METHOD AND MOBILE CONNECTING APPARATUS FOR THERMALLY CONNECTING TWO ADJUSTING MATERIAL PATHWAYS VIA A CONNECTING PIECE

Description

[0001] The present invention relates to a method and a mobile joining apparatus, in particular a mobile welding apparatus, for thermally joining two adjacent material webs via a connecting piece lying flat on an underside, wherein the material webs are arranged abutting one another with a respective side surface facing one another and resting flatly on an upper side of the connecting piece at least partially with a respective underside.

[0002] Such material webs typically consist of a meltable and / or fusible material. For example, the material webs can be made of a plastic material, in particular a thermoplastic material. However, the material webs can also be bitumen sheets. However, they can also be material webs whose material is not meltable and / or fusible and which are at least partially provided on an underside with a thermally activated adhesive that can be melted and / or fusible accordingly.

[0003] The material webs are web-shaped and therefore flat, sometimes with a surface structure. The material webs have a low height (thickness or strength of the material) compared to their lateral dimensions (length and width). The same applies to connecting pieces, whereby the connecting pieces, with lengths comparable to the material webs, are usually significantly narrower than the material webs. Therefore, the connecting pieces are alternatively characterized as "web-shaped" or "strip-shaped."

[0004] Both the material webs and the connecting pieces are typically provided rolled up on rolls prior to processing and are unrolled and laid on a substrate at the processing site. The substrate can be a floor or a wall of a building, for example, and the material webs are sealed against liquids, such as water, that might otherwise enter or escape by means of a liquid-tight connection of the material webs to form a liquid-tight material layer on the substrate. This can be used to seal (flat) roofs, basins, canals or tunnels, for example. When processing the material webs, the first step is usually to lay the material webs in the intended positions on the substrate and to fasten them to the substrate.The one of the two large, flat sides across the thickness of a material sheet that lies flat on top of the substrate when the material sheet is laid on a substrate is usually referred to as the underside of the material sheet. The other large, flat side, facing away from the top of the substrate, is accordingly referred to as the top side of the material sheet. In the following, the narrow outer edge of a material sheet between the top and underside of the material sheet is referred to as the side surface(s). The same procedure applies to connecting pieces.

[0005] When processing material webs in common applications, the material webs are laid overlapping on a substrate and connected. In this case, one material web rests on a directly adjacent material web along mutually facing side surfaces of the material webs, at least in one connecting area in the vicinity of their mutually facing side surfaces, with a portion of the underside resting on a portion of the top side of the other material web. If the material webs are, for example, thermoplastic plastic webs, the material webs can be at least partially plasticized by simultaneous and successive heating of certain areas in the connecting area and then connected to one another by subsequent application of pressure in the connecting area.As the heated material of the material webs subsequently cools, an overlapping connecting seam (or lap seam for short) is created between the material webs along the facing side surfaces of directly adjacent material webs. The material web lying on top of the other material web in the joining area is successively heated in sections from its underside, while the material web lying below in the joining area is heated simultaneously from its top side. State-of-the-art, often largely automated welding devices with hot-air welding devices or contact welding devices ('heating wedges') are often used to heat the material webs to be joined. This allows the joining of the material webs and, if necessary, even the fixing of the material webs to a substrate to be carried out quickly and efficiently.

[0006] In some applications, overlapping installation and joining of material sheets is undesirable. This can be for aesthetic reasons, for example. A common material layer resulting from overlapping installation and joining of material sheets is not smooth on the top or surface as a result of the overlap and has seam transitions in the form of edges at the overlap seams. The edges correspond to the side surfaces of the material sheets resting on top of directly adjacent material sheets due to the overlap. One example of overlapping installation and joining of material sheets that is undesirable for aesthetic reasons is the waterproofing of swimming pools. The material sheets used in this application are typically PVC membranes.The edges resulting from the overlapping installation and bonding of such PVC membranes in the shared material surface can be concealed by applying a seam sealant made of liquid PVC after joining the material sheets. This softens the abrupt seam transition at the edges. Furthermore, it prevents dirt from accumulating at the seam transition. However, complete concealment of the overlap seams or the edges in the shared material surface, in the sense that the edges are 'invisible', cannot be achieved. Especially on a calm water surface and under the nighttime lighting of a swimming pool, the seam transitions are clearly visible despite the concealment.

[0007] The problems described above regarding the overlapping laying and joining of material webs can be avoided by laying and joining the material webs butt-to-end. In this case, directly adjacent material webs to be joined are laid with their respective side surfaces facing each other, in contact with each other, or butt-to-end, and then joined together. The connection is made using connecting pieces. These are arranged beneath the material webs to be joined, at a transition between any two directly adjacent material webs to be joined. The connecting pieces are inserted into corresponding recesses in a base arranged between the material webs to be joined and a substrate on which the material webs are laid for connection. The base can also consist of a web-like material, e.g., webs of fleece.

[0008] The joining of the material webs via the connecting pieces takes place in at least two essential steps. First, the first of two directly adjacent material webs to be joined via a connecting piece is joined to the connecting piece. This is a conventional overlapping joining of two material webs - one of which is a connecting piece - and can in principle be carried out using (automated) welding equipment known from the state of the art. Subsequently, the second material web is joined to the connecting piece. Since a connection to the other material web is also made by joining the material webs along their mutually facing side surfaces, this is not a conventional overlapping joining.The second material web is joined to the connecting piece and the first material web in several steps by hand using hand-held welding devices, often hot air hand-held devices, to avoid damage to the visible edge of the first material web due to excessive exposure to heat energy (burns). A visible edge of a material web is an upper side edge of the material web where the top side and one side of the material web adjoin one another. Joining the second material web to the connecting piece and the first material web by hand is time-consuming. To achieve an adequate result when joining the second material web to the connecting piece and the first material web, at least two people are usually required to carry out the connection, each helping each other.

[0009] US 3,523,176 discloses an electric iron for heat-sensitive adhesive tape for hemming carpets.

[0010] Against this background, it is an object of the present disclosure to provide a method and a mobile joining apparatus with an improved device for thermally joining two material webs with a joining piece. In particular, it would be desirable to provide a mobile joining apparatus with a device that can increase the working speed. Furthermore, it would be desirable to further improve the seam quality when butt-welding the side edges of adjacent material webs over an underlying joining piece.

