WELDING MACHINE AND METHOD FOR THERMALLY JOINING MATERIAL WEBS

Description

[0001] The present invention relates to an automatic welding machine for thermally joining material webs. The present invention further relates to a corresponding method for thermally joining material webs.

[0002] Automatic welding machines for thermally joining material webs are generally known from the prior art. Such welding machines are used, for example, for thermally joining or welding thermoplastic material webs, such as plastic films or plastic or bitumen sheets, along their overlapping edge regions. In addition to a drive and at least one hot air unit or a hot wedge device, such welding machines have a chassis with one or more drive rollers, pressure rollers, and / or support rollers, or a combination thereof. During the automatic welding process, the welding machine moves over a substantially flat (surface) surface on which the materials to be welded are welded by the welding machine.In the case of hot-air welding, at least one hot-air nozzle, located at the hot-air outlet of a hot-air unit of the welding machine, is guided between the overlapping edge regions of the materials to be welded in a welding zone in order to plasticize the materials in the welding zone by applying heat. Subsequently, the plasticized areas of the materials are pressed together, creating a positive connection, for example, by a pressure roller arranged downstream of the hot-air nozzle in the working direction or direction of movement of the welding machine.

[0003] DE 20 2018 101 429 U1 discloses an automatic welding machine for edge-welding flat, thermoplastic materials, comprising a housing, at least one drive and at least one hot air unit for heating the materials to be welded in a welding area, wherein the hot air unit is arranged on the automatic welding machine in such a way that the hot air unit is rotatable about an axis aligned parallel to the transverse axis of the housing and displaceable along this axis.

[0004] To increase stability, especially against lateral tipping, ground-level hot-air welding machines often have additional support wheels that are spaced as far apart as possible. An example of this type of welding machine is described in EP 3 028 836 B1. In certain applications close to edges (roof parapets, etc.), these support wheels sometimes get in the way or prevent welding close to the edge. Therefore, the two side support wheels in EP 3 028 836 B1 are fixed together on a movable support and can thus be moved together to one side or the other of the machine, depending on the welding task.

[0005] According to the abstract, EP 3 028 836 B1 discloses an automatic welding machine for the edge-to-edge joining of material webs that overlap at the edge and can be joined to one another by means of heat and subsequent pressure, comprising a chassis on which at least rollers, a heating device, and at least one pressure roller are arranged. The heating device has a laterally projecting contact heating element that can be inserted between the edges of the material webs, wherein the chassis is driven by an electric motor arranged on a longitudinal leg of the chassis. According to the invention, the electric motor is designed as a brushless DC motor and the reduction gear as an epicyclic gear, which are combined to form a drum drive motor. The DC motor is preferably a disc motor.

[0006] The chassis in EP 3 028 836 B1 has a cross leg that is adjustable relative to the longitudinal leg perpendicular to the working direction of travel. This allows the entire cross leg with the non-driven rollers to be moved laterally relative to the longitudinal leg on which the heating device and the control system of the automatic welding machine are arranged and to which the drum drive motor carrying the drive roller is attached. The shape of the chassis can thus be changed, from a first L-shaped variant in which the cross leg only protrudes to the left beyond the longitudinal leg in the working direction of travel, via T-shaped variants in which the cross leg extends to the left and right beyond the longitudinal leg, to a second L-shaped variant in which the cross leg only protrudes to the right beyond the longitudinal leg in the working direction of travel.This advantageously enables welding close to the edge along upstands or bevels of the support surface carrying the material webs, e.g. upwardly extending wall, door, shaft or parapet connections and flat end edge finishes of flat roofs.

[0007] US 2008 / 0066870 A1 discloses a welding device for joining laterally overlapping sealing sheets.

[0008] US 5 234 533 A discloses a portable hot air welding device for material webs.

[0009] US 6,187,122 B1 discloses an apparatus for welding roof membranes with two weld seams and methods for using the same.

[0010] Against this background, one object of the present disclosure is to provide a further improved automatic welding machine for thermally joining material webs. In particular, it would be desirable to provide an automatic welding machine that is easy to handle and / or reduces maintenance costs. Furthermore, it would be desirable to reduce manufacturing complexity.

[0011] According to a first aspect of the present disclosure, an automatic welding machine for thermally joining material webs, in particular for edge-to-edge joining of an overlapping upper material web to a lower material web, which can be joined together in a material-to-material manner under the influence of heat and subsequent application of pressure, is provided, comprising: a heating device for at least partially heating the material webs to be joined in a joining region; a support frame with a housing; a pressure roller; at least two casters; wherein the pressure roller and the casters are arranged on the support frame and, together with the support frame, form a chassis, wherein the chassis has a longitudinal axis and a transverse axis perpendicular thereto, which define a chassis plane;wherein at least a first caster of the two casters is arranged to be movable relative to the support frame by means of a telescopic extension in directions parallel to the transverse axis. The first caster and the heating device can be arranged on opposite sides of the chassis with respect to a longitudinal center of the chassis. The telescopic extension has an axle, wherein the first caster is fixedly attached to the axle of the telescopic extension, wherein the axle is pulled out of the housing of the support frame in an extended state and received by the housing of the support frame in a retracted state; and wherein the elements of the telescopic extension are pushed into one another.

