JP7600615B2 - Furniture grounding device and furniture - Google Patents

Description

The present invention relates to a furniture grounding device suitable for use in furniture such as school desks, and to furniture with such a grounding device attached to its bottom surface.

Many conventional school desks are equipped with adjusters to prevent wobbling during use, but those that use normal adjusters have the inconvenience that the adjuster must be properly adjusted every time the desk is moved in order to prevent wobbling (see, for example, Patent Document 1).

To solve this problem, a device has been developed that has a grounding body at the end of the adjuster that can be raised and lowered using an oil damper, but oil dampers have low durability and are prone to problems such as oil leaks.

One possible solution to this problem is a grounding device that compresses the elastic member with a grounding body that can be raised and lowered. However, the usual approach would involve compressing the elastic member vertically with a grounding body that can be raised and lowered, which could lead to an increase in the size of the device (issue 1).

In addition, there is a demand for such a grounding device to be able to adequately follow unevenness in the floor surface. Specifically, there are various demands, such as a sufficient stroke of the grounding body to quickly respond to unevenness in the floor surface, and a demand to prevent the desk from being too hard and causing wobble, or too soft and causing the desk to wobbly during use. However, if a solid elastic member is used in a conventional manner, the only way to meet these demands is to select the size and characteristics of the elastic member, and if the dimensions of the device are restricted, there is a difficulty in that there is a limit to how well it can be met (issue 2).

These issues are not limited to school desks used by students, but also exist for other furniture.

Japanese Patent Application Publication No. 11-206472

The invention according to claim 1 aims to solve the above-mentioned problem 1. The invention according to claim 3 aims to solve the above-mentioned problem 2 in addition to problem 1.

The furniture grounding device according to the invention described in claim 1 comprises a housing, a rotating member supported by the housing so as to be rotatable up and down and having a grounding body on the underside thereof that contacts the floor surface, and an elastic member having viscoelasticity that is disposed within the housing and is compressed by the rotation of the rotating member.

The furniture grounding device according to the invention described in claim 2 is the one described in claim 1, and the housing has a space inside with a curved ceiling surface corresponding to the rotation trajectory of the rotating member, and the elastic member is housed in the space of the housing in a curved position along the ceiling surface, with one end of the elastic member abutting against the upper surface of the rotating member and the other end abutting against the upright surface of the housing that intersects with the end of the ceiling surface.

In the present invention, "corresponding to the rotation trajectory" is not limited to being the same as the rotation trajectory, but includes the concept of approximating the rotation trajectory, etc.

The furniture grounding device according to the invention described in claim 3 is the one described in claim 1 or 2, and the grounding body is provided with a grounding cam surface whose grounding position with the floor surface changes as the rotating member rotates.

The furniture grounding device according to the invention described in claim 4 is the one described in claim 1, 2 or 3, in which the rotating member has a support shaft protruding from both sides of the base end, and the support shaft is pivoted to both side walls of the housing and disposed at the lower end opening of the space.

The furniture grounding device according to the invention described in claim 5 is the one described in claim 4, in which the rotating member is held within the housing by a lid attached to the underside of the housing, and the lid is provided with a window for allowing the grounding member of the rotating member to protrude to the outside.

The furniture grounding device according to the invention described in claim 6 is the one described in claim 4 or 5, in which the housing and the lid are fastened together to the furniture by a common bolt, and a temporary fastening element is provided between the housing and the lid to prevent the lid from falling off before it is fastened by the bolt.

The furniture grounding device according to the invention described in claim 7 is the one described in claim 1, 2, 3, 4, 5 or 6, and the elastic member is made of urethane gel, low-resilience urethane or elastomer.

The furniture according to the invention described in claim 8 is equipped with furniture grounding devices described in claims 1, 2, 3, 4, 5, 6, or 7 that can expand and contract independently of one another at multiple points on the bottom surface.

The furniture according to the invention described in claim 9 is the furniture described in claim 8, in which the furniture grounding device is attached to four places on the bottom surface.

The present invention provides a highly durable furniture grounding device that can adequately prevent or suppress furniture wobbling without increasing the size of the furniture.

