sandbox

Abstract

In winter, sandboxes are cold and the sand is cold, so children tend to prefer playing indoors rather than outside. This invention aims to provide a sandbox that effectively maintains a suitable sand temperature for children to play in, while reducing the amount of electricity required to power the heating equipment, in order to encourage children to actively play outside when heating is installed in the sandbox. [Solution] A sandbox is provided having a sandbox body, the sandbox body being filled with sand, and characterized in that the entire outer periphery, bottom, and top of the sandbox body are surrounded by an insulating material.

Description

Technical Field

[0001] This invention relates to a sandbox where children can actively play even in cold winter seasons.

Background Art

[0002] Sandboxes are recommended by educational scholars as educational play equipment, but in winter, sandboxes are cold and few children play with sand.

Prior Art Documents

Patent Documents

Patent Documents

Summary of the Invention

Problems to be Solved by the Invention

[0003] Although sandboxes in winter are cold and the sand is cold, children tend to want to play indoors rather than outdoors. However, there is a demand for the development of a sandbox that encourages children to actively play with sand outdoors even in winter.

Means for Solving the Problems

[0004] The above object of the present invention is achieved by a sandbox having a sandbox body filled with sand, wherein the entire outer peripheral portion, bottom portion, and upper portion of the sandbox body are surrounded by a heat insulating material. According to such a sandbox, for example, when a heating facility (such as a heater) is installed near the bottom of the sandbox body so that the entire sand becomes warm, it is possible to suppress a decrease in the temperature of the sand heated by the heater or the like. Even in winter, children can actively play with sand in the sandbox. In addition, when heating by a heating facility (such as a heater), heat is less likely to escape to the outside of the sandbox body, so the amount of electric power required to drive the heater can be reduced. Also, the time until the temperature of the sandbox is set to a desired temperature, for example, 15°C or higher and 45°C or lower, can be shortened

[0005] Furthermore, the above-mentioned objectives of the present invention can also be achieved by a sandbox having a sandbox body, wherein the sandbox body is filled with sand, and the sandbox body is characterized in that the heat insulating material itself constitutes the sandbox body. Even with such a configuration, the same effects as described above can be obtained.

[0006] Furthermore, with respect to the sandbox described above, it is preferable to provide a space between the bottom surface of the sandbox body and the ground surface. For example, by providing a space of about 10 to 15 cm between the sandbox body and the ground surface and installing ground surface insulation material, and installing exterior wall insulation material in the outer wall section while also ensuring space, an insulating effect and a heat retention effect can be achieved. If the space between the ground surface and the sandbox body is too large, a part of a child's body may get caught and become dangerous, so a space of about 10 to 15 cm is preferable. If ground surface insulation material is not installed, a space of about 10 cm is preferable.

[0007] Wood used outdoors swells when it rains and shrinks when it dries, so even if lock nuts are used, it is necessary to tighten them further. If there is a space of about 10 cm above the ground surface, it is possible to tighten them further.

[0008] The walls and floor of the sandbox are constructed of wood, and in the walls, it is preferable to use metal pipes as spacers to ensure gaps between the pieces of wood for drainage and ventilation.

[0009] It is preferable that the sandbox has a structure in which all surfaces, including the outer perimeter, bottom, and top, are insulated with heat-insulating material.

[0010] Since the heater in the sandbox is only installed during the winter, it is preferable to design the structure so that the insulation can be removed in the spring and reinstalled in the winter.

[0011] By creating multiple interconnected through-holes in the insulation material and adding ribs, the insulation material can be strengthened and its drainage properties improved, allowing the sandbox to be formed using the insulation material itself.

[0012] By providing multiple through-holes that connect from the inside to the outside, the insulation material improves the drainage of the sandbox and prevents mold growth. The insulation material can also be treated to protect against UV degradation and have its surface treated, allowing the insulation material itself to function as a drainage component of the sandbox.

[0013] By attaching a permeable sheet to the inner surface of the sandbox structure, it prevents sand from leaking out and clogging through the insulation material which has multiple perforations, and also prevents insects from entering from the outside. The permeable sheet also has the effect of acting as a filter, as rainwater washes away the sand in the sandbox, keeping it clean.

[0014] Starting from the bottom of the sandbox, an insulating material is placed on top of the bottom material, followed by a permeable sheet, then cushion sand, then a metal plate with a heater wire attached, then another permeable sheet, and finally sand is placed on top to warm the sand in the sandbox, thus creating a heated sandbox.

