sandbox

Abstract

In winter, sandboxes are cold and the sand is cold, so children tend to prefer playing indoors rather than outside, but this project provides a sandbox that will make children want to play outside. [Solution] A heater wire 9 is laid on the bottom of a box-shaped sandbox with good drainage and ventilation, heating the sand 12 in the sandbox and keeping the entire sandbox warm. Insulation is provided on the bottom of the sandbox, which is raised about 10 cm above the ground, and the heater wire 9 is attached to an aluminum plate 10, preferably aluminum punched metal, taking advantage of the thermal conductivity of aluminum to heat the entire sandbox. This sandbox is a box-shaped sandbox with good drainage, raised about 10 cm above the ground, and a permeable sheet 8 is attached to the inside to prevent sand leakage and to prevent the entry of germs and insects from underground. The permeable sheet 8 washes away the sand in the sandbox when it rains, and on sunny days the heater wire 9 is placed in a clean sandbox where the sand is sterilized by sunlight, providing a warm sandbox.

Description

[Technical Field]

[0001] This invention relates to a playground equipment that allows children to play in a slightly warm sandbox during the cold winter months. [Background technology]

[0002] Educators recommend sandboxes as educational play equipment, but in winter they are so cold that few children play in them. [Prior art documents] [Patent documents] [Patent documents] none. Summary of the Invention [Problem to be solved by the invention]

[0003] In winter, sandboxes are cold and the sand is cold, so children tend to prefer playing indoors rather than outside, but this project provides a sandbox equipped with heating facilities that will encourage children to play outside even in winter. [Means for solving the problem]

[0004] It is preferable to attach the heater wire to a metal plate, for example, an aluminum plate or aluminum punched metal, and utilize the thermal conductivity of aluminum to conduct the heat from the heater wire to the aluminum plate, thereby uniformly heating and keeping the entire sand in the sandbox warm.

[0005] By leaving a space of about 10cm to 15cm between the sandbox itself and the ground surface and using ground insulation, and by using exterior wall insulation in the exterior walls while still leaving space, it is possible to achieve insulation and heat retention effects. If the space between the ground surface and the sandbox itself is too large, it is dangerous as part of a child's body could get inside, so a space of about 10cm to 15cm is preferable. If no ground insulation is used, a space of about 10cm is preferable.

[0006] Wood used outdoors swells and expands when it rains and shrinks as it dries, so even if you use anti-loosening nuts, you will need to retighten them, and retightening is possible if there is a space of about 10 cm above the ground surface.

[0007] The walls and floor of the sandbox are constructed of wood, with metal pipes preferably used as spacers between the pieces of wood in the walls to provide gaps for drainage and ventilation.

[0008] It is preferable that the outer periphery, bottom and top surfaces of the sandbox are all insulated with insulating material.

[0009] Since heaters are only installed in the sandbox in winter, it is preferable to use a removable structure so that the insulation can be removed from spring onwards and then reinstalled in winter.

[0010] By providing the heat insulating material with a plurality of communicating through holes and ribbing, the heat insulating material can be made strong and have improved drainage properties, and a sandbox can be formed from the heat insulating material itself.

[0011] By providing the insulation with multiple through holes that connect the inside to the outside, the sandbox can have good drainage and prevent mold growth. The insulation can also be given a surface treatment to prevent UV degradation, making the insulation itself the sandbox's framework with drainage capabilities.

[0012] By attaching a water-permeable sheet to the inside of the sandbox's structure, the insulation material with multiple through holes is prevented from leaking sand or clogging, and the structure is designed to prevent insects from getting in from the outside.The water-permeable sheet also has the effect of filtering the sand in the sandbox, washing it away with rain when it rains, making it clean.

[0013] The heated sandbox is provided with a heat insulating material on a bottom member, a water-permeable sheet on top of that, cushion sand on top of that, a metal plate with a heater wire attached on top of that, a water-permeable sheet on top of that, and sand put on top of that to heat the sand in the sandbox.

[0014] To improve drainage and heat retention, it is preferable to leave a space of about 10 to 15 cm above the ground surface between the sandbox itself.

