Total containment welding of plastic tubes

Abstract: Plastic tubes are welded together by placing each tube in a nest (16) which includes a pair of grooves and an anvil (26) centrally located between the grooves. Each tube is positioned in the grooves around the anvil for being juxtaposed the other tube. A wafer (W) of movably mounted to move to the gap between the anvils so as to heat the ends of the tubes and melt the tubes without actually cutting through the tubes. The melted ends are then joined together so that the two tubes are thereby connected with one section of each tube being in flow communication with a corresponding section of the other tube.

Description: Background of Invention The present invention relates to the sterile and total containment welding techniques for fluid filled plastic tubes. There are many applications which require a plastic tube to be connected to another plastic tube. Such applications include, for example, the taking of samples from a bioreactor, the treating of blood, CAPD and other medical applications. Prior patents generally dealing with this subject include U.S. patents 4,793,880; 4,610,670; 4,369,779; and 4,753,697. US-A-4,793,880 relates to a linear welding process and apparatus connects fluid-filled tubes in a sterile manner. The linear welder includes a base on which a carriage is slidably mounted. A pair of side by side arms are secured to the carriage as are a pair of tube holders. A pair of clamping jaws are mounted on the arms to clamp a pair of tubes in the holders. The arms are moveable for passing the clamped tubes into contact with a heated wafer which cuts the tubes into tube sections. The tube sections are realigned and a pair of sections are butt welded together. US-A-4,753,697 relates to a process and apparatus for making a connection between two fluid-filled plastic tubes that ensures total containment of potentially dangerous fluids and maintaining sterility of the connection. The tubes are folded to remove all fluid from the weld site and positioned to cause the connection to take place in this fluid free zone. Each folded section is first cauterized to create a bacteria free zone, the tubes are slit in the zone, and cauterized a second time to ensure sterility and melt the tube ends. The tubes are urged together and as the thermoplastic resin cools, a totally contained, sterile weld is formed. Summary of Invention An object of this invention is to provide a total containment welding system for plastic tubes. A further object of this invention is to provide such a welding system which could be conveniently manipulated to insert and remove the tubes. In accordance with the present invention a nest for use in the welding of plastic tubes as set forth in claim 1 and a method of melt/wipe welding sections from two plastic tubes as set forth in claim 20 are provided. Preferred embodiments of the invention are disclosed in the dependent claims. The Drawings Figure 1 is a top plan view of a total containment welding system in accordance with this invention; Figure 2 is an end elevational view of the nest used in the system of Figure 1; Figure 3 is a side elevational view of the nest shown in Figure 2; Figure 4 is a top plan view showing a step in the insertion of a tube in the nest of Figures 2-3; Figure 5 is a top plan view of a modified nest in accordance with this invention; Figure 6 is a side elevational view of a pair of tubes welded together in accordance with this invention; Figure 7 is a cross-sectional view taken through Figure 1 along the line 7-7; Figure 8 is a top plan view of a further form of nest in accordance with this invention; Figure 9 is a top plan view of the nest shown in Figure 8 with the arms in their closed position; Figure 10 is a side elevational view of the nest shown in Figures 8-9; Figure 11 is an end elevational view of the nests shown in Figures 8-10; Figure 12 is a top plan view showing a method of using the nest of Figures 8-11 for breaking the weld seam flange that holds two joined tubes together; Figure 13 is a perspective view of a nest of the type shown in Figure 1 mounted in a sealed packet; Figure 14 is a top plan view of a further nest in accordance with this invention; Figure 15 is a top plan view of the nest shown in Figure 14 in its closed condition; Figure 16 is a top plan view schematically showing one application in the practice of this invention; Figures 17A-17D are top plan views showing the application of this invention for the taking of samples with intermediate sealing; Figures 18A-18D are top plan views showing the taking of continuous samples in accordance with this invention; Figures 19A-19C are top plan views showing the application of this invention for CAPD application; Figures 20A-20C are top plan views showing the practice of this invention for removing a sample ring or a depleted consummable; and Figures 21A-21C are top plan views showing the practice of the invention in installing a consumable reagent or