[0012] According to a further aspect of the present disclosure, a method for thermally joining material webs, in particular for edge-to-edge joining of an overlapping upper material web to a lower material web, which can be joined to one another in a material-to-material manner under the influence of heat and subsequent application of pressure, is proposed, comprising the steps of: providing an automatic welding machine as described in the context of the present disclosure; transferring the heating device for at least partially heating the material webs to be joined in a joining region from a rest position to a working position by means of the telescopic extension; and thermally joining the material webs to the automatic welding machine.

[0013] Accordingly, in the automatic welding machine for thermally joining material webs according to one aspect of the present invention, it is proposed to provide a telescopic extension which can be extended in a direction parallel to the transverse axis. The movement with the telescopic extension takes place in that the elements of the telescopic extension are pushed into one another. A first roller of the two rollers is arranged on the telescopic extension. A first telescopic extension for the heating device and a second telescopic extension for the first roller can also be provided. By means of a telescopic extension, the first roller of the two rollers can be moved in a direction parallel to the transverse axis. Accordingly, the heating device can be moved in a direction parallel to the transverse axis by means of a telescopic extension. The telescopic extension is arranged and designed in such a way that a displacement of the first roller transverse to a longitudinal axis, i.e. transverse to a working direction orFeed direction of the automatic welding machine during the thermal joining of material webs. The telescopic extension can have a holder fixedly arranged on or in the support frame of the automatic welding machine, into which holder a shaft of the telescopic extension is (fully) inserted. This protects the shaft of the telescopic extension from the holder when retracted. The inventors have recognized that the use of a telescopic extension is particularly advantageous in an automatic welding machine for the thermal joining of material webs, as maintenance effort can be reduced. In the retracted state, the shaft of the telescopic extension can be protected from contamination. Furthermore, corrosion of exposed elements can be avoided. This can reduce the susceptibility to repair and increase the reliability of the automatic welding machine.

[0014] A further advantage of the proposed solution is that, thanks to a telescopic extension extending into the housing of the welding machine, additional components can be protected and located inside the housing. For example, a start-up switch for activating a drive of the welding machine can now be relocated inside the housing. This allows this additional component to be better protected and its reliability further increased.

[0015] A further advantage of the proposed solution is that it enables simple, ergonomic retraction. Furthermore, handling can be improved by eliminating any rigid axles protruding from the welding machine thanks to the telescopic extension. This can also increase work safety, as an operator cannot get caught on a protruding element.

[0016] In the context of the present disclosure, a telescopic extension can be understood as a longitudinally extendable device comprising two or more coaxially nested elements. Each of the inner telescopic parts can be axially extended from the next larger one, which therefore directly accommodates it. In other words, this is not merely a displacement of a rigid axis, but rather a telescoping of elements, with the longitudinal extension being reduced when nested.

[0017] The telescopic extension has an axle (also referred to as a shaft in the present disclosure), wherein the first castor is fastened to the axle of the telescopic extension, wherein the axle is pulled out of the housing of the support frame in an extended state and is received by the housing of the support frame in a retracted state, in particular is completely received or completely pushed into the housing of the support frame. In that the first castor is fastened to the axle of the telescopic extension, the movement thus occurs together with the axle of the telescopic extension. It is understood that the fixed connection can be released, for example, for maintenance purposes. The axle is in turn pushed into the housing of the support frame and is preferably completely received by it. This protects the axle from contamination and can prevent corrosion. This can reduce maintenance costs.In particular, when the heating device is operated in the retracted state, the susceptibility to repairs can be reduced, since the axis is retracted into the housing in the working position, i.e. during the welding process, and is therefore less susceptible to corrosion and dust accumulation.

[0018] The heating device can be arranged so as to be rotatable relative to the support frame about an axis parallel to the transverse axis, wherein the heating device can be axially and rotationally fixed relative to the support frame at least in a first axial and rotational position and can be fixed at least axially relative to the support frame in a further, second axial and rotational position, which is at least axially different from the first position. The axis can be an axis of the further telescopic extension to which the heating device is attached. The first position can be a rest position of the heating device. In the rest position, the heating device can be fixed in a fixed rest position both in the axial direction and with regard to rotation about the axis. The second pose can be a working position of the heating device. In the working position, the axis with the heating device is primarily axially locked.However, a rotational movement can still be enabled, at least over a limited angular range. This allows the working height of a heater's outlet nozzle to adapt to the surface, or allows for the flexible attachment of different outlet nozzles to a heater. In the case of a heating wedge device, different heating wedges can be used flexibly.

