This application claims priority from Japan Patent Application No. 2020-92787, filed May 27, 2020, the entire contents of which are herein incorporated by reference.
This invention concerns a table, which includes a top plate, several support columns which support the top plate and can change its height by operation, and foot sections, each of which is attached to the lower end of the support columns, and can support said support columns at ground level.
Conventionally, the structure of such devices as office tables, furniture, setting tables, and working platforms (hereinafter defined as “tables” in this specification as a general term) included a top plate for setting items on its top surface or performing various operations, and one or more support columns to support the top plate. A solution with a height adjustment device for changing the height of the top plate is proposed.
A chair for one person, or a lifting platform for small item display has a narrow top plate area, and only one s support column is usually used to support the seat of the chair and top plate of the table, and an air spring (also known as a “cylinder piston”) is equipped on the support columns. In such devices, a lifting device is proposed for changing and adjusting the height of the seat and top plate by manipulating the length of the support columns. In this lifting device, the support columns is a cylindrical outer column and an inner column that can be loosely inserted inside it. Each end of the air spring is fixed to the inner and outer columns respectively, and the inner and outer columns are guided in the telescopic direction by the nesting of the protrusions and grooves. Both the inner and outer columns are relatively non-rotatable, and the top plate is prevented from rotating with respect the column. The expansion and contraction of the air spring makes it possible to adjust the height of the top plate.
On the other hand, in the case of a table with a corresponding top plate area, a plurality of s support columns with at least two or more air springs should be mounted on the left or right side of the top plate in general (cf. Patent Document 1). In this height adjustment device of the top plate, the lower end of the air spring is supported in a rotatable way, and a special structure with a linkage, rollers, etc. is provided between the upper end of the air spring and the table. Regarding the adjustment of the upper thrust by changing the position of the upper end of the column, the action of the above structure is carried out by means of a shaft part and is linked to the structure on the side of the other column. The adjustment of the top plate height is done by operating with a pedal the air spring set on at least either the left or right of the table, but how to adjust the two air springs when the air springs are set on each column is not disclosed in Patent Document 1.
As an example of a height adjustment device of a top plate supported by two support columns, there is proposed a structure that can change and adjust the length of the two support columns simultaneously with one operation (Patent Document 2). This height adjustment device of the top plate is vertically set on the lifting support columns on both sides of the top plate of the table, and it is set so that it can move upward and downward but cannot move backward and forward. The two lifting support columns are linked by chains engaged around multiple pullies pivotally set on the immovable members of the table, and the rocking plate is pivotally set on the immovable members of the table, thereby the rocking plate and the chains are connected. Further, a screw shaft which has an axis extending in the up-down direction is set pivotally on the rocking plate but does not move up and down on the rocking plate. At the same time, a movable air spring is provided at one end of the immovable member of the table, and the other end of the spring is pivotally mounted on an adjustment fitting threaded to the screw shaft. Thus, in the table supporting the top plate with multiple support columns, in order to move the top plate up and down synchronously and smoothly with all support columns, it is necessary to synchronize the start and end timings and the operation amount of the height adjustment operation. In the height adjustment mechanism of the top plate disclosed in Patent Document 2, it requires a linkage mechanism with a complex structure for the adjustment operation, which takes time to manufacture, assemble and adjust, and also is the reason for the increased cost.
In addition, in the combination of a chair and a table, there is proposed a table in which that changes the front and rear position based on the tilt state of the back of the chair (Patent Document 3). In this table, two metal round tubes are bent into a top view U-shape and an inverted U-shape respectively, and the two metal round tubes have two struts connected by a plurality of connecting members, and the two struts are rotatably supported on the ground by their respective connecting units. The connecting units are mounted on the struts so that the two struts are rotatable between the forward tilting position and the backward tilting position, respectively. The top plate is movable in parallel while remaining horizontal, the top plate of the table is allowed to move backward and diagonally downward depending on the tilt of the chair
In addition, there has been proposed a workstation with a monitor and a keyboard, position of them being changeable according to the posture of the computer user sitting in the chair (Patent Document 4). In this workstation, a hold part can move parallel while maintaining a horizontal state, even when support arms, which corresponds to legs of the table, are tilted. The keyboard base is supported to the hold part, and the keyboard base elevation angle is adjustable by changing the tilt angle relative to the hold part. The keyboard base of this workstation is not support directly to support arms. In addition, the adjustment of the keyboard base elevation angle requires a separate structure, the detailed structure of which is not disclosed in Patent Document 4.