[0015] The shape of the sandbox can be rectangular, round, or diamond-shaped; there is no restriction on the shape. [Effects of the Invention]

[0016] The heat from the heater wire can be transmitted through the metal plate to evenly heat the sand in the sandbox, so the entire sandbox stays gently warm even in the cold winter, providing a sandbox that children will want to play in.

[0017] Unlike ordinary existing sandboxes, the top of this invented sandbox is raised about 50 to 60 cm above the ground, so children can climb up and down the sandbox or use the walls to play, making it a new type of play equipment that increases their physical activity. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view showing the interior of a sandbox in an embodiment. [Figure 2] 2 is a cross-sectional view taken along the line A-A' in FIG. 1, showing a spacer installed in the gap between the logs of the wall portion. [Figure 3] FIG. 10 is a cross-sectional view of the sandbox according to the embodiment when it is set up. [Figure 4] 1 is a diagram illustrating an arrangement of heater wires according to an embodiment. [Figure 5] FIG. 2 is a plan view of the heat insulating material and the sandbox body in the embodiment. [Figure 6] FIG. 2 is a cross-sectional view of the heat insulating material and the sandbox body in the embodiment. [Figure 7] FIG. 1 is a detailed view of the sandbox body and heat insulating material according to an embodiment. [Figure 8] 1 is a diagram showing a sandbox constructed using insulating material according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] An experiment in which heater wire 9 was attached to aluminum plate 10, a metal with high thermal conductivity, and placed inside the bottom of the sandbox body while electricity was applied confirmed its effectiveness. Even greater effectiveness was confirmed when leaving a gap of about 10 cm between the ground surface and the sandbox body, and installing ground surface insulation 14 on the ground surface, sandbox interior bottom insulation 7 inside the bottom of the sandbox, and exterior wall insulation 15 on the outer peripheral wall. Furthermore, by installing an insulation lid 16 when the sandbox was being heated or when it was not in use, it was possible to heat the sand 12 in the sandbox body 20 even more effectively. Based on these experiments, an economical method of heating a sandbox was discovered.

[0020] Figures 1 and 2 show an image of the sandbox body installed on the sandbox support 2 and a cross-section of the wall part. The bottom of the box-shaped sandbox is provided with a bottom member 3, and on the outer periphery of the bottom member 3, spacers 5 for the wall members are provided to ensure gaps 24 between the wall member logs 4, and the sandbox is constructed with fastening bolts 19.

[0021] The bottom of the sandbox body is covered with ribbed sandbox interior bottom insulation 7 with multiple communicating through-holes 21, which drains water from the bottom of the sandbox while preventing the escape of heated water. Wall member gap spacers 5 are provided to ensure gaps 24 between the logs 4 of the sandbox wall members that make up the sandbox body, and a permeable sheet 8 is laid to prevent the sandbox sand 12 from leaking out through the gaps 24 between the wall member logs 4 and to prevent the through-holes 21 of the sandbox interior bottom insulation 7 from clogging, ensuring drainage throughout the sandbox and providing a clean, heated sandbox.

[0022] The reason for laying 3 to 5 cm of cushion sand 18 under the heater wire on top of the permeable sheet 8 at the bottom of the sandbox is that a bend is required when bending the heater wire 9 at a right angle, so the sand is laid as a cushioning material in that bend. This cushion sand 18 under the heater wire is not used for sand play, so a minimum thickness is preferable. If the heater wires 9 overlap or are placed too close to each other, it can cause malfunctions or accidents, so cushion sand 18 under the heater wire is necessary to fill the bend.

[0023] 2 is a cross-sectional view for ensuring a gap 24 between the logs 4 of the wall members or between the coping 6 and the logs 4 of the wall members. By providing spacers 5 for gaps between the logs 4 of the wall members at predetermined intervals, drainage and breathability can be obtained from the gaps 24 between the logs 4 of the wall members.

