Welding device for tube

Abstract: The first electrode (9) is supported on the end surface of the main body case (7), and the second electrode (11) is supported on the movable member (10) set to counterpose the end surface of the above-described main body case. The above-described movable member is displaced to the front and rear direction toward the end surface of the main body case, when the manipulation member is manipulated. The above-described manipulation member is returned to a prescribed position by the first elastic member, when it was opened. Also, the second elastic member for endowing elasticity to the displacing direction when the above-described movable member is approached to the end surface direction of the main body case by the above-described manipulation member, is equipped.

Description: The present invention relates to the improvement of a simple type welding device for a tube in which the middle part of a tube made of a heat weldable material such as vinyl, a synthetic resin, etc. is pressed, and is welded so that the internal passage of the tube is closed, and sure and stabilized welding is made possible by carrying out the welding of the tube with a uniform force. Description of the Prior Art For example, in the case when blood collecting procedure is carried out in a blood donating car or the like, a blood collecting bag constituted of a soft quality plastic material such as vinyl chloride and the like is used. A vinyl tube made of the same material as that of the blood collecting bag is connected to this blood collecting bag, and a blood collecting needle is connected to the tip of the tube. In the case of collecting blood, the blood collecting needle is stung into blood tube of the blood donor, and the blood of the blood donor is absorbed into the blood collecting bag by negative pressure in the inside of the case in which the above-described blood collecting bag is received. When the blood of a predetermined amount has been absorbed in the blood collecting bag, blood collecting procedure is stopped, and the intermediate part of the above-described vinyl tube is closed. Thereby, the flow out of the blood in the blood collecting bag through the vinyl tube is prevented, and the entrance of external atmosphere into the blood collecting bag is made not to occur. In order to shut the intermediate part of the vinyl tube and the like such as described above hermetically, a welding device utilizing the high frequency dielectric heating method has been hitherto used. The vinyl tube welding device by use of the high frequency dielectric heating method is equipped with a pair of electrodes, and is in such a constitution that vinyl tube and the like are put between these electrodes, and high frequency current is supplied between both electrodes. As a result, the vinyl tube put between both electrodes is heated by dielectric loss and temperature is raised, and the softened vinyl tube is pressed between the above-described one pair of electrodes and is welded. As the vinyl tube welding device by the high frequency dielectric heating method, although various kind structure ones are hitherto known, but as a comparatively simple device portable in hand is known, for example, the device disclosed in the Japanese Utility Model Application Laid-Open No. 43101/1979. This conventional welding device for tube is constituted, as shown in Fig. 7, of a control box 1 built-in with a high frequency wave generation source, a pair of levers 6 mutually displacing by making rotation axis 5 as the center, a pair of electrodes 2 and 2 (welding part 3) provided at the tip part of 6, and the cable 4 for connecting this welding part 3 to the above-described control box 1. In the case of welding the tube, the intermediate part of the tube is put between the electrodes 2 and 2, and high frequency current is supplied from the control box 1 between the electrodes 2 and 2 through the cable 4. As a result, the vinyl tube or the like is softened by the heating due to the high frequency dielectrics and is pressed between the electrodes and is welded. According to this conventional device, the force applied to the levers 6 and 6 becomes the force of pressing the tube between pair of electrodes 2 and 2, and there is generated the difference of pressing force of the tube by the grasping farce of the operator grasping the levers 6 and 6. Therefore, in the case of carrying out the welding many tubes, fluctuation is liable to be generated in welding, and skill is required in order to carry out good welding safely. Similar problems exist in the case of a known portable welding device according to the preamble of claim 1 as disclosed in DE-C-4014037. The movable electrode is pressed against the tube to be welded by actuation of a rotatable manipulation member, said member acting on the movable electrode against the force of a spring. Summary of the Invention An object of the present invention resides in proposing a welding device for tube which can always put the tube between the electrodes with uniform force, and can weld the tube surely and in a stabilized state. The welding device for tube of the present invention is a portable type device and is equipped with the first electrode supported on the end surface