Pallet dryer apparatus

Abstract

The invention relates to a device for drying or curing objects made of clay or concrete. The device comprises a pallet (1) with a support surface (3) having upper longitudinal edges (4), from which side walls (5) project downwards, which in turn have lower longitudinal edges (6). A reinforcing profile (16) is welded to the underside of the support surface (3), preferably in the longitudinal direction of the pallet (1). In order to ensure uniform drying of the objects to be dried despite the presence of the reinforcing profile, the invention provides that the reinforcing profile (16) is U-shaped and is welded by the free ends of its side walls (17) in at least one joining region (18) to the underside of the support surface (3) by resistance welding, in particular resistance web welding.

Description

[0001] The invention relates to a device for drying or curing objects made of clay or concrete, for example, bricks, paving stones, or paving bricks. The device comprises a pallet with a storage surface for the objects, which has upper longitudinal edges, from which side walls project downward, which in turn have lower longitudinal edges. A reinforcing profile is welded to the underside of the storage surface. The invention also relates to a method for manufacturing such a device.

[0002] Such metal pallets are traditionally used for drying bricks or paving stones. The metal pallets are predominantly made of hot-dip galvanized sheet metal. The pallet support surfaces are perforated to allow moisture from the bricks to evaporate from the underside. They are often equipped with an additional reinforcement profile in the center of the support surface to reduce longitudinal deflection.

[0003] DE 28 45 524 A1 discloses a pallet consisting of a continuous sheet of metal with a rectangular storage area for bricks, which has support profiles bent along opposite longitudinal edges. Each support profile consists of a sheet of metal that runs approximately vertically downwards and is bent horizontally inwards at the lower edge to form an elongated standing area. In this case, an extension of the sheet is bent 180° at the inner edge of the standing area and runs adjacent to the inside of the support profile down to below the rectangular storage area, resting against it at the edge. Resistance to bending of the pallet is achieved by connecting the adjacent, vertically running sheets, i.e. of the support profile, to one another at certain points by spot welds.

[0004] There is no reinforcement provided in the transverse direction, so that the storage area between the two longitudinal folds can bend under the load of the bricks to be dried.

[0005] DE 297 05 369 U1 discloses a dry goods carrier for ceramic preforms such as bricks or roof tiles, which can be designed as flat and / or accessory tiles, with a frame formed from profile strips and cross strips and / or cross profiles. The frame is equipped with support surfaces made of perforated metal sheets for at least partial areas of the preforms. At least the support surfaces for the preforms are designed as expanded metal connected to the frame.

[0006] A disadvantage is that if the reinforcement profiles used have a hat-shaped cross-section, they then cover some of the holes, if any, in the pallet storage area. Alternatively, storage areas are also known in the prior art that have no perforation in the area of ​​the flanges of the hat profiles in order to facilitate the creation of the welded connection there. The lateral flanges of the hat profiles do enable a secure welded connection. However, both the at least partial covering of the existing holes and the absence of holes in the storage area in the area of ​​the flanges lead to uneven drying on the underside of the objects to be dried, and thus to disadvantageous drying stresses or even cracks in the objects.

[0007] The invention is therefore based on the object of developing a known device for drying objects and a known method for producing the device in such a way that, despite the presence of a reinforcement profile, uniform drying of the objects to be dried is ensured.

[0008] This object is achieved according to the invention with regard to the claimed device by the subject matter of patent claim 1. Accordingly, the device is characterized in that the reinforcing profile is U-shaped and is welded to the underside of the storage surface by resistance welding, in particular resistance web welding, with the free ends of its side walls in at least one joining area.

[0009] The term "U-shaped reinforcement profile" means that the reinforcement profile has a U-shaped cross-section, with the free ends of its side walls forming the legs of the U-profile. The free ends of at least one of the side walls, preferably both side walls, in the present invention expressly have no bevels / flanges, neither to the outside of the U-profile nor to the inside of the U-profile. In other words, the reinforcement profile used according to the invention expressly does not have a hat-shaped cross-section on at least one of its side walls, and preferably does not have a hat-shaped brim on only one side. The support surface of the reinforcement profile on the underside of the support surface and the joining area are therefore limited—apart from the thickness of the welded joint—to the thickness or the end faces of the side walls of the reinforcement profile, unless a gap is already provided between them.

[0010] The inventive use of a reinforcement profile with such a U-shaped cross-section ensures that the support surface has at least a largely continuous hole pattern in the form of perforations, even in the welded joint area. The area of ​​the perforations in the support surface covered by the reinforcement profile is significantly reduced compared to the use of reinforcement profiles with hat-shaped cross-sections. This offers the advantage of more even drying on the underside of the objects to be dried, and thus a significant reduction in drying stresses or even cracks in the objects to be dried.