[0015] To enhance drainage and heat retention, it is preferable to leave a gap of approximately 10 to 15 cm above the ground level in the sandbox.

[0016] The sandbox can be rectangular, round, or diamond-shaped; the shape doesn't matter. [Effects of the Invention]

[0017] When installing heating equipment in a sandbox, it is possible to reduce the amount of electricity required to drive the heating equipment while effectively maintaining a suitable sand temperature for children to play in. [Brief explanation of the drawing]

[0018] [Figure 1] This is a perspective view showing the interior of the sandbox in the embodiment. [Figure 2] This is a cross-sectional view A-A' showing spacers installed in the gaps between the logs in the wall section of Figure 1. [Figure 3] This is a cross-sectional view of the sandbox installed in the embodiment. [Figure 4]This is a drawing showing the arrangement of heater wires in an embodiment. [Figure 5] This is a plan view of the heat insulating material and the sand field body in an embodiment. [Figure 6] This is a cross-sectional view of the heat insulating material and the sand field body in an embodiment. [Figure 7] This is a detailed view of the sand field body and the heat insulating material according to an embodiment.

Mode for Carrying Out the Invention

[0019] When the heater wire 9 is attached to the aluminum plate 10 made of a metal with high thermal conductivity and energized inside the bottom surface of the sand field body for experiments, an effect was recognized. By leaving a space of about 10 cm between the ground surface and the sand field body, and by providing a ground surface heat insulating material 14 on the ground surface, a sand field internal bottom heat insulating material 7 inside the bottom surface of the sand field, and an outer wall heat insulating material 15 on the outer peripheral wall surface, a higher effect could be confirmed. Also, by providing a heat preservation lid 16 when the sand field is being heated and when not in use, the sand 12 in the sand field body 20 could be heated more effectively. Based on these experiments, an economical method for heating the sand field was found.

[0020] FIG. 1 and FIG. 2 are an image diagram of installing the sand field body on the sand field pedestal 2 and a cross-sectional view of the wall portion. A bottom member 3 is provided on the bottom surface of the box-shaped sand field. In order to secure a gap 24 between the round timbers 4 of the wall member on the outer peripheral portion of the bottom member 3, a gap spacer 5 for the wall member is provided and it is a perspective view of the sand field constituted by fastening bolts 19.

[0021] On the bottom surface of the sand field body, a ribbed sand field internal bottom heat insulating material 7 provided with a plurality of communicating through holes 21 is laid to drain water from the bottom surface of the sand field while preventing the escape of heat generated by heating. In order to secure a gap 24 between the round timbers 4 of the wall member constituting the sand field body, a gap spacer 5 for the wall member is provided. By stretching a water permeable sheet 8 to prevent the outflow of the sand 12 in the sand field from the gap 24 between the round timbers 4 of the wall member and to prevent clogging of the through holes 21 of the sand field internal bottom heat insulating material 7, drainage of the entire sand field can be ensured and a clean heating sand field can be provided.

[0022] The reason for laying a layer of cushion sand 18 about 3cm to 5cm thick on top of the permeable sheet 8 at the bottom of the sandbox is that a bend is needed when bending the heater wire 9 at a right angle, and the sand is laid down as a cushioning material for that bend. This cushion sand 18 under the heater wire is not for sand play, so a minimum thickness is preferable. Overlapping the heater wires 9 or having them too close together can cause malfunctions or accidents, so the cushion sand 18 under the heater wire is necessary to allow for bending.

[0023] Figure 2 is a cross-sectional view showing how to secure the gap 24 between the wall member logs 4 and the wall member logs 4, or the gap 24 between the coping 6 and the wall member logs 4. By providing wall member gap spacers 5 at predetermined intervals on the wall member logs 4, drainage and ventilation can be obtained from the gap 24 between the wall member logs 4.

[0024] If the log 4 of the wall member absorbs a lot of moisture, it will expand and try to push up the log 4 of the wall member above it. However, since the bottom member 3 and the coping 6 are fastened together with fastening bolts 19, the log 4 of the wall member may deform. To prevent this problem, it is preferable to use a metal pipe as the spacer 5 for the gap 24 between the log 4 of the wall member. If the log 4 of the wall member swells, the spacer will bite into the log 4 of the wall member. Therefore, it is preferable to use a metal pipe for the spacer 5 for the gap between the log 4 of the wall member.

