The invention relates to one of two walking devices for walking on solar modules, with a carrying device, to which a damping device intended for stepping on the solar modules is connected at the bottom, with a foot mount provided above the carrying device and with a compensating device arranged between the carrying device and the foot mount, which enables the foot receptacle to be moved and locked.
The closest prior art includes walking devices which are described in documents FR 2 584 277 A1, DE 20 2012 000 072 U1, DE 20 2015 001 998 U1 and WO 2020/160721 A1 Walking devices according to the last-mentioned patent application have been tested in practice. Although these walking devices were equipped with a relatively thick damping device, harmful hair cracks were nevertheless detected in the glass plates of the solar modules after the solar modules have been walked on.
The document DE 20 2020 001 533 U1 also includes the prior art. The solution proposed in this document is concerned with a special design of the compensating device in conjunction with the carrying device and the foot mount. However, the document mentioned does not contain a proposed solution as to how the formation of hairline cracks in the glass plates of the solar modules can be avoided when walking on solar modules.
It is the object of the invention to further develop the two walking devices of the present type in such a way that the formation of hairline cracks in the solar modules is avoided when walking on the solar modules.
First solution of the object is described in the characterizing part of claim 1.
Second solution of the object is provided by the characterizing part of claim 2.
When walking on solar modules, their framed glass plates are bent downwards. The maximum allowable deflection is approximately 12 mm. A solar module is comparable to a carrier mounted on all sides, which is exposed to a migrating load during the walking process. The so-called torque line, which results from the migrating load and the resulting different large bending moments, extends approximately parabolic with the exception of the four edge regions of the solar module.
This is where the two proposed solutions start in an advantageous manner. In the first solution, at least the underside of the damping device intended to rest on the surface of the glass plate and/or at least the underside of the carrying device is/are curved downwards in a spatial manner so that when walking on a solar module, this is/are approximately adapted to the surface region of the solar module that is bent downwards. As a result, in particular with the aid of the flexible damping device, the largest possible contact of the walking device proposed on a solar module is achieved. The surface loads per unit area are thus considerably reduced. In particular, a spherical cap-shaped or a paraboloid-shaped design of the underside of the carrying device and/or the underside of the damping device is suitable for an extensive adaptation to the spatial curvature profile of a loaded solar module.
The second proposed solution also proves advantageous because an all-round edge region is created here on the carrying device, which is designed to be resilient. The edge region of the carrying device, which is thus easily bendable, is therefore able to adapt, in a large area, to the course of the curvature of a bent solar module in the event of a load, and to rest on it, so that the surface pressing forces acting on a solar module are likewise substantially smaller per unit area than that of the surface pressing forces which occur in the previously known manner and are caused by the previously known walking devices.
In all walking devices which are used for the prior art, the carrying device thereof and the damping device thereof are designed as flat plates, wherein the carrying device is designed to be rigid. Since, during the spreading of a solar module, the glass plate thereof bends downwards, the glass plate thus bent is comparable to a flat shell. If you stand with a previously known walking device on a solar module, the walking device with its rectangular, rigid carrying device and with its likewise rectangular damping device, due to the deflection of the solar module that occurs, only supports itself with its four corner areas on the bent solar module. This results in four small-area or even only linear support regions with the result that high surface pressure values per unit area are inevitably produced in these corner or support regions. These high surface pressure values ultimately cause the formation of the hair cracks in the brittle glass plates of the solar modules. In the now proposed walking devices, the support does not only take place over these corner regions, but at a maximum over a large area and spatially, so that smaller surface pressure values are set per unit area and the formation of harmful hair cracks at the solar modules is thereby avoided.
Further advantage of the invention is achieved if the damping device consisting of foam is equipped with foam-free spatial zones such as breakthroughs, depressions or cavities. The foam suitable for walking devices must be water-resistant and must therefore not have water-absorbing properties. However, these conditions give rise to a foam which has a greater hardness and stiffness and is actually not compliant enough to achieve an ideal damping effect. By incorporating foam-free spatial zones into the damping device, optimum flexibility can be achieved while maintaining sufficient stability. The damping device can therefore be formed both from a single thickness and from at least two thinner foam sheets, which are likewise equipped with the foam-free spatial zones, wherein the size, i.e. the spatial circumference of the foam-free spatial zones, is decisive for achieving the aforementioned positive properties of the damping device. Since the aim is to design walking devices with the lowest possible weight, the spatial zones contribute to a reduction in weight. Such spatial zones can also be provided on the support device for weight reasons.