the like; Figures 22A-22D are top plan views showing the practice of the invention for tube sealing without separation. Detailed Description Figure 1 illustrates a total containment welding system 10 which includes a holder 12 having a channel 14 across one end. A pair of nests 16 are fixedly mounted in the channel disposed toward each other. It is to be understood that the particular holder 12 is shown and described herein for illustrative purposes only and that the invention may be practiced by any arrangement which includes some means for mounting a pair of nests 16,16 in a fixed relationship with each other and for moving a heated wafer through the junction or slight gap formed by the bent tubes so as to perform a melt/wipe operation. In the broad practice of the invention, the tubes may be cut by the wafer and one of the nests may be slidable toward the other nest to perform the welding of the tubes with each other. Such mounting of tube holders which are slidable relative to each other is known in the art. The known tube holders, however, do not include the nest structure of this invention. The invention is preferably practiced by the melt/wipe operation described in parent application serial no. 07/604,979. Each nest 16 is best illustrated in Figure 4. As shown therein the nest is in the form of a metal block 18 having a pair of tube receiving areas in the form of grooves 20 of arcuate shape for snuggly receiving the tube T. Each nest is provided with a partition or separating wall 24 which terminates at its forward end in a pointed anvil 26. Anvil 26 is disposed at least at the edge of block 18 and preferably beyond the outer edge to assure that block 18 does not interfere with the sliding wafer W. The lower surface of block 18 includes a pair of locking pins 28 provided with a peripheral groove 30 for snapping into a corresponding hole in the holder 12. Figure 7, for example, illustrates holder 12 to include a resilient 0-ring 32 in each hole 34. When the pin 28 is snapped into hole 34 the 0-ring 32 fits around groove 30 to firmly hold nest 16 in its proper position in channel 14 of holder 12. In practice, before nest 16 is assembled onto holder 12 a tube T is inserted in one groove 20 of nest 16 and the tube is then bent around anvil 26 with the pointed end and sloping surfaces of the anvil causing a flattening of the tube at the bent portion. The other portion of the tube is then inserted in the other groove 20. Both grooves 20,20 are side by side and parallel to each other. After the tube T has been mounted in nest 16, the assembly of the tube and nest is then mounted in channel 14 of holder 12 so that the pair of tubes are juxtaposed each other making slight contact or having a slight gap therebetween. The wafer W moves through heater H and then through the junction or gap to separate the two tubes into four sections T A , T B , T C , and T D . Initially T A and T B form part of the same tube while T C and T D form part of the other tube. After the wafer has passed through the junction to perform the melt/wipe operation the sections become joined with T A being connected with T D and T B being connected to T C . A weld seam flange F joins all four sections together as illustrated in Figure 6. Eventually the weld seam is broken so that the new tubes formed by the newly formed sections can be separated from each other. The invention may be practiced with disposable nests by using a suitable plastic material. Where the anvil 28 itself is plastic, the melting can take place over an area from the flat portion of the partition 24 including melting the tubes and the plastic anvils. Figure 5 illustrates a modified form of this invention wherein a pair of nests 36 are mounted in channel 14. Nests 36 also include the pair of grooves 20,20 and the separating wall or partition 24 which terminates in an anvil 26. Nest 36, however, differs from nest 16 in that a pair of clamp arms 38,40 are provided alongside each groove. In the embodiment of Figure 5, clamp arm 36 is fixedly mounted so that its bent end 44 is only slightly spaced from anvil 26 in the operative position of nests 36. Clamp arm 40, however, is pivotally mounted by being secured to pivot pin 42. A further difference between nest 36 and nest 16 is that only a single pin 28 secures the nest in channel 14 for nest 36. As a result, the entire nest 36 may pivot within the limits provided by its abutment with fixed arm 38. In the practice of the embodiment of Figure 5, when it is desired to insert a tube in nest 36 arm 40 is pivoted away from block 18. Block 18 would then be rotated toward the open arm 40 thereby moving anvil 26 away from the curved end 44 of fixed arm 38. This pivotal movement thereby maximizes the spacing between curved end 44 and anvil 26 to permit the tube T to be inserted in its groove 20 adjacent fixed arm 38. The tube would be bent around anvil 26 while the block 18 is still in its pivoted position because of the access provided by the curved