This applicant for this patent has already proposed in the established literature (Patent Document 5) a lifting table with top plate height adjustment device which comprises a top plate and two or three support columns whose lengths are variable to support the top plate. Each support column is equipped with an air spring, such as used in chairs and the like, the length of the support column is variable by changing the length of the air springs with an operation pressing a push valve provided on the upper end of the support column. In general, it is conceivable that two air springs are operated simultaneously by operating a single operating lever, but with respect to such structure, it is inevitable that various errors occur inevitably in manufacturing and assembling the components that form the path from the operating lever to the push valve. It is very difficult, for each table specification, to balance between such manufacturing and assembling errors and the rigidity of the operating rod which leads to deformation and distortion during the operation of the operating rod. That is, if the rigidity of the operating rod is too high, the error appears directly as a difference in timing of pushing the valve, and if the rigidity of the operating rod is too low, the amount of operation of the operating rod is absorbed by the deformation and distortion, and the time of pushing the push valve changes, which does not ensure a sufficient amount of pushing pressure for the valve. The result is that two or more air springs sometimes make it difficult to move up and down equal amounts, that is, it is difficult to carry out synchronized action.
In the lifting table equipped with the above height adjustment device, in order to adjust the height of the top plate, it is proposed to improve the operability of adjusting the table height by coordinating the change of the lengths of any air spring of support columns, although the operation performed by the user is just one simple operation. That is, backlash is provided in the operating path from a handle to the push valve of each support column, and in operating that handle, after all the backlashes are absorbed, by making the operation of pushing down all the push valves start, all the support columns obtain a height adjustment action synchronized in timing and amount of action.
In the lifting table where the above height adjustment is performed, there is not disclosed setting the top plate to an arbitrary tilt angle, and there is no intention to do so. Also, in the form of tilting the top plate relative to a plurality of support columns to change the position of the table in the front-back direction, in many cases support columns are formed in parallel rinks and the top plate is moved in parallel. On the other hand, as an extreme example, depending on what is being worked on the table, such as a drafting table, a lectern, a display table/display stand for merchandise or items, in some cases it is preferable that the top plate can be tilted rather than horizontal. In order to tilt the top plate relative to the support columns performed as parallel rinks, a mechanism for tilting the top plate and maintaining its tilted state is required between the top plate and the top plate support portion set on the upper part of the support columns, and the structure of the upper part of the support column and the top plate support portion has to be more complicated.
Patent literature 1: Texu Bulletin No.11-127964
Patent literature 2: Texu Bulletin No. 10-262741
Patent literature 3: Texu Bulletin No. 4364981
Patent literature 4: Texu Bulletin No. 3642391
Patent literature 1: Texu Bulletin No. 2017-029453
Therefore, in the table, which includes a top plate, several support columns which support the top plate and can change its height by operation, and foot sections, each of which is attached to the lower end of the support columns, and can support said support columns at ground level, the subject to be solved is how to selectively and easily adjust the height and inclination of the top plate.
The purpose of the present invention is to provide a table capable of adjusting the height of the top plate, by using a mechanism for changing the length of the support columns, even by the user, who can simply configure the structure. The present invention achieves its purpose by providing a lifting table capable of selectively or easily adjusting the height and inclination of the top plate.
The table of the present invention is provided with a top plate, a plurality of leg units and a plurality of operation units, said each leg unit has a support column and a foot section, said support column has upper and lower ends, the length of the direction connecting the upper and lower ends being changeable, and the upper end being connected to the top plate, and said foot section is connected to said lower end of said support column and is adapted for seating on the floor, said lengths of said support columns of said plurality of leg units are changeable by operating one or more said operation units, wherein said each leg unit belongs to either a first leg unit group which includes one or more leg units and arranged on one side of the top plate or a second leg unit group which includes one or more leg unit and arranged on the other side of the top plate, said each operation unit comprises a first operating section for changing the lengths of the support columns of the leg units belonging to the first leg unit group, and a second operating section for changing the lengths of the support columns of the leg units belonging to the second leg unit group, the second operating section being operable independently of the first operating section.
