scispace - formally typeset
Search or ask a question

Showing papers on "Butt welding published in 1989"


Journal ArticleDOI
TL;DR: In this paper, a single pass girth butt welding of a carbon-manganese pipe is studied numerically using the finite element codes ADINAT/ADINA, and a rotationally symmetric finite element model is employed in both the thermal and mechanical analysis.
Abstract: Single‐pass girth butt welding of a carbon‐manganese pipe is studied numerically using the finite element codes ADINAT/ADINA. A rotationally symmetric finite element model is employed in both the thermal and mechanical analysis. This model is used to investigate the influence on the residual stress state of pipe geometry, mesh density and material modelling. The results from the present study are compared with previous results from two different FE analyses and an experimental investigation. One of the FE analyses was fully three dimensional and the other employed shell elements. The calculated residual stresses were found to differ significantly only when different material models were employed. The thermal strain seemed to be the material parameter with the largest influence on the residual stress state. Especially the changes in thermal strain during phase transformations seemed to have a great influence. This means that the temperature field should be determined accurately enough to predict when and where the different phase transformations occur. Almost the same residual stresses were obtained for two pipes with different pipe geometries and weld parameters.

47 citations



Journal ArticleDOI
TL;DR: In this paper, a study of vibration butt welds between plaques of polypropylene has been made and the quality of the welds, as determined by impact tests, has been examined as a function of the welding variables: pressure and vibration amplitude.
Abstract: A study has been made of vibration butt welds between plaques of polypropylene. The quality of the welds, as determined by impact tests, has been examined as a function of the welding variables: pressure and vibration amplitude. In addition, the microstructure of the welds has also been examined, classified, and correlated with the welding variables and weld quality. Penetration as a function of time shows three distinct regimes and It is shown that the impact strength of the welds is independent of time once the third regime is reached. The time required to reach the third regime decreases as pressure or amplitude increases and is more sensitive to amplitude of vibration than to pressure. The highest quality welds were produced at low pressure and low amplitude with corresponding long times to reach regime three and exhibited a unique, readily identifiable microstructure.

37 citations


Patent
04 May 1989
TL;DR: In this paper, a welding machine for butt welding of plastic profiles is outfitted with profile clamping units (2, 3) capable of sliding in relation to each other, and a heat reflector (15) which can be introduced between the front surfaces of two profiles to be welded.
Abstract: A welding machine for butt welding of plastic profiles is outfitted with profile clamping units (2, 3) capable of sliding in relation to each other, and a heat reflector (15) which can be introduced between the front surfaces of two profiles to be welded, whereby the clamping units (2, 3) comprise weld boundary blades (2b, 2f, 3b, 3f) aligned parallel to the profile front surfaces and mounted on the profiles. In order to enhance welding efficiency and produce precisely coordinated weld joints, the clamping units (2, 3) are designed to accommodate two superimposed profiles (U, O), and feature in addition to the external boundary blades (2b, 2f, 3b, 3f) an intermediate boundary blade (5, 6) insertable between the profiles (U, O), yielding elastically in the clamping direction of the profiles and moving along with the clamping units (2, 3) in the direction of displacement.

27 citations


Patent
10 Mar 1989
TL;DR: In this article, an electric welding apparatus for automatically welding heating coil fittings substantially of plastic material is described, where a scanner for scanning fitting data is connected via a converter to a first input of a controller (8) which via a power station (13) controls, for a welding period, the welding power output.
Abstract: In an electric welding apparatus for automatically welding heating coil fittings substantially of plastic material a scanner (3) for scanning fitting data is connected via a converter to a first input of a controller (8) which via a power station (13) controls, for a welding period, the welding power output. In order to reach an optimal welding factor of the welding the scanner (3) and the converter (4) are provided for scanning naominal welding energy data of said fitting (1). At least a second input (at 12) of the controller (8) is connected to circuits (calculator 11) which generate signals of the actual welding energy from welding power output data as well as from the actual welding period.

20 citations


Journal ArticleDOI
TL;DR: In this paper, the different process phases are described by means of dimensionless characteristic parameters that have been obtained by applying similarity principles to heated-tool butt welding, and the best weld quality is attained when the welding parameters are selected such that identical sheaf deformations result in the joint zones of small and large pipes.
Abstract: In order to achieve high fatigue strengths in heated-tool butt welds in plastic pipes used in gas and water supply lines, it is essential that optimum welding parameters be selected. In this paper, the different process phases are described by means of dimensionless characteristic parameters that have been obtained by applying similarity principles to heated-tool butt welding. On the basis of strength studies conducted on welded Joints, it is shown that the best weld quality is attained when the welding parameters are selected such that identical sheaf deformations result in the joint zones of small and large pipes. Laws for scaling data from small-pipe to large-pipe welds are then based on the values of these nondimensional numbers.