end 46 of pivoted clamp arm 40 being disposed away from anvil 26. In the illustrated practice of this invention clamp arms 38,40 are permanently mounted in channel 14 of holder 12 with the nest 36 being detachably mounted in channel 14. It is to be understood, however, that the invention may also be practiced by mounting the clamp arms 38 and 40 to a common support with nest 36 wherein the resulting assembly and support itself would then be secured in channel 14. An alternative manner of mounting the tubes, which is the preferred practice for nests 36, would be to premount the tubes on the nests 36 before the nests are secured in channel 14. In this arrangement, when the nests are then mounted in channel 14, the arms 40 would be pivoted away from the nests and the nest block 18 would be pivoted toward the movable clamp arm 40 to provide the sufficient clearance between end 44 of fixed arm 38 and anvil 26. After the nest and its mounted tubes have been secured in channel 14 it is necessary to close movable clamp arms 40. This is accomplished by sliding a wedge member 48 into the space between the movable clamp arm 40 and the corresponding wall of channel 14. Figure 5, for example, illustrates one of the wedge blocks 48 on the left hand side to be fully inserted so as to hold its clamp arm 40 in the clamped condition whereby the tube T is flattened around anvil 26. Figure 5 also illustrates the initial stage of inserting wedge block 48 against clamp arm 40 in the right hand portion of Figure 5. As is apparent, the sliding of wedge block 48 causes arm 40 to pivot to its straight position which in turn causes nest 36 to be pivoted to its straight position. Figures 8-11 illustrate a further embodiment of this invention wherein the nest 50 is provided with a pair of pivoted resilient clamp arms 52,52. As with the prior embodiments, nest 50 includes the block 18 having the central partition 24 which terminates in an anvil 26. This embodiment illustrates that the provision of tube receiving areas in the form of physical grooves to hold the bent tube in place is not actually necessary. Thus, for example, partition 24 may have straight walls and the top surface of block 18 may be straight. The tube would still be held in its proper position by being clamped between partition 24 and a corresponding clamp arm 52. If desired, shallow grooves may be formed in the upper surface of block 18 or grooves may be formed in the side walls of partition 24 and the corresponding flat portions of clamp arms 52. Block 18 also includes a pair of fixed lock members 54 which extend upwardly away from the top surface of block 18. Each clamp arm 52 is also provided with a complementary locking structure 56 which engages locking members 54 when the clamping arms 52 are moved to their closed positions as shown in Figure 9. The clamping arms 52 are unlocked by pressing the arms at their thin portions near the locking structures to bend the arm inwardly and snap its locking structure away from the locking structure of member 54. Figure 8 illustrates the advantage of nest 50 in that it provides access around anvil 26 for facilitating the mounting of the tube in a bent fashion on nest 50. Figure 12 illustrates a further advantage of this invention wherein a movable clamp arm is used. As shown therein, the tube T which has been welded together in the manner illustrated in Figure 6 is inverted so that, for example, the joined sections TA and TD are mounted above joined sections T B and T C . When in this position the joined tube sections T B and T C are disposed in nest 50 with the seam flange F being located at anvil 26. The corresponding arm 52 is then moved to a closed position as shown by the arrow and this closing movement causes the seam F to sever so that the joined sections T A and T D are separated from the remaining joined sections T B and T C . The various pivoted clamp arms in the different embodiments could also be used as pliers to open communication of joined sections. Figures 14-15 illustrate a further embodiment of this invention wherein the nest 60 includes a single pivoted clamp arm 62 having locking structure 64 which engages locking'structure 66 on block 18. A fixed clamp arm 68 is provided on the other portion of block 18. Movable clamp arm is connected to block 18 by a flexible hinge 70 which is disposed below anvil 26. The flexible hinge permits clamp arm 62 to be moved a sufficient distance away from block 18 so that a tube T can be placed between partition 24 and fixed clamp 68 while the tube is still in a straight condition as illustrated in Figure 14. Arm 62 may be moved at least in line with and preferably beyond clamp 68. The tube would then be bent around anvil 26 against the opposite side of partition 24. This manipulation is again done while there is minimal obstruction because clamp arm 62 is located in its remote position. After the tube T has been bent around anvil 26, clamp arm 62 is closed and locked in position by engagement