NO770433L - DEVICE INCLUDING HOLE FILAMENTS AND PROCEDURES AND APPARATUS FOR THE MANUFACTURE OF HOLE FILAMENTS. - Google Patents

Description

The present invention relates to a method and

an apparatus for use in the manufacture of dialyzers of the type used in artificial kidney systems.

Artificial kidney systems include dialyzers or membrane diffusion devices through which blood from a patient flows for treatment. One type of dialyzer is known as a hollow fiber dialyzer. A hollow fiber dialyzer comprises an elongated housing of generally cylindrical shape in which many very fine, hollow and semipermeable fibers are placed and attached to the housing at their ends. Blood from the patient flows through the dialyzer in the interior of the fibers. Dialysis solution flows through the dialyzer around and in contact

with the fibres, so that waste products are absorbed from the blood and removed from the dialyser.

The fibers are produced from a long, hollow filament of cellophane or of a cellulose derivative such as "Cuprophan". The filament is continuous and is supplied on a spool.

During manufacture of the dialyzer, it is impractical to cut the filament into individual fibers, group or bundle the fibers, and then assemble the dialyzer. According to a known method for bundling the fibers, the filament is formed into a coil bundle by winding the filament on a wheel, gripping the wound filament at two points, after which the coil bundle is removed from the wheel. The coil bundle is then pulled into a cylindrical housing. In this form, the filament is still continuous, but after further processing, the bent ends of the coil bundle are cut off in such a way that fibers with open ends are formed. As it will appear can

only one device is produced from each coil bundle.

It is therefore an object of the invention to produce a method and an apparatus for use in the production of fiber bundles which are suitable for use in the mass production of hollow fiber dialyzers.

In other known winding systems, the filament is wound onto a carrier device which eventually becomes part of the apparatus. In the dialyzer, the support device is unfortunately an inactive element that takes up space and thereby reduces the device's efficiency.

It is thus another object of the invention to produce a winding apparatus with which the carrying or supporting device for the winding does not become part of the dialyser.

According to the present invention, a method and an apparatus have been developed for winding a filament in such a way that several fiber bundles are produced for use in the manufacture of hollow fiber dialyzers.

The apparatus according to the invention comprises a base, at least one supply coil for a continuous filament and a winding wheel with several radially separated supports around which the filament is wound and bundled between. A movable filament guide is placed between the supply coil and the take-up wheel to continuously control the position of the filament in the lateral direction in such a way as to ensure a loose take-up of the filament, so that a top filament mandrel

crosses into an underlying thorn. This loose packing and crossover ensures an efficient flow of dialysis solution in the dialyzer, and thus its efficiency is brought up to a maximum. The guide moves or oscillates in a lateral or axial direction in relation to the winding wheel at a speed that is proportional to the turning speed of the winding wheel, so that proper crossing is ensured.

The invention will be explained in more detail below

with reference to the accompanying drawings, in which:

Fig. 1 shows a perspective view of one side of a winding apparatus according to the invention and shows the winding wheel, two filament supply coils and the filament guide. Fig. 2 shows a schematic perspective view of a drive system for operating the winding wheel and for moving the filament guide. Fig. 3 shows a perspective view, partly in section, of a system with two cam discs for controlling the movements of the filament guides on each side of the apparatus. Fig. 3a shows an alternative system with only one cam disc

for controlling the guides.

Fig. 4 shows an enlarged perspective view of a filament guide structure.

Fig. 5 shows a side view of the winding wheel.

Fig. 6 shows a section along the line 6-6 in fig. 5 and shows a hub and locking mechanism for the winding wheel. Fig. 7 shows a greatly enlarged side view of part of the winding wheel. Fig. 8 shows a section along the line 8-8 in fig. 7 and shows

the filament crossing.

Fig. 9 shows a perspective view of a split bushing for use

when bundling the filament with a view to cutting it into fibres.

Fig. 10 shows an end view of the split bushing with one

page opened.