of the main body case; a movable member set by counterposing to the end surface of the above-described main body case; the second electrode supported at a position counter-posing to the above-described first electrode in the above-described movable member; a manipulation member for displacing the above-described movable member to forward and backward directions toward the end surface of the main body case; the first elastic member for making said manipulation member return to a predetermined position, when the above-described manipulation member is released; and the second elastic member for endowing elasticity to the displacement direction of the above-described movable member, when the above-described movable member is made approach to the end surface direction of the main body case. Brief Description of Drawings Fig. 1 is an schematic perspective view for showing the first embodiment of the present invention. Fig. 2 is an schematic side surface view for showing the second embodiment of the present invention. Fig. 3 is an schematic side surface view for showing the third embodiment of the present invention. Fig. 4 is an schematic essential part side view for showing the fourth embodiment of the present invention Fig. 5 is an schematic essential part side view for sowing the fifth embodiment of the present invention. Fig. 6 is an outline longitudinal sectional side view for showing another example of the lever support structure of the present invention, and Fig. 7 is a perspective view for showing an example of the conventional welding device for tube. Description Preferred Embodiments Fig. 1 shows the first embodiment of the present invention. This welding device for tube is equipped with a main body case 7, a movable plate 10, and a lever 12. In the inside of the main body case 7, the high frequency oscillation circuit (not shown in the figure) and the like are provided, and on one end surface 8 of that main body case 7, the first electrode 9 is supported. On the lower end part of the movable plate 10, arm part 10a is extruded, and this arm part 10s is supported on the main body case 7 and is displaceable along the lengthwise direction of the main body case side surface part. On the inside surface of the movable plate 10, the second electrode 11 is provided at the part counterfacing to the first electrode 9. In the manipulation lever 12, the end part of the support piece 12a is pivoted on the side surface part of the main body case 7, and a pulling spring 13 is provided between the intermediate part of this support piece 12a and the base end part of the movable arm part 10a. When the manipulation lever 12 is rotated in the direction of the arrow mark a of Fig. 1, the movable plate 10 displaces to the direction of the end surface 8 of the main body case, and the second electrode 11 elastically approaches toward the first electrode 9. Also, between the main body case 7 and the middle part of the manipulation lever support piece 12a, another pulling spring 14 is provided, and elastic force of reverse direction to the arrow mark a is endowed. By this pulling spring 14, the manipulation lever 12 always returns to predetermined position. When the manipulation lever 12 returns to the predetermined position, the second electrode 11 separates from the first electrode 9 to a predetermined distance. That is, since the pulling spring 14 contracts in free state, accompanying to the return of the manipulation lever 12, it pushes the movable plate 10, and makes the first and second electrodes 9 and 11 separated. The return position of the manipulation lever 12 is restricted by the stopper or the like not shown in the figure. In the case when the welding device for tube is operated, the manipulation lever 12 is manipulated in the state where the grip 15 is grasped. By the way, although it is not shown in the figure, the movable plate arm part 10a is also provided in the opposite side of the movable plate 10, and in the same manner, the pulling springs 13 and 14 are provided on the contrary side of the main body case 7. In the case when the intermediate part of the tube made of heat weldable material is welded by the welding device for tube shown in Fig. 1, after inserting the tube between the first electrode 9 and the second electrode 11, the manipulation lever 12 is rotated to the direction of the arrow mark a of Fig. 1. As a result, the movable plate 10 displaces to the one end surface 8 of the main body case, and the intermediate part of the above-described tube is got between the second electrode 11 and the first electrode 9 supported on the inside surface of this movable plate 10. In this state, since the prescribed elastic force accompanying to the elongation of the pulling spring 13 has been added to the tube, the tube becomes pressed with an approximately constant force, without relation to the strength of the rotational movement of the manipulation lever 12 which differs by the operator. Also, for example, by providing a stopper or the like not shown in the figure, the displacement amount of the manipulation lever 12 can be suitably regulated. In such a manner as described above, when high frequency current is passed between the first and second electrodes 9 and 11, by the high frequency