[0019] In one embodiment, the heating device can be arranged on the support frame by means of a further telescopic extension. The further telescopic extension can have a bearing fixed to the support frame and a shaft. The shaft can extend between a first axial shaft end and a second axial shaft end along a shaft axis parallel to the transverse axis, wherein the second axial shaft end is the axial shaft end facing away from the housing. The shaft can be mounted on the bearing so as to be movable along the shaft axis and rotatable about the shaft axis. The heating device can be arranged on the shaft in a region of the second axial shaft end.

[0020] To secure the heating device in the first pose and / or in the second pose, the shaft can be releasably fixed to the bearing by means of a locking device of the bearing. The locking device can have at least one locking bolt, wherein the locking bolt is aligned in the direction of a locking axis intersecting the shaft axis perpendicularly and is movable in the direction of the locking axis, and wherein the shaft can be fixed at least in the first pose and / or in the second pose by an at least partial engagement of the locking bolt radially to the shaft axis into the shaft. In this case, the locking bolt can be acted upon by a spring force in the direction of the shaft axis. To enable a limited rotational movement in the second pose in a working position, the shaft can have a longitudinal hole for engagement of the locking bolt.

[0021] A handle lever can be arranged at the second axial shaft end. The handle lever and the further telescopic extension can be configured to provide manual rotation of the shaft about the shaft axis. The handle lever and the further telescopic extension can be configured to provide manual displacement of the shaft in directions along the shaft axis. The handle lever and the further telescopic extension can be configured to provide manual release of a fixation of the shaft from the bearing.

[0022] In a further development, a coaxial bolt can be accommodated in an interior of the shaft of the further telescopic extension, wherein the coaxial bolt extends at least partially through the shaft parallel to the shaft axis, wherein the coaxial bolt is movable in directions relative to the shaft axis, wherein the locking bolt can be brought at least partially (into engagement and / or) into engagement with the coaxial bolt at least at the first position and / or the second position, and wherein the locking bolt can be brought (out of engagement and / or) out of engagement with the coaxial bolt by a movement of the coaxial bolt in a direction along the shaft axis relative to the shaft. In particular, the coaxial bolt can be designed such that the locking bolt can be removed from engagement with the coaxial bolt by a longitudinal movement of the coaxial bolt in the direction of the shaft axis.In other words, the locking of the shaft axis by the locking bolt can be released by the longitudinal movement of the coaxial bolt within the shaft axis. This allows the locking bolt to be actuated in a simple manner. Such a defined actuation of the locking bolt can preferably reduce mechanical stress and, for example, prevent the locked bolt from breaking off. A further advantage can thus be improved reliability.

[0023] The coaxial bolt can protrude beyond the second shaft end from the shaft with an axial end, wherein the handle lever is arranged at this axial end of the coaxial bolt, wherein a spring element is clamped between the handle lever and the second shaft end, wherein a stop inside the shaft in combination with a counter-stop of the coaxial bolt limits movement of the coaxial bolt along the shaft axis in the direction of the second shaft end. An axial end of the coaxial bolt can be an extension of the coaxial bolt belonging to the coaxial bolt. In other words, the coaxial bolt is not necessarily formed in one piece. Optionally, the handle lever can be inclinable relative to a plane with a normal parallel to the shaft axis at an acute angle to the plane.One advantage of this design is that the heating device (together with the axle) can be moved very easily and ergonomically using the handle at the axial end. Furthermore, this handle can also be used to release the locking mechanism. Thus, the heating device can be swiveled in and out, preferably with one hand.

[0024] The automatic welding machine can have a drive device. The drive device can be coupled to a start-up switch, which is designed to provide an enable signal for the drive device, wherein the start-up switch is arranged inside the housing and is designed to be actuated by retracting the telescopic extension into the interior of the housing, in particular by a retracting shaft of the telescopic extension. An advantage of this design can be that the switch is accommodated in the housing and is thus well protected from external influences. For example, the axis of the telescopic extension can actuate an electromechanical switch in the housing when retracted, which switch transmits a signal to a controller with which the drive (feed of the automatic welding machine) can be switched on or off.Optionally, a delay can be provided so that the user can switch from a handle used to operate the telescopic extension to a guide rod for guiding the welding machine.

