit time.

Consider now the particular embodiment shown in FIGS. In the illustrated embodiment, the capstan 16 is
It has a radius of 6 inches and a width of 0.5 inches. The width of the gap 54 between the side surface of the capstan 16 and the inner surface of the adjacent side of the shoe 18 is 0.002 inches. The lateral overlap between the shoe and capstan (indicated by 56) is 1 inch. Finally, the fan-shaped surface of the shoe 18 adjacent to the capstan 16 (shown at 58 in FIG. 1).
The angle is 2/3 pyradians. 1.00 per second
Cable length of 32.808 feet (10 kilometers) with desired cable speed of 0 feet, capstan rotation speed of 19.099 rpm, initial tank pressure of 200 psia, 150 psia at 288 ° K temperature.
Assuming the total pressure of the shoe mechanism of No. 2, under Fano flow conditions, the flow rate is 0.003819 slugs per second, the exit face pressure is 48.83 psia, and 32.
It requires a tank volume of 18.1 cubic feet for an operating time of 8 seconds. This is less than the approximate tank volume of 29.23 cubic feet calculated when air viscosity was ignored.

The air stored in the tank is a polytropic process when a flow occurs from the tank 30 to the pinch shoe pressure chamber 20.
process) to expand. If the total pressure in the shoe 18 is maintained at a constant value by using a suitable pressure reducing valve, the reduction in total temperature during travel will be significantly less than the normally considered range of tank pressures. A choke mechanism with constant stagnation provides a constant flow rate. This may simplify the approximation given the required tank dimensions and pressures in advance. Fundamentally, the approximation given below provides an approximation of the required tank volume.

Where V is equal to the required tank volume for tank 30; T is the time required for the pressure drop between the initial pressure P1 and the final pressure P0 in the tank; m ' Flow rate; n is 1.2; and c is 1.767 × 10 ⁶ .

The effect of viscosity on flow is estimated by assuming Fano flow. That is, the flow of Fano is the length L,
An adiabatic flow of a certain region of friction in the pipe equal to the actual gap with a hydraulic diameter D equal to 4 times the total region of the outlet gap divided by the wetting of the outlet gap.

The use of the pressure chamber 20 ensures sonic flow conditions in the exit face of the gap. The coefficient of friction f is properly assumed. The Mach number at the gap entrance is determined using the flow table. The remaining flow rate at the inlet is calculated and the flow is determined. The inlet condition is then used to find the Reynolds value and to obtain a new value for the coefficient of friction f. If the calculated magnitude for the coefficient of friction f does not match the initially assumed value, then the procedure is repeated in an iterative manner until the assumed and calculated value is within the desired error rate. . As mentioned above, the tank requirements and outlet pressure are drawn through the final iteration.

Using the physical dimensions of the pneumatic shoe 18 described above, a total area of 0.05589 square inches of exit clearance and 5
A 1.89 inch wet area is calculated. Hydrodynamic diameter is 0.0043 inches, 0.00 per second
This is an isentropic flow velocity of 6171. Running time is 1
It is given as 32.8 seconds, which corresponds to paying out approximately 10 kilometers of filament at 1.000 feet per second. Without the influence of fluid viscosity, the pressure on the outlet surface is 7
Expected to be 9.2 psia and for an initial pressure of 200 psia the required tank volume is expected to be 29.32 cubic feet. This corresponds to a cylindrical tank with a diameter of 2.5 feet and a length of 6 feet.

However, viscous is considered and, assuming f = 103.2 / Re, ie the coefficient of friction for the flow of pheno given by f = 0.01, 0.03819 per second
A slag flow rate and outlet face pressure of 49.83 psia is produced. Under these conditions, a tank with a diameter of 2.5 feet and a length of 6 feet far exceeded the requirements52.
It will be a running time of 8 seconds. Instead, for the transit time under consideration, only a tank volume of 18.1 cubic feet is required, which has a tank volume of 38% compared to an isentropic flow that does not consider air viscosity.
% Decrease.

Referring to FIG. 4 showing another embodiment of the present invention, the shoe 11 is different from that shown in FIG. 4 except that baffles having annular inner surfaces facing each other are alternately provided to form a complicated labyrinth duct.
8 is similar to shoe 18, and capstan 116 is similar to capstan 16. In particular, in FIG. 4, the shoe 118 comprises a plurality of annular baffles 1 extending in the radial direction.
Have twenty. Each baffle extends into a corresponding recess 122 formed in the outer surface of the capstan 116.
The recesses 120 are formed between baffles 124 that are annular and extend radially. The non-contacting interlocking arrangement of the baffles 120 and 124 forms a tortuous air duct that enhances the effect of air viscosity and reduces the amount of high pressure air required to complete a given filament payout run. Decrease. Assuming that the "pipe length" of the entire duct is equal to the total path length of the labyrinth as shown in FIG. 4, and also a common reservoir, ie two pipes parallel to each other, fed from the shoe pressure chamber 20. Assuming the Feno flow of the mechanism of (1), a similar calculation considering viscosity as described above is performed in connection with the embodiment of FIG. Thus, the overall flow for the mechanism is 0.003292 slugs per second and the tank value for a running time of 32.8 seconds is 15.59 cubic feet, which is comparable to the embodiment of FIGS. 1-3. That would be a reduction of 13.8%.