18 citations


Journal ArticleDOI
TL;DR: In this article, a computer-controlled heated-tool butt welding machine is used to determine the parameters of the welding process and a simple new method for determining these parameters is presented.
Abstract: Welding represents one of the key stages in the manufacture of injection molded or blow molded plastics products. One process frequently employed is heated-tool butt welding. However, the high seam quality associated with this process can only be attained through reliable process control and optimized welding parameters. This paper presents a simple new method for determining these parameters. Mathematical and physical descriptions of the individual process stages and a computer-controlled heated-tool butt welding machine serve as the basis for determining the parameters.

17 citations


Patent
30 Jan 1989
TL;DR: In this paper, the welding device for deep-drawn pressed parts has two slides (2, 3) on whose supports (4, 5) interchangeable contour beds (11, 12) are arranged, the clamping surface of which corresponds to the desired spatial form of the pressed parts (6, 7) to be welded.
Abstract: Flat thin plates as well as thin plates formed by deep drawing are needed in the manufacture of motor vehicle bodies and other vehicle components. The joining of two plates by laser welding at their edges imposes high demands on the dimensional and positional accuracy of the plates to be welded and on the guidance accuracy of the laser. First of all the two plates to be welded are restrained in a fixed manner with their edges in alignment and are positioned with a distance between the two facing edges (9, 10) to be welded. A track-guided laser head (13) or two laser heads track-guided together then trim the two plate edges (9, 10). The two laser-trimmed plate edges are then brought together until they abut by displacing at least one of the plates restrained in a fixed manner; a laser head (9) controlled by the same track guidance then welds the two plate edges (9, 10) together. The welding device for deep-drawn pressed parts has two slides (2, 3) on whose supports (4, 5) interchangeable contour beds (11, 12) are arranged, the clamping surface of which corresponds to the desired spatial form of the pressed parts (6, 7) to be welded.

17 citations


Book ChapterDOI
01 Jan 1989
TL;DR: In this article, the development of stresses and strains during butt welding of a thin walled pipe is followed numerically by use of the finite element method (FEM) and, in parallel, measured experimentally.
Abstract: The development of stresses and strains during butt welding of a thin walled pipe is followed numerically by use of the finite element method (FEM) and, in parallel, measured experimentally. Three different FE-models of the pipe, one fully three dimensional, one rotationally symmetric and one shell type, were used in the numerical part of the study. For all three models the pipe material was taken as thermo-elasto-plastic with strongly varying temperature dependent material properties. Calculated results for the weld metal and HAZ were found to be heavily dependent on the constitutive modelling of the final phase transformation. The qualitatively best agreement with the experiments for the residual stress field was obtained with a simplified FE-model which did not consider such effects. During welding, the transient stress field was found to be strongly rotationally nonsymmetric.

14 citations


Patent
28 Jul 1989
TL;DR: In this article, an automatic welding of plastic parts possessing a built-in winding is described, which is used particularly for the production of systems for the distribution of gas under pressure by means of plastic pipelines.
Abstract: The invention relates to the automatic welding of plastic parts possessing a built-in winding. In order to carry out an automatic welding operation without risking damaging the parts by subjecting them to an excessive welding temperature, there are regulating means for varying the electrical energy supplied to the winding, in order, during the welding phase, to maintain the temperature of the winding between a minimum temperature, below which welding cannot be carried out, and a maximum temperature, beyond which the parts will be damaged. The invention is used particularly for the production of systems for the distribution of gas under pressure by means of plastic pipelines.

14 citations


Patent
07 Nov 1989
TL;DR: In this paper, the welding head assembly is arranged on a centering system made up of gripping clamps (1,2) which each hold a tube and adjustment devices (4,5,6) which can move one tube with respect to the other in the x, y and z directions.
Abstract: Welding appts. for joining two tubes together consists of a welding head assembly (15,16) arranged on a centering system made up of gripping clamps (1,2) which each hold a tube (12) and adjustment devices (4,5,6) which can move one tube with respect to the other in the x, y and z directions. ADVANTAGE - The positioning of the tubes with respect to each other can be remote controlled followed by remote controlled welding.