[0025] The first castor is attached to the support frame by the telescopic extension. The telescopic extension for the castor can have a dovetail guide. This can be a second telescopic extension for the first castor. The heating device can be arranged on the welding machine via a separate first telescopic extension that can be adjusted in the transverse direction. By attaching the first castor to the support frame by the telescopic extension, the width of a track can be adjusted. However, one axle with both castors is not moved. The second castor on the opposite side transversely can be firmly connected to the frame and cannot be moved. Preferably, the first castor can disappear completely into the frame when retracted, so that nothing protrudes laterally. This enables welding close to the edge.One advantage of designing the telescopic extension for the castor as a dovetail guide can be that the telescopic extension can be mounted particularly smoothly even when subjected to a transverse load transverse to the extension direction and at the same time can offer minimal play, which in turn promotes stability and guide precision.

[0026] In a further development, the telescopic extension with the first caster can be configured at least so that, with a minimal distance of the caster from the longitudinal center of the support frame parallel to the transverse axis, it does not protrude beyond the support frame in a direction parallel to the transverse axis. The telescopic extension with the first caster can be configured so that an axial boom end facing away from the longitudinal center is flush with the support frame. This enables welding processes particularly close to the edge.

[0027] The welding machine can further include an adjustment device for adjusting the track of at least one of the casters. An advantage of this design can be that it can improve straight-line running. For example, an adjustment screw can be provided on a second caster, which is located opposite the telescopic extension with the first caster parallel to the transverse axis of the chassis. This adjustment screw can be used to adjust the track or straight-line running of the welding machine.

[0028] The advantages described in detail above for the first aspect of the invention apply accordingly to the other aspects of the invention.

[0029] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0030] Exemplary embodiments of the invention are illustrated in the following drawings and are explained in more detail in the following description.

[0031] They show: Fig. 1 a perspective schematic representation of a low-level welding machine in a working position; Fig. 2 another perspective schematic representation of the low-level welding machine from Fig. 1 in a rest position; Fig. 3 a front view of the welding machine from Fig. 1 in the working position; Fig. 4 a front view of the welding machine from Fig. 2 at rest; Fig. 5 a perspective schematic representation of a telescopic extension for a heating device for a welding machine in a retracted state, Fig. 6 a perspective schematic representation of the telescopic extension from Fig. 5 in an extended state, Fig. 7 a side view of the telescopic extension from Fig. 5 . in retracted position and actuation of a start-up switch with the start-up switch closed; Fig. 8 a side view of the telescopic extension from Fig. 5 . in extended position with open start switch; Fig. 9 a sectional view of the telescopic extension from Fig. 7 along axis IX-IX; Fig. 10 a sectional view of the telescopic extension from Fig. 7 along axis XX; Fig. 11 a perspective view of an automatic welding machine with a telescopic extension for a castor; Fig. 12 a perspective view of a section of the automatic welding machine with castor in an extended state; Fig. 13 a perspective view of a section of the automatic welding machine with castor in a retracted state; Fig. 14 a further perspective view of a section of the automatic welding machine with castor in an extended state from Fig. 12 ; Fig. 15 a further perspective view of a section of the welding machine with castor in a retracted state from Fig. 14 ; Fig. 16 a side view of a telescopic extension for a castor with a dovetail guide; Fig. 17 shows a front view of a section of the welding machine with castor in an extended state; Fig. 18 shows a front view of a section of the welding machine with castor in a retracted state; Fig. 19 a perspective view of a second fixed castor with adjustment device for track adjustment; Fig. 20 a flow diagram of a method for thermally joining material webs.

[0032] Fig. 1 und Fig. 2 show a perspective schematic representation of an exemplary automatic welding machine 1 for thermally joining material webs. The automatic welding machine 1 is configured for edge-to-edge joining of an overlapping upper material web with a lower material web, which can be joined together in a material-to-material bond by applying heat and subsequent pressure. The automatic welding machine 1 comprises a heating device 10 and a chassis 20 with a guide rod 30 for guiding the automatic welding machine.

[0033] The heating device 10 is configured to at least partially heat the material webs to be joined in a joining area. In the illustrated embodiment, the heating device 10 is designed as a hot air blower with a blower body 11 with an internal heating element and a fan for generating an air flow, and a hot air nozzle 12. Fig. 1 the heating device 10 is in a working position. In Fig. 2 In contrast, the heating device is in a rest position, preferably extended laterally and tilted upwards. In the working position, the hot air nozzle is inserted in an overlapping area between an upper material web and a lower material web (not shown). This allows the heating device to heat an underside of the upper material web and an upper side of the lower material web and, in particular, to at least partially plasticize or melt them. Alternatively, the heating device 10 can be designed as a heating wedge device with an electrically heatable heating wedge.