[0011] The claimed subject matter is defined in the independent claims. According to aspects of the present disclosure, a method for joining two material webs via a connecting piece having the features of claim 13 and a mobile joining apparatus for joining two material webs via a connecting piece having the features of claim 1 are provided. Further advantageous embodiments can be found in the respective dependent claims.

[0012] Accordingly, a proposed device of the mobile joining apparatus for thermally joining two material webs comprises a base body with a front edge, a rear edge opposite the front edge, and two opposite longitudinal edges, wherein a surface side and a lower surface side of the base body opposite the surface side each extend between the front edge and the rear edge as well as between the two longitudinal edges. The surface side, the lower surface side, the front edge, the rear edge, and the two longitudinal edges can completely define a volume of the base body. The device can be designed, in particular with respect to the base body, to be guided between the upper side of the connecting piece and the undersides of the material webs.The surface side of the base body can face the undersides of the material webs, and the lower surface side can face the top side of the connecting piece. Furthermore, the base body of the device can be designed to guide the material webs, at least in regions of their respective undersides adjacent to their side surfaces, from the front edge to the rear edge over the surface side in such a way that, starting from the front edge of the base body, the material webs are guided at a distance from one another with their respective side surfaces facing one another over at least a quarter, in particular over at least one half, in particular over at least two-thirds, and in particular over at least three-quarters of a maximum extension of the base body between the front edge and the rear edge.In addition, the device can be designed to simultaneously heat at least partially the underside of the material webs, the top side of the connecting piece and the respective mutually facing side surfaces of the material webs in such a way that (simultaneously) parallel connections, in particular parallel weld seams, can be produced between each of the two material webs and the connecting piece as well as between the material webs.

[0013] In other words, the proposed device of the mobile joining apparatus can be designed as a butt welding device. Within the scope of the present disclosure, a welding device can also be understood as a device for thermal joining. The proposed device can be designed to slide between the two butt-to-butt material webs and the underlying connecting strip, thereby creating two parallel weld seams on both sides in a single step. At the same time, the two butts, i.e., the mutually facing (short) sides of the material webs, can be at least partially welded or thermally joined together.

[0014] The proposed solution can offer one or more of the following advantages. As the thermal connection of the two material webs and preferably also of the web-shaped connecting piece can be produced in a single operation, several work steps can be saved. This can shorten working time and increase efficiency, for example when producing butt welds. A further advantage can be improved welding quality. The thermal connection can be carried out in a single operation with constant process parameters. A further advantage can be physiological relief for the operator, particularly when the device is combined with a mobile joining device. A further advantage can be a pure-type connection of the material webs. In contrast to conventional procedures in which, for example, an additional adhesive is used or a seam transition orIf the overlap is covered with a joint compound, a thermally produced, homogeneous joint can be created. Furthermore, companies using this device can benefit from advantages such as expanding their product range, strengthening their market position as an innovative company, and securing an exclusive solution, for example, for (seamless) swimming pools or sports surfaces, especially in outdoor areas.

[0015] The base body can be designed such that the two material webs can be guided over the surface of the base body in such a way that the two material webs abut each other (again) at the second end edge or at the rear edge of the base body with their mutually facing side surfaces. Particularly preferably, the parallel weld seams between the underside of the material webs and the top side of the connecting piece, as well as between the two material webs, merge seamlessly into one another and form a common weld seam.

[0016] The device of the mobile joining apparatus can be designed as a hot-air heating device or as part of a hot-air heating device, in particular in the form of a hot-air nozzle. The material webs and the connecting piece are exposed to hot air via the device for heating. Alternatively, a device according to the invention can be designed as a contact heating device. The heating of the material webs and the connecting piece occurs through heat transfer during thermal contact between the device, in particular the base body of the device, and the material webs and the connecting piece.Because physical contact generally occurs between a device according to the invention and the material webs and the connecting piece when the material webs are connected via the connecting piece, heat transfer can also occur through thermal contact between the device and the material webs and the connecting piece when the device is configured as a hot air nozzle or similar device. However, the heating of the material webs and the connecting piece essentially occurs by exposure to hot air.

[0017] The device of the mobile connecting apparatus is preferably made of a heat-resistant material. If the device is designed as a contact heating device, it is also preferred to be made of a material with good heat conductivity. The device can be constructed in multiple pieces or in one piece, with a single piece being preferred. The device can be manufactured using an additive manufacturing process (3D printing).

[0018] Within the scope of the present disclosure, the front edge, the rear edge, and the side edges of a base body of the device can be understood not only as linear, but optionally alternatively and / or additionally as planar / flat. The front edge, the rear edge, the longitudinal edges, the surface side, and the bottom surface side can be segmented, i.e., each formed from at least two segments. The front edge is the edge of the base body of the device which, when two material webs are connected via a connecting piece, is located at the front and faces the direction of movement during a movement of the device relative to the material webs and the connecting piece in a (feed) direction along the mutually facing side surfaces of the material webs. The rear edge is accordingly located at the rear in the direction of movement and faces away from the direction of movement.To connect two material webs at a time using a connecting piece, the device can be moved relative to the material webs and the connecting piece along the mutually facing side surfaces of the material webs, with the material webs and the connecting piece considered stationary. Alternatively, however, the material webs and the connecting piece can also be moved relative to the device, which is considered stationary.

[0019] The proposed device of the mobile joining apparatus for joining two material webs via a connecting piece can, in particular, enable the material webs to be joined via the connecting piece in a single operation. A particular advantage of the proposed solution is that no further work or steps are required to join the first material web to the second material web. Furthermore, both the first material web and the second material web can be joined to the connecting piece in a single operation.

[0020] The base body of the device of the mobile joining apparatus can be designed as a hollow body and have at least one opening for hot air to exit the hollow body at the rear edge of the base body into a cavity between the rear edge of the base body, the top side of the connecting piece, and the undersides of the material webs. The base body or the device as a whole can thus be designed like a hot air nozzle. Through the at least one air outlet at the rear edge, hot air can penetrate between the material webs and the connecting piece, thus heating the underside of the material webs and the top side of the connecting piece.

