Method and device for connecting plastic tubes end to end

Abstract

In order to connect two plastic tubes end to end, the extremities of which are closed by compression and welding or gluing of the tube wall, the two closed extremities of the tubes are axially aligned and placed in abutment, the two closed and abutting extremities of the tubes are heated from a distance and without contact and the two extremities of the tubes are axially brought together, so as to splay and weld together the extremities of the tubes end to end, while constantly maintaining said extremities in abutment.

1 . A method for connecting two plastic tubes end to end, the extremities of which are closed by compression and welding or gluing of the tube wall, wherein the two closed extremities of the tubes are axially aligned and placed in abutment, the two closed and abutting extremities of the tubes are heated from a distance and without contact and the two extremities of the tubes are axially brought together, so as to splay and weld together the extremities of the tubes end to end, while constantly maintaining said extremities in abutment. 
     
     
         2 . The method of  claim 1 , wherein order to heat at a distance and without contact the two closed and abutting extremities of the tubes, a laser beam is used. 
     
     
         3 . The method of  claim 2 , wherein the laser beam simultaneously comes into contact with the two closed and abutting extremities of the tubes. 
     
     
         4 . The method of  claim 3 , wherein the laser beam is orientated transversally to the compression plane of the two extremities. 
     
     
         5 . The method of  claim 4 , wherein the laser beam scans the closed and abutting extremities of the tubes of a direction (T) transversal to the axis (A) of the tubes. 
     
     
         6 . The method of  claim 1 , wherein order to heat at a distance and without contact the two closed and abutting extremities of the tubes, a hot air stream is used. 
     
     
         7 . The method of  claim 1 , wherein order to heat at a distance and without contact the two closed and abutting extremities of the tubes, microwave radiation is used. 
     
     
         8 . The method of  claim 1 , wherein order to heat at a distance and without contact the two closed and abutting extremities of the tubes, infrared radiation is used. 
     
     
         9 . The method of  claim 1 , wherein order to heat at a distance and without contact the two closed and abutting extremities of the tubes, a laser beam and at least one of the means from the following list are used: hot air stream, microwave radiation, infrared radiation. 
     
     
         10 . The method of  claim 1 , wherein the two closed and abutting extremities of the tubes are heated at a distance and without contact inside an enclosure. 
     
     
         11 . The method of  claim 1 , wherein the temperature of the extremities of the tubes is detected and the tubes are brought closer together in function of this temperature detection. 
     
     
         12 . The method of  claim 1 , wherein the extremities are initially closed by high-frequency welding. 
     
     
         13 . The method of  claim 1 , wherein subsequent to the connection of the two tubes, traction is carried out on the connected tubes. 
     
     
         14 . The method of  claim 1 , wherein the tubes are made of PVC. 
     
     
         15 . A device for the connection of tubes and comprising abutment means enabling two tubes to be axially aligned and brought into abutment, and means of heating without contact, wherein the abutment means are designed to automatically displace the two extremities of the two tubes in abutment in a translation movement one towards the other during the implementation of the heating means. 
     
     
         16 . The device of  claim 15 , wherein it includes optical temperature detection means positioned close to the abutment zone of the tubes, and the abutment means are suitable for causing a translation movement of the tubes in function of the temperature detection signal issued by said detection means. 
     
     
         17 . The device of  claim 15 , wherein it includes a heating enclosure and the abutment means include means for causing a translation movement of the tubes, which are inside the enclosure. 
     
     
         18 . The device of  claim 15 , wherein the abutment means include two aligned carriages, which are mobile and guided in translation movement, each carriage being equipped with a means for temporarily fixing a tube on the carriage, and with actuating means enabling the carriages to be brought closer together or further apart. 
     
     
         19 . The device of  claim 18 , wherein the actuating means of the carriages include an endless screw and a two-way motor coupled to the screw, allowing the screw to be rotated in one or the other sense. 
     
     
         20 . The device of  claim 18 , wherein the actuating means of the carriages include for each carriage at least one linear two-way actuator of the elevating screw type. 
     
     
         21 . The device of  claim 18 , wherein the actuating means include elastic means constantly exercising spring forces on the carriages, pushing them towards one other. 
     
     
         22 . The device of  claim 15 , wherein the heating means without contact include a laser source. 
     
     
         23 . The device of  claim 15 , wherein the heating means without contact include at least one hot air blowing nozzle. 
     
     
         24 . The device of  claim 15 , wherein the heating means without contact include at least a microwave source or an infrared source. 
     
     
         25 . Use of the method of  claim 1 , for connecting in a sterile manner the closed tubes of two bags, one of which contains blood platelets. 
     
     
         26 . Use of the device of  claim 15  for connecting in a sterile manner the closed tubes of two bags, one of which contains blood platelets.