[0034] Particularly in roof waterproofing applications, the material webs, such as waterproofing membranes, are welded in their overlapping area using so-called ground-level hot-air welding machines. A hot-air nozzle attached to a hot-air blower slides between the overlapping material webs. This nozzle, or rather the entire hot-air blower, is to be retracted or extended into the overlap at the beginning or end of the welding process. A so-called retraction device can be used for this purpose, which moves the hot-air blower in a controlled manner between a rest position ( Fig. 2 ) and a job position ( Fig. 1 ) back and forth. The hot air blower is usually moved laterally along a transverse axis (axial) and simultaneously rotated around an axis (rotational).

[0035] A working direction of the welding machine 1 is in Fig. 1 represented by an arrow and designated by reference numeral 32. The working direction of travel here designates a feed direction in which the automatic welding machine 1 is guided along the overlapping material webs during operation for edge-to-edge joining. The chassis 20 has a pressure roller 21 which is designed to apply pressure to the material webs behind the heating device 10 in the working direction. The pressure roller 21 can also be designed as a drive roller which automatically drives the automatic welding machine 1. In the exemplary embodiment shown, however, an optional separate drive roller 22 is provided. In the exemplary embodiment shown, the chassis further has a first roller 23 and a second roller 24. The rollers are arranged at the front in the working direction of travel 32. The first roller 23 can therefore be referred to as the left roller, and the second roller 24 can be referred to as the right roller.

[0036] To further improve the air flow and heat input between the overlapping material webs, a pressure belt 23 can optionally be provided. The pressure belt 23 extends from between the pressure roller 21 to a preferably tensionable belt guide pulley 24, which is arranged next to or in front of the hot air nozzle in the working direction, to press the edge of an overlapping upper material web (not shown in the figure) against an overlapped lower material web (likewise not shown). The pressure belt 23 can be configured to press the overlapping edge of the upper material web against the lower material web and thus prevents the hot air stream from the hot air nozzle 12 from penetrating beneath the overlapping upper material web. By sealing the side of the overlapping edge, power loss can be reduced and the hot air stream can be guided against the working direction of the automatic welding machine 1.

[0037] As in the Fig. 1 und Fig. 2 As shown in the exemplary embodiment, the automatic welding machine 1 can further comprise a controller 27 (also referred to as a control unit) and a display unit 28. In the present exemplary embodiment, the controller 27 and the display unit 28 are arranged on an upper side of the automatic welding machine. It is understood, however, that the controller 27 and / or display unit 28 can also be designed as wireless units that are connected to the automatic welding machine via a communication interface. For example, a smartphone or tablet with appropriate software can be used as a display unit 28 or as an operating interface for a controller.

[0038] The welding machine 1 can further comprise a receptacle 40 for one or more additional weights 50, which are designed to increase the pressure on the pressure roller 21. Fig. 1 shows a perspective view of the welding machine 1 with an additional weight 50. Furthermore, the welding machine 1 can also have a permanently installed weight 51, by which a minimum contact pressure is defined without additional weights.

[0039] As in Fig. 1 bis Fig. 3 As shown, the chassis 20 is formed by a support frame 61 with a housing 62 as well as by the pressure roller 21 and the two casters 23, 24. The chassis has a longitudinal axis parallel to the working direction 32 and a transverse axis perpendicular thereto, which span a chassis plane. At least one caster 24 of the two casters 23, 24 is arranged so as to be movable relative to the support frame 61 with the housing 62 by means of a telescopic extension 80. In addition, the heating device 10 can be arranged so as to be movable relative to the support frame 61 with the housing 62 by means of a further telescopic extension 70. In other words, the heating device 61 and / or the caster 24 can be extended transversely to the drive direction 32 by means of a telescopic extension.

[0040] In the case of Fig. 1 bis Fig. 10 In the embodiment described, the heating device 10 is arranged on the support frame 61 with the housing 62 so as to be movable in the transverse direction by means of the telescopic extension 70.

[0041] The odd numbers show Fig. 1 , Fig. 3, Fig. 5, Fig. 7 as well as Fig. 9 und Fig. 10 the welding machine or parts thereof with the telescopic extension in a retracted state in a working position. The straight Fig. 2 , Fig. 4, Fig. 6 und Fig. 8 In contrast, show the welding machine or parts of it with the telescopic extension in an extended state in a rest position. Fig. 3 and Fig. 4 show a front view of the welding machine 1 in a working position with retracted telescopic extension 70 for the heating device 10 ( Fig. 3 ) compared to a front view of the welding machine 1 in a rest position with extended telescopic extension 70 for the heating device 10 ( Fig. 4 ). The Fig. 5 and Fig. 6 show a perspective schematic representation of a telescopic extension for a heating device for a welding machine in a retracted state ( Fig. 5 ) or in an extended state ( Fig. 6 ). Accordingly, show Fig. 7 a side view of the telescopic extension 70 from Fig. 5 . in a state retracted into the housing 62 and Fig. 8 a side view of the telescopic extension Fig. 5 . in a state extended from the housing 62.

