Packaging method and device for the wrapping of a bundle of welding electrodes

Abstract: In accordance with a method and a device for packaging a bundle (13) of welding electrodes (1) with the aid of an elastic wrapping material (19) the electrodes (1) are applied in a retainer (8), whereupon the wrapping material (19) is wound by means of a winding device (18) in one or several turns about the bundle (13) and the retainer (8) in the lengthwise direction of the bundle, over and in abutment against the free ends (14) of the electrodes (1) to immobilize said electrodes in the bundle (13) in their mutual positions, and finally the thus wrapped and packaged bundle (13) is separated from the retainer (8) by means of a separating device (24).

Description: The subject invention concerns a method and a device for packaging of a number of bundled welding electrodes of essentially equal lengths, preferably coated electrodes, with the aid of an elastic wrapping material. In packaging welding electrodes in the form of bundles containing e.g from 10 to 100 electrodes, it is essential that the electrodes of each bundle, which electrodes generally have a circular cross-sectional shape, are maintained as far as possible in a mutually immobilized position in order to prevent relative movement of the electrodes with consequential damage thereto in the subsequent handling of the bundles, for instance during transportation and storage. In accordance with a previously tested and known method one or several straps of an elastically shrinkable material, such as a plastics film, is applied around the ends of a bundle of electrodes, whereupon the film is shrunk in order to immobilize the electrodes. During the shrinkage of the straps, the bundle is tightened and, depending on the number of electrodes in the bundle, the latter takes on a profile configuration that more or less resembles that of a polygon or a circle. Bundles having this profile configuration take up a great deal of room during transport and storage because of the considerable large dead inter-bundle space formed when the bundles are stacked. Although this has a certain electrode immobilizing effect the remaining relative electrode movability is still sufficient to constitute a risk for damage to the electrodes during the handling thereof. In accordance with another prior-art method, a bundle of electrodes is packaged in an individual box of paper-board or in a case of plastics material having a closable lid. Also in both these cases the electrodes are more or less free to move relatively one another and thus to cause damage to one another and even to the very package during handling. The purpose of the subject invention is to avoid the disadvantage outlined in the aforegoing by providing a positively shape-permanent bundle of immobilized electrodes, and a bundle profile of optimum configuration to achieve space economy for transportation and storage of the packaged bundles. This purpose is achieved by the method in accordance with the invention in that in order to form a bundle of electrodes, the latter are placed in a retainer with their external free ends projecting from the retainer in opposite directions and essentially in alignment, that the wrapping material is wound in one or several turns about the bundle in the longitudinal direction thereof and in abutment against the free ends of the electrodes for the purpose of mutually immobilizing the electrodes making up the bundle, and in that the bundle thus packaged is separated from the retainer. The tightening fixes every single electrode in its position. Vibrations cannot either cause dislodging of the electrodes. A device developped in accordance with the invention for the performance of this method is characterized by a retainer in which the electrodes, designed to form a bundle, are insertable in such a manner that the outer free bundle ends project from said retainer in opposite directions and essentially in alignment, by a device for winding wrapping material in one or several turns about the bundle in the longitudinal direction thereof above and in abutment against the free ends of the electrodes for the purpose of mutually immobilizing the electrodes making up the bundle, and by a device for separation of the bundle thus packaged from the retainer. The invention will be described in closer detail in the following with reference to the accompanying drawings illustrating one presently preferred embodiment of a device in accordance with the invention for performance of the method. In the drawings, Fig. 1 illustrates in a perspective view the main components of this device necessary to understand the functioning of said device, as well as some ancillary equipment, whereas Figs. 2A-2C, 3A-3C and 4A-4C schematically show a sequence of different steps for wrapping a bundle of electrodes according to the method of the invention, to form a package. Coated welding electrodes 1 of a conventional design which have been manufactured in a preceding station, not shown, are transported one by one on a belt conveyor 2 or similar forwarding device in the direction indicated by arrow A, up to a transfer device 3 formed with electrode collection pockets 4 arranged to transfer the electrodes 1 in the direction indicated by arrow B onto the packaging and wrapping device in accordance with the invention, generally designated by reference 5. The wrapping device 5 in accordance with the embodiment described and illustrated herein comprises a belt 7 of rubber or other similar material which travels around pulleys 6 at least one of which is driven by a motor, not shown, and a transmission associated therewith. The upper part of the belt 7 travels in the direction of arrow C. On its external face, the belt 7 supports a number of retainers 8 extending transversely across the belt as seen in the lengthwise direction thereof, said retainers being shorter than the electrodes 1. The material of the retainers 8 is a matter of choice and could be for instance extruded or welded aluminium. The retainers are formed with a space 10 which opens upwards and at the retainer ends 9 for reception therein of electrodes 1 in a manner to be described in closer detail in the following. The space 10 is laterally delimited by upwardly projecting guide walls 11, thus giving the space a configuration most closely resembling that of an upwardly open cradle. At the end of the wrapping device 5 turned towards the transfer device 3 there is arranged a transfer station 12 for transfer of electrodes 1 from the transfer device 3 to a retainer 8 below. When the electrodes 1 are transferred to or are placed inside this retainer 8, they form a bundle 13, in accordance with the example shown comprising 16 electrodes, but obviously