[0011] The above-mentioned object of the invention is achieved with respect to the claimed method by the method according to claim 9. The advantages of this solution correspond to the advantages previously described for the device.

[0012] Further advantageous embodiments of the invention are the subject of the dependent device and method claims.

[0013] The description is accompanied by three figures, where Fig. 1 is a plan view of the device according to the invention with the head piece firmly connected to the pallet; Fig. 1 is a plan view of the device according to the invention with the head piece separated in a spatial representation; and Fig. 3 is a plan view of the underside of the device according to the invention with the head piece detached shows.

[0014] The invention is described in detail below with reference to the figures mentioned in the form of exemplary embodiments. In all figures, identical technical elements are designated by identical reference numerals.

[0015] In Figure 1A device for drying initially damp objects that still need to be dried, such as bricks, paving stones or paving clinkers, is shown. The device consists in particular of a pallet 1 with a head piece 2'. The head piece 2' is in Fig.1 an integral part of the pallet 1 and permanently connected to it. The pallet 1 has a storage surface 3 on which the objects are placed for drying. The storage surface 3 has upper longitudinal edges 4, from which side walls 5 protrude downwards or are folded over. The side walls 5 have lower longitudinal edges 6. From the lower longitudinal edges 6, optional lower support surfaces 7 are folded over and aligned parallel to the storage surface 3. The device rests on the lower support surfaces 7 when it is placed on a shelf or dryer trolley.

[0016] A reinforcement profile 16 with the above-defined U-shaped cross-section is welded to the underside of the support surface 3, which reduces the deflection of the support surface in both the longitudinal and transverse directions I, Q. Due to the strictly U-shaped cross-section according to the introductory definition, the support surface of the reinforcement profile 16 on the underside of the support surface 3 and the joining area 18 - apart from the thickness of the welded joint - are limited to the thickness of the side walls 17 of the reinforcement profile 16, unless a gap 21 is provided therebetween; see also Fig. 2 This advantageously results in minimal coverage of the holes 19 in the storage surface 3, thus ensuring good ventilation of the objects to be dried, even on their underside. The welded joint is produced by resistance welding, as described below with reference to the method according to the invention.

[0017] The devices are manufactured in different dimensions depending on the respective requirements. The thickness of the material of the reinforcement profile 16, and in particular of its side wall 17, and thus the contact area with the underside of the storage surface 3, varies, for example, between 1 mm and 3 mm.

[0018] In Figure 2 the device is shown spatially from above.

[0019] The head piece 2 is in the embodiment according to Fig. 2 intended for a detachable connection to the pallet 1 at its head end. The detachable connection is realized, for example, by the interlocking of tabs 10, 11 in pockets 14, 15.

[0020] Holes 22, 20 in the side walls 5, 17 of the pallet and the reinforcing profile 16 and / or a continuous perforation 19 in the storage surface 3 advantageously enable drying air supplied from the side in a dryer or in a drying system to have unhindered access to the objects to be dried, in particular under the storage surface 3 and in this way also to the underside of the objects to be dried on the storage surface.

[0021] According to the Fig. 2In the exemplary embodiment of the invention shown, the free ends of the side walls 17 of the reinforcing profile 16, hereinafter also called sheet metal edges, which abut the underside of the storage surface 3 and are connected to it by welding, are stepped, optionally with multiple steps. The stepping has the effect that, before welding, the sheet metal edges only rest on the underside of the storage surface 3 at certain points in the areas of a first, foremost step 17-1 and / or in a short, linear section. The welding current melts the sheet metal edges at the contact points, i.e. in particular at the first steps 17-1, and the resulting melt then flows at least partially into the holes 19 in the storage surface 3 and thereby connects the reinforcing profile 16 to the storage surface 3 of the pallet 1. The design of the sheet metal edges with the first and second steps 17-1, 17-2 ensures that after orWhen the first steps 17-1 are melted away, the reinforcement profile 16 is positioned precisely on the underside of the support surface up to the second step 17-2. If the first step 17-1 is missing, the welding between the reinforcement profile 16 and the underside of the support surface 3 can also be performed at the second step 17-2 adjacent there.

[0022] The steps 17-1, 17-2, 17-3 differ in each case by different heights H of the side walls 17 of the reinforcement profile 16. The side walls 17 are highest at the first step 17-1, less high at the second step 17-2 than at the first step 17-1 and less high at the third step 17-3 than at the second and first step.

[0023] Figure 3 shows a view of the underside device according to Fig. 2 in welded condition. The first stages 17-1 are melted and therefore in Fig. 3can no longer be recognized. The joining area, ie the location of the weld, is indicated by reference numeral 18.