[0025] The spacer 5 for the gaps in the wall components can be made of materials other than metal, such as resin, wood, concrete, or stone.

[0026] Figure 3 is a cross-sectional view showing a sandbox support base 2 placed on the ground surface 1, with the sandbox body 20 installed on the sandbox support base 2. The next figure is a cross-sectional view of a heated sandbox where a sandbox support base 2 is installed on the ground surface 1, a bottom member 3 is placed on the sandbox support base 2, an insulating material 7 is laid on the bottom of the sandbox interior, a permeable sheet 8 is laid on top of that, cushion sand 18 for under the heater wires is placed on top of that, an aluminum plate 10 with heater wires 9 attached is placed on top of that, and sandbox sand 12 is placed on top of that.

[0027] Figure 4 is a plan view showing the arrangement of the heater wires 9. The heater wires 9 are energized from the controller box 13, converting electricity into thermal energy and transferring heat to the sand 12 in the sandbox. Since the sandbox is installed for young children, the controller 13 and temperature sensors control the temperature to ensure it is within a range that will not cause burns and is appropriate for children to play in the sand. For example, the temperature of the sand filling the inside of the sandbox is controlled to be between 15°C and 45°C, more preferably between 25°C and 30°C. It is preferable to install multiple temperature sensors on the bottom and sides of the sandbox and use the average value of the detected temperatures to control the temperature so that the temperature of the sand as a whole is between 15°C and 45°C.

[0028] A box-shaped sandbox body 20 with good drainage and ventilation is constructed by attaching heater wires 9 to a material with high thermal conductivity, such as an aluminum plate 10, and laying it on the inner surface of the bottom of the sandbox, thereby uniformly and efficiently heating the sand 12 in the sandbox body 20 and insulating the entire sandbox body 20 with insulation material.

[0029] Since the thermal conductivity of liquids is lower than that of solids, and the thermal conductivity of gases is lower than that of liquids, the space between the sand grains in the sandbox can be expected to have a heat retention and heat storage effect. As this is a sandbox in a children's facility, it is preferable to configure the heater to turn off when the temperature reaches 55°C. Depending on the size of the sandbox (the sandbox itself), for example, by controlling the heater to turn off when the temperature reaches 55°C and to turn it back on to reheat when the temperature drops to 40°C, the entire sandbox can be kept at a slightly warm temperature of around 25°C.

[0030] Figure 5 is a plan view of the sandbox body 20, showing the log 4 wall members surrounded by exterior wall insulation 15. The exterior wall insulation 15 is provided to insulate the sandbox body 20. The ground surface insulation 14 is shorter than the exterior wall insulation 15.

[0031] Figure 6 is a cross-sectional view showing the sandbox body 20 surrounded by exterior wall insulation 15, ground surface insulation 14, and heat-insulating lid 16. It shows the installation method of the ground surface insulation 14, exterior wall insulation 15, and heat-insulating lid 16, with the sandbox support 2 placed on the ground surface 1 beneath the sandbox. The sandbox body 20 is raised about 10 to 15 cm above the ground, and the sandbox support 2 is used to support the sandbox body 20. The reason for raising the sandbox is that in the summer, the exterior wall insulation 15 can be removed, allowing air to pass underneath the sandbox to dry the sand 12 and maintain clean sand. In winter, the sandbox body 20, along with the ground surface insulation 14, exterior wall insulation 15, and heat-insulating lid 16 installed on the ground surface 1, heat and insulate the entire sandbox.

[0032] The sandbox wall is constructed with fastening bolts 19 that pass through the wall members (logs 4), including the coping 6, and the spacers 5 that create gaps between the wall members (logs 4) and the exterior wall material. If the wall members (logs 4) dry out and need to be tightened, there is a gap 23 between the sandbox body 20 and the ground insulation material, providing enough space to tighten the bolts with a wrench.

[0033] Please refer to Figure 7 for explanation. This is a cross-sectional view of the sandbox body surrounded by insulation material. The outer wall of the sandbox body is surrounded by outer wall insulation material 15, ground surface insulation material 14 is installed below the sandbox body, and a heat-retaining cover 16 is installed on top of the sandbox. The gap 23 above the ground surface insulation material 14 installed on the ground surface 1 serves to retain heat. In the summer, the outer wall insulation material 15 is removed, so if this space is too large, a part of a child's body may get trapped, which is dangerous, so a gap of about 10 cm is preferable. The insulation material is generally about 5 cm thick, so the gap 23 between the ground surface insulation material 14 and the bottom of the structure will be around 5 cm to 10 cm, providing insulation, heat retention, and safety for children.