[0042] The telescopic extension 70 has an axis 71, wherein the heating device 10 is fixedly attached to the axis 71 of the telescopic extension 70. In the illustrated embodiment, a connecting plate 72 is arranged on the axis 71. The heating device 10 can be fixedly but detachably attached to the connecting plate 72, for example by means of a screw connection. The housing 62 can have a bearing housing 63 fixedly arranged on or in the housing. The bearing housing 63 is simultaneously part of the telescopic extension and, together with the further housing 62, serves to accommodate the telescopic extension in the retracted state, as for example in Fig. 3 und Fig. 7 shown.

[0043] The axis 71 can be mounted in the fixed bearing housing 63 so that it can be moved and rotated. In order to move the heating device 10 in a controlled manner between the rest position ( Fig. 2 , Fig. 4 ) and the working position ( Fig. 1 , Fig. 3 ) back and forth, the heating device 10 is axially displaced along the axis 71 and simultaneously rotated about the axis. In the rest position ( Fig. 2 , Fig. 4 ) the axis 71 of the telescopic extension 70 can be locked both axially and rotationally. In the embodiment shown, a radial, spring-loaded locking bolt 73 is provided for this purpose, which is attached to the bearing housing 63 and can engage in a bore 74, 74' provided on the axis 71. In a further development, the locking is released by a preferably spring-loaded long bolt 75, which is axially inserted into the axis, pressing the locking bolt 73 out of the bore 74, 74', as shown for example in Fig. 9 und Fig. 10 The long bolt 75 is also called a coaxial bolt because it is arranged coaxially in the axis 71.

[0044] In the resting position (see Fig. 2 , Fig. 4 ) as a first axial and rotational position relative to the support frame, the heating device can be fixed both axially and rotationally by means of the proposed telescopic extension. Here, as in Fig. 5 As shown, a bore 74 is provided in the axis 71, the size of which is adapted in a longitudinal and transverse direction to the size of the locking bolt 73. This fixes the axis both axially and rotationally. In contrast, in the working position (see Fig. 1 , Fig. 3 ) is desirable if the heating device 10 is axially locked by means of the telescopic extension, but allows rotational movement over a certain angular range. As for example in Fig. 8 As shown, the hole 74' can therefore be designed as an elongated hole instead of a (round) hole. The locking can be released using the same long bolt or coaxial bolt 75, but a different recess is used. As shown in Fig. 9 und Fig. 10 As shown, the locking bolt 73 is guided through the bore 74' into a recess of the coaxial bolt. When the coaxial bolt is moved in the axial direction of the axis 71 towards the housing 62 (see e.g. Fig. 8 ), the locking pin 73 can be pushed radially outward, for example, by a beveled side wall of a recess in the coaxial pin. The locking mechanism can thus be released in a simple manner.

[0045] As in Fig. 9 As shown, a handle 77 is provided at an outward-facing end of the axis 71 with the coaxial bolt 75. The automatic welding machine is configured so that the heating device 10 can be moved with the axis 71 of the telescopic extension 70 using the handle 77. In addition, the handle 77 serves to release the locking mechanism, since the handle 77 is connected to the coaxial bolt 75. The handle 77 with the coaxial bolt 75 can be supported on the axis 71 by means of a spring 76. When the handle 77 is not actuated, the spring 76 ensures that the coaxial bolt is positioned such that the locking bolts engage in the recesses of the coaxial bolt 75, enabling secure locking.

[0046] The welding machine preferably has a drive device for automatic propulsion. It would be desirable to ensure that the welding machine does not automatically start moving or is not accidentally activated in the rest position. The drive device can therefore be coupled to a start-up switch configured to provide an enable signal for the drive device. This can be a control signal. Alternatively, the start-up switch can be used to establish or interrupt a power supply to the drive device. Fig. 7 and 8 show an advantageous schematic arrangement of a start-up switch 68, wherein the start-up switch is arranged inside the housing 62. This protects the start-up switch and reduces the risk of malfunction. In the rest position, as shown in Fig. 4 und Fig. 8 As shown, the start-up switch is open. In the working position, as shown in figures 3 and 7, the start-up switch is closed. In the illustrated embodiment, the start-up switch is actuated by the retracted axis 71 of the telescopic extension 70. In the retracted state, the axis in the housing can, for example, actuate an electromechanical switch, which transmits a signal to the control system with which the drive (feed) of the welding machine can be switched on or off. Optionally, a delay can be provided to allow the operator to reach for the guide rod.