[0024] By forming a third step 17-3 on the sheet metal edge, a defined gap 21 remains between the reinforcement profile 16 and the underside of the support surface 3. This allows the two components 16, 3 to oscillate freely there in the event of impacts during transport, thereby reducing noise generation. Noise generation can be further reduced by optionally providing a damping element 23 in the gap 21. The damping element 23 can, for example, be designed to be attachable to the third step 17-3. List of reference symbols

[0025] 1. Pallet 2. Head piece as a separate component 2' Head piece as an integral part of the pallet 3 Storage area 4 Upper long edge 5 Side wall 6 Lower long edge 7 Support surface 10 Top outer flap 11 Bottom outer flap 14 Top pocket 15 Bottom pocket 16 Reinforcement profile 17 Side wall Reinforcement profile 17-1 First step 17-2 Second step 17-3 Third step 18 Joining area 19 Perforation 20 Holes in side wall of the reinforcement profile 21 Gap between a side wall of the reinforcement profile and the underside of the storage area 22 Holes in side wall of the pallet 23 Damping element H Height of side wall L Longitudinal direction of the pallet Q Transverse direction of the pallet

Claims

1. Device for drying or hardening objects made of clay or concrete, comprising a pallet (1) with a storage surface (3) with upper longitudinal edges (4), from which side walls (5) project downwards, which in turn have lower longitudinal edges (6), wherein a reinforcing profile (16) is welded to the underside of the storage surface (3), preferably in the longitudinal direction of the pallet (1); characterized by that the reinforcing profile (16) is U-shaped and is welded to the underside of the storage surface (3) by resistance welding, in particular resistance web welding, with the free ends of its side walls (17) in at least one joining area (18).

2. Device according to claim 1, characterized by thatthe free ends of the side walls (17) of the reinforcement profile (16) each have at least one of the following steps: - a first step (17-1) which is melted during the welding process to form the joining region (18) and to weld the reinforcement profile (16) to the underside of the storage surface (3); - a second step (17-2) which, when the reinforcement profile (16) is mounted on the underside of the storage surface (3) and the first step (17-1) is melted off or not present at all, rests on the underside of the storage surface (3) and is optionally also welded to it to form the joining region (18); and / or - a third step (17-3) which forms a gap (21) to the underside of the storage surface, the first step protruding further than the second step and the second step protruding further than the third step.

3. Device according to claim 1 or 2, characterized by thatthe support surface (3) also has a continuous hole pattern in the form of the hole (19) in the joining area (18) of the weld.

4. Device according to one of claims 1-3, characterized by that the side walls (17) of the reinforcing profile (16) are provided with holes (20).

5. Device according to one of claims 1-4, characterized by that the side walls (5) of the pallet (1) are provided with holes (22).

6. Device according to one of the preceding claims, characterized by that the pallet (1) has a head piece (2) on at least one of its head sides, which is formed integrally with the pallet or as a separate component for preferably detachable insertion into the head side of the pallet (1).

7. Device according to claim 6, characterized by that the head piece (2) has rounded corners which preferably project beyond the side walls (5) of the pallet (1).

8. Device according to one of claims 2 to 7, characterized by a damping element (23) which can be arranged in the gap (21) between the free end of the side wall (17) and the underside of the storage surface (3), and which can preferably be plugged onto the free end of the side wall (17).

9. A method for producing a device according to one of the preceding claims, wherein the method for resistance welding the reinforcement profile (16) to the underside of the support surface (3) comprises the following steps: - pre-assembling and clamping the reinforcement profile (16) to the underside of the support surface (3), wherein only the free ends of the side walls (17) of the reinforcement profile (16) preferably only partially contact the underside of the support surface (3); and - resistance welding the reinforcement profile to the support surface (3) in the joining regions (18) by applying a welding current to the two components (16, 3) by connecting the two components to different poles of a welding machine.

10. Method according to claim 9, characterized by thatduring pre-assembly - as far as the steps (17-1... -3) are present at the free ends of the side walls (17) of the reinforcement profile (16) - initially only the first or second steps (17-1, 17-2) rest on the underside of the storage surface (3).

11. Method according to claim 10, characterized by that in the resistance welding step, the first steps (17-1), at which the side wall (17) of the reinforcement profile (16) is higher than in the second steps (17-2), are melted to form the joining regions (18) and to weld the reinforcement profile (16) to the underside of the support surface (3); and that If the second steps (17-2) are present, these come into contact with the underside of the support surface (3) after the first steps have melted.

12. Method according to claim 11, characterized by thatin the presence of the third steps (17-3), at which the side wall (17) of the reinforcing profile 16 is less high than at the second steps (17-2), a gap (21) is formed towards the underside of the storage surface (3).

13. Method according to claim 12, characterized by a damping element (23) in the gap (21) between the free end of the side wall (17) and the underside of the storage surface (3), wherein the damping element is preferably plugged onto the free end of the side wall (17).

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