[0034] The exterior wall insulation material 15 has multiple through-holes 21 that connect from the inside to the outside, ensuring drainage while also retaining the heat of the sand 12 in the sandbox body 20.

[0035] The ground surface insulation material 14, like the exterior wall insulation material 15 described above, has multiple through-holes 21 that connect from top to bottom, and has ribs 22 on the bottom surface to ensure strength while allowing for efficient drainage and ensuring insulation and heat retention.

[0036] In the case of the sandpit's internal bottom insulation material 7, it is preferable to attach ribs not only to the bottom surface but also to the top surface, as this improves both strength and drainage. Drainage is further improved by laying a permeable sheet 8 on top of the top surface ribs.

[0037] The sandbox body 20, which makes up the sandbox, uses logs as wall members, and spacers 5 for gaps between wall members are provided to create gaps 24 between the wall member logs 4, and fastening bolts 19 are used to connect them, and the sandbox body 20 is made up of a retaining wall and a bottom member 3, resulting in a sandbox with good drainage and ventilation.

[0038] For outdoor sandboxes, it is preferable to use wood that has been pressure-treated for rot and termite resistance. Alternatively, sandboxes constructed from rot-resistant chestnut or ironwood with locking nuts are even preferable.

[0039] At the bottom of the sandbox, a permeable sheet 8 connected to the inside of the outer wall is attached to the bottom member 3, on top of the sandbox interior bottom insulation material 7, and then a cushion sand 18 for under the heater wire is spread to a depth of 3-5 cm on top of the permeable sheet 8. An aluminum plate 10 with the heater wire 9 attached is then laid, and sand 12 is placed on top of the aluminum plate 10 to form a heated sandbox. The heater wires 9 are generally installed at intervals of about 10 cm, but since heat only warms the area around the heater wire 9, the thermal conductivity of aluminum is used to conduct heat from the heater wire 9 to the aluminum plate 10, thereby uniformly warming the sand 12 on top of the aluminum plate 10. By using aluminum perforated metal for the aluminum plate 10, there is the advantage that the heater wires 9 can be easily placed and fixed at intervals using cable ties 11 through the holes in the aluminum perforated metal.

[0040] By using the aluminum plate 10, there is no risk of accidentally damaging or breaking the heater wire 9 when turning over the sand 12 in the sandbox with a shovel or the like for disinfection or removal of foreign matter. Preferably, a water-permeable sheet 8 may be provided on top of the aluminum plate 10.

[0041] Although the aluminum plate 10 is specified, any metal plate with high thermal conductivity is acceptable, not just aluminum.

[0042] The bottom surface of the sandbox body 20 is enclosed with ground surface insulation material 14, the outer walls are enclosed with exterior wall insulation material 15, and the top of the sandbox is covered with a heat-insulating lid 16 that also serves as a cat-repellent sheet, thereby preventing damage from dog and cat feces and urine, and further reducing the radiant heat that warms the sand 12 in the sandbox.

[0043] When children play in the sandbox, they dig into the sand 12 and heat escapes from the surface, but heat is supplied from below, so a gentle warmth is transmitted, making winter sand play enjoyable for the children. When the sandbox is not in use, the entire sandbox is surrounded by ground insulation 14, exterior wall insulation 15, and an insulating lid 16, creating an insulating structure that prevents heat from escaping from inside the sandbox to the outside.

[0044] The lower end of the exterior wall insulation material 15 installed on the outer wall surface is L-shaped because this exterior wall insulation material 15 is used only in winter and removed from spring onwards to improve the ventilation and drainage of the sandbox body 20. It is preferable to have a removable structure that allows the insulation material to be reattached in winter.

[0045] As shown in Figure 7, the ground surface insulation material 14 laid on the ground surface 1 is shorter than the outer perimeter insulation material because the outer wall insulation material 15 is only used during the cold winter months, and the outer wall insulation material 15 is removed from spring onwards. This is to prevent the ends of the ground surface insulation material 14 from being damaged by children's mischief or shoes getting caught on it. In addition, making the lower end of the outer wall insulation material 15 L-shaped makes it easier for the outer wall insulation material 15 to stand on its own, which has the advantage of simplifying installation.