[0047] In the case of Fig. 11 bis Fig. 18 In the embodiment described, the castor 24 is arranged on the support frame 61 with the housing 62 so that it can move in the transverse direction by means of the telescopic extension 80. Optionally, in addition to the telescopic extension 80 for the castor 24, a further telescopic extension 70 can be provided for the heating device 10. Fig. 11, Fig. 12, Fig. 14 and Fig. 17 the telescopic extension 80 in an extended state. Fig. 13, Fig. 15 and Fig. 18 show the telescopic extension 80 in a retracted state. An advantage of this embodiment may be that the support with the caster can be fully retracted into the machine housing using the telescopic extension 80 if necessary, for example, for transport or in tight workspaces. In the extended state, however, high stability and good straight-line driving characteristics can be provided.

[0048] The telescopic extension 80 has an axle 81, wherein the castor 24 is arranged at a transversely outer end of the axle 81. The housing 62 can have a bearing housing 64 fixedly arranged on or in the housing. The bearing housing 64 is also part of the telescopic extension and, together with the further housing 62, serves to accommodate the telescopic extension in the retracted state, such as in Fig. 13 The other caster 23 is firmly connected (in the transverse direction on the opposite side) to the chassis, in particular to a support frame 61 of the chassis. The firmly connected caster 23 can further improve the stability and tracking of the welding machine, since no movable or sliding elements are required.

[0049] As in Fig. 16 As shown, the telescopic extension 80 for the caster 24 can have a dovetail guide. An advantage of designing the telescopic extension for the caster as a dovetail guide can be that the telescopic extension can be mounted particularly smoothly even under transverse loads transverse to the extension direction and, at the same time, can offer minimal play, which in turn promotes stability and guide precision.

[0050] As in Fig. 17 und Fig. 18 As shown, the telescopic extension 80 can optionally have an actuating lever 85, with which different positions 86, 86', 86" can be set in the longitudinal direction of the telescopic extension 80. For example, a plate can be mounted on the axis 81, which can engage in corresponding recesses on the housing 62 depending on the lateral position. This allows predefined lateral positions (in this case three) to be set repeatably and precisely.

[0051] Fig. 19 shows a perspective view of a second fixed caster 23 with an adjustment device 90 for track adjustment. The adjustment device 90 can have a display 91 that indicates the alignment of the caster 23. The alignment or track of the caster can be adjusted, for example, using one or more adjusting screws 92.

[0052] Fig. 20shows a flowchart 100 of a method for thermally joining material webs, in particular for edge-to-edge joining of an overlapping upper material web to a lower material web, which can be joined to one another in a material-to-material manner under the influence of heat and subsequent application of pressure. In a first step S101, an automatic welding machine, as described in the context of the present disclosure, is provided. In a second step S102, the heating device 19 is transferred from a rest position to a working position by means of the telescopic extension for at least partially heating the material webs to be joined in a joining region. In a third step S102, the material webs are thermally joined to the automatic welding machine.

[0053] In summary, the solutions proposed herein provide an improved automatic welding machine for thermally joining material webs, particularly for edge-to-edge joining of an overlapping upper material web with a lower material web, which can be bonded together by applying heat and subsequent pressure. The proposed solution makes it possible to provide a welding machine with easy handling and / or reduce maintenance requirements. Furthermore, the manufacturing complexity can be reduced compared to fully automatic lowering and swiveling systems.

Claims

1.

1. Automatic welding machine (1) for thermal joining of material sheets, in particular for edge-side joining of an overlapping upper material sheet to a lower material sheet, to be connected to one another in a materially bonded manner under the application of heat and subsequent application of pressure, comprising - a heating device (10) for at least partially heating the material sheets to be joined in a connection region, - a support frame (61) with a housing (62), - a pressure roller (21), - at least two travelling rollers (23, 24), wherein the pressure roller (21) and the traveling rollers (23, 24) are arranged on the support frame (61) and together with the support frame form a chassis (20), wherein the chassis (20) comprises a longitudinal axis and a transverse axis perpendicular thereto, which span a chassis plane, wherein at least a first travelling roller (24) of the two travelling rollers (23, 24) is arranged to be movable by a telescopic pull-out (80) relative to the support frame (61) in directions parallel to the transverse axis, wherein the first travelling roller (24) and the heating device (10) are with respect to a longitudinal center of the chassis arranged on opposite sides of the chassis (20); wherein the telescopic pull-out (80) comprises an axle (81), wherein the first traveling roller (24) is fixedly attached to the axle (81) of the telescopic pull-out, wherein in an extended state the axle is pulled-out of the housing (62) of the support frame (61) and in a retracted state is received by the housing (62) of the support frame (61); and wherein the elements of the telescopic pull-out are pushed into one another.