The table has, as a basic structure, a top plate, a plurality of leg units each having a support column and foot section, and a plurality of operation units, the load of the top plate (including the weight carried on the top plate) being supported on the floor by the leg units. The support column and foot section constitute a leg unit, and said each leg unit belongs to either a first leg unit group which includes one or more leg units and arranged on one side of the top plate or a second leg unit group which includes one or more leg unit and arranged on the other side of the top plate. That is, any support column belongs to either of the first leg unit group or the second leg unit group only, and here, each support column does not belong to the first leg unit group and the second leg unit group at the same time. No leg unit belongs to either leg unit group. The length of the support column of the leg unit belonging to the first leg unit group is changed by operating the first operating section, and the length of the support column of the leg unit belonging to the second leg unit group can be changed by the operation of the second operating section. The length of the support column of the leg unit belonging to the first leg unit group and the length of the support column of the leg units belonging to the second leg unit group can be changed independently by operating the first operation unit and the second operation unit individually. In case the lengths of the support columns belonging to first leg unit group and the lengths of the support columns belonging to the second leg unit group are changed to different lengths, the top plate is tilted relatively on one side to the other side, or can be tilted while changing the height of the top plate. The height of the top plate can be changed when the lengths of all legs are changed to the same length. In addition, because the operation unit is divided into two operating sections of the first operating section and the second operating section, in the case of narrower size of the top plate, even one person user uses both hands to operate each operating section thereby allowing the height and tilt of the top plate to be adjusted, and in the case of a wider width of the top plate, two people can operate operation units by sharing the on each side of table, and the height and tilt of the top plate can be adjusted.
In this table, the foot section of said each leg unit comprises a foot body portion which is mounted on said support column and extends in a direction between said one side of the top plate and the other side, and plurality of foot portions which are spaced in the direction of their extension and are adapted for seating on the floor.
When the top plate is in a tilted state with one side relative to the other side, the position of the table's center of gravity is moved causing load imbalance. On the table acts a moment which tends to make the the table tip in the tilt direction connecting one side and the other said of the top plate. Each leg section is provided by spacing with the foot portions that are adapted to land on the floor in the tilt direction. The counteracting moment is obtained with a reaction force from the floor to the foot portions, the resistance to table tipping can be improved by this counteracting moment.
In this table, the foot body portion of said leg unit is fixedly mounted on said support column, the foot portions are mounted on said foot body portion in a manner that the length of each foot portion protruding relative to the foot body portion in the direction to the floor can be changed, said protruding lengths of said foot portions relative to the foot body section can be changed corresponding to the tilt angle of the top plate.
The foot body portion is fixedly mounted on the support column, the foot body portion also tilts together with the support column when the top plate and support column tilt. Due to the special mounting structure in which the foot portions are mounted on said foot body portion in a manner that the length of each foot portion protruding relative to the foot body portion in the direction to the floor can be changed, even if the foot body portion tilts according to the tilt of the top plate, each foot portion can be on the floor in its own way and can transfer the load of the table to the floor by adjusting the protruding height in the direction. In this case, each foot portion includes a joint structure such as a ball joint, and the foot body portion is supported so that each foot portion is preferentially seated on the ground in its own way, even if it is tilted with the support column.
In this table, the foot body portion of said leg unit is mounted on said lower end of the said support column in a manner that the mounting angle can be changed,
the mounting angle of the foot body portion relative to said support column can be changed corresponding to the tilt angle of the top plate.
Since it is possible to change the mounting angle of the foot body portion relative to the lower end of the support column, even if the support column tilts corresponding to tilting of the top plate, the mounting angle of the foot body portion relative to the support column can be changed according to the tilt of the support column, so that any foot portions can land on the floor in its own way, and the table can transmit the load to the floor. Since the foot body portion and the foot portions can be an integrated structure, the foot part can be constructed as a simple structure.
In this table, both the first and second leg unit groups have more than two leg units, the support columns of the leg units belonging to the first leg unit group are in a common first support column configuration plane, the support columns of the leg units belonging to the second leg unit group are in a common second support column configuration plane, and said first configuration surface and second configuration surface are parallel to each other.
When operating the first operation section to change the length of the support columns of the leg units belonging to the first leg unit group, all support columns of the leg unit belonging to the first leg unit group and arranged in a common first support column configuration plane synchronize and be adjusted to the same length. When operating the second operation unit, all support columns of the leg unit belonging to the second leg unit group and arranged in a common second support column configuration plane synchronize and be adjusted to the same length. In making the lengths of the support columns of the leg units belonging to the first leg unit group and belonging to the second leg unit group to the same length, only the height of the top plate is changed, and when the two lengths are changed to different lengths, the top plate is tilted according to the difference in length, or it can be tilted while changing the height of the top plate.
In this table, said foot portions mounted on the support columns of the leg unit belonging to the first leg unit group and said foot portions mounted on the support columns of the leg unit belonging to the second leg unit group are connected by the connecting member so that the relative position changes of the both said foot portions resulting from the inclination of said top plate can be absorbed.