Alternatively, the labyrinth baffle may be deleted and an elastic seal may be used instead.

Therefore, the use of a pneumatic shoe in connection with a capstan wheel having a V-shaped groove as a means for deploying filaments in the laboratory condition at very high speeds can be achieved by the present invention. In all cases considered, the pressure in the mechanism is kept adequately above the minimum required to prevent the filament from separating from the rim due to the action of centrifugal forces on the cable. In addition, the total stagnant pressure acts on most of the length of the cable. The pressure exerted by the pneumatic shoe on the capstan is very evenly supplied without any pressure points, i.e. points where stress is highly concentrated, and what is the required pulling force to pull the cable from the supply reel quickly. It can be obtained without debilitation or without the damage caused by the prior art.

Many variations may be made by one of ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, it is described solely for the purpose of the drawings and drawings, and not for the purpose of limiting the invention as set forth in the following claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view of a pneumatic pinch shoe and a mechanism for operating the pinch shoe according to the present invention for withdrawing a filament.

FIG. 2 is an end view of the pinch shoe of FIG.

FIG. 3 is a schematic enlarged partial sectional view of a portion of the pinch shoe of FIGS. 1 and 2 taken along the line 3-3 of FIG.

FIG. 4 shows a second embodiment of the present invention, which is shown in FIG.
FIG. 6 is a schematic partial cross-sectional view of another embodiment of a pinch shoe along line 3.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kotxson, Moran, USA 85715 Tucson, East Nasumpute Drive 6822 (56) Bibliography SHO 55-82254 (JP, U)

Claims (13)

[Claims] 1. A capstan having a pressure gas source, a side surface, and a peripheral wall formed with an exhaust groove for receiving a filament, and a capstan that frictionally engages with the filament and draws out the filament at a high speed, and covers the capstan. And a shoe having a pressure chamber in communication with the pressure gas source, the shoe including a side surface and a peripheral surface of the capstan,
Between these, there is a part that is separated so as to form a circumferential gap and a lateral gap that communicate with the pressure chamber and the atmosphere, and the pressure chamber supplies pressure gas from the filament to the exhaust of the filament. A device that draws filaments at high speed to frictionally engage grooves. 2. The capstan forms a first disc, a second disc, and the exhaust groove between the discs.
An apparatus for pulling out filaments at high speed according to claim 1 having a separating means for separating these disks. 3. An apparatus for withdrawing a filament at high speed as claimed in claim 1 having means for increasing the frictional engagement of said filament with a capstan. 4. An apparatus for rapidly drawing filaments as set forth in claim 3 wherein said means for increasing frictional engagement comprises a plurality of annular baffles. 5. An apparatus for drawing filaments at high speed according to claim 4, wherein the plurality of annular baffles have a plurality of baffles extending alternately from the shoe and the capstan. 6. The apparatus of claim 3, wherein the means for increasing frictional engagement comprises an annular baffle extending radially from the shoe toward the capstan to rapidly withdraw filaments. 7. The apparatus of claim 3, wherein the means for increasing frictional engagement comprises an annular baffle extending radially from the capstan toward the shoe to rapidly withdraw filaments. 8. An apparatus for drawing out filament at high speed according to claim 1, further comprising a pressure reducing valve for selectively throttling the pressure gas flowing from the pressure gas source to the pressure chamber in the shoe. 9. An apparatus for drawing filaments at high speed according to claim 1, wherein said pressure gas source supplies dry pressure gas. 10. A rotatably provided centering on a long axis,
A capstan having a groove having a pair of side surfaces that extend along the outer peripheral surface and are spaced apart from each other, and a capstan that is provided near the outer peripheral surface of the capstan and that extends in a predetermined region through which the capstan rotates. A shoe assembly having a gas discharge means for discharging a gas having a pressure higher than atmospheric pressure so that the optical filament is temporarily brought into frictional contact with the groove when the outer peripheral surface of the capstan is in the predetermined region; And a gap provided in the capstan so that direct fluid communication can be achieved between both portions of the groove located inside and outside the predetermined region. While the gap is provided and one side of the optical filament is maintained at about atmospheric pressure, the other side of the optical filament facing the shoe assembly is given and maintained at a pressure higher than atmospheric pressure. , Without giving unnecessary stress to the optical filaments during fast drawer optical filament draws filaments to maintain frictional contact of the optical filament to inclined side surface of the groove at a high speed device. 11. The capstan according to claim 10, wherein the capstan has a pair of circular members which are parallel to each other and have a predetermined gap, and between which a circular spacer is disposed. A device that pulls out the described filaments at high speed. 12. An apparatus for drawing filaments at high speed according to claim 11, wherein the spacer forms an inner wall of the gap, and the groove forms an outermost portion of the gap. 13. An apparatus for drawing filaments at high speed according to claim 10, wherein said inclined side surface defines a V-shaped groove.