Fig. 1 shows a winding apparatus 10 which comprises a stand 12 which is equipped on both sides with a winding mechanism. The stand comprises a box-like main section 14 which is supported by two legs 16 and 18. A control console and mounting section 20 for supply coils is carried in a cantilever-like manner from the rear end of the stand's main section 14.

Two largely identical winding mechanisms are arranged on either side of the stand. If desired, two wrapping operations can thus be carried out at the same time.

Each winding mechanism includes an upper and a lower spool support shaft 22 and 24, respectively, projecting outwardly to the side from the mounting section 20. Two filament supply spools 26 and 28, each carrying a wound continuous hollow filament, are mounted on the shafts 22 and 24 Filaments 30 and 32 run from the spools through a filament guide 34 and to a driven take-up wheel 36. A transparent protective screen 38 with two access doors 38a and 38b is carried by the main section of the stand so that the guide and take-up wheel are enclosed.

The rotation of the winding wheel 36 and the movements of the filament guide 34 are controlled by a drive system which is enclosed by the stand's main section 14. The drive system comprises an electric motor 40 which drives both the winding structure and the guide structure. The engine speed can vary between 0 and 2000 rpm.

The motor 40 is connected to the winding wheel via a gear and a timing belt system as described below. The motor 40 is connected to a reduction gear 42 of worm type, which has a

gear ratio of 5:1 and which has an output sprocket 44. A toothed output drive belt 46 is passed around the sprocket 44 and around a driven sprocket 48, which is mounted on a transverse or intermediate shaft 50. An output sprocket 52 is mounted on the transverse shaft 50 and is connected to a revolution counter 54 by means of a belt 56.

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The gear system is arranged so that the counter is synchronized with the winding wheel, so that the counter indicates the number of revolutions of the winding wheel.

A take-up wheel drive gear 58 is also mounted on the shaft 50 and is connected to a take-up wheel drive shaft 60 by means of a gear 62 on the shaft 50 and a timing belt 64. The take-up wheel 36 is mounted on one end of the shaft 60. The take-up wheel is thus driven by the motor 40 via the reduction gear 42, the toothed wheel 44, the belt 46 and the toothed wheel 48, via the shaft 50, the toothed wheel 58, the belt 64 and the toothed wheel 62 as well as via the shaft 60. With the help of this system, the revolving wheel can be driven with a number of revolutions between 0 and 400 revolutions. /my.

The filament guide 34 is mounted so that it causes the filament to move back and forth or laterally in relation to the winding wheel 36 at a speed which is proportional to the rotation of the winding wheel. The motor 40 drives the filament guide via a variable speed control 64 which is mounted on the motor 40. The speed control comprises a manual speed adjuster 65 and an output gear 66, and the speed of the output gear 66 can be set between 0 and 400 rpm. A register drive belt 68 is passed around the output gear 66 and around a smaller, driven gear 70. For each revolution of the output gear gear 66, the driven gear gear 70 turns 2.25. times, and an exchange ratio of 2.25:1 has thus been produced. The driven gear 70 is attached to one end of a shaft 72 which runs into a gearbox 74. Another shaft 76, flush with the shaft 72, runs out of the gearbox, and a gear 78 is attached to the outermost end of the shaft 76. A rotatable cam drive shaft 80 runs upwardly from the gearbox 74 and is driven by the shaft 72. A bevel gear arrangement, not shown, is arranged inside the gearbox for driving the shafts 76 and 80.

Another timing belt 82 is passed around the sprocket 78 and a sprocket 84 for operating another rotatable cam drive shaft 86 as well as a counter 88 through a gearbox arrangement 89, which is arranged

in a similar way to that just described in connection with the gearbox 74. The counter 88 is synchronized with the rotation of the shafts 80 and 86, which in turn is in relation to the swing speed of the guide arm, so that the counter indicates the speed of the filament guide arm's advance and back movement or swing.