The connecting member connects foot portions mounted on the support columns of the leg unit belonging to the first leg unit group and said foot portions mounted on the support columns of the leg unit belonging to the second leg unit group, in the state of absorbing the changes of relative spacing and rotation of the two foot sections approaching and separating from each other according to the tilt of the top plate. Further displacement or deformation of the two foot sections that increases the relative spacing or rotation of the two foot sections in connected state can be prevented, and displacement or deformation of the two foot sections in connected state that causes the relative lateral movement or twisting can be suppressed. The leg and foot structure can improve the rigidity of the structure and contribute to stability.
In this table, said leg units includes four leg units, each arranged at point corresponding to the four vertices of the parallelogram, said one side and said other side of the top plate are the two opposite sets of sides of said parallelogram, with respect to each of the two sets of sides of the top plate, said foot units are defined as belonging to either a first leg unit group or a second leg unit group, and two operating sections are defined as belonging to either a first operating section or a second operating section.
Regarding this table, there exists two pairs of opposite sides in the table, each set consisting of one side and the other side of the table, because with respect to each of two pairs of opposite sides in a parallelogram, there are one side and the other side. With respect to the four leg units, two leg unit group are determined in each pairs of sides of the table. With respect to the operation unit, a first operation section and a second operation section for operating the two leg unit groups are provided in each pairs of sides of the table. That is, since there are two sets of operating sections with respect to the first and second operating sections, the set of operation units to be operated in the case of tilting the top plate is selected according to the tilting direction selected between the two tilting directions.
In this table, said each leg unit includes a top plate support structure that is mounted on the top plate and the upper end of the support column, for connecting the upper end of the strut to the top plate, in each of said leg units, one of the operating sections belonging to said first operating section and one of the operating sections belonging to second operating section extends into said top plate support structure, and the length of the support column can be changed by operating either of said two operating sections.
In this table, in order to support the top plate, corresponding to the four vertices of the parallelogram (four corners), the top plate receiving structure is mounted in the upper end portion of each support column, one of one set of operation units and another set of operation units is extended along the two sides across each corner and into the top plate receiving structure. For each support column corresponding to the four corners, the length of support column is set to be changeable by operation from any of the operating sections on either side. Thus, the top plate is tilted in one of the two groups on one side and the other side, and since it can be operated on either group, the top plate can be tilted in one of the two tilt directions.
In this table, the foot sections are rotatably mounted on said support columns according to the selected tilt direction so that the direction in which said foot body portion extends follows said tilt direction.
The foot section is mounted in a rotating form relative to the support column with a direction of its extension in line with the direction of tilt according to the selected direction of tilt. By making the foot section rotate relative to the column, the foot section can readjust the tilt to the selected group even in the case of tilting on the other side because it can make the direction of extension coincide with the direction of tilting with the top plate. Therefore, this structure can easily counteract the tipping moment of the table due to tilting.
In this table, the height of the top plate can be changed by changing the support column lengths of the leg units belonging to the first and second leg unit groups to the same length.
With respect to wide table with four support columns, one person cannot operate the table with two operating sections of horizontal length at the same time. Even in the case of two people operating, the invention can change the height by operating equal amounts separately.
The table of this invention can have the following unique effects.
This table has, as a basic structure, a top plate, a plurality of leg units each having support column and foot, and a plurality of operating portions, each leg unit belonging to either a first leg unit group provided on one side of the top plate or a second leg unit group provided on the other side of the top plate; the support columns of the leg units belonging to the first leg unit group are variable in length by operating the operating portion, and the supports of the leg units belonging to the second leg unit group. The length of the support column of the leg unit belonging to the first leg unit group and the length of the support column of the leg unit belonging to the second leg unit group are changed by the operation of the first operation section or the second operating individually. When the lengths of the support columns are changed to the same length, the height of the table is changed. When the lengths of the support columns are changed to the different lengths, the table is tilted from one side to the other side, or the height and tilting of the table are changed. Since the operation unit is divided into two operation units of the first operation section and the second operation section, the user can make height adjustment and tilt adjustment by operating each operation section alone. Alternatively, two people can operate the respective operation sections. Each of the first operation section and the second operation section is itself a mechanism for changing the length of the leg unit which has been used in a lifting table capable of changing the height of the top plate. The table of this invention is provided, by utilizing and devising this mechanism, in which the structure thereof can be made as simple as possible, and the height and tilting of the top plate can be easily adjusted by operating the first operation section and the second operation section individually.