[0024] If the logs 4 of the wall members absorb a lot of moisture, they will expand and try to push up the logs 4 of the wall members above, but because the bottom member 3 and the coping 6 are fastened together with fastening bolts 19, there is a possibility that the logs 4 of the wall members will deform. To prevent this problem, metal pipes can be used as spacers to be inserted in the gaps 24 between the logs 4 of the wall members, so that when the logs 4 of the wall members swell, the spacers will bite into the logs 4 of the wall members, so it is preferable that the spacers 5 for the gaps between the logs 4 of the wall members be metal pipes.

[0025] The spacer 5 for the gap between the wall members may be made of resin, wood, concrete or stone, in addition to metal.

[0026] 3 is a cross-sectional view of a sandbox tray 2 placed on ground level 1, with a sandbox main body 20 installed on said sandbox tray 2. The sandbox tray 2 is placed on ground level 1, and with a bottom member 3 placed on said sandbox tray 2, an insulating material 7 is laid inside the sandbox bottom, and then a water-permeable sheet 8 is laid on top of that, and cushion sand 18 under the heater wire is placed on top of that, and then an aluminum plate 10 with a heater wire 9 attached is placed on top of that, and sandbox sand 12 is placed on top of that. This is a cross-sectional view of a heated sandbox.

[0027] Figure 4 is a plan view showing the arrangement of heater wires 9. The heater wires 9 are energized by a controller box 13, converting electricity into thermal energy and transferring the heat to the sand 12 in the sandbox. As the sandbox is intended for small children, the controller 13 and sensors are used to manage the temperature to prevent burns.

[0028] A heater wire 9 is attached to a member with high thermal conductivity, for example, an aluminum plate 10, and laid on the inner surface of the bottom of a box-shaped sandbox body 20 with good drainage and ventilation, so that the sand 12 in the sandbox body 20 is uniformly and efficiently heated and the whole sandbox body 20 is kept warm by the heat insulating material.

[0029] Liquids have a lower thermal conductivity than solids, and gases have a lower thermal conductivity than liquids, so the space between sandbox sand 12 can be expected to have a heat retention and heat storage effect. Because this is a sandbox at a childcare facility, the heater is equipped with a controller 13 that turns on when the temperature reaches 40 degrees and turns off at 55 degrees, and temperature control is performed using a sensor, so sandbox sand 12 can be kept at a slightly warm temperature of around 25 degrees.

[0030] 5 is a plan view of the sandbox body 20, with the logs 4 of the wall members surrounded by the exterior wall insulation material 15. The exterior wall insulation material 15 is provided for the purpose of keeping the sandbox body 20 warm with insulation. The ground surface insulation material 14 is shorter than the exterior wall insulation material 15.

[0031] Figure 6 is a cross-sectional view of a sandbox body 20 surrounded by exterior wall insulation 15, ground insulation 14, and an insulated lid 16. A sandbox support 2 is placed on the ground surface 1 below the sandbox, and the diagram shows how to install the ground insulation 14, exterior wall insulation 15, and insulated lid 16. The sandbox body 20 is installed with the sandbox support 2 so that it is raised approximately 10 to 15 cm above the ground. The purpose of raising the sandbox is to remove the exterior wall insulation 15 in the summer, allowing air to pass under the sandbox, drying the sand 12 in the sandbox and maintaining clean sand. In the winter, the entire sandbox is heated and kept warm by the sandbox body 20, the ground insulation 14 installed on the ground surface 1, the exterior wall insulation 15, and the insulated lid 16.

[0032] The walls of the sandbox are made up of fastening bolts 19 that pass through the logs 4 of the wall members, including the coping 6, and the spacers 5 for the gaps between the logs 4 of the wall members and the exterior wall material. If the logs 4 of the wall members dry out and need to be tightened, there is a gap 23 between the sandbox body 20 and the ground surface insulation material, which ensures space for tightening with a wrench.

[0033] The following explanation will be given with reference to Figure 7. This is a cross-sectional view of the sandbox body surrounded by insulation. The outer walls of the sandbox body are surrounded by exterior wall insulation 15, ground surface insulation 14 is installed below the sandbox body, and an insulation cover 16 is installed on top of the sandbox. The gap 23 above the ground surface insulation 14 installed on the ground surface 1 serves to retain heat. Since the exterior wall insulation 15 is removed in the summer, if this space is too large, it is dangerous as part of a child's body may get inside, so a gap of about 10 cm is preferable. Since the insulation is generally about 5 cm thick, the gap 23 between the ground surface insulation 14 and the bottom of the structure is around 5 to 10 cm, which provides insulation, heat retention, and child safety.