Fig. 3 shows that each of the shafts 80 and 86 at the top carries a cam disc 90 and 92, respectively, which controls the oscillation of the guide 34

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as well as the filaments. A push rod 94 runs from the interior of the rack section 14 through a side wall 14a and is connected at its outer end to the guide 34. At the inner end, the rod 94 abuts against a cam follower 96 which is biased against the cam 90 by means of a helical compression spring 98 which forms an abutment against a bearing plate 100 and the cam follower 96. Turning the cam disc 90 causes the rod 94 to move back and forth, and the filament guide arm, not shown, on the other side of the apparatus is similarly controlled by the cam disc 92.

With this arrangement, the swing speed of the control arm can

regulated between 0 and 900 oscillations per my.

According to an alternative cam construction shown in fig. 3a, only one cam disc 102 is used which is equipped with a groove. In this construction, only one drive shaft 80a is included which drives the cam disc which in turn controls two shock rods 93a and 94a.

As will be seen, the speed of the cam drive shaft 80 in relation to the winding wheel drive shaft 60 can be regulated and set using the speed adjuster 65. If this is not done

a setting or regulation, the ratio between the swing of the drive arm and the rotation of the winding wheel will be constant regardless of the speed of the winding wheel. The use of the adjuster 65, however, makes it possible to set and control the relationship between the swing of the guide arm and the rotation of the winding wheel.

The control arm construction 34 is mounted on the outside of the side wall 14a by means of a vertically adjustable mounting plate 101, a rotatably adjustable side plate 102 and a back and forth adjustable carrier plate 104. An upper filament sensor contact 106 is mounted on the upper side of the plate 104, while a lower filament sensor contact 108 is carried by and is placed under the plate 104. Each of these contacts comprises a blade-like member 110 which is biased in the direction of the filament and which is in contact with the filament 30 or 32 and senses its presence. In the event that the filament breaks during the winding, the member 110 moves upwards and thereby activates devices not shown for disconnecting the drive system and for imposing a controlled braking action on the supply spool shafts as well as on the winding wheel in order to reduce breakage of filaments on other winding wheels to a minimum.

An elongated and pivotable guide arm 112 is rotatably mounted at its rear end on the support plate 104 in front of the contact 106 by means of a pin 114. The push rod 94 is connected to the arm at a point f

in

between the ends of the arm by means of a universal joint 116. A head 112a on the front end of the guide arm carries upper and lower spring-like filament guides, such as a guide 118, which cooperate with other spring-like filament guides, such as a guide 119, which is connected to the contacts 106 and 108. As the push rod 94 moves back and forth, the head 112 oscillates back and forth in a manner controlled by the cam 90.

The winding wheel 36 comprises, as shown in fig. 5 and 6 a filament winding plate 120 as well as a hub and locking system 122 for removable attachment of the plate to the apparatus.

The plate 120 has a large, circular and centrally located opening that defines an inner edge 124, and the plate has six support sections 126, 128, 130, 132, 134 and 135. Each of these sections is placed radially outward from the center of the plate and evenly distributed along the circumference of the plate.

On each of the plate's support sections is mounted a V-shaped filament support structure, such as a structure 136 on the section 126. Each of these support structures comprises two protruding,

U-shaped filament supports 138 and 140 each terminating in a lower or inner chamfered edge 138a and 140a. Each of the supports is attached to the plate 120 by means of screw receiving openings therein. As can be seen from fig. 5, the filament support structures can be movably placed in one of three different radial positions. The filament supports 138 and 140 can thus be moved from the inner position shown to an intermediate position at 14 2 and 144 or to an outer position at 146 and 148. With such changes in the positions, the length of the filament bundles between the support devices can be reduced or increased. E.g. the length of the bundles between two successive support devices can be increased by moving the supports radially outwards. This enables the production of hollow fiber dialyzers of different lengths.