of locking members 64 and 66 to clamp one section of the tube between clamp arm 62 and partition 64 with the other section being clamped between stationary clamp member 68 and partition 24 as illustrated in Figure 15. The embodiment of nest 60 is particularly advantageous for use by people with impaired eyesight, including blind people or people having limited dexterity since it maximizes the open area and minimizes the number of manipulations necessary for the mounting of the tube in nest 60. Figure 13 illustrates an advantageous feature of this invention wherein a tube is premounted in a nest, such as nest 16 and the premounted end of the tube and its nest are packaged in a sterile envelope 72. This assures maintaining the tube end in a sterile condition until it is time for actual mounting of the nest on the holder. The use of a sterile package is particularly desirable when the tube terminates in an open end rather than terminating in a factory made hematron type seal. Figure 16 illustrates one application of the invention for use, for example, in blood sampling or processing. In the illustrated embodiment a tube T 1 would be mounted in a nest 16 A . It is intended to have flow communication between tube T 1 and tube T 2 . Accordingly, tube t 2 would be mounted in nest 16 B . A pair of prepackaged nests 16 C and 16 D would be provided having their tubes T 3 and T 4 communicating with a bag or container 74. The ends of tube T 3 and T 4 might be initially packaged in sterilzed packet 72. The pair of nests 16 A and 16 C are mounted in the same holder to connect sections of tubes T 1 and T 3 while nests 16 B and 16 D are mounted in the same holder to connect sections of tubes T 2 and T 4 . After such connection has been made, a partition in bag 74 is broken so that the blood or other fluid may mix with fluid in the partitioned bag 74 on the side 76 of the partition remote from the portion of the bag which is connected to tubes T 3 and T 4 . Alternatively, bag 74 may include capsules which could be broken by a squeezing to introduce some form of reagent, etc. into the blood or other fluid flowing through the tubes. It is to be understood that while Figure 16 illustrates the nest to be in the form of nest 16 the other forms of nest herein may be used. Similarly, Figures 17-22 illustrate various practices of the invention which may include any form of nests described herein. Figures 17A-17B illustrate the practice of the invention for use in the taking of samples with intermediate sealing. As shown therein, a bioreactor B is provided having a tube T with a sealed end 78. It is desired to connect bioreactor B with sample S. Sample S in turn includes a tube T having a sealed end 80. In general, the invention is practiced by providing a presealed package 72 whenever the tube end is not hemotron closed. Conversely, where the tube end is hematron closed the prepackaging is not necessary. In Figures 17-22 an "X" is used to designate the sealed end of a tube. Figure 17A illustrates the general arrangement before bioreactor B is connected to sample S which contains various consummables. Figure 17B illustrates the arrangement for the taking of a first sample. As shown therein, the tube T leading from bioreactor B is mounted in a nest 16 juxtaposed the tube T from sample S. After the tube sections have been connected together a stub 82 results with the other tube sections being connected together to form a single main tube 84. Material from bioreactor B then flows into sample S to fill the sample. Figure 17C shows the steps in the closing of the system. As shown therein, after the sample S has been filled the tube 84 is mounted in a nest 16 and the stub 82 is mounted in a corresponding nest 16. By use of the melt/wipe operation, a new tube 86 results formed from a portion of tube 84 and a portion of tube stub 82 which leads from bioreactor B. Similarly, a tube 88 is formed which communicates with sample S. The two new tubes are sealed. The sample S can then be refrigerated, assayed, etc. while the bioreactor remains sealed. Figure 17D illustrates how a further sample S 1 could be taken in a manner similar to the taking of sample S. Figures 18A-18D illustrate the practice of this invention for continuous sampling. Figure 18 A shows the initial state which is the same as Figure 17A. Similarly, Figure 18B illustrates the formation of a tube 84 and a stub 82 similar to Figure 17B. Figure 18C, however, illustrates the steps for taking the next sample S 2 . As shown therein, a portion of the tube 84 is joined to a portion of tube 90. The result is, the formation of a new tube 92 which communicates the bioreactor B with sample S 2 until S 2 is filled. The first sample S 1 is separated with its tube 94. The above steps would be repeated for taking any number of samples up to sample S n . Figure 18 D illustrates the steps for closing the system after n number of samples has been taken. As shown therein tube 84 is to be connected to stub 82 which