the number could be increased or decreased according to wish. The retainer 8 is arranged to be affected by a vibrating mechanism 29, the latter becoming active when a predetermined number of electrodes 1, to be bundled together, have been transferred to the retainer 8. As a result of the vibrations, the electrodes 1 will assume mutual positions displaying a high fill factor. As a rule, the number of electrodes used to form the bundle does not make it possible to assemble the electrodes into a bundle having an essentially rectangular cross-sectional configuration; on the contrary, the top layer in the bundle will be only partly filled with electrodes. When the electrodes are placed inside the retainer 8, the outer free ends of the electrodes 1 of the bundle 13 will project in opposite directions from the ends 9 of the retainer 8. Owing to the shape of the space 10 in the retainer 8, as described previously, the bundle 13 will essentially assume the configuration of a square block, which is the optimum configuration for wrapping, transporting and storing the bundles. In accordance with the preferred embodiment, the vibrating mechanism 29 is in the form of a vibrator 30 which is fixedly mounted below the upper part of the belt 7 and in abutment against the lower face of that belt part. Via the upper belt part, the vibrator 30 imparts a vibratory motion to the retainer 8 above, which is filled with the bundle 13 of electrodes 1, whereby the electrodes 1 are "compacted" and takes on the above described configuration of a square block inside the space 10. In order to ensure that the outer free ends 14 of the electrodes 1 are in alignment, i.e. that they project by the same amount from the respective adjacent end 9 of the retainer 8, a centering station 15 is provided after the transfer station 12 as seen in the direction of arrow C, said centering station including centering means 16 which are arranged to move to and fro in the direction indicated by arrow D by means of drive means, not shown, and which means are arranged to be moved into abutment against the free ends 14 of the electrodes to position the electrode ends in alignment with one another in the way indicated in the aforegoing. After the centering station 15 as seen in the direction of arrow C a winding-on station 17 is provided, comprising a winding device 18 arranged to wrap the bundle 13 of electrodes 1 with the aid of an elastic wrapping material 19. The winding device in accordance with the embodiment shown comprises a stand 20 in the form of an arm one end of which is fixedly attached to a hollow shaft 21, the latter being rotated in the direction of arrow E by a drive means, not shown. At the opposite end, the stand 20 supports a supply 22 of wrapping material 19, in the embodiment shown in the form of a roller. The winding device 18 performs its wrapping action by orbiting the supply 22 of wrapping material 19 around the bundle 13 in one or several turns, usually 3-5 turns, in the longitudinal direction of the bundle 13, as most - clearly apparent from particularly Fig. 1, over and in abutment against the free ends 14 of the electrodes 1, in order to immobilize the electrodes 1 making up the bundle 13 in their relative positions. In this operation, wrapping material 19 is applied also around the retainer 8, more precisely on the retainer guide walls 11, see Figs. 3A-3C. In order to prevent the electrodes 1 of the bundle 13 from moving inside the space 10 of the retainer 8 during the winding-on of the wrapping material 19 about the bundle 13 and the retainer 8, a holding device 31 is provided. The holding device 31 comprises a plate 31 which is coupled to a drive means, not shown, by means of a rod 33 extending through the hollow shaft 21. Prior to the winding-on operation, the drive means is arranged to be activated for the purpose of displacing the plate 32 in a downwards direction by means of the rod 33, into abutment against the upper face of the bundle 13 of electrodes 1, thus holding the electrodes 1 in position during the winding-on operation. When the winding-on is completed, the plate 32 is moved in the opposite direction upwards, away from the upper face of the bundle 13, in order to release the bundle. After the winding-on station 17 as seen in the direction of arrow C, a separation station 23 is provided, including a separator mechanism 24 which is arranged to separate the bundle 13 of electrodes 1, now wrapped and forming a package, from the retainer 8 and transfer the package to a belt conveyor 25 or similar transporting device to be discharged. In accordance with the embodiment shown the separator mechanism 24 comprises pusher means 26 which are arranged to move up and down in the direction indicated by arrow F so as to lift the bundle 13 out of the retainer 8 and lift it to the level of the belt conveyor 25. In the lifting movement, the wrapping material is removed or separated from the retainer and as consequence of the elasticity of the material it clings to the electrodes 1. At the belt level a transfer device 27 including a transfer means 28 is provided, said means arranged to be displaced to and fro in the direction of arrow G by drive means, not shown, to transfer the bundle 13 of electrodes 1 from the pusher means 16 onto the belt conveyor 25. The wrapping material 19 proper is in the form of a film possessing shrinkage and/or tensile properties and consisting of a material adequate for the purpose. When a film possessing shrinking properties is used, it is shrunk into enclosing engagement with the free ends 14 of the electrodes 1 so as to ensure immobilization of the electrodes 1 in an absolute shape-permanent relationship once the packaged bundle 13 has been separated from the retainer 8 in the separating station 23. When this kind of film is used, a source of heat, for example an IR heater or an oven, may be provided in the area of the belt conveyor 25 in order to heat the film to effect shrinkage thereof. On the other hand, when a film possessing tensile properties is used, the film is stretched into enclosing engagement with the free ends 14 of the electrodes 1 in order to provide the immobilization of the electrodes in the absolute, shape-permanent relationship thereof, when the film is wound about the bundle 13 inside the winding-on station 17. Following transfer of the bundle 13 onto the belt conveyor 25 the shape-permanent bundle 13 of electrodes 1 preferably is packaged in an hermetically enclosed and moisture sealed manner in a wrapping that is impervious to air and moisture. The invention must not be regarded as limited to the features shown and described herein but a number of modifications are possible within the scope of the claimed protection as defined in the appended claims.