The system 122 for attaching the plate 120 to the machine is shown both in fig. 5 and in fig. 6. This system comprises a hub construction 150 which is attached to one end of the shaft 60 by means of a set screw 151. The hub construction comprises a button-like body 152 which is equipped with a flange and to which a wheel-like carrier plate 154 is attached. The bearing plate comprises three radial spokes 156, 158 and 160, each of which is equipped with an elongated guide slot 162. The outer circumference of the plate is L-shaped in section and delimits an axial or laterally running projection 164 and an annular projection 166.

The wind-up plate 120 for the wind-up wheel is arranged so that the inner edge 124 can be fitted onto the shoulder 164 so that the plate forms contact with the ring-shaped shoulder 166. This fit prevents radial movements of the plate 120 in relation to the hub 150. The plate 120 is removably attached, but in drive connection with the hub structure by means of six pins, such as a pin 167a, which runs outwards from the shoulder 166 and which engages with six openings, such as an opening 167b, in the plate 120.

Three generally radial locking arms 168, 170 and 172 are adapted to secure the spool plate 120 to the carrier plate 154 by preventing axial movement of the spool plate relative to the shoulder 166. These arms are attached at their inner ends to the hub 150 by means of a pin, such as a pin 174 in fig. 6, as well as a rotatable collar-like body 17 6. Each of the arms carries a guide block, such as a block 178 in fig. 6, which moves radially in the slot 162 in the carrier plate 154. The guide block 178 is attached to the arm and lies in the slot by means of a pin 180. Each of these locking arms has such a length that when the arms are in the radially outwardly

and locking position, the outer end of each arm is placed radially outward over the shoulder 164, and the arm end lies over the plate 120.

With this device, the arm can lock and hold the winding plate 120 on the winding machine in a fixed connection with the shaft 60.

The collar 176 is rotatable relative to the shaft 60 and the support arms, such as the arm 160 in fig. 6. As can be seen from fig. 5, a stop pin 182 defines the limits for the movements of the collar 176, and the collar can be held firmly in the locked position by a spring-loaded hook mechanism, not shown. In the one in fig. 5 in the position shown with solid lines, the arms are arranged for locking the plate in position. A rotation of the collar 176 causes the arms to retract and the guide blocks, such as block 178 in FIG. 6, slides into the slot 162 until the outer ends of the arms move within the inner edge of the shoulder 164. With the locking arms retracted, the winding plate 120 can be removed from the apparatus by pulling it axially outwards.

During the operation and function of the winder, the two filament spools are mounted on the shafts 22 and 24, and each filament is drawn through the filament guide 34 and started on the winder wheel 36. The machine is started so that the motor turns the winder wheel 36, and when this happens, the winder wheel pulls filament from the supply coils through the filament guide. The function o of the cam 90 causes the guide arm 112 to swing or move inward and outward in the lateral direction, while the winding wheel rotates. The cam disc is arranged in such a way that it produces an even distribution of the filament on the guides. The shape of the cam disc helps to prevent the accumulation of filament at the edges of the guide by increasing the arm speed at each end of the oscillation. In addition, the cam disc prevents a tight packing of the filament mandrels, and the cam disc brings the filament that is being wound to cross over the previously applied mandrel of the filament. This crossover is shown schematically in fig. 8, from which it appears that an upper filament spike 190 crosses over a lower filament spike 192.

It has proven to be appropriate to use two supply coils from the point of view that a sufficient amount of filament can thereby be supplied to feed the winding wheel continuously, thereby avoiding having to stop the winding operation and start a new supply coil. Such a stop has been shown to be detrimental to the dialyzer's efficiency, as unwanted large flow channels can be formed where one supply coil is released and another begins. It is assumed that this flow channel can be formed as a result of differences in the filament voltage at the end of the first coil and at the beginning of the second coil.

During the winding, it has proven to be appropriate to turn the winding wheel at a speed that is greater than the swing speed of the lead arm. In a certain operating condition, the winding wheel can be driven at a revolution rate of 200 rev/min, while the guide arm performs 160 oscillations per revolution. my.