[0021] The surface side and / or the underside of the base body of the device can have at least one opening for hot air to escape from the base body. Hot air can escape from the base body to the underside of the material webs through one or more openings on the surface side of the base body. This allows the material webs to be preheated or pre-heated on the underside before the (significant) part of the hot air, which escapes from the base body through the at least one opening on the rear edge of the base body, hits the undersides of the material webs and heats them further. Hot air can escape from the base body to the top side of the connecting piece through one or more openings on the underside of the base body. This allows the connecting piece to be preheated or pre-heated on the top side.be preheated before the (significant) portion of the hot air exiting the base body through at least one opening at the rear edge of the base body hits the upper side of the material webs and further heats them. By providing additional openings for the exit of hot air from the base body on its surface side and / or on its underside, the heating of the material webs to be joined and the connecting piece can be further improved, for example, with regard to the speed at which the heating takes place. The working speed can thus be further increased.

[0022] A fin can protrude from the surface side of the base body. The fin can extend parallel to the maximum extension of the base body at least partially between the leading edge and the trailing edge. From an end of the fin facing away from the surface side, hot air can be introduced through the fin into the base body. The fin is therefore at least partially designed as a hollow body and / or has one or more hollow bodies through which hot air can be introduced into the base body designed as a hollow body. The hollow body or bodies of the fin preferably extend through the fin between the end of the fin on the surface side up to a respective transition to the hollow body of the base body.

[0023] The fin can be formed integrally with the base body. A maximum extension of the fin in a direction parallel to a maximum extension of the base body between its two longitudinal edges can be shorter than the maximum extension of the base body between its two longitudinal edges. For example, the fin can extend parallel to the maximum extension of the base body between its longitudinal edges to at most a quarter, in particular to at most a fifth, and in particular to at most a sixth of the maximum extension of the base body between the longitudinal edges. Preferably, the maximum extension of the fin in a direction parallel to the maximum extension of the base body between its two longitudinal edges can also be significantly smaller than a maximum extension of the fin in a direction parallel to a maximum extension of the base body between its leading edge and trailing edge.For example, the maximum extension of the fin in a direction parallel to the maximum extension of the base body between its longitudinal edges is only one-third, very particularly preferably at most one-quarter, and very particularly preferably at most one-sixth of a maximum extension of the fin in a direction parallel to a maximum extension of the base body between its leading edge and trailing edge. For example, the fin extends in a direction parallel to the maximum extension of the base body between its leading edge and trailing edge not all the way to the trailing edge of the base body, but preferably ends at a distance of at least one-sixth of the maximum extension of the base body between its leading edge and trailing edge in front of the trailing edge of the base body.

[0024] The surface side of the base body can be designed to guide the material webs past the fin in such a way that thermal contact between a lower side edge of a material web at a transition between the respective underside and the respective side surface of the material webs along an extension of the fin between the front edge and the rear edge occurs only on a second half, in particular only on a last third and in particular only on a last quarter of an extension of the fin between the front edge and the rear edge of the base body. By means of a corresponding design, the risk of excessive input of heat energy under thermal contact between the mutually facing side surfaces of the material webs and the fin and any resulting damage to the material webs in the region of the respective side surface or butt surface for a butt seam of the side surfaces is reduced.

[0025] The end of the fin can be connected to a shaft tube, which is designed to guide an air flow to the end of the fin and at the same time to be fixed to a hot air device in a region of the hot air device intended for the outlet of the hot air flow generated by a hot air device. The shaft tube can be placed and / or fixed, for example, on an outlet-side end of a heating tube of a hot air device intended for the outlet of hot air. The hot air device, in turn, can be part of a hot air welding device, e.g. an automatic hot air welding machine. In other words, the shaft tube can be provided on an upper side of the fin. On the one hand, it can serve to attach the device and / or serve as the inlet opening for hot air.

[0026] The underside of the base body can be concave. With such a design, the underside of the base body can also be curved inward. This creates a cavity between the underside of the base body and the top side of the connecting piece, into which cavity hot air can be introduced if at least one corresponding opening is provided in the underside for hot air to escape from the base body. This can further improve top-side preheating and the overall top-side heating of the connecting piece. The cavity is preferably not completely closed to prevent air buildup in the cavity. In particular, the cavity can be open at least in the region of the rear edge of the base body.In this case, the base body can be designed at a transition between the lower surface side and the rear edge in such a way that at least one opening of the cavity to an environment results between the lower edge of the base body and the upper side of the connecting piece.

[0027] The device of the mobile joining apparatus can be designed as an electrically heatable contact heating device. In this configuration, the heating of the top side of the joining piece and / or the heating of the bottom side of the material webs can be achieved by transferring heat energy through thermal contact—with simultaneous physical contact—between the base body of the device and the joining piece and the material webs. At least large portions of the surface side of the base body can be in (successive) thermal contact with portions of the respective underside of the material webs, and at the same time, significant portions of the bottom surface side of the base body can be in (successive) thermal contact with portions of the top side of the joining piece.

[0028] For example, it can be provided that the device is at least partially formed from a heating plate that can be directly supplied with electrical current. The heating plate or plates can form at least part of the surface side and / or the underside of the base body of the device. Alternatively or additionally, it can be provided that the device for thermally joining two material webs is at least partially formed as a solid block of material made of a thermally conductive material with at least one receptacle for at least one electrical heating element. Such an electrical heating element can be a heating cartridge, which can be arranged at least partially in the base body, for example in a bore provided for this purpose in a preferably solid partial region of the base body of the device.

[0029] At least two guide profiles can protrude outwardly from the surface side of the base body, wherein the guide profiles can extend at least partially between the front edge and the rear edge over the first surface side. The guide profiles can be designed to guide the material webs with their respective side surfaces spaced apart from one another over the surface side for at least a quarter, in particular at least a half, in particular at least two-thirds, and in particular at least three-quarters of the maximum extension of the base body between the front edge and the rear edge, and to bring the material webs into contact with one another with their side surfaces abutting one another as they approach the rear edge.

[0030] By providing guide profiles on the surface side, the guidance of the material webs over the surface side of the base body of the device, and in particular the joining of the material webs at the rear edge of the base body, can be improved such that the material webs (again) abut one another with their mutually facing side surfaces. If the device has a fin, the guidance of the material webs over the surface side of the base body of the device can also be improved with a view to fundamentally avoiding thermal contact or at least avoiding excessive thermal energy being introduced into the side surfaces under thermal contact between the mutually facing side surfaces of the material webs and the fin of the device.