would have been left over from, for example, the taking of the first sample or could comprise a new tube section. After that operation a new tube 92 is formed which has a sealed end and leads from bioreactor B while the last sample S n has its tube 94. Figures 19A-19C illustrate the practice of the invention for use in CAPD with bag-off. As shown therein, the patient P would have a tube 96 and might, for example, have joined thereto at weld 98 a second tube 100 having a factory made hematron seal. It is intended to reinstall a bag for the next exchange. This is accomplished by providing an empty bag E having its tube 102 positioned in a nest with the tube 96,100 positioned in a corresponding nest. After the melt/wipe operation and a draining operation the patient is connected by the newly formed tube 104 with the bag E and a stub 106 remains which is later used for the bag-off operation. Figure 19C illustrates the steps for a bag exchange. As shown therein, the patient has the tube 104 connected to the used bag U while the new bag N has its tube 108. Each tube is placed in the corresponding nest and the tubes are connected to each other so that the patient is connected to the new bag N by resulting tube 110 while the used bag U has its tube 112. The used bag is capped and discarded. Figure 19D illustrates the bagging-off operation wherein the stub 106 which had previously been formed is mounted in a nest associated with the nest for tube 110. After the wipe/melt operation the patient has a resulting tube 114 which is sealed at its end with the now empty new bag end having its tube 116 which again would be sealed. Figures 20A-20C illustrate the practice of the invention for removing a sample ring or depleted consummable. Figure 20A illustrates the initial state where the depleted consummable DC has a pair of tubes 118,120 extending therefrom. Figure 20B illustrates the loading operation wherein tube 118 is mounted in a nest while tube 120 is mounted in a corresponding nest. The welding operation is then performed and Figure 20C illustrates the depleted consummable to have a closed loop tube 124 resulting from the welding operation while a tube formed from tube 126 results from sections of tubes 118 and 120. Figures 21A-21C illustrate the practice of the invention for installing a consummable reagent, filter pack etc. As shown in Figure 21A, in the initial state, a tube 128 is provided in closed form connecting with the system. The consummable C which is to be installed is similarily provided with its closed tube 130. Both tubes 128 and 130 are then loaded in nests 16,16 as shown in Figure 21B. The result illustrated in FIgure 21C is the formation of a tube 132 which extends from the system to consummable C with a second tube 134 extending from consummable C back to the system. The resulting stubs could be discarded. Figures 22A-22D illustrate the practice of the invention for tube sealing without separation. Figure 22A illustrates the initial system wherein a tube 136 is provided which would be connected to two different parts of the system. The tube would be mounted in a pair of nests 16,16 as shown in Figure 22B. In accordance with the practices described in parent application 07/604,979 one tube section from each tube is aligned with each other while the other tube sections are misaligned. This could be accomplished by having anvil 26B thicker than anvil 26A. As a result, the tube around anvil 26B would have its bent sections spaced further apart than the sections bent around anvil 26A. One set of sections would be aligned, while the other set would contact in mis-alignment. See Figure 22C. The result after the welding operation is illustrated in Figure 22D wherein a closed loop 138 results along with a misaligned weld 140 which functions to both seal and connect the tube sections 142,144. The present invention thus provides various nest structures which may be utilized for joining tube sections. The embodiments range from a fixed nest which could be permanently mounted to a holder and which would represent the most economical version of the invention to a self-loading nest that is detachably mounted to the holder and to a preloaded, prepositioned tube which permits loading by an individual having impaired eyesight or limited dexterity. The invention may be practiced by having all of the welded tube sections temporarily closed and then selectively opened by placing the tubes which are to be opened in one side of the nest. During the closing action on that side of the nest the clamp arm acts as a pliers to open the joined tubes. Accordingly, one or both joined tubes sections may be opened. Advantageously, the nest also provides a ready means for breaking the seal flange which secures the two newly formed tubes together so that the tubes can be separated. The invention permits tubes to be joined in this manner for a wide variety of applications, only some of which have been illustrated and described for exemplary purposes.