FIG. 1 is a side view showing a desk equipped with a grounding device according to an embodiment of the present invention. FIG. 2 is a perspective view showing a desk equipped with the grounding device according to the embodiment. FIG. FIG. 4 is a view taken along the X arrow in FIG. 5 is a cross-sectional view taken along line YY in FIG. 4. FIG. 2 is a perspective view showing the grounding device according to the embodiment. FIG. 2 is an exploded perspective view showing the grounding device according to the embodiment. 4A to 4C are diagrams illustrating the operation of the grounding device according to the embodiment. FIG. 4 is an explanatory diagram showing a compression direction of the elastic member according to the embodiment. FIG. 4 is a side view showing a grounding device according to another embodiment of the present invention. FIG. 11 is a view taken along the arrow α in FIG. Cross-sectional view taken along line β-β in FIG. FIG. 2 is an exploded perspective view showing the grounding device according to the embodiment.

One embodiment of the present invention will be described with reference to Figures 1 to 9.

In this embodiment, a furniture grounding device 4 according to the present invention is attached to a school desk D, which is a piece of furniture.

As shown in Figures 1 and 2, desk D is for school children to use and is placed on the floor surface F of a classroom. It has a top plate 2 supported by left and right legs 1, and a back panel 3 installed between the left and right legs 1 near their upper ends.

As shown in Figures 1 and 2, the left and right legs 1 each have a leg support 12 erected from the inside of the rear end of the leg base 11, and furniture grounding devices 4 are provided at the front and rear ends of the leg base 11.

As shown in Figures 3 to 7, the furniture grounding device 4 comprises a housing 5 attached to the leg base 11, which is the bottom of the furniture, a rotating member 6 supported by the housing 5 so as to be rotatable up and down and having a grounding body 62 on its underside that contacts the floor surface F, and an elastic member 7 with viscoelasticity that is disposed within the housing 5 and compressed by the upward rotation of the rotating member 6.

As shown in Figures 5 and 7, the housing 5 has a space 5s inside, in which the ceiling surface 5a is curved to correspond to the rotation trajectory 6k of the rotating member 6, and the elastic member 7 is accommodated in the space 5s of the housing 5 in a curved position along the ceiling surface 5a. One end 7a of the elastic member 7 is in contact with the upper surface 6a of the rotating member 6, and the other end 7b is in contact with the upright surface 5b of the housing 5 that intersects with the end of the ceiling surface 5a. The housing 5 is a box-shaped unit made of, for example, synthetic resin, and has bolt insertion holes 5c that penetrate vertically at both ends, and the aforementioned space 5s in the middle region. The space 5s is open downward, and its ceiling surface 5a is formed outside the rotation trajectory 6k of the rotating member 6 and is formed to approximate the rotation trajectory 6k. Specifically, the ceiling surface 5a is composed of an upright one-end flat surface 5a1, a cylindrical surface 5a2 continuing from the one-end flat surface 5a1, and a horizontal other-end flat surface 5a3 continuing from the cylindrical surface 5a2. The end of the other-end flat surface 5a3 is perpendicular to the vertical upright surface 5b. As shown in Figures 4 to 7, the lower surface, i.e., the bottom surface 5d of the housing 5 has a peripheral ridge 5d1 formed on its periphery, and the lid 8, which will be described later, is fitted into the area surrounded by the peripheral ridge 5d1. The rotating member 6 is accommodated in the bottom of the housing 5 configured in this way so that it can rotate up and down.