Referring now to the embodiments of the invention shown in the attached drawings,
In the case of this embodiment, the top plate 2 is a plate that is rectangular in a plane view and is most commonly used as a top plate of the table for office use or for work. The top plate 2 is supported on the floor surface F by a leg structure 3 consisting of four leg units U1 to U4 in the four corners corresponding to the top plate 2. Each leg unit U1 to U4 has a support column 5 of variable length on the upper end of which is mounted the top plate 2, and a foot section 6 mounted on the lower end of the support column 5. In case the upper end of the support column 5 is mounted on the top plate 2 by means of a top plate receiving structure 4 mounted slightly inboard of each corner of the top plate 2, Each leg unit U1 to U4 may include the top plate support structure 4. The load of the top plate 2 and objects placed on the top plate 2 is transferred from the top plate receiving structure 4 to the support column 5, and the load applied to the support column 5 is supported on the ground F via the foot section 6. In this embodiment, each support column 5, as shown in
In this embodiment, four leg units U1 to U4 are arranged along the long side edges “a”, “a”, and are classified into two leg unit groups, i.e., the first leg unit group G1 and the second leg unit group G2. Each leg unit U1 to U4 belongs to either of the leg unit groups G1 or G2. The first leg unit group G1 arranged along one long side edge “a” of the top plate 2 (the front side in
The longitudinal centerline (in line with the centerline of the long axis direction of the support column 5) of each leg unit U1 to U4, mounted on the top plate 2 through the top plate receiving structure 4, is perpendicular to a plane defined with respect to the top surface of the top plate 2. The top plate 2 and each leg unit U1 to U4 are always in an orthogonal state. As shown in
In the table 1, the top plate 2 is placed, at its four corners, on the leg units U1 to U4, and supported on the ground F by the foot section 6 set on the lower end of each support column 5. Each foot section 6 has a foot body portion 7 in the shape of one square tubular and a plurality (in this example, two) of footing portions 8, 8, the foot body portion 7 being fixedly mounted on the lower end portion 5b of the support column 5, and footing portions 8, 8 being mounted on the foot body portion 7 in the longitudinal direction thereof and spaced apart relative to each other at the positions on both sides of the support column 5 and adapted to seat on the ground F. The foot body portion 7 extends in the direction parallel to the short side edges “b”, “b” of the top plate 2 corresponding to that inclination direction, when assuming an inclination of the top plate 2.
In each foot section 6, one foot portion 8 passes through the foot body portion 7 and extends upward, and the mounting position of the foot portion 8 in the height direction relative to the foot body portion 7 is changeable by means of the foot axis 9 for when trying to tilt the top plate 2. One foot portion 8 has a variable height of protrusion to the ground F side relative to the leg body portion 7 according to the angle at which the top plate 2 is tilted, but the other leg portion 8 is fixed without penetrating the foot body portion 7 in a way that is buried in the foot body portion 7. In the case of the tilted state of the top plate 2 raised on the side of the second leg unit group G2, a long foot shaft 9, 9 that penetrates the foot body part 7 is used in the foot portions 8, 8.
The foot sections 6, 6 (first foot section group 6G1) mounted on the two support columns 5, 5 of the leg units U1, U2 belonging to the first leg unit group G1 are connected to each other by an elongated foot connector 10. The foot connector 10 has a function of increasing unity(rigidity) of the first leg unit group consisting of the leg units U1, U2. For the foot sections 6, 6 (second foot section group 6G2) of the leg units U3, U4 belonging to the second leg unit group G2, another leg connector 10 improves the unity(rigidity).
The foot connectors 10,10 are bent to each other and close to the central side in order not to obstruct the feet of the user using the table 1. The foot connectors 10,10 may be made in the straight shape as shown by imaginary lines, if they do not obstruct the feet of the user using the table 1. The foot connectors 10a,10a can be made of a bar or barrel material having a suitable cross-sectional shape, and in addition. Each support column 5 may be mounted on the connector 10 for connecting the foot sections 6, 6, instead of being mounted to the foot body portion 7 itself.
As described later, the support column 5 have a nested outer cylinder 11 and an inner cylinder 12, and in the event that the outer cylinder 11 and the inner cylinder 12 do not adequately ensure the length of the support column 5, a complementary connecting cylinder 5c can be used in the manner of replenishment to the outer cylinder 11 (refer to
The outer cylinder 11 (the connecting cylinder 5c in the case where the connecting cylinder 5c is attached below the outer cylinder 11) is mounted with the lower end 14 (equivalent to the lower end 5b of the support column 5) standing on the foot body portion 7. The top plate receiving structure 4 mounted on the lower surface of the top plate 2 and the upper end 15 of the inner cylinder 12 (equivalent to the upper end 5a of the support column 5) are made of iron or resin such as polypropylene reinforced by fiberglass, and each of them may be manufactured separately, and a plurality of parts or materials can be assembled by fixing, for example, with blind rivets and the like. They can be also manufactured by integral molding. In addition, the structure of each support column 5, as the table of the present applicant, is disclosed in the application that has been filed (Patent literature 5).