Claims: A nest (16) for use in the melt/wipe welding of plastic tubes (T) comprising a block (18) having an upper surface, a pair of side by side parallel longitudinal tube receiving areas (20) on said upper surface, an upstanding partition (24) on said upper surface separating said tube receiving areas (20) from each other, said partition (24) terminating at its forward end in an anvil (26), and said anvil (26) extending to at least the edge of said upper surface whereby a tube (T) may be bent around and flattened against said anvil (26) with sections of the tube (T) in said tube receiving areas (20) and with the bent and flattened portion of the tube (T) extending beyond said upper surface whereby the bent and flattened portion of the tube (T) may be contacted by a heated wafer (W) movable beyond said upper surface to permit the tube (T) to be welded to another tube (T). The nest (16) of Claim 1 wherein said anvil (26) terminates in a pointed tip. The nest (16) of Claim 2 including at least one locking member (28) extending downwardly from said block (18) for engagement with a support surface whereby said nest (16) is locked to the support surface, and said anvil (26) extending beyond said edge of said upper surface of said block (18). The nest (16) of Claim 3, in combination therewith, a plastic tube (T) being mounted on said upper surface with a section of said tube (T) in each of said tube receiving areas (20) and with said sections of said tube (T) being joined by a portion of said tube (T) which is bent and flattened around said anvil (26), and said sections of said tube (T) and said nest (16) being mounted in a sealed packet (72). The nest (16) of Claim 2, in combination therewith, a holder (12), said holder (12) having an upper surface and said nest (16) being mounted to said upper surface, said nest (16) being a first nest (16), a second nest (16) disposed in line with an adjacent to said first nest (16), said second nest (16) having an anvil (26), and said anvils (26) of said first and second nests (16) disposed toward each other. The combination of Claim 5 wherein said holder (12) includes a channel (14) on said upper surface of said holder (12), said nests (16) being mounted in said channel (14), and a wafer (W) movably mounted for movement through the space between said anvils (26). The combination of Claim 6 wherein said tube receiving areas (20) comprise grooves (20) in said upper surface of said block to define curved walls for receiving said sections of said tube (T). The combination of Claim 6 wherein a pin (28) extends downwardly from each of said blocks (18), said pin (28) having a peripheral groove (30), said channel (14) having a hole (34) for each of said pins (28), each of said holes (34) having an O-ring (32), and said O-ring (32) being mounted to said peripheral groove (30) of its respective pin (28) when its respective nest (16) is mounted in said channel (14). The combination of Claim 6 including a fixed clamp arm (38) mounted in said channel (14) adjacent one of said tube receiving areas (26) of each of said nests (16), a pivoted clamp arm (40) mounted in said channel (14) adjacent the other of said tube receiving areas (20) of each of said nests (16), and each of said nests (16) being pivotally mounted in said channel (14). The combination of Claim 9 including a wedge slidably mounted for movement between each of said pivoted clamp arms (40) and the channel wall to cause said clamp arm (40) to move to a closed position and to cause said clamp arm (40) to pivot said nest (16) to a straight position. The combination of Claim 10 wherein each of said clamp arms (38, 40) terminates in a curved end (44). The nest (16) of Claim 3 wherein said locking member (28) comprises a pin (28) having a peripheral groove (30), and said anvil (26) is made of a meltable plastic material. The nest (16) of Claim 2 including a pair of pivotally mounted clamp arms (52) on said block (18) with each of said clamp arms (52) being disposed at a respective one of said tube receiving areas (20). The nest (16) of Claim 13 including a locking post (54) for each of said clamp arms (52) mounted on said upper surface of said block (18), each of said locking posts (54) and its respective arm (52) having complementary locking means (56) for mounting said arm (52) to said locking post (54) when said arm (54) is in its clamped position. The nest (16) of Claim 14, in combination therewith, a holder (12), said holder (12) having an upper surface, a channel (14) extending across said upper surface of said holder (12), said nest (16) comprising a first nest (16) mounted in said channel (14), a second nest (16) mounted in said channel (14) adjacent said first nest (16), said second nest (16) having an anvil (26), said anvils (26) of said nests (16) disposed toward each other, and a wafer (W) movably mounted in said holder (12) through the space between said anvils (26). The nest (16) of Claim 2 including a fixed clamp (68) on one side of said partition (24), a hinged clamp (62) on the side of said partition (24) opposite said fixed clamp (68), and said hinged clamp (62) being movable to an open position which is at least in line with said fixed clamp (68) so that both of said tube receiving areas (20) are readily accessible. The nest (16) of Claim 16 wherein said hinged clamp (62) is mounted to said block (18) by a flexible hinge (70), and said flexible hinge (70) permitting said hinged clamp (62) to be pivoted beyond