[0031] According to a further aspect, a method for thermally joining two material webs via a web-shaped connecting piece is proposed, comprising the steps: a. Providing at least one connecting piece lying flat on an underside and two material webs to be connected via the connecting piece, which are each arranged abutting one another with a mutually facing side edge and each at least partially lying flat with an underside on an upper side of the connecting piece; b. At least partially (successively and / or simultaneously) heating the undersides of the material webs, the side edges of the material webs and the upper side of the connecting piece in a connecting region such that in the connecting region between each of the material webs and the connecting piece and between the material webs, parallel zones of melted and / or molten material of the material webs and melted and / or molten material of the connecting piece are formed, which preferably merge into one another without a gap; c.Application of pressure in the connection area to the material webs from their upper sides immediately after heating for the simultaneous formation of a connection (connecting seam or weld seam) between each of the material webs and the connecting piece as well as a further connection (connecting seam or weld seam) between the material webs upon cooling of the material of the material webs which has been melted and / or molten in the zones by heating and the melted and / or molten material of the connecting piece, wherein the weld seams extend parallel to one another without any gap.

[0032] One advantage of the proposed method for thermally bonding two material webs via a connecting piece is that the material webs can be joined quickly and efficiently in one step, with their respective facing side surfaces abutting against each other. Furthermore, a connection to the underlying connecting piece can be established in the same step.

[0033] The heating of the underside of the material webs, the side edges of the material webs and the top side of the connecting piece in the connecting region can be carried out by means of a device for thermally joining two material webs in each case according to one of the embodiments or according to any combination of the embodiments as described in the preceding sections.

[0034] According to a further aspect of the present disclosure, a mobile joining apparatus, in particular a mobile welding apparatus, for joining two material webs each via a web-shaped connecting piece lying flat on an underside, wherein the material webs are arranged with a mutually facing side surface abutting one another and at least partially resting flat with an underside on an upper side of the connecting piece, has at least one support frame and a chassis formed from at least one pressure roller and a driving roller arranged on the support frame. With reference to a preferred direction of movement or feed direction of the welding apparatus along the side surfaces of the material webs when joining the material webs, the driving roller can be arranged on the support frame in a front region of the support frame and the pressure roller in a rear region of the support frame.Such a mobile joining apparatus may comprise a device for thermally joining two material webs in each case according to one of the embodiments or according to any combination of the embodiments as described in the preceding sections.

[0035] The device for thermally joining two material webs at a time can be designed to be height-adjustable relative to the chassis of the joining device. The device can therefore be designed to be adjustable along a vertical line relative to a plane in which the welding device is movable on a flat surface. An advantage of this design can be that material webs of different thicknesses can be processed. For example, plastic sealing membranes are usually thinner than outdoor sports surface membranes.

[0036] The joining apparatus can have at least one guide aid (also referred to as a guide device) arranged upstream and / or downstream of the device in the preferred direction of movement or feed direction of the joining apparatus for visually indicating the position of the mutually facing and abutting side surfaces of the material webs. This makes it easier for an operator to align the device for thermally joining two material webs at a time along the mutually facing side surface of the material webs to be joined at the beginning of the joining process. If a joining apparatus according to the invention is designed as a semi-automatic device, i.e. is to be guided by an operator, this makes it easier for an operator to guide the joining apparatus along the mutually facing side surfaces of the material webs to be joined when joining the material webs with the joining apparatus.A guide aid can be designed integrally with a driving roller and / or a pressure roller.

[0037] 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.

[0038] Exemplary embodiments of the invention are illustrated in the following drawings and explained in more detail in the following description. Further advantages, features, and details of aspects of the invention emerge from the claims, the following description of preferred embodiments, and the drawings, in which identical or functionally equivalent elements are provided with identical reference numerals. In the following: Fig. 1 shows a schematic representation of an initial situation when joining two material webs via a connecting piece; Fig. 2 shows a first perspective view of an embodiment of a device of the mobile joining apparatus for thermally joining two material webs via a web-shaped connecting piece lying flat on an underside, designed in the manner of a hot air nozzle; Fig. 3 shows a second perspective view of the device from Fig. 2 ; Fig. 4 a rear view of the device from the Figures 2 and 3 ; Fig. 5 a first perspective view of a further embodiment of a device of the mobile joining apparatus for thermally joining two material webs via a web-shaped connecting piece lying flat on an underside, designed as a contact heating device; Fig. 6 a second perspective view of the device from Fig. 5; Fig. 7 a rear view of the device from the Figures 5 and 6 ; Fig. 8 a first perspective view of an embodiment of a joining apparatus, in particular a mobile welding apparatus, in a position in preparation for a joining process for joining two material webs via a connecting piece; Fig. 9 a second perspective view of the mobile joining apparatus from Fig. 8 in a position when connecting two material webs; and Fig. 10 a schematic representation of the two material webs to be connected via a connecting piece from Fig. 1 after a connection has been established.

[0039] In Fig. 1The initial situation for the connection of two material webs MB1, MB2 via a flat connecting piece VS is shown. The arrangement of the two material webs MB1 and MB2 and the connecting piece shown in a section in a transverse direction to parallel longitudinal directions of the material webs MB1 and MB2 as well as the connecting piece VS lies flat on a Fig. 1 For the sake of clarity, the flat surface is not shown. The surface can be, for example, the floor of a swimming pool. The connecting piece VS lies in a recess provided for this purpose in a base for the material webs MB1 and MB2, which are Fig. 1is also not shown. The underlay can be formed from nonwoven webs laid out flat on the substrate. The connecting piece VS rests flat on the substrate with a bottom side UVS (= bottom side of the connecting piece). On an upper side OVS (= top side of the connecting piece) of the connecting piece VS opposite the bottom side UVS, edge regions of a bottom side US1 of the material web MB2 and a bottom side US2 of the material web MB2 lie flat in the vicinity of respective mutually facing side surfaces of the material webs MB1 and MB2. Outside the respective edge regions of the material webs MB1 and MB2, the bottom sides lie flat on an upper side of the underlay (not shown). The material webs MB1 and MB2 abut one another with their respective mutually facing side surfaces. In the schematic representation in Fig. 1 This is represented by the butt edge SK.

[0040] In the Fig. 2 to Fig. 4 is an exemplary embodiment of a device 1 of a mobile joining apparatus for joining two material webs, ie a first material web MB1 and a second material web MB2, via a flat connecting piece VS in the manner of a hot air nozzle. Fig. 2 and Fig. 3 show the device 1 in a different perspective view. The Fig. 4 shows the device 1 in a rear view. In Fig. 2 To describe the device 1, axes 4, 5 and 11 are shown, which are shown in the Fig. 3 and Fig. 4 are not shown for the sake of clarity. For the same reason, the Fig. 2 to Fig. 4 There is no representation of material webs MB1 and MBs as well as connecting piece VS.