The invention is explained in more detail with reference to exemplary embodiments. In the drawings:
FIG. 1 shows a side view of a first walking device;
FIG. 2 shows the same walking device in front view;
FIG. 3 shows a solar module loaded with this walking device;
FIG. 4 shows a geometric representation of the underside of a walking device with a perforated solar module;
FIG. 5 shows a second walking device in a side view;
FIG. 6 and FIG. 7 show the carrying device of the second walking device;
FIG. 8 and FIG. 9 show two further embodiments of the carrying device;
FIG. 10 shows a walking device in a side view with a sectioned damping device;
FIG. 11 shows the damping device shown in FIG. 10 from above;
FIG. 12 shows a sectional representation of a damping device consisting of two foam sheets with spatial zones, and
FIG. 13 shows a top view of a further damping device equipped with offset spatial zones.
The bending of the solar modules is relatively low, based on the size thereof, and can be reproduced very poorly. In the following drawings, the recognizable curvatures and sagging are therefore shown in an exaggerated size. Likewise, individual forces marked by arrows are to be considered merely as an example.
FIG. 1 shows a first walking device 1 located on a horizontal plane 24, which is intended for walking on solar modules 21. The walking device 1 can be placed in a weight-less and unloaded manner, so that the damping device 9 thereof is shown as not loaded. The walking device 1 has a carrying device 2, to which the damping device 9 connects downwards. A foot receptacle 12, which is formed by a plate and, for example, by a shoe arranged on the plate, is provided above the carrying device 2. Between the carrying device 2 and the foot receptacle 12 there is a compensating device 11, which determines the mobility of the foot receptacle 12. After a locking is released, the foot receptacle 12 can be pivoted only up and down by means of the compensating device 11 in a known manner, either about a horizontal axis or can be moved on all sides by means of a ball joint-like connection and then locked again for use. It can be seen from the indicated straight plane 24 that the carrying device 2 and the damping device 9 are curved downwards, so that the lower side 10 of the damping device 9 rests only partially on the plane 24.
FIG. 2 shows the same walking device 1 in a side view. Here too, it can be seen with the aid of the indicated plane 24 that the carrying device 2 and the damping device 9 are bent downwards. In this manner, taking into account the deflection according to FIG. 1, a spatially curved deformation of the carrying device 2 and of the damping device 9, bent downwards, is present. The exemplary embodiment according to FIGS. 1 and 2 permits a simple production method. In this case, the carrying device 2 originates from a planar plate, which is bent downwards in a spatially curved manner with the aid of an embossing device. The damping device 9 is in turn formed from a planar flexible foam sheet, which is glued with its upper side to the now spatially curved underside 3 of the carrying device 2, so that the underside 10 of the damping device 9 likewise has a spatially curved, downwardly curved shape. Nevertheless, the carrying device 3 and the damping device 9 can also be designed as molded parts originating from a mold, the lower sides 3 and 10 of which are formed in a spatially curved manner pointing downwards. The lower sides 3 and 9 of all the embodiments mentioned thus have a spatially curved surface region 14 which is curved downward or formed downward, wherein each surface region 14 can preferably be spherical, that is to say rotationally symmetrical or spheroidal. A spherical dome-shaped surface region 14 is ideal, which is simple to produce or another rotationally symmetrical surface region 14, for example in the manner of a paraboloid. On the other hand, the spatially curved surface region 14 can also be selected to be non-rotationally symmetrical, in which, for example, at least two spatially curved portions of the surface region 14 are interrupted by at least one non-spatially curved surface portion. These examples are intended to show that the spatially curved, downwardly curved or shaped surface region 14 can be provided differently.
If only the underside 10 of the damping device 9 is curved or formed in a spatially curved downward direction, the thicker region of the damping device 9, which extends centrally, is first loaded during the occurrence onto a solar module, before the edge regions thereof then participate after and after the force transmission. This results in the same force pattern as shown below in FIG. 3.
In order to ensure that the compensating device 11 is resting on the carrying device 2 and is fastened thereto, it is possible, in the case of a spatially curved carrying device 2, which is designed for example by a plate, to provide centrally a planar horizontal surface portion which interrupts the surface region 14 of the carrying device 2. In the example, this surface portion, not shown in the drawing, of a planar circular surface would correspond, since the compensating device 11 shown here by way of example has a cylindrical outline. In this case, the surface region 14 is only partially spatially curved and only partially curved downward.