2. Automatic welding machine according to any of the preceding claims, wherein the heating device (10) is arranged rotatably relative to the support frame (61) about an axis parallel to the transverse axis, wherein the heating device (10) is fixable axially and rotationally relative to the support frame (61) at least in a first axial and rotational pose and is fixable at least axially relative to the support frame (61) in a further, second axial and rotational pose which is at least axially different from the first pose.

3. Automatic welding machine according to claim 2, wherein the heating device (10) is arranged on the support frame (61) by a further telescopic pull-out (70), wherein the further telescopic pull-out comprises a receptacle (72) fixed to the support frame and a shaft (71), wherein the shaft extends between a first axial shaft end and a second axial shaft end along a shaft axis parallel to the transverse axis, wherein the second axial shaft end is the axial shaft end facing away from the housing (62), wherein the shaft is mounted at the receptacle so as to be movable along the shaft axis and rotatable about the shaft axis, and wherein the heating device (10) is arranged on the shaft in a region of the second axial shaft end.

4. Automatic welding machine according to claim 3, wherein for fixing the heating device (10) in the first pose and / or in the second pose the shaft can be releasably fixed to the receptacle by a locking device (73) of the receptacle (72).

5. Automatic welding machine according to claim 4, wherein the locking device comprises at least one locking bolt (73), wherein the locking bolt is oriented in a direction of a locking axis perpendicularly intersecting the shaft axis and is movable in the direction of the locking axis, and wherein the shaft (71) can be fixed at least in the first pose and / or in the second pose by an at least partial engagement of the locking bolt (73) radially to the shaft axis into the shaft; in particular wherein the locking bolt is loaded by a spring force (76) in direction of the shaft axis.

6. Automatic welding machine according to one or more of claims 2 to 5, wherein a handle lever (77) is arranged at the second axial shaft end, which is configured to provide a manual rotation of the shaft (71) about the shaft axis, a manual displacement of the shaft in directions along the shaft axis and / or a manual release of a fixation of the shaft (71) from the receptacle (72).

7. Automatic welding machine according to claim 5, wherein a coaxial stud (75) is received in an interior of the shaft (71) of the further telescopic pull-out (70), wherein the coaxial stud (75) extends parallel to the shaft axis at least partially through the shaft (71), wherein the coaxial stud (75) is movable in directions to the shaft axis, wherein the locking bolt (73) can be at least partially brought into engagement with the coaxial stud (75) at least in the first pose and / or the second pose, and wherein the locking bolt (73) can be disengaged from the coaxial stud by a movement of the coaxial stud (75) in a direction along the shaft axis relative to the shaft (71).

8. Automatic welding machine according to claim 7, wherein the coaxial stud (75) projects with an axial end beyond the second end of the shaft out of the shaft (71), wherein the handle lever (77) is arranged at this axial end of the coaxial stud (75), wherein a spring element (76) is clamped between the handle lever (77) and the second shaft end, wherein a movement of the coaxial stud along the shaft axis in the direction of the second shaft end is limited by a stop inside the shaft (71) in combination with a counter-stop of the coaxial stud (75).

9. Automatic welding machine according to any of the preceding claims, wherein the automatic welding machine (1) comprises a drive (22), wherein the drive is coupled with a start-up switch (68) which is configured to provide a release signal for the drive, wherein the start-up switch (68) is arranged in the interior of the housing (62) and is configured to be actuated by retraction of the telescopic pull-out into the interior of the housing (62), in particular by a retracting shaft of the telescopic pull-out.

10. Automatic welding machine according to any of the preceding claims, wherein the first traveling roller (24) is arranged on the support frame (61) by the telescopic pull-out (80), wherein the telescopic pull-out for the traveling roller (24) comprises a dovetail rail.

11. Automatic welding machine according to claim 10, wherein the telescopic pull-out (80) with the first traveling roller (24) is configured not to protrude beyond the support frame at least at a minimum distance of the traveling roller (24) from the longitudinal center of the support frame (61) parallel to the transverse axis in a direction parallel to the transverse axis.

12. Automatic welding machine according to claim 11, wherein the telescopic pull-out (80) with the first traveling roller (24) terminates flush with the support frame (61) with an axial cantilever end facing away from the longitudinal center.

13. Automatic welding machine according to one or more of claims 1 to 12, further comprising an adjusting device (90) for adjusting the alignment of at least one of the traveling rollers (23).

14. Method (100) for thermal joining of material sheets, in particular for edge-side joining of an overlapping upper material sheet to a lower material sheet, to be joined together in a materially bonded manner under the application of heat and subsequent application of pressure, comprising the steps of - providing an automatic welding machine (1) according to any of the preceding claims (S101); - transferring the heating device (10) for at least partially heating the material sheets to be joined in a connection region from a rest position to a working position using the telescopic pull-out (70) (S102); and - thermal joining of the material sheets with the automatic welding machine (1) (S102).