[0041] The device 1 of the mobile joining apparatus has a base body 2. In the illustrated embodiment of the device 1 in the form of a hot air nozzle, the base body 2 is designed as a hollow body. The base body 2 extends in a plane spanned by a longitudinal axis 3 and a first transverse axis 4 in a direction of the longitudinal axis 3 between a front edge 5 and a rear edge 6 and at the same time in a direction along the first transverse axis 4 between two longitudinal edges 7. The base body 2 is in Fig. 1 bordered or limited on the upper side by a surface side 8 and on the lower side by a lower surface side 9. The surface side 8 and the lower surface side 9 each extend between the front edge 5 and the rear edge 6 and between the two longitudinal edges 7. The surface side 8 and the lower surface side 9 are spaced apart from one another in a direction along a second transverse axis 11.

[0042] A fin 10 protrudes from the surface side 8 in a direction of the second transverse axis 11. The fin 10 extends in a direction along the longitudinal axis 3 between the leading edge 5 and the trailing edge 6. The longitudinal extent of the fin 10 is preferably smaller than the maximum longitudinal extent of the base body 2 between the leading edge 5 and the trailing edge 6 parallel to the longitudinal axis 3. The longitudinal extent of the fin 10 between the leading edge 5 and the trailing edge 6 ends at a distance in front of the trailing edge 6. The longitudinal extent of the fin 10 between the first leading edge 5 and the trailing edge 6 begins at the leading edge 5. The fin 10, like the base body 2, is also hollow. This allows hot air to be introduced into the base body 2 through the fin 10. At an end of the fin 10 facing away from the surface side 8 along the second transverse axis 11, the fin 10 continuously merges into a shaft tube 14.Starting from the fin 10, the shaft tube 14 extends in a direction along the second transverse axis 11. The shaft tube 14 enables the guidance of hot air to the fin 10 and through the fin 10 further into the base body 2. Furthermore, the shaft tube 14 enables the fixation of the entire device 1 to an end region of a hot air generating device 22 provided for the outlet of hot air, for example in the region of an outlet opening for hot air of a hot air pipe 23 of the hot air generating device 22 (see also . Fig. 8 and Fig. 9 ). The shaft tube 14 can be designed similar to a pipe clamp for the purpose of fixing it to a hot air pipe 23 or the like at an axial end facing away from the fin 10 along the second transverse axis 11.

[0043] At a front end of the longitudinal extension of the fin 10 on the side of the front edge 5, a flag 17 can be connected to the fin 10, which extends parallel to the longitudinal axis 3 from the fin 10 beyond the front edge 5. The optional flag 17 serves as an indicator device for aligning the device 1 or a mobile welding device 21 (see also Fig. 8 and Fig. 9) with the device 1 in preparation for joining two material webs MB1, MB2 via a connecting piece VS in the direction of the mutually facing and abutting side surfaces of the material webs MB1 and MB2. When joining two material webs MB1 and MB2 via a connecting piece VS, the flag 17 facilitates the guidance of the device 1 or a welding apparatus 21 with the device 1 as a whole along the mutually facing and abutting side surfaces of the material webs MB1 and MB2. The flag 17 thus points in a preferred direction of movement of the device 1 or a welding apparatus 21 with the device 1 as a whole.

[0044] When connecting two material webs MB1 and MB2 along their mutually facing and abutting side surfaces (butting edges) via a connecting piece VS to the device 1, the underside 9 of the base body 2 faces an upper side OVS of the connecting piece VS and is at least partially in thermal (and physical) contact with it. The surface side of the base body of the device 1 is simultaneously at least partially in thermal (and physical) contact with a respective underside US1, US2 of the two material webs MB1, MB2. In the device 1 designed in the form of a hot air nozzle, Fig. 2 to Fig. 4However, direct physical contact is limited and not crucial for the underside heating of the material webs MB1, MB2 and the topside heating of the connecting piece VS. The fin 10 is located between the two material webs MB1 and MB2. The surface side 8 of the base body of the device 1 is divided by the fin 10 into two longitudinal partial top sides, which are opposite one another in a direction along the first transverse axis 4 via the fin 10 or via a plane spanned by the longitudinal axis 3 and the second transverse axis 11.

[0045] The trailing edge 6 can be viewed as being divided into two partial trailing edges (without separate reference numerals), which border an outlet opening 12 and converge towards the longitudinal edges 7 of the base body. The outlet opening 12 at the trailing edge 6 of the base body enables hot air to escape from the base body 2 into the environment. The hot air escapes from the base body 2 essentially in a direction parallel to the longitudinal axis 3, counter to the feed direction or preferred direction of movement of the device 1 when two material webs MB1, MB2 are connected via a connecting piece VS and thus between the upper side OVS of the connecting piece VS and the undersides US1, US2 of the two material webs MB1, MB2.In addition to the outlet opening 12 on the rear edge 6, the base body 2 can have various further outlet openings 13 on the surface side 8 and / or on the lower surface side 9 for the outlet of hot air from the base body 2. The hot air exiting the outlet openings 13 in the surface side 8 of the base body 2 exits towards the underside UVS of one of the material webs MB1, MB2. The hot air exiting the outlet openings 13 in the lower surface side 9 exits towards the upper side OVS of the connecting piece. These further outlet openings 13 serve to preheat the connecting piece VS and material webs MB1, MB2. The upper-side heating of the connecting piece VS and the lower-side heating of the material webs MB1, MB2 can be achieved primarily by means of hot air exiting the outlet opening 12 on the rear edge 6 of the base body 2.A large part of the hot air quantity that can be introduced into the base body 2 exits the base body 2 through the outlet opening 12 at the rear edge 6.