Claims: A method of packaging a number of bundled welding electrodes (1) of essentially equal lengths, preferably coated electrodes, with the aid of an elastic wrapping material (19), characterized in that in order to form a bundle (13) of electrodes, the latter are placed in a retainer (8) with their external free ends projecting from the retainer in opposite directions and essentially in alignment, that the wrapping material (19) is wound in one or several turns about the bundle in the longitudinal direction thereof and in abutment against the free ends (14) of the electrodes for the purpose of mutually immobilizing the electrodes making up the bundle, and in that the bundle thus packaged is separated from the retainer. A method as claimed in claim 1, characterized in that the electrodes are vibrated inside the retainer, either before their ends have been brought into alignment or during such alignment operation. A method as claimed in claim 1 or 2, characterized in that the wrapping material is wound also about at least part of the retainer or guide means covering the latter, and that it is removed from the retainer or the guide means, when the wrapped bundle is separated from the retainer. A method as claimed in claim 1 or 3, characterized in that the wrapping material is formed by a film possessing shrinking properties, and in that it is shrunk into enclosing engagement with the free ends of the electrodes to ensure the immobilized shape-permanent relative positions of the electrodes after the packaged bundle has been separated from the retainer. A method as claimed in claim 1 or 3, characterized in that the wrapping material is formed by a film possessing tensile properties, and in that it is stretched into enclosing engagement with the free ends of the electrodes to ensure the immobilized shape-permanent relative positions of the electrodes when the film is wound about the bundle. A method as claimed in any one of the preceding claims, characterized in that the bundle is given substantially the shape of a square block. A device for packaging of a number of bundled (13) welding electrodes (1) of essentially equal lengths, preferably coated electrodes, with the aid of an elastic wrapping material (19), characterized by a retainer (8) in which the electrodes (1), designed to form the bundle (13), are insertable in such a manner that the outer free bundle ends project from said retainer (8) in opposite directions and essentially in alignment, by a device (18) for winding the wrapping material (19) in one or several turns about the bundle (13) in the longitudinal direction thereof above and in abutment against the free ends (14) of the electrodes (1) for the purpose of mutually immobilizing the electrodes (1) making up the bundle (13), and by a device (24) for separation of the bundle (13) thus packaged from the retainer (8). A device as claimed in claim 7, characterized by a vibrating mechanism (29) subjecting the retainer (8) and the bundle (13) of electrodes (1) supported therein to vibration in order to make the electrodes assume mutual positions giving a high fill factor, and by centering means (16) which are arranged to be moved into abutment against the outer free ends (14) of the electrodes (1) in order to bring said ends essentially into alignment. A device as claimed in claim 7 or 8, characterized in that the retainer (8) is shorter than the electrodes (1) and in that it comprises a space (10) which is open at least at the ends (9) for application of the electrodes (1), said space giving the bundle (13) of electrodes essentially the shape of a square block. A device as claimed in claim 9, characterized in that the space (10) is limited sidewise by walls (11) around which the wrapping material (19) may also be wound concurrently with the winding of said material about the bundle (13) in the longitudinal direction thereof, and from which walls the wrapping material may be removed, when the packaged and wrapped bundle is removed from the retainer (8). A device as claimed in claim 7, characterized in that the winding device (18) comprises at least one supply (22) of wrapping material (19) which is mounted in a stand (20) and which supply (22) is arranged to orbit about the retainer (8) with a bundle (13) therein in the longitudinal direction of the latter in order to wind the wrapping material (19) around the bundle. A device as claimed in claim 7, characterized in that the winding device comprises at least one supply of wrapping material which is mounted in a stand, and in that the retainer (8) with the bundle (13) of electrodes (1) therein is arranged to be rotated past the supply in order to wind on the wrapping material (19) about the bundle in the longitudinal direction thereof. A device as claimed in claim 7, characterized in that the separating means (24) comprises pusher means (26) arranged to be moved into abutment against the bundle (13) of electrodes (1), said pusher means preferably being positioned on either side of the retainer (8).

Inventors: BERNIN GUILLERMO, BERNIN, GUILLERMO
Applicants: ESAB AB, ESAB AKTIEBOLAG
Application year: 1992
Main classification: B65B11
IPC codes: B65B19, B65B11