Patent
05 Oct 1989
TL;DR: In this article, the sheet-metal parts are held with a projecting border in the weld area in an overlapping, positionally defined manner relative to one another and are simultaneously trimmed in a common trimming cut by means of a laser beam which is guided along the subsequent weld path.
Abstract: In this method, the sheet-metal parts are held with a projecting border in the weld area in an overlapping, positionally defined manner relative to one another and are simultaneously trimmed in a common trimming cut by means of a laser beam which is guided along the subsequent weld path. After the cut-off borders are removed, the sheet-metal parts are positioned with their surfaces in alignment and with their ends abutting and, with otherwise unaltered mounting, are butt-welded along the component joint likewise by means of a laser beam. So that the edges of the sheet-metal parts can abut against one another with direct contact preferably without displacement of the sheet-metal parts in the sheet-metal plane, the trimming cut is carried out with the beam axis guided at an angle. The welding can possibly be carried out with the same beam head, if need be even at the same beam inclination, even if with altered machining conditions. Defocussing and/or superimposition of an oscillating or circular movement is not absolutely essential thanks to the minimised joint gap. The installed beam energy can be optimally utilised for the welding and in addition the heat input per unit of length of weld can be reduced.

Patent
29 Sep 1989
TL;DR: In this article, a butt welded and lined flange connector allows the joining of pipe sections lined with a brittle material, and a conventional flange face gasket is modified to protrude into the lined zone to perform a dual sealing function.
Abstract: A butt welded and lined flange connector allows the joining of pipe sections lined with a brittle material. Spacing and a sleeved liner at the weld end protects the liner during butt welding. A conventional flange face gasket is modified to protrude into the lined zone to perform a dual sealing function. Like conventional flanged joints, the modified gasket forms a seal sandwiched between the flange interface surfaces. However, departing from current practice, the single gasket also fills the gap and seals the liner edges, protecting the pipe sections from the flowing materials. The invention avoids separate putty-like or elastomeric liner seals as well as exotic liner surface configurations. The present invention is expected to be tolerant of severe conditions and cost effective in many applications.

Patent
11 May 1989
TL;DR: In this article, an induced current is generated on the open pipe 1 inserted into a work coil 52 for heating by applying a current of prescribed frequency to the coil 52 by the first heating power source 51.
Abstract: PURPOSE: To suppress the quantity of a bead discharged and to improve machinability of the bead and to improve working efficiency by heating both side edge parts of an open pipe up to the temperature above the Curie point by a first heating power source. CONSTITUTION: An induced current is generated on the open pipe 1 inserted into a work coil 52 for heating by applying a current of prescribed frequency to the coil 52 by the first heating power source 51. The vicinities of both side edge parts 1a and 1a of the open pipe 1 are preheated up to the temperature above the Curie point by the induced current. The current is then applied to a work coil 62 for welding by a second heating source 61 and both side edge parts 1a and 1a are heated up to the temperature above the sufficient melting temperature. Both edges 1a and 1a are then subjected to butt welding between squeeze rolls 3 and 3 to obtain the title resistance welded tube. By this method, the quantity of the bead discharged is suppressed and machinability of the bead is improved and working efficiency is improved. COPYRIGHT: (C)1990,JPO&Japio

Patent
22 Mar 1989
TL;DR: In this paper, a transformer is used to connect the welding transformer to the electrodes located on the other side of the welding plane and close the welding current circuit for single spot welding.
Abstract: A convertible single or double spot welding machine operating by the electrical resistance method for producing grids or bar grates by single spot welding or double spot welding, has a transverse row of electrodes and at least one welding transformer on one side of the welding plane. Electrically conductive connections, which pass through the welding plane, connect the welding transformer to the electrodes located on the other side of the welding plane and close the welding current circuit for single spot welding. In order to convert from single spot welding to double spot welding, the connections which pass through the welding plane are removed, selected electrodes on the side of the welding plane remote from the welding transformer are connected in pairs by current bridges, and the supply lines from the welding transformer are respectively connected to the two electrodes opposite the electrodes connected by the current bridges.