[0046] On the surface side 8 of the base body 2, three guide profiles 15 can optionally be formed on each side of the fin 10. The guide profiles 15 extend from the front edge 5 in the direction of the rear edge 6, optionally up to the rear edge 6, across the surface side 8. In the exemplary embodiment shown, the guide profiles 15 run from the front edge 5, initially parallel to the longitudinal axis 3 across the surface side 8 and finally at an (acute) angle towards the longitudinal axis 3, whereby they previously end in front of or at the rear edge 6 of the base body 2. The guide profiles 15 serve to bring together two material webs MB1, MB2, which are guided on both sides of the fin 10 past the fin 10 over the surface side 8 (close) to the rear edge 6, so that the two material webs MB1, MB2 are brought into contact with each other again in the region of the rear edge 6 with their mutually facing side surfaces or abutting surfaces. The guide profiles 15 have been used in the Fig. 2 to Fig. 4 The exemplary embodiment shown has a triangular cross-section. However, other configurations are also conceivable.

[0047] At a transition between the surface side 8 and the fin 10 protruding from the surface side 8, a shoulder 16 running around the fin 10 can be formed as part of the surface side 8. In the exemplary embodiment shown, the shoulder 16 lies in a plane that intersects the plane spanned by the longitudinal axis 3 and the first transverse axis 4 at an acute angle and is inclined downwards from the front edge 5 of the base body 2 to the rear edge 6. In a section through the base body 2 perpendicular to the longitudinal axis 3, the first support surface side has a cross-sectional profile on both sides of the fin 10 that rises from the longitudinal edges 7 to the shoulder 16. In a front region of the base body 2 near the front edge 5, the cross-sectional profile can be concave and the slope can be greatest directly at the transition to the shoulder 16.At the transition to the shoulder 16, wherein the cross-sectional profile in the region of the shoulder 16 runs parallel to the first transverse axis 4, the gradient of the cross-sectional profile can change abruptly. Towards the rear edge 6 of the base body 2, the extent of the concavity of the cross-sectional profile of the surface side 8 on both sides of the fin 10 between the longitudinal edges 7 and the shoulder 16 can decrease and, near the rear edge 6, can merge into a straight line that rises only slightly on both sides of the fin 10 between the longitudinal edges 7 and the shoulder 16. In the exemplary embodiment shown, the base body 2 has its greatest thickness in the region of the shoulder 16 near the front edge 5. The exemplary embodiment of the device 1 described above can be seen from the perspective views and the rear view of the device 1 in . Fig. 4clearly visible. This configuration can be used to avoid pronounced thermal contact between the respective mutually facing side surfaces of two material webs MB1 and MB2 guided over the surface side 8 of the base body 2 of the device 1 with the fin 10. Otherwise, there is a risk of damage to the material webs MB1 and MB2 on their respective mutually facing side surfaces due to excessive input of heat energy through excessive thermal contact with the fin 10. In particular, damage to the upper side edges of the mutually facing side surfaces of the material webs MB1 and MB2, which is detrimental to the visual impression of an overall surface of the joined material webs MB1 and MB2 resulting from the upper sides OS1 and OS2 of the two material webs MB1 and MB2 when they are joined, is to be avoided. A limited thermal orLimited direct physical contact between the mutually facing side surfaces of the material webs MB1 and MB2 and the fin 10 near the rear edge 6 of the base body 2, i.e. in an area surrounding the rear end of the extension of the fin 10 along the longitudinal axis 3, is, however, possible without causing excessive thermal stress.

[0048] In addition, from the rear view of the device 1 in the Fig. 4It can be seen that the lower surface side 9 of the base body 2 of the device 1 can be designed concave. This results in a cavity between the lower surface side 9 of the base body 2 and the upper side OVS of the connecting piece VS when two material webs MB 1 and MB 2 are connected via a connecting piece VS using the device 1. Hot air from the base body 2 can be introduced into the cavity through the openings 13 in the lower surface side 9 of the base body 2. The cavity can be open towards the rear edge 6 of the base body 2 and / or the front edge 5 of the device 1. This prevents air from accumulating in the cavity, whereby hot air from the base body 2 can be continuously introduced into the cavity. The possibility of being able to continuously introduce hot air into a cavity between the lower surface side 9 of the base body 2 of the device 1 and an upper side OVS leads to an improved preheating of the connecting piece VS.

[0049] In the Fig. 5 to Fig. 7 A further embodiment of a device 1' according to the invention of a mobile joining apparatus for joining two material webs MB1 and MB2 via a flat connecting piece VS is shown, now designed as a contact heating device. The type of representation of the device 1' designed as a contact heating device according to the Fig. 5 to Fig. 7 corresponds to the type of representation of the device 1 designed as a hot air nozzle according to the Fig. 2 to Fig. 4 For the sake of simplicity, the device 1' designed as a contact heating device is shown in the Fig. 5 to 7 in the following primarily based on the differences to the device 1 designed as a hot air nozzle from the Fig. 2 to Fig. 4 described.

[0050] The base body 2 of the device 1' configured as a contact heating device can be formed as a solid, one-piece block of material made of a thermally conductive material. The undersurface side 9 of the base body 2 of the device 1' can be flat, except for a respective limited transition area to the longitudinal edges 7 of the base body 2 and the front edge 5 of the base body 2. This serves to maximize thermal contact between an upper side OVS of a connecting piece VS and the base body 2 of the device 1' for the top-side heating of the connecting piece VS. The design of the surface side 8 of the base body 2 of the device 1' can basically correspond to the surface side 8 of the device 1, including identically designed guide profiles 15 on the surface side 8. However, the device 1' does not need to have a hollow fin 10 or outlet openings 12 or 13 for hot air.

[0051] The rear edge 6 of the base body 2 of the device 1' can be flat, rectilinear, or elongated. Starting from the front edge 5 of the base body 2 of the device 1', one or more holes, in the illustrated embodiment a total of four holes, can extend parallel to the longitudinal axis 3 into the base body. Three of the holes are provided for receiving a heating cartridge 18 for heating the base body 2 of the device 1'. The further, fourth hole serves as a receptacle for a thermal probe 19. The four holes are shown in the illustrations of the device 1' in the Fig. 5 to Fig. 7 not visible. In the Fig. 5 and Fig. 6 Parts of the three heating cartridges 18 and the thermal probe 19 are already visible protruding from the holes. On the front edge 5 of the base body 2, the device 1' can also have an angled holder 20 for connecting the device 1' to a welding device or the like.