oscillation circuit provided in the main body case 7, the above described tube is heated and the temperature is raised, and further pressed and welded between the above-described first and second electrodes 9 and 11. After the tube has been welded, when the force added to the manipulation lever 12 is released, the manipulation lever 12 is pulled back by the elastic force of the pulling spring 14, and the second electrode 11 and the first electrode 9 separate, and the welded tube can be taken out from between both electrodes 11 and 9. The second embodiment of the present invention is shown in Fig. 2. In this embodiment, alternate mechanism 16 is provided in the main body case 7 for constituting the welding device for tube. This alternate mechanism 16 is hitherto built in the magnet catch provided in a sharp pencil, ball pen, various kinds of cabinet, etc. and repeats elongation and shrinkage corresponding to the compression force repeatingly added. That is, in this alternate mechanism 16, total length shrinks when compression force is once added to the axial direction (left and right direction of Fig. 2), and when the compression force is added again, total length elongates. In the alternate mechanism 16, one end part (right end part in Fig. 2) is connected to the main body case 7, and another part (left end part in Fig. 2) is connected to the connection piece 17 for connection use of the pulling spring 13 pivoted on the intermediate part of the manipulation lever 12. The other constitution of the welding device for tube is the same as that shown in Fig. 1. The operation in the case of welding a tube made of a heat welderable material by use of the welding device for tube showing in Fig. 2 is almost same as that in the case of the welding device for tube of the above-described first embodiment. That is, after inserting the tube 18 between the first and second electrodes as shown in Fig. 2, the manipulation lever 12 is rotated with fingers in a state such that the grip 15 is grasped, from the position shown by a sold line in Fig. 2 to the position shown with a chain line. As a result, via the pulling spring 13 as an elastic member, the movable plate 10 is pulled, and the second electrode 11 supported on the inside surface of this movable plate 10 is displaced toward the first electrode 9. Then, the intermediate part of the tube 18 is put between these first and second electrodes 9 and 11, and the intermediate part of the tube 18 is welded by the above-described high frequency heating. In the welding device for tube of Fig. 2, when the total length of the alternate mechanism 16 shrinks by rotating the manipulation lever 12 to the chain line position of Fig. 2, even after the release of the rotation force added to the manipulation lever 12, this manipulation lever 12 is supported in the chain line state of Fig. 2. Therefore, the second electrode 11 is pushed toward the first electrode 9 by always with a constant force on the basis of the elastic force of the above-described pulling spring 13. As a result, the fluctuation of the welding of the tube becomes perfectly absent, and stabilized and sure welding can be always carried out. When the desired position of the tube 18 has been welded, the manipulation lever 12 is operated once more, and pressing force is again added to the alternate mechanism 16, and this alternate mechanism 16 is elongated. As a result of elongation of the alternate mechanism 16, the lever 12 is returned to the solid line position of Fig. 2, and the second electrode 11 separates from the first electrode 9. Fig. 3 shows the third embodiment of the present invention. In this embodiment, the binding piece 17 owned in the intermediate part of the manipulation lever 12, an adsorption plate 19 of a magnetic member made of iron or the like is mounted. Also, at a position counterposing to the adsorption plate 19 in the inside of the main body case 7, a permanent magnet 20 is mounted. This permanent magnet 20 has a magnetic force capable of supporting this adsorption plate 19 in the state as it has adsorbed this adsorption plate 19, without relation to the elastic force of the above-described pulling spring 14. Also, at the rear end part (right end part in Fig. 3) of the main body case 7, the pressing rod 21 as a releasing member is provided in the axial direction (left and right direction in Fig. 3) to be free to displace. The rear end part of this pressing rod 21 is protruded from the rear end part of the above-described main body case 7, and by pushing this protruded part forward (left side in Fig. 3), the above-described adsorption plate can be pushed forward. In the welding device for tube shown in Fig. 3, when the manipulation lever 12 is rotated to the chain line position of Fig. 3, the adsorption plate 19 mounted on the binding piece 17 of the manipulation lever 12 is adsorbed on the permanent magnet 20, and after releasing the force added to the manipulation lever 12, this manipulation lever 12 is preserved at the position as it is. Therefore, the tube 18 is pressed with a constant force between the first and second electrode 9 and 11, and the welding of the tube 18 can be carried out without fluctuation and always in a stabilized state. When the tube 18 has been