the in line position of said fixed clamp (68). The nest (16) of Claim 17, in combination therewith, a holder (12), said holder (12) having an upper surface, a channel (14) extending across said upper surface of said holder (12), said nest (16) comprising a first nest (16) mounted in said channel (14), a second nest (16) mounted in said channel (14) adjacent said first nest (16), said second nest (16) having an anvil (26), said anvils (26) of said nests (16) disposed toward each other, and a wafer (W) movably mounted in said holder through the space between said anvils (26). The combination of Claim 5 wherein one of said anvils (26) is thicker than other of said anvils (26) whereby one tube section in one of said nests (16) would be aligned with a corresponding tube section in the other of said nests (16) and another of said tube sections would be misaligned with but positioned to contact a corresponding tube section in the other of said nests (16). A method of melt/wipe welding sections from two plastic tubes (T) comprising the steps of bending and flattening one of the tubes (T) around and against an anvil (26A) of a nest (16) having two side by side tube receiving areas (20), locating the sections of the tube adjacent the bent and flattened portion in the tube receiving areas (20), repeating the bending, flattening and locating steps with the other of the tubes (T) around a second anvil (26B) of a second nest (16), clamping the tubes (T) in the nests (16), mounting the nests (16) on a support surface with the bent and flattened portions of the tubes (T) disposed toward each other, passing a heater wafer (W) through the area where the bent and flattened portions of the tubes (T) are disposed toward each other to contact and melt the bent and flattened portions, and melt/wipe welding a tube section (T A , T B ) from each tube (T) with a corresponding tube section (T D , T C ) of the other tube (T). The method of Claim 20 including mounting each nest (16) to a holder (12) having a wafer (W) which is movable through the space between the anvils (26) of the nests (16). The method of Claim 21 wherein each of said nests (16) is permanently mounted to the holder (12). The method of Claim 21 including mounting each nest (16) in a channel (14) in the upper surface of the holder (12). The method of Claim 23 including detachably mounting each nest (16) in the channel (14). The method of Claim 24 wherein each nest (16) includes at least one pin (28) extending downwardly from the nest (16) with a peripheral groove (30) in the pin (28) and including the step of snapping the pin (28) into a corresponding hole (34) in the channel (14) with an O-ring (32) in the hole (34) being snapped into the peripheral groove (30). The method of Claim 24 including removing at least one of the tubes (T) and its nest (16) from a sealed packet (72) with the tube (T) mounted to the nest (16) before the tube (T) and nest (16) assembly is mounted in the channel (14). The method of Claim 24 wherein each nest (16) includes a partition (24) having a fixed clamp (38) on one side and a pivoted clamp (40) on the other side and including the steps of pivotally mounting each nest (16) in the channel (14), pivoting each clamp (40) and its nest (16) away from its fixed clamp (38), inserting one tube section in a tube receiving area (20) adjacent the fixed clamp (38), bending and flattening the tube (T) around and against the anvil (26) inserting an adjacent tube section in the area adjacent the pivoted clamp (40), and pivoting the clamp (40) and its nest (16) toward the fixed clamp (38). The method of Claim 27 including sliding a wedge (48) against the pivoted clamp (40) and a wall of the channel (14) to pivot the clamp (40) to a closed position and the pivoting action of the clamp (40) causing the clamp (40) to press against the nest (16) to pivot the nest (16) to its straight position. The method of Claim 28 wherein each of the clamps (38, 40) terminates in a curved end (44) and flattening each tube section between the curved end (44) and pointed end of the anvil (26). The method of Claim 24 wherein each nest (16) has a pair of pivoted clamp arm (52) on each side of a partition (24) in the nest (16) separating the tube receiving areas (20) and including the steps of pivoting each clamp arm (52) away from its tube receiving area (20) to expose the tube receiving area (20) and permit the insertion of a tube section therein, and moving each pivoting clamp arm (52) to a locked position after each tube section has been inserted in its tube receiving area (20). The method of Claim 30 including joining two sets of tube sections together as a result of the melt/wipe welding step, the two sets of tube sections being connected to each other by a web flange (F), inserting the joined sets in a nest (16) with one set in a tube receiving area (20) and the other set disposed above that set, and closing the respective clamp arm (52) to break the flange and separate the two sets from each other. The method of Claim 30 including inserting a welded tube section in a tube receiving area (20), closing the clamp arm (52) to press against the welded tube section and open communication therein by means of the clamp arm (52) acting as a pliers. The method of Claim 24 wherein each of the nests (16) includes a partition (24) between the two tube receiving areas (20) with a fixed clamp (68) on one side of the partition (24) and a hinged clamp (62) on the other side of the