[0034] The outer wall heat insulating material 15 is provided with a plurality of through holes 21 communicating from the inside to the outside, and serves to keep the sand 12 in the sandbox body 20 warm while ensuring drainage.

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

[0036] For the sandbox interior bottom insulation 7, it is preferable to attach ribs not only to the bottom but also to the top, as this improves strength and drainage. Drainage can be further improved by laying a water-permeable sheet 8 on top of the top ribs.

[0037] The sandbox body 20 constituting the sandbox uses logs as wall members, and spacers 5 for gaps between the wall members are provided between the logs 4 of the wall members to leave gaps 24, and fastening bolts 19 are used to construct the sandbox body 20 with the retaining wall and bottom member 3, making the sandbox well-drained and breathable.

[0038] For outdoor sandboxes, it is preferable to use wood that has been treated with pressure-injected wood preservatives and anti-termite agents. Even better, sandboxes made of rot-resistant chestnut or urin wood with locking nuts are recommended.

[0039] At the bottom of the sandbox body, a permeable sheet 8 is attached to the bottom member 3 and the sandbox interior bottom insulation 7, and is connected to the inside of the outer wall portion. Approximately 3 to 5 cm of cushion sand 18 under the heater wire is laid on top of the permeable sheet 8, and an aluminum plate 10 with a heater wire 9 attached is then laid. Sand 12 for the sandbox is then placed on top of the aluminum plate 10 to form a heated sandbox. The heater wires 9 are typically installed at intervals of approximately 10 cm. However, since only the area around the heater wire 9 becomes warm, for efficient heat conduction, the heat from the heater wire 9 is conducted to the aluminum plate 10 using the thermal conductivity of aluminum, uniformly heating the sand 12 above the aluminum plate 10. Using aluminum perforated metal for the aluminum plate 10 has the advantage of making it easy to secure the heater wires 9 at intervals with Insiloc 11, using the holes in the aluminum perforated metal.

[0040] By using the aluminum plate 10, there is no need to worry about accidentally damaging or breaking the heater wire 9 when turning the sand 12 in the sandbox over with a shovel or the like for the purpose of disinfecting or removing foreign matter. Preferably, a water-permeable sheet 8 may be further provided on the aluminum plate 10.

[0041] Although the aluminum plate 10 is used as the above-mentioned plate, it is not limited to aluminum and any other metal plate having high thermal conductivity may be used.

[0042] The bottom of the sandbox body 20 is surrounded by a ground surface heat insulating material 14, and the outer wall surface is surrounded by an outer wall heat insulating 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 excrement and reducing radiant heat that warms the sand 12 in the sandbox.

[0043] When children play in the sandbox, they dig up the sand 12 and the heat on the surface escapes, but heat is supplied from below, providing a gentle warmth, making this play equipment enjoyable for children to play in the sand in winter.When the sandbox is not in use, the entire sandbox is surrounded by ground insulation 14, exterior wall insulation 15, and a thermal insulation lid 16, creating an insulation structure that makes it difficult for heat inside the sandbox to escape to the outside.

[0044] The outer wall insulation 15 installed on the outer peripheral wall has an L-shaped lower end, and this outer wall insulation 15 is used only in winter and is removed from spring onwards to improve the breathability and drainage of the sandbox body 20, and it is preferable that the insulation be made detachable so that it can 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 periphery because the exterior wall insulation material 15 is only used during the cold winter months, and the exterior wall insulation material 15 is removed from spring onwards, to prevent the ends of the ground surface insulation material 14 from being damaged by children's mischief or getting caught on shoes, etc. Another advantage is that by making the lower end of the exterior wall insulation material 15 on the periphery L-shaped, the exterior wall insulation material 15 can stand on its own more easily, making installation easier.