Patent
23 May 1989
TL;DR: In this paper, a workpiece manipulator is used for welding fan wheels for welding ventilation and industrial fans, where the correspondingly shaped parts (1, 2, 3) of the fan wheels are stapled and after removal of the upper part of the clamping device (31, 30, 29) to be welded.
Abstract: When welding fan wheels expensive auxiliary are usually elements for positioning and locking the parts of the wheel or special tools to manufacture the parts of the Radesbenotigt. The effort is great in all cases. The invention will enable Her position large quantities of welded impellers with ge little effort. For this purpose, the welding of the fan wheels is performed on a workpiece manipulator (48), wherein the correspondingly shaped parts (1, 2, 3) of the fan wheels in a two-part clamping device initially stapled and after removal of the upper part of the clamping device (31, 30, 29) to be welded. The inventive method is used for welding of ventilation and industrial fans.

Patent
31 Jul 1989
TL;DR: In this article, the authors proposed a method to prevent cracking of a weld zone by reducing the welding speed at the starting end, once finishing welding just before the finishing end, then, welding the end end at the speed lower than that at the stationary time from the reverse direction and setting meeting port where welding finishing ends are superposed on each other at a part where machining strain is reduced.
Abstract: PURPOSE:To prevent cracking of a weld zone by reducing the welding speed at the starting end, once finishing welding just before the finishing end, then, welding the finishing end at the speed lower than the welding speed at the stationary time from the reverse direction and setting meeting port where welding finishing ends are superposed on each other at a part where machining strain is reduced. CONSTITUTION:At the time of welding the starting end, since the welding speed is lower than that at the stationary time, a projecting part is formed on the end face. After passing the starting end, the welding speed shifts to the stationary speed and a joining part is welded. Just before the finishing end, welding is once finished and then, this finishing end is welded at the speed lower than that at the stationary time from the reverse direction. A projecting part can be formed on the finishing end in the same way as on the starting end. In addition, it is considered that weld defects are easily caused on meeting part where the welding finishing end at the time of forward welding and the welding finishing end at the time of backward welding are superposed on each other and the occurrence of cracking in accordance with forming machining is feared and the position of can be set at the part where machining strain at the time of forming is reduced. By this method, cracking from the weld zone can be surely prevented.

Journal ArticleDOI
TL;DR: In this paper, Magnetically impelled arc butt welding of aluminium pipes is described and compared to the traditional arc-butt welding of aluminum pipes. But the welding process is different.
Abstract: (1989). Magnetically impelled arc butt welding of aluminium pipes. Welding International: Vol. 3, No. 11, pp. 941-946.

Journal ArticleDOI
TL;DR: In this article, the welding defects are divided into two types, i.e., the crack-like defect and the uncrack-like defects, based on the experimental and analytical results, and the criterion for distinguishing the defect type is tentatively proposed.

Patent
18 Aug 1989
TL;DR: In this article, a sound-insulating layer applied to a profile by injection molding consists of a thermoplastic elastomer, and the profile can be severed in the region of the sound insulating layer and joined together by butt welding.
Abstract: of EP0357551The profile (1) has a body (3) made of thermoplastic. A sound-insulating layer (4) applied to this body (3) by injection moulding consists of a thermoplastic elastomer. The body (3) projects at its ends from the sound-insulating layer (4). Welding sleeves (2) are welded on to these non-coated regions (5) of the body (3). In the event of a repair, the profile (1) can also be severed in the region of the sound-insulating layer (4) and joined together by butt welding. The thickness of the sound-insulating layer (4) is comparatively small.

Patent
18 Sep 1989
TL;DR: In this article, the authors proposed a method to monitor the quality during welding and to improve the quality of a weld zone by repeatedly performing the welding by a laser beam until the blue flame by the laser welding is observed over the whole length of the butt weld line of a thin sheet.
Abstract: PURPOSE:To monitor the quality during welding and to improve the quality of a weld zone by repeatedly performing the welding by a laser beam until the blue flame by the laser welding is observed over the whole length of the butt weld line of a thin sheet. CONSTITUTION:In case of the gap 2 between the butt 1a, 1a of thin sheet 1, 1 exceeding the allowable value of one pass welding a laser beam 7 reaches up to the back face side of the thin sheet 1, 1, the lower part is melted and the lower part of the gap 2 is filled. At this time no blue flame is generated. After one pass completion the gas 2 becomes narrow by the heat contraction. With further laser welding the whole body is remelted and a stabilized blue flame is generated because the gap 2a of the butt part is made narrow at this time. Good butt laser welding can be executed by repeatedly projecting the laser beam 7 until the blue flame is observed over the whole length of the butt weld line like this.