welded, the rear end part of the pressing rod 21 is pushed forward, and the adsorption pale 19 is separated from the permanent magnet 20. As a result, the above-described manipulation lever 12 is returned to the position shown by a solid line in Fig. 3 by the elastic force of the pulling spring 14, the second electrode 11 is separated from the first electrode 9. The constitution of the welding device for tube and others are same with those in Fig. 1. Fig. 4 shows the fourth embodiment of the present invention. In this embodiment, the pressing rod 21 in the above-described third embodiment was omitted, and in place of it, coil 23 is wound on the iron cores 22 and 22 contacting to the permanent magnet to constitute an electromagnet 24. Then, by selecting the winding direction or current direction suitably, a magnetic field contrary to the magnetic field formed by the permanent magnet 20 is formed in the case when the switch 24a is closed and current is supplied to the coil 23. Therefore, in the case when the adsorption of the adsorption plate 19 and the permanent magnet 20 is released, when current is passed to the electromagnet 24, the magnetic field formed by this electromagnet 24 cancels the magnetic field formed by the permanent magnet 20, and the adsorption plate 19 separates from the permanent magnet 20. Constitution and action other than that are the same with those of the above-described third embodiment. As a variation example of the above-described fourth embodiment, such a constitution can be taken that the permanent magnet 20 is omitted, and the adsorption plate 19 is made possible to adsorb only in the case of passing current to the electromagnet 24, and accompanying to the release to current passing to the electromagnet 24, the adsorption of the adsorption plate 19 is released. Fig. 5 shows the fifth embodiment of the present invention. In this embodiment, in the intermediate part of the manipulation lever 12, a hooking member 26 is pivoted, and in the rear end part (right end part of Fig. 5) of the hooking member 26 a nail part 25 is formed. Also, in the position corresponding to the hooking member nail part 25 of the main body case 7, a solenoid 27 for making release means is provided, and the stopper member 28 for displacing by this solenoid 27 is hooked to the hooking member nail part 25. This stopper member 28 hooks to the hooking member nail part 25 accompanying to the rotation of the manipulation lever 12 against the elastic force of the pulling spring 14 when current is not supplied to a solenoid 27. Also, accompanying to the current passing to the solenoid 27, the stopper member 28 is displaced, and the hook to the hooking rear part slips out. According to the embodiment of Fig. 5, the force for pressing the tube of the first and second electrodes 9 and 11 (cf. Figs. 1 to 3) each other can be made always constant. Also, as the version example of Fig. 5, the apparatus can be constituted in such a manner that in the case when the distance of the first electrode 9 and the second electrode 11 has become less than a constant value, the solenoid 27 automatically passes current, and after completion of the welding, the first and second electrodes 9 and 11 are made automatically separated. In any of the above-described embodiments, although one end of the manipulation lever 12 is pivoted in the main body case 27, but as shown in Fig. 6, the apparatus can be also constructed in such a manner as that the guide rod 29 fixed to the manipulation lever 12 is inserted into the thrust bearing 30 on the grip 15, and the above-described manipulation lever 12 is linearly displaced. In Fig. 6, the upper end part of the manipulation lever 12 is connected to the above-described alternate mechanism 16. In Fig. 6, when the manipulation lever 12 is pulled with fingers to the right direction, the movable plate 10 mounted with the second electrode 11 displaces to the right direction, and after the tube to be welded is supported in the most suitable interval of the first and second electrode, the high frequency is oscillated, and sealing is carried out. The oscillation of this high frequency is displayed (not shown in the figure) by an emission diode (LED) that is active during oscillation. When the emission diode is put out or discolored, the oscillation of the high frequency is finished, and the sealing action is finished. Therefore, by pulling the manipulation lever 12, the gap of the first electrode and the second electrode is opened by the action of the alternate mechanism 16, and is returned to the original position. In the above-described embodiments, any of the devices is mounted with the high frequency oscillation circuit and an electric source circuit. The electric source part may be connected to outside with a cable, but a small type high performance battery capable of charging can be mounted also For example, in Fig. 1, a battery mounting room 15a is provided in the main body case 15, and the above-described battery can be mounted therein. According to the above-described welding device for tube of the present invention, notwithstanding whether the operator is skilled or not, the tube can be held together always with a uniform force, and a sure and stable welding can be carried out.