[0052] In the Fig. 8 and Fig. 9 An embodiment of a mobile joining device or welding device 21 for joining two material webs MB1 and MB2 via a connecting piece VS is shown. In addition to the welding device 21 itself, Fig. 8 and Fig. 9 also depicts two material webs MB1 and MB2 to be joined via a connecting piece VS. In the illustrated embodiment, the joining device is a hot-air welding device with a hot-air device (hot-air blower) 22 for generating a hot air flow. The hot-air device 22 is rotatably / pivotably mounted relative to a support frame 24 and a housing 25 of the welding device 21. The hot-air device 22 can therefore be moved from a rest position, as in Fig. 8 shown, into an operating position as shown in Fig. 9The hot air device 22 has a hot air pipe 23, wherein at an outlet end of the hot air pipe 23 or of the hot air device 22 as a whole, a device 1 for connecting two material webs MB1, MB2 via a connecting piece VS in accordance with the Figures 2 to 5 device 1 shown.

[0053] The welding apparatus 21 may further comprise castors 26, of which Fig. 8 and Fig. 9two are visible, a pressure roller 27, which, connected to an electric drive, also serves as a drive roller, a material web lifting device 31, a front guide aid 29, a rear guide aid 30 and a guide rod 28. The guide aids 29, 30 facilitate the alignment of the welding apparatus 21 along the mutually facing and abutting side surfaces of the material webs MB1 and MB2 in preparation for a connection of the material webs MB1 and MB2 by means of the welding apparatus 21 and the guidance of the welding apparatus 21 along the side surfaces of the material webs MB1 and MB2 during the connection of the material webs MB1 and MB2. The welding apparatus 21 can be guided by an operator via the guide rod 28. The front guide aid 29 is at the front in the sense that the front guide aid 29 is arranged close to a front end of the welding apparatus 21.The front end of the welding apparatus 21 is the (longitudinal) end of the welding apparatus 21 that is at the front in a preferred direction of movement of the welding apparatus 21 when joining material webs MB1 and MB2. A rear end of the welding apparatus 21 is a (longitudinal) end of the welding apparatus 21 opposite the front end. Accordingly, the rear guide aid 30 is arranged near the rear end of the welding apparatus 21. The two guide aids 29, 30 are arranged laterally on a long side of the welding apparatus 21, with the hot air device 22 on the welding apparatus 21 also being arranged on this long side.

[0054] In Fig. 8The welding apparatus is shown in a position during preparation for joining the two material webs MB1, MB2 via the connecting piece VS. The hot air device 22 with the device 1 is folded up into the rest position. By means of the optional material web lifting device 31, the material webs MB1, MB2, which abut one another with a respective side surface facing one another, are locally spread apart, i.e., they are locally lifted slightly at the edges by the connecting piece VS located underneath and are out of contact with one another. This enables the positioning of the device 1 with its base body 2 between the connecting piece VS and the two material webs MB1, MB2 by folding down the hot air device 22 of the welding apparatus 21 with the device 1 from the rest position into the working position.

[0055] In Fig. 9The hot air device 22 is shown in the working position, whereas the material web lifting device 31 is folded up in a rest position, i.e., it no longer engages locally between the two material webs MB1, MB2 and spreads them apart. The material web lifting device 31 can be automatically folded up when the welding device 21 is set in motion or starts moving. The device 1 of the hot air device 22 of the welding device 21 is positioned in the working position with its base body 2 between the material webs MB1, MB2 and the connecting piece VS. Starting from the Fig. 9In the position shown, the hot air device 22 of the welding device 21 is activated and the welding device 21 is set in motion along the mutually facing and abutting side surfaces of the material webs MB1, MB2. At the same time, the material webs MB1, MB2 are successively heated in sections on the underside and the connecting piece VS is successively heated in sections on the top side by means of hot air generated by the hot air device 22 via the device 1 designed as a hot air nozzle. Immediately after the heating, pressure can be exerted successively by means of the pressure roller 27 from the top sides OS1, OS2 of the material webs MB1, MB2 onto heated areas of the material webs MB1, MB2 and the connecting piece VS in order to join the material webs MB1, MB2 and the connecting piece together. The connection of the material webs MB1, MB1 via the connecting piece is advantageously carried out in one go.Further work and / or work steps are not necessarily required.

[0056] In Fig. 10 is based on the Fig. 1 As a representation of the initial situation, the result of joining two material webs MB1 and MB2 via a connecting piece VS is schematically shown. Parallel weld seams are formed between each of the two material webs MB1, MB2 and the connecting piece VS, as well as between the two material webs MB1, MB2, which preferably form a common weld seam SN. In the illustrated embodiment, the weld seam SN is cooled, molten material from the two material webs MB1, MB2 and the connecting piece VS.

[0057] In summary, the solutions proposed herein provide a further improved device for thermally joining a first material web and a second material web with a connecting piece, and also for a butt joint between the first material web and the second material web. The proposed solution allows for increased working speed. In particular, the proposed solution allows the joints to be produced in a single operation.

Claims

1. Movable joining apparatus, in particular movable welding apparatus (21), for thermal joining of respective two material sheets (MB1, MB2) over a strip-shaped connecting piece (VS) lying areally on a bottom side (UVS), wherein the material sheets (MB1, MB2) are arranged with a respective side surface facing one another abutting against each another at least partially with a bottom side (US1, US2) lying areally on a top side (OVS) of the connecting piece (VS), wherein the welding apparatus (21) comprises at least a support frame (24) and a chassis formed by at least one pressure roller (27) and one traveling roller (26) arranged on the support frame (24), wherein the traveling roller (26) is arranged on the support frame (24) in a front region of the support frame (24) and the pressure roller (27) is arranged in a rear region of the support frame (24) with respect to a travel direction of the joining apparatus (21) along the side surfaces of the material sheets (MB1, MB2) upon joining the material sheets (MB1, MB2), further comprising a device (1, 1') for thermal joining of respective two material sheets (MB1, MB2) over a strip-shaped connecting piece (VS) lying areally on a bottom side (UVS), wherein the material sheets (MB1, MB2) are arranged with a respective side surface facing one another abutting against each other at least partially with a respective bottom side (US1, US2) lying areally on a top side (OVS) of the connecting piece (VS), wherein the device (1, 1') comprises a base body (2) with a front edge (5), a rear edge (6) opposite the front edge (5) and two opposite longitudinal edges (7), wherein a top surface side (8) and a bottom surface side (9) opposite the top surface side (8) of the base body (2) respectively extend between the front edge (5) and the rear edge (6) as well as between the two longitudinal edges (7), wherein the top surface side (8), the bottom surface side (9), the front edge (5), the rear edge (6) and the two longitudinal edges (7) entirely border a volume of the base body (2), wherein the device with the base body (2) is configured to be guided between the top side (OVS) of the connecting piece (VS) and the bottom sides (US1, US2) of the material sheets (MB1, MB2) with the top surface side (8) facing towards the bottom sides (US1, US2) of the material sheets (MB1, MB2) and the bottom surface side (9) facing towards the top side (OVS) of the connecting piece (VS), wherein the base body (2) is configured to guide the material sheets (MB1, MB2) at least in areas of their respective bottom sides (US1, US2) adjacent to their side surfaces from the front edge (5) to the rear edge (6) over the top surface side (8) such that the material sheets (MB1, MB2) are guided starting from the front edge (5) at least over a quarter, in particular at least over a half, in particular at least over two-thirds of a maximum extension of the base body (2) between the front edge (5) and the rear edge (6) with their respective side surfaces facing one another separated from one another, and wherein the device (1, 1') is configured to simultaneously heat at least partially the bottom side (US1, US2) of the material sheets (MB1, MB2), the top side of the connecting piece (OVS) and the respective side surface of the material sheets (MB1, MB2) facing one another so as to produce respectively between each of the two material sheets (MB1, MB2) and the connecting piece (VS) as well as between the material sheets (MB1, MB2) parallel connections, in particular parallel weld seams.