Each support column 5 has air spring 13 built in, the length of which can be changed by operating the operation unit 30. As for the air spring 13, although not specifically illustrated, a well-known structure can be used, which has a cylinder and piston rod being able to enter and exit by sliding relative to the cylinder, such as used in the field of the chair. Also, as for the air spring 13, the lower base end portion of the cylinder is fixed to the lower end portion 14 of the outer cylinder 11, and the upper end of the piston rod is fixed to the upper end 15 of the inner cylinder 12. The load acting on the top plate 2 is transmitted to the ground F from the top plate receiving structure 4 mounted directly on the top plate 2 via the support column 5 through the leg structure 3. That is, this load is transmitted, in each support column 5, from inner cylinder 12 via the air spring 13 and the outer cylinder 11, to the foot structure 3, and supported on the ground F.
Referring to
In order to make it possible to operate the air spring 13, the upper end of the piston rod protrudes through the upper end portion 15 of the inner cylinder 12 toward the internal space determined by the central concave portion 21 of the top plate supporting structure 4, and the push valve 16 of the air spring 13 is exposed in the internal space. To operate the push valve 16 exposed into the interior space, the operation tip portion of the operation unit 30 extends into the interior of the top plate receiving structure 4. The push valve 16 is pushed in by operating the operation portion 30, whereby the movement of the gas within the air spring 13 is controlled and the piston rod advances or retracts from the cylinder. By such action of the air spring 13, the inner and outer cylinders 11 and 12 perform a telescopic action, changing the length of the support column 5. Depending on the weight placed on the top plate 2 of the table 1, the gas pressure (5 kg, 8 kg, 10 kg, 20 kg, etc.) inside the air spring 13 is adjusted. The structure of the operating section 30 inside the top plate support structure 4 (connection 34 and the lever pivot part 35, etc.) to operate the air spring 13 will be described later referring to
When the top plate 2 is set to a tilted state, the center of gravity as a whole on the table 1 moves in the tilted direction. Load imbalance causes a tilting moment that tends to fall the table 1 in the tilted direction as a whole. The support column 5 is secured to the foot body portion 7 in the position biased to the side lifted by tilting (foot portion 8b side) with respect to the longitudinal center position of the foot body portion 7. By fixing the support column 5 to the foot body part 7 in the offset position, it is possible to make the distance d2 from the attachment position of the support column 5 to the foot portion 8b extending to the downwardly inclined side longer than the distance d1 from the attachment position of the support column 5 to the foot part 8a extending to the upwardly inclined side, and the foot part 8b can be mounted at a position away from the support column 5.
Such a structure makes it easy to obtain the large countering moment acting on the table 1 when the lifting platform 1 is tilted, based on the reaction force acting from the floor surface F on the foot portion 8b on the downwardly inclined side. That is, the footing portions 8a, 8b of each foot section 6 are spaced apart in line with the tilting direction and in line with longitudinal direction thereof, and the lower end portion 5b of the support column 5 is intervened between the footing portions 8a, 8b, the distance of the support column 5 from the lower end portion 5b to the foot portion 8b extending down the tilting side is set to a larger configuration. As a result, even if a tipping moment is generated on the table 1, it is possible to obtain the large moment countering to the tipping moment, based on the reaction force acting on the foot portion 8a, 8b from the floor surface F, and resistance to a fall of the table 1 can be improved.
For the longer foot shaft 9a, as shown in the example of
With respect to the lengths of the support columns 5, 5 belong to the first and second leg units U1, U2 of the first leg unit group G1, and the lengths of the support columns 5, 5 belong to the third and fourth leg units U3, U4 of the second leg unit group G2, the lengths of the former and the lengths of the latter can be changed respectively(independently), and within each leg unit group G1, G2, the lengths of the former and the lengths of the latter can be separately. In order to coordinate such length changes between the former and the latter, an operation unit 301 is provided for the leg unit group G1 and an operation unit 302 is provided for the leg unit group G2 (refer to
As shown in
As shown in
In the fabrication of the operation unit 30, machining errors or assembly errors may arise due to machining or assembly incorrectness. For example, the handle portion 31, the first rod portion 33a, 33a and the second rod portion 33b, 33b are not precisely in one plane, the first rod portion 33a and 33a are not integrated in one common line, and furthermore there is even the second rod portion 33b and 33b are not parallel to each other. In these cases, it will be extremely difficult to operate the push valve 16,16 of the air spring 13,13 simultaneously and in equal amounts by the handle portion 31 alone. In addition, in the case of making the first rod portion 33a,33a and the second rod portion 33b,33b as one continuous and integral piece from a long rod material without using the connector 34,34, it is difficult to make the two sets of first and second rod portions 33a and 33b to be arranged in one plane. When increasing the rigidity of the rod as one piece, the push valve 16,16 of the air spring 13,13 work at different operation timings, which makes difficult the tuning action of the push valve 16,16. On the contrary, when decreasing its rigidity, large deformation of bending or twisting is easily produced at the bent portion from the first rod portion 33a to the second rod portion 33b, and even if the operating amount of the handle portion 31 is increased, the operating amount cannot be transferred to the second rod portion 33b,33b, eventually resulting in the inability to fully press the push valve 16,16. In this case, it takes much time to change the height of the top plate 2.