Claims: A portable welding device for welding a heat weldable tube through a movable electrode and an immovable electrode, comprising an immovable first electrode (9) fixed to a main body case (7) at a front face portion thereof, a movable member (10) provided movably in the direction of the front face portion, a movable second electrode (11) provided at the movable member, a manipulation member (12) mounted for manual movement by the operator for moving the movable member (10) toward the immovable electrode (9) of the main body case (7), tube compression means (13), recovering means (14) for the manipulation member for recovering said manipulation member (12) to a predetermined position after the tube having been welded, and high frequency energy supply means for supplying high frequency energy to both electrodes (9, 11) for a required time when holding the tube at a predetermined space between the movable elctrode (11) and the immovable electrode (9), characterized by predetermined space maintaining means (16) for holding, at a predetermined compression force, the tube between the movable electrode (11) and the immovable electrode (9) during welding the tube. The device as claimed in claim 1, wherein the tube compression means is an elastic member (13) connected between the manipulation member (12) and the movable member (10). The device as claimed in claim 1, wherein the predetermined space maintaining means is an alternate mechanism (16) which alternately repeats contraction and expansion following the rotation of the manipulation member (12), and which, at contraction, holds the movable electrode (11) in relation with the immovable electrode (9), and, at expansion, separates the movable electrode (11) from the immovable electrode (9). The device as claimed in claim 1, wherein the predetermined space maintaining means is asscociated with the manipulation member (12) and has a connection member (17) provided with an absorption member (19) thereon, a magnet (20) disposed at a rear part of the case main body, and a releasing member (21) for separating the binding member (17) from the magnet (20), and holds the movable electrode (11) and the immovable electrode (9) at a predetermined space under a condition so that the absorption member (19) of the connection member (17) attracts the magnet (20). The device as claimed in claim 4, wherein an electromagnet (24) is substituted for the releasing member in vicinity of the magnet (20), which generates magnetism in opposition to the magnet (20). The device as claimed in claim 4, wherein the magnet is an electromagnet to be attracted to said connection member (17) at passing a current, and the attraction is released at not passing the current. The device as claimed in claim 1, wherein the predetermined space maintaining means is an engaging mechanism for engaging the movable member (10) at a predetermined position when moving the movable member (10) toward an end part of the case, and a solenoid (27) releases an engagement between an engaging member (26), which is connected to said movable member (10) via an elastic member and is moved with respect to the case main body due to the rotation of the manipulation member (12), and a stopper member (28) to be engaged with the engaging member (26) by displacing the stopper member (28). The device as claimed in claim 3, wherein the manipulation member (12) includes a guide rod (29) which is slidably inserted into a bearing part (30) provided within a grip of the main body, and the manipulation member (12) is connected at its upper portion to the alternate mechanism. The device as claimed in claim 1, wherein a battery mounting room (15a) is provided in the main body case (15) and a chargeable electric source battery is removably mounted in said room (15a). The device as claimed in claim 1, wherein a high frequency oscillation circuit, an electric source circuit and an emitting display means are provided, the high frequency being oscillated and concurrently the emitting display means emitting when the tube is supported between the movable electrode (11) and the immovable electrode (9), and the emitting display means being switched off or discolored at the same time when the oscillation of the high frequency is finished.

Inventors: SHIOIRI HARUKI, SHIOIRI, HARUKI, Shioiri, Haruki, c/o Tiyoda Electric Co., Ltd.
Applicants: KAWASUMI LAB INC, KAWASUMI LABORATORIES, INC.
Application year: 1992
Main classification: B29C65
IPC codes: B29C65