As shown in FIG. 7, the rotating member 6 has a support shaft 61a protruding from both sides of the base end, and the support shaft 61a is pivoted in a support groove 5f formed in both side walls 51 of the housing 5 and is arranged at the lower end opening of the space 5s. More specifically, as shown in FIG. 5 and FIG. 7, the rotating member 6 is integrally provided with a member body 61 having a support shaft 61a at the base end and a grounding body 62 protruding from the lower surface of the member body 61, and is made of, for example, synthetic resin. On both inner surfaces 5e forming the space 5s of the housing 5 described above, a support groove 5f is formed to rotatably support both support shafts 61a of the rotating member 6. The lower ends of both support grooves 5f are open to the bottom surface 5d of the housing 5, and the rotating member 6 can be attached to the housing 5 by engaging both support shafts 61a with both support grooves 5f from below. The grounding body 62 is provided so as to hang down from the member body 61, and a grounding cam surface 62a is formed on the lower surface thereof, the grounding position of which changes with respect to the floor surface F as the rotating member 6 rotates. The grounding body 62 in this embodiment is gradually narrowed toward the lower end. The rotating member 6 is held in the housing 5 by a lid body 8 attached to the bottom surface 5d of the housing 5, and the lid body 8 is provided with a window 8a for projecting the grounding body 62 of the rotating member 6 to the outside. As shown in Figures 6 and 7, the housing 5 and the lid body 8 are plate-shaped and fastened together to the leg base 11 of the desk D by a common bolt 9, and a temporary fastening element K is provided between the housing 5 and the lid body 8 to prevent the lid body 8 from falling off the housing 5 before being fixed by the bolt 9. In this embodiment, the temporary fastening element K is formed by inclining the inner circumferential surface 5d2 of the peripheral ridge 5d1 of the housing 5 and the outer circumferential surface 8b of the lid 8 in a dovetail shape, and the lid 8 is engaged with the inside of the peripheral ridge 5d1 by utilizing temporary elastic deformation of the member. As shown in Figures 4 to 7, the lid 8 is a rectangular flat plate with screw insertion holes 8c at both ends that match the bolt insertion holes 5c of the housing 5, and the aforementioned window 8a in the middle region. 6c is the rotation center of this rotating member 6.

The elastic member 7 is made of, for example, low-resilience urethane, and is accommodated in the space 5s of the housing 5 by bending and deforming a rectangular block along the ceiling surface 5a of the housing 5 as shown in Figures 5 and 7. The elastic member 7 may also be manufactured by punching a thick plate material. In that case, the initial shape will be a curved shape as shown in the example. More specifically, the elastic member 7 in the accommodated state is accommodated in the space 5s of the housing 5 with one end 7a abutting against the upper surface 6a of the rotating end side of the rotating member 6 and the other end 7b abutting against the upright surface 5b of the housing 5.

The grounding devices 4 described above are attached to the rear and front ends of the left and right legs 1 of the desk D. Specifically, as shown in FIG. 6, the leg base 11 of each leg 1 is formed with recesses 11a into which the housing 5 can be fitted from below, and the housing 5 fitted into these recesses 11a is fastened together with the cover 8 to the leg base 11 by a common bolt 9. In this embodiment, the grounding device 4 attached to the rear end of the leg base 11 is set so that the rotating end of the rotating member 6 faces backward, and the grounding device 4 attached to the front end of the leg base 11 is set so that the rotating end of the rotating member 6 faces forward.

When the rotating member 6 is grounded and rotates, one end 7a of the elastic member 7 is pressed against the upper surface 6a of the rotating end side of the rotating member 6, and the other end 7b is compressed between the abutting upright surface 5b. At this time, the elastic member 7 partially expands due to elastic deformation, but since there is an expansion margin in the area above the rotation center 6c in FIG. 5 and the distance between the side walls 51 of the housing 5 is set larger than the thickness dimension of the elastic member 7 in the unloaded state, there is also an expansion margin on both sides in the thickness direction of the elastic member 7, so that the rotating member 6 can rotate widely while receiving moderate resistance from the elastic member 7.

FIG. 1 is a side view of a desk D with a plurality of such grounding devices 4 attached at required locations, and FIG. 2 is a perspective view of the desk D observed from below. FIG. 3 is a side view of one of the grounding devices 4, FIG. 4 is a view taken along the X arrow in FIG. 3, FIG. 5 is a cross-sectional view of line Y-Y in FIG. 4, and FIG. 6 is a perspective view of the grounding device 4 observed from below. FIG. 7 is an exploded perspective view of the grounding device 4. For convenience of explanation, FIG. 3 to FIG. 6 are illustrated in an unloaded state in which the grounding body 62 is not in contact with the floor surface F, and FIG. 8(a) is a schematic diagram of this state. FIG. 8(b) is a schematic diagram of a state in which the grounding body 62 sinks in response to a reaction force from the floor surface F and the elastic member 7 is compressed. FIG. 9 is an explanatory diagram for comparing the compression direction of the elastic member 7 according to this embodiment (the compression direction line connecting the compression directions of each part is indicated by a) with the compression direction of a virtual elastic member 7 (the compression direction line connecting the compression directions of each part is indicated by b).