As the geometry of the winding wheel, e.g. as the size and diameter of the take-up wheel changes, the oscillations of the guide arm must also be changed to produce a proper crossover.

When the filaments have been wound up on the winding wheel and the bundles on this are of sufficient size for use in hollow fiber dialyzers, the winding operation is stopped.

In the production of fiber bundles, an elongated, split sleeve 200 is used, such as the one shown in fig. 9, to form the fiber bundles from the filaments and to remove the bundles from the take-up wheel. The split sleeve comprises an upper, semi-cylindrical part 202 and a lower, semi-cylindrical part 204, which are joined by means of two flexible hinges 206 and 208. As can be seen from o fig. 10, the sleeve parts or sections can be opened and brought to clamp about the wound filament bundles.

When the sleeves are in the one in fig. 7 shown position, they tightly grip the intermediate filament bundles, and the filament can then be cut at both ends of the sleeve to form fibers with open ends, and the bundles can be removed from the winding wheel. The cuts convert the continuous filament into individual, hollow fibers used in the dialyzer. After over-cutting and removal, the individual fiber bundles are processed, and they are designed into hollow fiber dialyzers.

Claims (20)

1. Process for producing a hollow, substantially continuous, semipermeable filament for use in a hollow fiber dialyzer containing several fibers of substantially the same length and with open ends formed by the continuous filament, characterized by producing at least one spool or roll of the filament, withdrawing the filament from the spool, winding the filament on a winding wheel with several separate filament support devices so that the filament may have several elongated sections each having several mandrels, gripping each of these sections, and cutting of the filament at the carriers to form multiple bundles of fibers with open ends. 2. Method in accordance with claim 1, characterized in that the filament, while being wound on the winding wheel, is guided in a way that prevents tight packing of the filament mandrels and ensures loose packing of the mandrels. 3. Method in accordance with claim 2, characterized in that the filament is guided in a manner that brings an overlying thorn to cross over an immediately underlying thorn. 4. Method in accordance with claim 2 or 3, characterized in that the filament is made to swing in a direction perpendicular to the plane of the winding wheel, and that the winding wheel is rotated at a speed greater than the filament's swing speed. 5. Apparatus for making a continuous hollow semipermeable filament for use in a hollow fiber dialyzer containing multiple fibers formed from the filament of substantially equal length and open ends, comprising a rack, at least one supply coil of the filament rotatably supported on the rack , a winding wheel with at least two radially separated support devices, around which the filament is wound and which are rotatably stored on the stand, as well as drive devices for turning the winding wheel, characterized by filament guide devices which are arranged to cooperate with the filament and which are placed on the stand between the winding wheel and the supply coil and is arranged to cooperate with the winding wheel to control the placement of the filament in the lateral direction on the winding wheel's support devices, while the wheel rotates in such a way that tight packing of the filament mandrels is prevented and loose packing of the mandrels is ensured. 6. Apparatus in accordance with claim 5, characterized in that the guide devices oscillate between a first lateral position and a second lateral position. 7. Apparatus in accordance with claim 5 or 6, characterized in that the guiding devices and the winding wheel are connected to each other so that the oscillation speed of the guiding devices is in proportion to the rotating speed of the winding wheel. 8. Apparatus in accordance with claim 7, characterized by devices for setting the speed of oscillation of the driving devices in relation to the speed of rotation of the winding wheel. 9. Apparatus for making a continuous hollow semipermeable filament for use in a hollow fiber dialyzer containing multiple fibers formed from the filament of substantially equal length and open ends, comprising a rack, at least one supply coil of the filament rotatably supported on the rack , a winding wheel with at least two radially separated support devices, around which the filament is wound and which is rotatably stored on the stand, as well as drive devices for turning the winding wheel, characterized in that the winding wheel comprises hub and locking devices which are drivenly connected to the drive devices, and a winding plate which carries filament support devices and which is designed to be inextricably attached in driving connection with the hub and locking devices. 10. Apparatus in accordance with claim 9, characterized in that the carrier devices are arranged to receive the filament and group this between successive carrier devices in a single bundle. 