According to the operation unit 30 of this embodiment, by using the connector 34, in the state before fixation, the connector 34 is allowed to rotate around two axis (axis 0 of the first rod portion 33a and axis δ of the second rod portion 33b) for the first rod portion 33a and the second rod portion 33b. Also, in the state before fixation, the first rod portion 33a and the second rod portion 33b can move within the allowed range defined by the gap Ga and a gap Gb in the axis direction X of the first rod portion 33a and the axis direction Y of the second rod section, respectively. Because such rotation and movement are allowed, the handle portion 31 of the operation unit 30 is operated in the state of loosening the small screws 34c, 34c, the insertion amount and rotation angle amount of the first rod portion 33a, 33a and the second rod portion 33b, 33b relative to the connectors 34, 34 are adjusted so that both of the air spring operating portions 36, 36 formed at the tip end of the second rod portion 33b, 33b contact with the push valve 16, 16 of the air spring 13, 13 (only in contact with it, not pushed in). In this contact state, the small screw 34c, 34c is screwed into the connectors, even after the operation of the operation unit 30 is released, the first rod portion 33a, 33a and the second rod portion 33b, 33b are holed in fixed condition to the connector 34, 34, and the operation unit 30 is maintained in an integrated structure as a whole. After absorbing such errors and gaps and maintaining a fixed state, the user operates the operation unit 30, and with the help of the high rigidity of the connectors 34, 34 against bending and twisting deformation, an operation on the handle portion 31 is not absorbed in the middle of the path, and is transferred to the air spring operation section 36, 36 of the second rod portion 33b, 33b, which tunes to the operation of the push valve 16, 16 of the air springs 13, 13, that is, the second rod portion 33b, 33b are in contact with the push valve 16, 16 at the same time and can be pushed in equal amounts. In this way, even if the handle portion 31, the first rod portion 33a, 33a and the second rod sections 33b,33b do not have precise alignment and parallelism in the manufacturing process, the operation unit 30 is assembled together with the top plate receiving structure 4, 4 in the state without manufacturing errors caused by both processing and assembly.
The structure of the operating rod portion 32 using connector 34 is not necessary for all operating rod portions 32 extending within each top plate receiving structure 4. That is, this applies not only to two leg units belonging to one group, but also to three or more leg units belonging to one group. One operating rod section 32 extends directly into the top plate receiving structure 4 without using the connector 34 (third rod section), and all remaining operating rod sections 32 may have a structure that uses the connector 34. The operating rod section 32 that extends directly into the top plate receiving structure 4 serves as a reference operating rod section when synchronizing with the other operating rod sections 32. That is, the operation unit 30 is operated in the state of loosening the small screws 34c and 34c in all the connectors 34 used, the third rod portion, which extends into the top plate receiving structure 4, is brought into contact with the push valve 16 of the air spring 13. In this state, in the remaining operating rod sections 32, the air spring operating portion 36 formed at the tip end of the second rod portion 33b can be brought into contact (only in contact and not pushed in) with the push valve 16 of the air spring 13, by adjusting the amounts of insertion and rotation angle of the first rod portion 33a and the second rod portion 33b relative to the connector 34. In this state of contact, all the small screws 34c, 34c are secured to the connector 34 by screwing into the connector 34, the first rod portion 33a and the second rod portion 3b are fixed to the connector 34, the operation unit 30 may be a one-piece assembly structure. Then, when the user operates the operating section 30, in all of the operating rod sections 32 including the third operating section, the operation on the handle portion 31 is not absorbed midway, but transferred to all of the air spring operating portions 36, allowing all of the push valves 16 of the air spring 13 to perform in synchronized operation.