FIG. 3 schematically shows a solar module 21, which is loaded centrally and uniformly by a walking device 1. There is an ideal load condition, so to speak. The planar plate 22 of the solar module 21 is largely curved downward for a spatial parabolic course. The glass body unit which is provided for power generation is meant with the plate 22. The arrow F indicates the size of the load by the walking device 1 resting on the solar module 21. In the example within the damping device 9, the bending elasticity of the damping device 9 is selected to be the same everywhere. The course of curvature of the underside 3 of the carrying device 2, i.e. the curved surface region 14, does not exactly follow the parabolic course of the glass plate 22. The underside 3 of the carrying device 2 is spatially more strongly curved than the spatial curvature profile of the glass plate 22. As a result, in the loaded state, the centrally measured distance a between the carrying device 2 and the glass plate 22 is smaller than the equally measured distance b at the edge regions 4 of the carrying device 2. In the example, due to the selected bending elasticity of the damping device 9, the weight force F is transmitted over the entire floor plan surface of the damping device 9. The diagram of forces drawn in (arrows) shows that the individual forces per unit area increase steadily towards the center and decrease towards the edge regions 4 and can even go to zero there. This decrease in force is caused by the fact that the distances between the underside 3 of the carrying device 2 and the surface of the glass plate 22 become larger, the more one is approaching the circumferential edge region 4 of the carrying device 2, since the more this region is reached, the less the damping device 9 is compressed. The bending elasticity of the damping device 9 is therefore to be selected in such a manner that the entire outline surface of the damping device 9 is involved in the transmission of the weight load of a person wearing the walking device 1. This optimal state allows low and harmless individual forces per unit area. The four edge zones 23 of the downwardly bent glass plate 22 gradually, as they approach the frame of the solar module 21, become horizontal, in order to then be attached to and in the frame of the solar module 21. Thus, a circumferential transition region is created in which the surface of the glass plate 22 transitions from a horizontal position into the parabolic shape when loaded. It has been found in tests that this circumferential transition region is highly susceptible to load and the formation of hairlines in the glass plate 22 is particularly possible here. However, since the surface loading by the walking device 1 decreases towards the edges of the carrying device 2, the above-mentioned transition regions of the solar module 22 are less stressed in an advantageous manner, so that no formation of hair cracks is to be gated here either. Based on the drawing, this state can be easily imagined by the walking device 1 being moved to the right or to the left.
FIG. 4 schematically shows the course of curvature of the underside 10 of the damping device 9 and the approximately parabolic profile of a curved solar module 21. The underside 10 of the damping device is designed as a spherical cap in the example, while the plate 22 of the solar module 21 is present as a calotte with a mostly parabolic cross section. Toward the center, the course of curvature of the underside 10 of the damping device 9 becomes closer to the parabolic profile of the glass plate 2. Viewed geometrically, the walking device 1 designed in this manner rests only on one point on the glass plate 22. As can easily be imagined, when loaded by the walking device 1, the damping device 9 is compressed more and more, so that as the load increases, an ever-growing, circular contact surface 20 is formed between the damping device 9 of the walking device 1 and the glass plate 22 when viewed from above. As already mentioned, it is desirable that, in the case of a weight load by a person, the support surface 20 mentioned is formed by the entire outline surface of the damping device 9.
The underside 10 of the damping device 9 can additionally be equipped with at least one slip securing means 13, so that the at least one anti-slip securing means 13 forms the underside 10 of the damping device 9 and is likewise curved in a spatially curved manner downward. In this case, the anti-slip securing means 13 is part of the damping device 9 and forms its underside 10.
FIG. 5 shows a second embodiment of a walking device 1′ located on a solar module 21. A preferably plate-shaped carrying device 2 is provided, on the underside 3 of which the damping device 9 is located. The walking device 1′ rests with its damping device 9 on the solar module 21. The compensating device 11 is arranged on the carrying device 2. The compensating device 11 carries the foot receptacle 12. With the aid of the compensating device 11, the foot receptacle 12 can be fixed in different angular arrangements, as already described. The carrying device 2 is formed in at least two parts.
FIG. 6 shows a preferred form of a carrying device 2 of the walking device 1′. The carrying device 2 has a first part 5 and a second part 6, wherein the damping device 9 being located on the underside of the second part 6, see FIG. 5. The first part 5 is placed on the second part 6 and is fixedly connected to the second part 6, for example by gluing or screwing or riveting.