[0046] By attaching the insulating cover 16 to the entire top of the sandbox, the insulation and heat retention performance are improved, and the heat release from the sandbox body 20 can be reduced. By securing the outer wall insulation material 15 and the insulating cover 16 with buckles or the like, it is possible to maintain heat retention and prevent the insulating cover 16 from being blown away by the wind.

[0047] As a variation, instead of forming the sandbox body with wood, as shown in Figure 8, the sandbox body can also be formed with the insulation material itself. The wall surface 25 of the sandbox body formed with the insulation material has multiple through holes 21A and ribs on the inside, and the bottom surface 26 of the sandbox body formed with the insulation material also has multiple through holes 21B and ribs on the top and bottom surfaces, and a permeable sheet 8 is stretched from the wall to the bottom surface on the inside of the sandbox body, so that the sandbox body with good drainage can be formed with the insulation material itself.

[0048] As described above, the sandbox according to the present invention is configured such that the entire outer perimeter, bottom, and top of the sandbox body are surrounded by insulating material, or the sandbox body is formed from the insulating material itself. Therefore, it exhibits both insulating and heat-retaining effects, and when heated by a heater, heat is less likely to escape to the outside of the sandbox body, thus reducing the amount of electricity required to drive the heater. In addition, the time required to set the temperature of the sandbox to a desired temperature, for example, between 15°C and 45°C, can be shortened.

[0049] We've discussed using logs for sandboxes, but the materials used to construct a sandbox are not limited to wood; they can also be made of resin, metal, concrete, etc. For example, the walls of a sandbox can be made of reinforced steel mesh covered with a permeable sheet. Alternatively, steel pipes or columns can be used as wall materials to construct the sandbox itself.

[0050] Furthermore, by incorporating the aforementioned sandbox structure, unlike conventional sandboxes, the top of this invention's sandbox is raised approximately 50-60 cm above the ground. This allows children to climb up and down the sandbox and use the sandbox walls to play, thus increasing their physical activity and making it a new type of playground equipment.

[0051] We have described sandboxes that float on the ground surface, but this can also be applied to existing underground sandboxes. [Explanation of symbols]

[0052] 1 Ground surface 2 Sandbox support 3 Bottom member 4. Logs for wall components 5. Spacers for gaps in wall components 6 Kasagi 7. Insulation material for the bottom of the sandbox 8. Permeable sheet 9 Heater wire 10. Aluminum plate (perforated aluminum) 11. Cable ties (Insylloc) 12 Sand in the sandbox 13 Controller Box 14. Ground surface insulation 15. Exterior wall insulation 16 Thermal lid 17 Buckle 18. Cushion sand under the heater wire 19 Fastening bolts 20 Sandbox 21 Through hole 21A Through-holes in the wall of the sandbox body, which is made of insulating material. 21B Through-holes in the bottom surface of the sandbox body formed of insulating material 22 Insulation ribs 23 Space between the building structure and the ground surface insulation 24. The gap between logs 25. The walls of the sandbox are formed from insulating material. 26 The bottom surface of the sandbox body, formed with insulating material.

Claims

1. A sandbox having a sandbox body and filled with sand, characterized in that the entire outer perimeter, bottom and top of the sandbox body are surrounded by an insulating material, the insulating material surrounding the outer perimeter of the sandbox body is provided with multiple through holes and has ribs on the inner surface of the insulating material, and the insulating material placed below the bottom of the sandbox body is provided with multiple through holes and has ribs on the lower surface, thus providing a drainage function.

2. A sandbox having a sandbox body filled with sand, characterized in that the sandbox body is made of thermal insulation material itself, the outer periphery of the sandbox body made of thermal insulation material itself is provided with multiple through holes, the inner surface is provided with ribs, and the bottom of the sandbox body is provided with multiple through holes and has ribs on the bottom and top sides to provide drainage.

3. The sandbox according to claim 1 or 2, characterized in that a space is provided between the bottom surface of the sandbox body and the ground surface.

4. The sandbox according to claim 1, characterized in that the wall portion of the sandbox body is made up of multiple stacked logs, and spacers are provided between each log to create gaps.

5. The sandbox according to claim 1, characterized in that the insulating material surrounding the sandbox body is removable.

6. The sandbox according to claim 1 or 2, characterized in that a water-permeable sheet is provided inside the sandbox body.

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