In
Referring to
The male threaded portion 65 of the knob 51 is made to pass through the sleeve 61 and the washer assembly 62, and then the male threaded portion 65 is screwed into the nut 60 in the foot body portion 7, the support column 5 being attached to the foot body portion 7. The male threaded portion 65 screwed into the nut 60 is able to extend into the foot body 7. The screw can be loosed by manipulating the knob 51, and the connection between the foot body portion 7 and the adapter 50 is made free. When tightened with knob 51, the spring washer 64 elasticity prevents the screw from loosening. Washer 67 is also inserted between the key portion 66 of knob 51 and adapter 50, this structure ensures that the threads of knob 51 with threads are securely tightened. The relative mounting angle of the adapter 50 against the foot body portion 7 can be changed depending on the tilt of the top plate 2. When the mounting angle is determined, the knob 51 is screwed in by operation, and the tilt angle of the support column 5 can be fixed and maintained as shown in
The connection structure of the support column 5 and foot section 6 shown in
The externally threaded portion 65 of the knob 51 passes through the sleeve 71 and washer assembly 72 provided in a penetrating state in the connecting cylinder 5c, and the externally threaded portion 65 is screwed into the nut 70 secured to the foot body portion 7, then the support column 5 is secured to the foot body portion 7. The externally threaded portion 65 screws into the nut 60 and can extend into the foot body portion 7. The connection of the foot body portion 7 and the adapter 50 is made free by loosening the screw by operating the knob 51. When tightening with the knob 51, the spring washer 72 prevents loosening of the screw. A washer 77 is also clamped between the knob portion 76 of the knob 51 and the support column 5 to ensure that the threaded knob 51 with threads is screwed. The mounting angle of the support column 5 relative to the foot body portion 7 can be changed according to the inclination of the top plate 2 in the same manner as in the case of the connection structure shown in
When the tilt angle of the top plate 2 is determined, by screwing the butterfly bolt 58, 58 through the long hole 57, 57 into the foot body portion 7, 7 of the two leg unit groups G1, G2 in the state of the elongated plate member 56 being clamped against the foot body portion 7, 7, the foot sections 6, 6 are connected by the connecting member 56. In this connected state, the connecting member 55 also suppresses the displacement of the foot section 6, 6 from shifting or twisting laterally with each other, so the rigidity of the leg structure 3b can be improved and contributes to stability. The elongated plate member 56 is shown as one member, but the elongated plate member 56 can also be formed as a connecting part consisting of two parts bolted to two foot sections 6, 6 respectively and overlapping each other with long holes.
In each of the above embodiments, both the first leg unit group G1 and the second leg unit group G2 include two support columns 5,5, but each group can simply include more than one support column 5. However, one of the groups preferably includes two support columns. Also, in the case of a large table, etc., either one or two support columns or even three support columns can be included depending on the size and shape of the top plate 2.
As explained above, the operation unit 30 is provided with a structure such as a lever structure having a tip end portion 36 moved up and down by the lever action with the lever pivot portion 35 located in the middle position, the tip end portion 36 operating to push down the push valve 16. In addition, as another structure of the operating unit 30, the operating tip end portion with a tapered surface is operated so that the tip end portion moves forward and backward, that is, in and out of the inner part of the top plate receiving structure. In this case, the push valve 16 is operated by the wedge action of the tapered surface of the operating tip end portion.
With respect to the operation units, one set of the first operation unit 301(i) and the second operation unit 302(i), like the first operation unit and second operation unit 301, 302 in the embodiment shown in
When only the first operation unit 301(i) is operated, the air spring operating portion 36 formed at the tip end of the second rod portion 33b of the first operation unit 301(i) directly pushes the push valve 16 in, causing the air spring to act. When the second operation unit 302(ii) is operated, the air spring operating portion 36 formed at the tip end of the second rod portion 33b of the second operating unit 302(ii) pushes the air spring operating portion 36 of the first operating unit 301(i), thereby the air spring operating portion 36 of this first operating unit 301(i) presses the push valve 16, causing the air spring to act. Regarding the other components of the top plate receiving structure 4a, since the structure is the same as that of the top plate supporting structure 4 shown in
Above, for the tiltable table of the present invention, several examples are listed for illustration, but various variations are optional. For example, the seating body 8c of the foot portion 8 may be a caster in order to be able to move on the floor surface F, or a caster with a rotation stop locking function. The top plate, although illustrated as a flat plate, can take various forms depending on the application. For example, the present table can be applied to an arbitrary lifting platform such as a bed or sofa where the top plate is a supporting base for a cushion or a pad.
In addition, the table according to the present invention is applicable to tables in general, such as a stove, a steering rack, a line stand, store stand, display table, study table, etc., which has a horizontal or nearly horizontal surface for placing items thereon and for operator's working while standing or sitting nearby, and has a function necessary for the up and down movement of the top plate.
Number | Date | Country | Kind |
---|---|---|---|
2020-092787 | May 2020 | JP | national |