FIG. 7 is a plan view of the carrying device 2 shown in FIG. 6. The first part 5 is placed centrally on the second part 6. The outline of the first part 5 is smaller than the outline of the second part 6. The first part 5 forms a central region 7 of the walking device 1′. Because the outline of the first part 5 is smaller than that of the second part 6, an edge region 4, which comprises the central region 7 on all sides, is formed together with the second part 6. At least the first part 5, optionally also the second part 6, is designed to be resilient in such a manner that, when walking on a solar module 21, at least the edge region 4 of the carrying device 2 adapts to the spatial curvature profile of the glass plate 22 of a solar module 21 that is set under load by means of slight upward bending. If the load is removed, the at least second part 6 resumes its initial position. Such resilient properties can be achieved by the use of spring steel or of suitable and known plastic. When spring steel is used, it is expedient to design the second part 6 of thin spring steel sheet in order to advantageously also reduce the overall height of the walking device 1′ and its weight.
FIGS. 8 and 9 show two exemplary embodiments of a carrying device 2. In these examples, the first part 5 and the second part 6 are joined in a form-fitting and force-fitting manner, i.e. in a stationary manner, as can be seen from the sectional views. Here too, the first part 5 forms the central region 7, while the second part 5 can form the edge region 4.
In the walking device 1 or 1′ shown in FIG. 10, the damping device 9 is formed in a known manner by a foam sheet 15 which is interrupted in an inventive manner by a number of foam-free spatial zones 16 which are designed as vertically arranged perforations 18 in the example. The cross section of the perforations 18 can be selected as desired. A round cross section is preferred.
Spatial zones 16 can also be provided in the same manner at least on the second part 6 and/or on the first part 5 of a carrying device 2, as are described in FIGS. 8 and 9. In this manner, a weight reduction can also be achieved in the carrying device 2.
FIG. 11 is a plan view of the damping device 9 described in FIG. 10. The drawing shows a plurality of spatial zones 16 designed as perforations 18. In the example, the openings 18 are selected to be the same size, which does not exclude the diameter of the cylindrical openings 18 also being able to be of different sizes.
FIG. 12 shows a sectional illustration of a damping device 9 having two superposed foam sheets 15, 15a. In both foam sheets 15, 15a, spatial zones 16 are provided as openings 18, the vertical axes 17 of which are respectively arranged congruently. The drawing further shows the carrying device 2 and an anti-slip securing means 13, between which the damping device 9 formed by the two foam sheets 15, 15a is located. More than two foam sheets 15, 15a, etc. can also be provided on top of one another in order to form a damping device 9. The spatial circumference, i.e. the size or diameter of the individual spatial zones 16, can be chosen to be different sizes between the foam panels 15, 15a, etc.
FIG. 13 shows a plan view of an axially offset arrangement of the spatial zones 16 formed as cylindrical openings 18 in two foam sheets 15, 15a. The arrangement and the size of the spatial zones 16 are selected in such a manner that the cylindrical contours 19 of the spatial zones 16 located in the upper foam 15 overlap with the cylindrical contours 19 of those spatial zones 16 which are located in the foam sheet 15a lying below. This arrangement can produce a relatively soft, but still stable damping device 9.
The spatial zones 16 can also be designed as inversely arranged depressions, in which no water can collect. The spatial zones 16 can also be designed as cavities located within the damping device 9.
It is left to the manufacturer of the walking devices 1, 1′ which combinations of spatial zones 16 he wishes to choose with or without an axis offset arrangement. It is also left to the manufacturer how large he wishes to determine the spatial range of the individual spatial zones 16. The spatial zones 16 can be selected to be of the same size as well as in combination of different sizes. By way of example, suitable and known cutting tools can be cut into the foam sheets 15, 15a etc. as openings 18 or spatial zones 16 designed as depressions. It depends on the respective strength of the foam sheets 15, 15a, etc., which cross-sectional shapes and arrangements for the spatial zones 16 are to be selected. The respective spatial extent or the size or the volume of the spatial zones 16 is in any case always larger than the spatial extent of the individual pores of the foam panels 15, 15a, etc. and thus of the damping device 9. As already described, the damping device 9 can be made of at least one commercially available foam sheet 15. However, it is also possible to produce the damping device 9, which is equipped with or without spatial zones 16, as a plastic foam part originating from a mold, in which, for example, only the underside 10 is curved in a spatially curved manner downwards. The same is also transferable to the carrying device 2.
Patent Application
20240285033