Patent
18 Apr 1989
TL;DR: In this paper, the authors proposed a method to prevent a joined part between belt-like metal plates from rupturing while being conveyed by subjecting a wide beltlike metal plate and a narrow metal plate to butt welding and rolling the joined part and trimming an end of the wide part of the same width as the narrow one.
Abstract: PURPOSE:To prevent a joined part between belt-like metal plates from rupturing while being conveyed by subjecting a wide belt-like metal plate and a narrow belt-like metal plate to butt welding and rolling the joined part and trimming an end of the wide belt-like metal plate to a linear part of the same width as the narrow belt-like metal plate. CONSTITUTION:The belt-like metal plate 10 is rewound from a roll 12 and its tip is cut by a pre-cutting device 18. It is then abutted or superposed on the rear of the belt-like metal plate 22 and welded together with welding equipment 24. A welded zone 40 between the belt-like metal plates 10 and 22 is then rolled by an action of a rolling roller 34 of a rolling device 32. In addition, an edge trimming device 42 is provided to the rear stage of the rolling device 32 and the welded zone of the wide belt-like metal plate 22 is trimmed to the linear part and a tapered part. Further, since a butt part or a superposed part between the belt-like metal plates 10 and 22 is cut with a gradient of an angle theta to the width direction of the belt-like metal plates, strength of the welded and joined zone 40 is improved. In addition, the welded zone 40 is rolled by the rolling device 32 and the difference in level is reduced and the belt-like metal plates 10 and 20 are transferred smoothly to a pass roller and conveyed thereby. Accordingly, there is no fear of rupturing in the belt-like metal plates 10 and 22.

Patent
22 Nov 1989
TL;DR: In this paper, the authors proposed a method to prevent the development of blow hole by using a wire containing the specific quantity or more of Cu and brazing under argon gas atmosphere in the method joining galonized, steel plates under superposing or butting plural pieces with laser beam heating source or plasma heat source.
Abstract: PURPOSE: To prevent the development of blow hole by using a wire containing the specific quantity or more of Cu and brazing under argon gas atmosphere in the method joining galonized, steel plates under superposing or butting plural pieces with laser beam heating source or plasma heat source. CONSTITUTION: By using a plasma welding machine, the galanized steel plates 1 are joined with a butt joint by using the wire containing ≥ 60% Cu. The brazing layer 1a is made at the joined part 10. In the case of using the plasma welding machine, the galvanized steel plate as the base material and the wire are heated by arc generated with W electrode. In the case of being the prescribed welding condition and the prescribed or lower welding current, the brazing is executed without existence of diffusion layer and in the case of being more than the prescribed welding current, the liquid phase diffusion brazing is executed. This plasma welding is executed under shield gas atmosphere of argon gas. By this method, the development of blow hole is prevented and the joined part having extremely good outward appearance can be obtd. COPYRIGHT: (C)1991,JPO&Japio

Patent
22 Apr 1989
TL;DR: In this paper, a cut-off part to insert Ti insert material and a groove angle was proposed to prevent fusion of Ti and base metal steel and to perform welding without a Ti backing plate.
Abstract: PURPOSE: To prevent fusion of Ti and base metal steel and to perform welding without a Ti backing plate by specifying a cut-off part to insert Ti insert material and a groove angle. CONSTITUTION: At the time of cutting off completely a part of Ti cladding material 1-2 of a butt part to provide a groove 13 thereon, the groove 13 having depth slightly deeper by t 3 than thickness of the cladding material 2-2 and besides, having 20-40mm bottom width l 1 of the cut-off part 10 of steel base metal 1-1 and 20-60° angle θ 2 is provided. In addition, the Ti insert material 11 to be inserted into the Ti cut-off part 10 is formed so that there is no clearance between the bottom and the steel base metal 1-1 and besides, the interval between both sides and the cut-off part end face of the Ti cladding material 1-2, namely, the Ti side groove 13 is made in a mouth-opened shape. At the time of welding, a single-V groove 14 formed on one side of the steel base metal 1-1 is first welded and then, the Ti insert material 11 is inserted into the Ti cladding material cut-off part 10 and the groove 13 formed by the insert material 11 and the Ti cladding material 1-2 is welded to complete butt welding of the title clad steel plate 1. COPYRIGHT: (C)1990,JPO&Japio