With this configuration, the grounding body 62 is caused to protrude and sink into the floor surface F by the elastic repulsive force of the viscoelastic elastic member 7, so there is no need to worry about oil leakage and higher durability can be ensured compared to hydraulic damper-type grounding devices.

Moreover, since the elastic member 7 is compressed by the grounding body 62 that rotates instead of the grounding body 62 that moves in the vertical direction, it is possible to make the compression direction of the elastic member 7 nonlinear by corresponding to the rotation trajectory 6k of the rotating member 6. Therefore, even if the substantial length dimension of the elastic member 7 in the compression direction is secured to be large, the increase in the height dimension of the entire grounding device can be suppressed, which is convenient when it is housed in the leg base 11, for example, as in this embodiment. Specifically, the substantial length dimension of the elastic member 7 in the compression direction in this embodiment corresponds to the length dimension of the curved line a in FIG. 9, but if a linear columnar elastic member 7 having the same compression direction length dimension (the length dimension of the line segment b in FIG. 9) is used, the height dimension of the entire grounding device will inevitably be large. Therefore, according to the grounding device 4 of the present invention, it is possible to naturally promote the compactification of the entire device. In other words, according to the configuration of this grounding device 4, it is possible to naturally reduce the vertical dimension of the entire device compared to the case where a linear elastic member is compressed in the vertical direction by a grounding body that rises and falls linearly.

In addition, since the grounding body 62 is formed with a grounding cam surface 62a whose grounding position with respect to the floor surface F changes with the rotation of the rotating member 6, the relationship between the distance dimension of the housing 5 from the floor surface F and the compression dimension of the elastic member 7 by the rotating member 6 can be set to a relationship other than direct proportionality. Therefore, by changing the shape of the cam surface 62a in various ways, it is possible to change the elastic rebound characteristics of the elastic member 7, and there is an advantage that it is easy to design a grounding device 4 with optimal characteristics. In other words, according to the configuration of this grounding device 4, since the grounding position of the grounding body 62 changes with the change in the compression dimension of the elastic member 7, the relationship between the compression dimension of the elastic member 7 and the lift dimension of the housing 5 can be adjusted by changing the shape of the cam surface 62a of this grounding body 62. Therefore, it becomes easier to set the elastic rebound characteristics of the elastic member 7 to an optimal one.

In addition, in this embodiment, low-resilience urethane is used as the elastic member 7, so this elastic member 7 can function as both a spring and a damper. This not only effectively prevents the entire desk D from continuing to rock, but also makes it possible to quickly respond to unevenness in the floor surface F by pushing and sinking the grounding body 62 with a relatively large stroke.

The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention.

For example, a furniture grounding device A4 having the configuration described below with reference to Figures 10 to 13 can be considered.

This differs from the furniture grounding device 4 of the above-mentioned embodiment in the following respects, but otherwise has the same configuration as the furniture grounding device 4 of the above-mentioned embodiment. Parts that are the same as or correspond to those in the furniture grounding device 4 of the above-mentioned embodiment are given the same reference numerals and descriptions are omitted.

This furniture grounding device A4 is equipped with a housing A5 that is attached to the bottom of the furniture, a rotating member 6 that is supported by the housing A5 so that it can rotate up and down and has a grounding body 62 on its underside that contacts the floor surface, and an elastic member 7 that is disposed within the housing A5 and has viscoelasticity and is compressed by the upward rotation of the rotating member 6.