2. Movable joining apparatus according to claim 1, wherein the base body (2) is configured as a hollow body and comprises at least one opening (12) for outlet of hot air from the hollow body at the rear edge (6) of the base body (2) into a space between the rear edge (6) of the base body (2), the top side (OVS) of the connecting piece (VS) and the bottom sides (US1, US2) of the material sheets (MB1, MB2).

3. Movable joining apparatus according to claim 2, wherein the top surface side (8) and / or the bottom surface side (9) comprises at least one opening (13) for outlet of hot air from the base body (2).

4. Movable joining apparatus according to claim 2 or 3, wherein a fin (10) protrudes from the top surface side (8) of the base body (2), wherein the fin (10) extends parallel to the maximum extension of the base body (2) at least partially between the front edge (5) and the rear edge (6), and wherein hot air can be introduced into the base body (2) through the fin (10) from an end of the fin (10) facing away from the top surface side (8).

5. Movable joining apparatus according to claim 4, characterized in that the top surface side (8) of the base body (2) is configured to guide the material sheets (MB1, MB2) past the fin (10) such that thermal contact with a side edge of a material sheet (MB1, MB2) at a transition between the respective bottom side to the respective side surface of the material sheets (MB1, MB2) along an extension of the fin (10) between the front edge (5) and the rear edge (6) is established only on a second half, in particular only on a last third and in particular only on a last quarter of an extension of the fin (10) between the front edge (5) and the rear edge (6) of the base body (2).

6. Movable joining apparatus according to claim 4 or 5, wherein a shaft tube (14) is connected to the end of the fin (10), which is configured for guiding an air flow to the end of the fin (10) and at the same time for fixing to a hot air device (22) in a region of the hot air device (22) for the outlet of the hot air flow to be generated by the hot air device (22).

7. Movable joining apparatus according to any of the preceding claims, wherein the bottom surface side (9) of the base body (2) is concave.

8. Movable joining apparatus according to any of the preceding claims, wherein the device (1, 1') is configured as an electrically heated contact heating device (1').

9. Movable joining apparatus according to claim 8, wherein the device (1') is at least partially configured as a directly electrically heated heating plate or the device (1') is at least partially configured as a solid block of material made of a thermally conductive material comprising at least one receptacle for at least one electrical heating element (18).

10. Movable joining apparatus according to any of the preceding claims, wherein at least two guiding profiles (15) protrude outwards from the top surface side (8) of the base body (2), wherein the guiding profiles (15) extend at least partially between the front edge (5) and the rear edge (6) over the first top surface side (8), and wherein the guiding profiles (15) are configured to guide the material sheets (MB1, MB2) for at least a quarter, in particular at least a half, in particular at least two-thirds of the maximum extension of the base body (2) between the front edge (5) and the rear edge (6) with their respective side surfaces separated from one another over the top surface side (8) and to bring the material sheets (MB1, MB2) towards the rear edge (6) into contact with the side surfaces abutting against each other.

11. Movable joining apparatus according to any of the preceding claims, wherein the device (1, 1') is configured to be adjustable in height relative to the chassis.

12. Movable joining apparatus according to any of the preceding claims, wherein the joining apparatus (21) comprises at least one guide aid (29, 30) arranged in front and / or behind the device (1, 1') in the travel direction of the joining apparatus (21) for visually indicating the position of the side surfaces of the material sheets (MB1, MB2) facing one another and abutting against each other.

13. Method for joining of respective two material sheets (MB1, MB2) over a strip-shaped connecting piece (VS), comprising the steps: a. providing a connecting piece (VS) lying areally on a bottom side (UVS) and two material sheets (MB1, MB2) to be joined over the connecting piece (VS), which are arranged with a respective side surface facing one another abutting against each other at least partially with a respective bottom side (US1, US2) lying areally on a top side (OVS) of the connecting piece (VS); b. at least partial heating of the respective bottom sides (US1, US2) of the material sheets (MB1, MB2), the side surfaces of the material sheets and the top side (OVS) of the connecting piece (VS) in a connecting region such that in the connecting region (VS) between each of the material sheets (MB1, MB2) and the connecting piece (VS) as well as between the material sheets (MB1, MB2) simultaneously zones of partially melted and / or melted material of the material sheets (MB1, MB2) and of partially melted and / or melted material of the connecting piece (VS) parallel to one another are formed in the connecting region (VS), in particular which merge into one another without a gap; c. applying pressure in the connecting region to the material sheets (MB1, MB2) from their top sides (OS1, OS2) immediately after the heating to simultaneously form a connection between each of the material sheets (MB1, MB2) and the connecting piece (VS) as well as a further connection between the material sheets (MB1, MB2) upon cooling of the by heating partially melted and / or melted material of the material sheets (MB1, MB2) and the partially melted and / or melted material of the connecting piece (VS) in the zones, wherein the connections extend parallel to one another.

14. Method according to claim 13, wherein the heating of the bottom side (US1, US2) of the material sheets (MB1, MB2), the side surfaces of the material sheets and the top side (OVS) of the connecting piece (VS) in the connecting region is carried out by a movable joining apparatus according to any of claims 1 to 12.