partition (24) including the steps of pivoting the hinged clamp (62) away from its tube receiving area (20) to a position at least in line with the fixed clamp (68) to completely expose both tube receiving areas (20) of the nest (16), inserting a tube section in each tube receiving area (20) when the tube receiving areas (20) are completely exposed, and closing the clamp (62) after the tube sections have been inserted in their tube receiving areas (20). The method of Claim 20 wherein a set of two nests (16) is provided on each side of a process container (74) with a tube (T) extending from each side of the process container (74) to a respective one of the nests (16) including the steps of joining a tube (T) from each of the sets as a result of the melt/wipe welding steps to create an assembly of melt/wipe welded tube sections which permits the flow of fluid from one side of the process container (74) through the process container (74) and to the other side, and mixing a substance from the process container (74) with the fluid flowing from the tubes (T) and through the process container (74). The method of Claim 20 including providing one tube (T) from a main source and another tube (T) from a sample container (S) wherein the method is used for taking a sample from the main source (B) and discharging it into the sample container (S) including the steps of creating a melt/wipe welded main tube (84) as a result of the melt/wipe welding step with the main tube (84) extending from the source (B) to the sample container (S), and filling the sample container (S) with fluid flowing from the main source (B) through the main tube (84) and into the sample container (S). The method of Claim 35 including creating a stub tube (82) from melt/wipe welded sections of the tubes (T) as a result of the melt/wipe welding step, closing the system which comprises the main source (B) and the sample container (S) by melt/wipe welding a section of the stub tube (82) to a section of the melt/wipe welded tube (84) to create two new tubes (86, 88), and sealing each end of the new tubes (86, 88). The method of Claim 36 wherein after the new tubes (86, 88) have been closed, a further sample (S 1 ) is taken by repeating the sample taking steps. The method of Claim 36 wherein the method is used for taking a new sample by repeating the sample (S 1 ) taking steps before the closing steps. The method of Claim 20 wherein the method is used for CAPD bag installation wherein the patient (P) is provided with a tube (96) and a first bag (E) is provided with a different tube (102) and including the steps of connecting the two tubes (96, 102) together by the melt/wipe welding step to create a new main tube (104) leading from the patient (P) to the first bag (E) and a stub tube (106) resulting from additional tube sections of the two tubes (96, 102). The method of Claim 39 wherein the method is used for replacing the first bag (E, U) with a second bag (N) having a tube (108) and including the steps of using the welding step to form a new main tube (110) which leads from the patient (P) to a section of the second bag (N) with a tube section (112) being connected to the first bag (U). The method of Claim 20 wherein the method is used to remove a tube section (118, 120) containing a consummable container (DC) wherein the consummable container (DC) has a tube (118, 120) leading from each side to a pair of main sources and including the steps of bending each tube to create a new main tube (126) which joins the two main sources and leaving a closed loop tube (124) connected to the consummable container (DC). The method of Claim 20 wherein the method is used to install a consummable container (C) and wherein a main source (System) is provided which provides a tube (128) connected at both ends to the main source (System) with the consummable container (C) having a closed loop tube (130) connected at each end to the consummable container (C) and including the steps of inserting each of the tubes (128, 130) in a nest (16) and using the melt/wipe welding step to form a first tube (132) leading from the main source (System) to the consummable container (C) and a second tube (134) leading from the consummable container (C) back to the main source (System). The method of Claim 20 wherein the method is used for forming a loop (138) from a tube (136) which joins one flow system to another flow system and including the steps of bending and flattening portions of the tube (136) around and against a respective anvil (26) of two nests (16), aligning a section of one tube portion in one nest (16) with a corresponding tube portion in the other nest (16), melt/wipe welding the aligned sections together to create a loop (138), and connecting the remaining systems to each other by the other tube sections. The method of Claim 43 including misaligning a different tube section in one nest (16) with a corresponding tube section in the other nest (16) wherein the tube sections are misaligned but disposed to contact each other, and sealing the misaligned tube sections as a result of the melt/wipe weld that occurs when the misaligned sections are melt/wipe welded together. The nest (16) of any of Claims 1 to 19 wherein said anvil (26) is made of a meltable plastic material.

Inventors: SHAPOSKA JOHN B, SPENCER DUDLEY W C, SHAPOSKA, JOHN B., SPENCER, DUDLEY W.C.
Applicants: DENCO INC, DENCO, INC.
Application year: 1992
Main classification: B29C65
IPC codes: B29C65, A61M39, B29L23