12 and 13, the housing A5 has a space A5s in which the ceiling surface A5a is curved in accordance with the rotation locus 6k of the rotating member 6, and the elastic member 7 is accommodated in the space A5s in a curved position along the ceiling surface A5a. The housing A5 is a box-shaped body made of synthetic resin, for example, and has bolt insertion holes A5c that penetrate vertically at both ends, and has the above-mentioned space A5s in the middle area. The space A5s is open downward, and the ceiling surface A5a is formed outside the rotation locus 6k of the rotating member 6 to approximate the rotation locus 6k. Specifically, the ceiling surface A5a consists of an upright one-end flat surface portion A5a1, a cylindrical surface portion A5a2 that is continuous with the one-end flat surface portion A5a1, and a horizontal other-end flat surface portion A5a3 that is continuous with the cylindrical surface portion A5a2. The end of the flat surface A5a3 on the other end side is perpendicular to the vertical upright surface A5b. As shown in Figures 12 and 13, a protrusion A5d1 is formed on the lower surface, i.e., the bottom surface A5d of the housing A5 so as to surround the opening edge of the space A5s, and an engagement protrusion A52 that can elastically engage with an engagement recess A8d of the cover A8 described later is protruded from the outer circumferential surface of this protrusion A5d1. The bottom of the housing A5 having such a configuration accommodates the rotating member 6 so as to be able to rotate up and down. Specifically, pivot grooves A5f are formed on both inner surfaces A5e (inner surfaces of both side walls A51) that form the space A5s of the housing A5, and both support shafts 61a of the rotating member 6 are rotatably supported by these pivot grooves A5f. The rotating member 6 is then held in the housing A5 by the cover A8 attached to the bottom surface A5d of the housing A5.

The cover A8 is a plate-like body with a window A8a for projecting the grounding body 62 of the rotating member 6 to the outside. As shown in FIG. 13, the housing A5 and the cover A8 are fastened together with a common bolt 9, for example, to the leg base of a desk. A temporary fastening element K2 is provided between the housing A5 and the cover A8 to prevent the cover A8 from falling off the housing A5 before fastening with the bolt 9. In this embodiment, the temporary fastening element K2 is formed by elastically engaging the engagement protrusion A52 provided on the outer peripheral surface of the protrusion A5d1 of the housing 5 with the engagement recess A8d provided on the inner peripheral surface of the cover A8. As shown in FIG. 10, FIG. 11 and FIG. 13, the cover A8 is a rectangular flat plate, has screw insertion holes A8c at both ends that match the bolt insertion holes A5c of the housing A5, and has the above-mentioned window A8a in the middle region.

Here, Figure 10 is a side view showing one of the grounding devices A4. Figure 11 is a view seen from the arrow α in Figure 10, and Figure 12 is a cross-sectional view taken along line β-β in Figure 11. And Figure 13 is an exploded perspective view of the same grounding device A4. For convenience of explanation, Figures 10 to 12 are shown in an unloaded state in which the grounding body 62 is not in contact with the floor surface F.

Even with this configuration, the same effects can be obtained as with the furniture grounding device 4 of the above-mentioned embodiment.

In addition, the height dimensions of the portions at both ends where the bolt insertion holes A5c are provided (depth dimensions of the bolt insertion holes A5c, dimensions of the screw insertion portion) of the housing A5 in this embodiment are different on one end and the other end, so that the depth of the recess on the furniture side into which the housing A5 can be fitted from below is made different on one end and the other end, thereby making it possible to guide the furniture grounding device A4 to be installed only in a pre-specified orientation.

Other variations are also possible:

For example, in the illustrated embodiment described above, the housing has an internal space with a curved ceiling surface that corresponds to the rotation trajectory of the rotating member, and the elastic member is housed in the space of the housing in a curved position along the ceiling surface, but the structure for holding the elastic member is not necessarily limited to this. However, with such a configuration, the elastic member can be inserted and held in the housing in a position suitable for compression, which simplifies the structure and minimizes the number of assembly steps.

In addition, in the illustrated embodiment, the rotating member has a support shaft protruding from both sides of the base end, and the support shaft is pivoted to both side walls of the housing and arranged at the lower end opening of the space, but the pivot structure of the rotating member is not limited to this. However, if a configuration like the illustrated embodiment is adopted, the rotating member can be easily attached to the housing, and the number of parts can be reduced compared to when a separate support shaft is used.