11. Apparatus in accordance with claim 10, characterized in that the support devices are radially movable for setting the length of the filament bundle between successive support devices. 12. Apparatus in accordance with claim 9, 10 or 11, characterized in that the winding plate comprises a large, central mounting opening, and that the hub and locking means comprise peripheral engagement devices for fitting with the mounting opening, locking arms which are movable between an advanced locking position for holding the winding plate in the fitting position and a retracted release position, as well as a central, rotatable collar which is connected to the arms for movement thereof between the locking and release positions. 13. Apparatus for making a continuous hollow semipermeable filament for use in a hollow fiber dialyzer containing multiple fibers formed from the filament of substantially the same length and open ends, comprising a stand, at least one supply spool of the filament, rotatably supported on the stand, a winding wheel with at least two radially separated support devices, around which the filament is wound and which are rotatably supported on the stand, as well as drive devices for turning the winding wheel, characterized by filament guide devices which o is arranged to cooperate with the filament and which is placed on the stand between the take-up wheel and the supply coil and is arranged to cooperate with the take-up wheel to control the placement of the filament in the lateral direction on the take-up wheel's carrier devices, while the wheel rotates in such a way that close packing of the filament mandrels is prevented and loose packing of the mandrels is ensured, and that the guide devices comprise (1) an elongated arm with a rear end which is rotatably fixed in relation to the apparatus and with a movable front end where guide elements are mounted and (2) a reciprocating rod if one end is attached to the arm in a position between its ends in such a way that the front end of the arm is caused to swing. 14. Apparatus in accordance with claim 13, characterized by cam devices which are operatively connected to the reciprocating rod for movement of this back and forth. 15. Apparatus in accordance with claim 14, characterized in that the cam devices are designed so that the arm is made to move in such a way that the filament is distributed on the support devices and that edge accumulations are prevented. 16. Apparatus in accordance with claim 14 or 15, characterized in that the cam devices are operatively and controllably connected to the drive devices of the winding wheel in such a way that the movement of the bar back and forth is linked to the rotation of the winding wheel. 17. Apparatus in accordance with one of claims 13-16, characterized in that the guide arm comprises means for guiding several filaments. 18. Apparatus in accordance with one of claims 13-17, characterized by sensing devices which are connected to the guide arm for sensing the presence of the filament on the arm and for deactivating the drive devices in the event that the filament is not present on the guide arm. 19. Elongate, coreless bundle of hollow and largely longitudinally oriented, semipermeable filaments that are without dir- '0 ( true mechanical attachment to each other, where the bundle is intended for use as a fluid-separating element in a diffusion apparatus, characterized by the filaments being placed in the bundle in such a way that virtually all filament lengths in this and the main direction of the filaments form an angle with the longitudinal axis of the filament bundle, and that the filaments are placed in a crossing and overlying relationship with adjacent filaments in such a way that the packing density of the filaments in the bundle is reduced compared to a corresponding bundle of axial filaments. 20. Elongated, coreless bundle of hollow and largely longitudinally oriented, semipermeable filaments without direct mechanical attachment to each other and for use as a fluid separating element in a diffusion apparatus, characterized in that the filaments are placed in the bundle in such a way that the majority of the filaments length and their axial direction form an angle with the longitudinal axis of the filament bundle, that the filaments are placed in a crossing and overlying relationship with adjacent filaments, and that the filaments generally occupy individual and parallel planes where filaments in a first set of generally parallel filaments form a first angle in relation to the longitudinal axis, and where another set of largely parallel filaments forms an opposite angle with the longitudinal axis compared to the first set, and where the filaments are arranged in the following way: a first element of the first set lies below a first filament in the other set which again lies under a second filament in it first set, with the second filament in the first set again lying under a second filament in the second set, and so on through the majority of the filaments in the first and second sets to form an interlacing where each element in each set lies across the immediately preceding filament in the second set and lies below the immediately following filament in the second set.