[0046] By attaching an insulated lid 16 to the entire top of the sandbox, it is possible to improve the insulation and heat retention performance and reduce heat release from the sandbox body 20. By fastening the exterior wall insulation material 15 and the insulated lid 16 with buckles or the like, it is possible to improve the heat retention effect and prevent the insulated lid 16 from being blown away by the wind.

[0047] As a modified example, instead of forming the sandbox body from wood, the sandbox body can also be formed from the insulating material itself, as shown in Figure 8. The wall surface 25 of the sandbox body made of insulating material has multiple through holes 21A and ribs on the inside, and the bottom surface 26 of the sandbox body made of insulating material also has multiple through holes 21B and ribs on the top and bottom surfaces, and a water-permeable sheet 8 is stretched from the wall to the bottom surface inside the sandbox body, making it possible to form a sandbox body with good drainage using the insulating material itself.

[0048] We have explained sandboxes made of logs, but the materials that make up the sandbox are not limited to wood; they can also be made of resin, metal, concrete, etc. For example, the walls of the sandbox can be made of rebar mesh with a permeable sheet attached. Alternatively, the sandbox itself can be made of steel pipes or columns as wall materials.

[0049] We have explained sandboxes that float on the surface of the ground, but this can also be applied to existing underground sandboxes. [Explanation of symbols]

[0050] 1 Ground surface 2 Sandbox stand 3 Bottom member 4 Wall logs 5 Wall component gap spacers 6 Kasagi 7. Insulation material for the bottom of the sandbox 8. Permeable sheet 9 Heater wire 10 Aluminum plate (aluminum punching) 11 Insiloc (cable ties) 12 Sand in the Sandbox 13 Controller box 14 Ground surface insulation material 15 Exterior wall insulation 16 Thermal lid 17 Buckle 18 Cushion sand under the heater wire 19 Fastening bolt 20 Sandbox body 21 Through hole 21A Through-hole in the wall of the sandbox body formed with insulating material 21B Through hole in the bottom of the sandbox body formed of heat insulating material 22 Insulation ribs 23 Space between the building frame and the insulation material on the ground 24 Gap between logs 25 Walls of the sandbox body made of insulating material 26 Bottom surface of the sandbox body formed with insulating material

Claims

1. This sandbox is filled with sand, and is characterized in that a heater wire attached to a member with high thermal conductivity is installed inside the bottom of the sandbox body to heat the sand, and the outer periphery, bottom, and top of the sandbox body are entirely surrounded by heat insulating material.

2. A sandbox filled with sand, in which a heater wire attached to a material with high thermal conductivity is placed inside the bottom of the sandbox body, making it possible to heat the sand, and the sandbox body is made up of the insulating material itself.

3. A sandbox as described in claim 1 or claim 2, characterized in that a space is provided between the bottom of the sandbox body and the ground surface.

4. A sandbox as described in claim 1 or claim 2, characterized in that the wall portion of the sandbox body is made up of a plurality of stacked logs, and gap spacers are provided between each log.

5. A sandbox as described in claim 1, characterized in that the insulation surrounding the sandbox body is removable.

6. A sandbox as described in claim 1, characterized in that the insulating material surrounding the outer periphery of the sandbox body has multiple through holes and ribs attached to the inner surface of the insulating material, and the insulating material placed below the bottom of the sandbox body has multiple through holes and ribs attached to the underside, thereby providing drainage functions.

7. A sandbox as described in claim 2, characterized in that the outer periphery of the sandbox body, which is made of insulating material itself, has multiple through holes and is equipped with ribs on the inner surface, and the bottom of the sandbox body has multiple through holes and is equipped with ribs on the lower and upper sides, providing drainage functions.

8. A sandbox as described in claim 1 or claim 2, characterized in that a water-permeable sheet is provided inside the sandbox body.

9. A sandbox as described in claim 1 or claim 2, characterized in that, from the bottom inside the sandbox body, an insulating material is placed on the bottom member, a water-permeable sheet is placed on top of that, cushion sand is placed on top of that, a metal plate with a heater wire attached is placed on top of that, and sand is placed on top of that.

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