Furthermore, the holding structure of the rotating member is not limited to the illustrated embodiment, but if it is as in the illustrated example, the installation of the rotating member is completed at the same time as closing the underside of the housing, and the configuration can be simplified. In particular, if the housing and the lid are fastened together to the desk, which is a piece of furniture, with a common bolt, as in the illustrated embodiment, it is possible to prevent the structure from becoming complicated and to reduce the number of parts. Moreover, if a temporary fastening element is provided between the housing and the lid to prevent the lid from falling off before it is fastened with the bolt, as in the illustrated embodiment, it becomes easier to manage the parts before assembly, and the work of assembling the grounding device to the desk is also simplified.

The elastic member is not limited to that shown in the illustrated embodiment, but may be made of, for example, urethane gel or elastomer.

Furniture to which the grounding device of the present invention can be attached is not limited to school desks, but can also include office desks, tables, shelves, counters, partitions, telephone stands, and many other items. Student desks are frequently moved and are often used in situations that require concentration, such as for exams and tests, so they require the ability to quickly and automatically eliminate any wobbling or bouncing whenever they are moved, making them the ideal application for the grounding device of the present invention.

Furniture such as a desk according to the invention described in claim 8 is equipped with the above-mentioned furniture grounding devices that expand and contract independently of each other at multiple points on the bottom surface, and can achieve the following effects. That is, even if any of the grounding points is higher or lower than the floor surface, the furniture grounding devices expand and contract independently of each other, so the furniture as a whole can be balanced and follow the floor surface.

In particular, when the furniture is a desk as in the above-mentioned embodiment, by attaching the above-mentioned furniture grounding devices to four points on the bottom surface, the following effects can be obtained. That is, in any of the cases where one of the grounding points is higher (or three are lower) than a horizontal floor surface, two of the grounding points are higher or lower, or one of the grounding points is lower (or three are higher), the furniture grounding devices expand and contract independently, so that the furniture as a whole can be balanced and follow the floor surface.

Various modifications may be made without departing from the spirit of the present invention.

D: Furniture (desk)
11... Bottom of furniture (leg base)
4, A4...Furniture grounding device 5, A5...Housing 51...Side wall 5a...Ceiling surface 5b...Upright surface 5d...Lower surface 5s...Space 6...Rotating member 61a...Support shaft 62...Grounding body 62a...Grounding cam surface 6a...Upper surface of rotating member 7...Elastic member 7a...One end of elastic member 8...Cover body 8a...Window 9...Bolt K, K2...Temporary fastening element F...Floor surface

Claims (9)

A furniture grounding device comprising a housing, a rotating member supported by the housing so as to be rotatable up and down and having a grounding body on the underside that contacts the floor surface, and an elastic member having viscoelasticity that is disposed within the housing and is compressed by the rotation of the rotating member. the housing has a space therein, the ceiling surface of which is curved in accordance with the rotation trajectory of the rotating member,
the elastic member is accommodated in the space of the housing in a curved position along the ceiling surface,
2. The furniture grounding device according to claim 1, wherein one end of the elastic member is in contact with the upper surface of the rotating member, and the other end is in contact with an upright surface of the housing that intersects with an end of the ceiling surface. The furniture grounding device according to claim 1 or 2, wherein the grounding body is provided with a grounding cam surface whose grounding position with respect to the floor surface changes as the rotating member rotates. The furniture grounding device according to claim 1, 2 or 3, wherein the rotating member has a support shaft protruding from both sides of the base end, and the support shaft is pivoted to both side walls of the housing and disposed at the lower end opening of the space. The furniture grounding device according to claim 4, wherein the rotating member is held in the housing by a lid attached to the underside of the housing, and the lid has a window for allowing the grounding member of the rotating member to protrude to the outside. The furniture grounding device according to claim 4 or 5, wherein the housing and the lid are fastened together to the furniture by a common bolt, and a temporary fastening element is provided between the housing and the lid to prevent the lid from falling off before being fastened by the bolt. The furniture grounding device according to claim 1, 2, 3, 4, 5 or 6, wherein the elastic member is made of urethane gel, low-resilience urethane or elastomer. Furniture equipped with furniture grounding devices as described in 1, 2, 3, 4, 5, 6 or 7 that can expand and contract independently at multiple points on the bottom surface. The furniture according to claim 8, in which the furniture grounding device is attached to four points on the bottom surface.

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