Patent
18 Jan 1989
TL;DR: In this article, an automatic welding operation without risking damaging the parts by subjecting them to an excessive welding temperature was carried out, where regulating means for varying the electrical energy supplied to the winding, in order, during the welding phase, to maintain the temperature of the winding between a minimum temperature, below which welding cannot be performed, and a maximum temperature, beyond which the parts will be damaged.
Abstract: not available for EP0299833Abstract of corresponding document: US4918292The invention relates to the automatic welding of plastic parts possessing a built-in winding. In order to carry out an automatic welding operation without risking damaging the parts by subjecting them to an excessive welding temperature, there are regulating means for varying the electrical energy supplied to the winding, in order, during the welding phase, to maintain the temperature of the winding between a minimum temperature, below which welding cannot be carried out, and a maximum temperature, beyond which the parts will be damaged. The invention is used particularly for the production of systems for the distribution of gas under pressure by means of plastic pipelines.

Patent
28 Apr 1989
TL;DR: The linear vibration welding process can be divided into several phases and the quality of the weld depends on which phase is achieved during the vibration and the conditions prevailing in the process phase as discussed by the authors.
Abstract: The linear vibration welding, the welding process can be divided into several phases. The quality of the weld depends on which phase is achieved during the vibration and the conditions prevailing in the process phase (3) of the vibration. According to the invention the machine is provided with a measuring and regulating system (Figure 5) for the joining path in order to determine the reaching of the process phase (3) in a simple manner and carry out a control of the joint rate in this phase.

Book ChapterDOI
01 Jan 1989
TL;DR: In this article, the authors described two types of rail fatigue which occurred in connection with residual stress at the joint area in railway track, i.e., upper fillet crack and horizontal web failure.
Abstract: This paper described two types of rail fatigue which occurred in connection with residual stress at the joint area in railway track. One is the “Upper fillet crack” on head hardened rails, it has been often observed at the bolted joint of rail in subway tracks in Japan. The other is the “Horizontal web failure”, which is often found at the flash butt welds in high strength rails subjected to high axle load as a mine track. In Order to analyze the cause of these rail failures, not only fractographic and metallurgical analysis of failures were conducted in the laboratory. (1) The initiation and propagation of the upper fillet crack which was observed at the bolted joint area in the subway track is caused by the so-called fretting fatigue with the aid of the tensile residual stress on the upper fillet surface of head hardened rails. (2) Head hardened rails the residual stress of which were controlled from tensile to compressive on the upper fillet no failure occurred. (3) The horizontal web failure, which have occurred at the flash butt welded joint in the track occured by failure due to running wheels. The failure is mainly caused by high tensile residual stress in the web of rails near welds by flash butt welding. (4) Decrease in tensile residual stress or change to compressive residual stress at the welded joint prevents completely the occurrence of horizontal web failure, even if there are some notch-like defects on the welds.

Journal ArticleDOI
TL;DR: In this paper, the authors present a method for ultrasonic testing of thin-walled (10-20 mm) austenitic welds, which is based on the existence of mode conversion between shear and longitudinal waves.

Patent
21 Jun 1989
TL;DR: In this article, the utility model relates to a clamp for gas pressure welding of reinforcing bar whose body is a rectangle, belonging to a welding tool, and the advantages that the welding quality is improved because the concentricity of the steel bar is guaranteed.
Abstract: The utility model relates to a clamp for gas pressure welding of reinforcing bar whose body is a rectangle, belonging to a welding tool. In the clamping chuck of the clamp for gas pressure welding of reinforcing bar, a pressure plate is connected by an adjusting threaded rod and adjusting nuts; the butt welding steel bar is clamped by a compression threaded rod and compression nuts. The utility model has the advantages that the welding quality is improved because the concentricity of the steel bar is guaranteed; the welding efficiency is improved because of the fast speed of the loading and unloading of the steel bar; the steel bar with different diameters can be welded depending on the action of the adjusting nuts and the adjusting threaded rod.

Patent
16 Feb 1989
TL;DR: In this article, a butt welding seam is provided as welding seam between semi-finished plastic products, in particular plastic sealing sheets, which runs at an angle of inclination of less than 45° with respect to the parts joined together.
Abstract: According to the invention a butt welding seam is provided as welding seam between semi-finished plastic products, in particular plastic sealing sheets, which runs at an angle of inclination of less than 45@ with respect to the parts joined together.