TECHNICAL FIELD

The present invention relates to an adjustable height table, and more

particularly to the table which can easily adjust the height of a table top no

matter what load is being carried by the table top in order to fit user's body

shape, and which can adjust the height of a footrest provided to pedestals,

so that the user can conveniently use the table which fits his body shape.

BACKGROUND ART

Modern offices or industrial environments provide work stations

having various types of functional furniture components. These furniture

components include work surfaces and table tops utilized for various

purposes, from drafting to clerical and word processing functions. These

surfaces therefore must be able to support a variety of equipment such as

typewriters and computer terminals, while at the same time are able to be

vertically adjusted to accommodate a variety of tasks and a variety of users

easily and effortlessly. The height of a footrest, which is provided with a

support of the table, must be also able to be adjusted to accommodate

various users needs.

Especially, it is a serious situation in elementary schools, middle and

high schools or colleges. Though, an individual physical condition is

quite different from one another even among the same classmates, the

schools still use tables that are standardized considering the average

physical conditions of a plurality of students. Thus, it is quite

inconvenient for students to use the table, which is not suitable for their

body shapes.

USP No. 5,289,782, which was published by John J. Rizzi, et al. on

March 1, 1994, discloses an example of an adjustable height table, which is

shown in Fig. 9 of the present application showing an example of the

conventional adjustable height table. As shown in Fig. 9 of the present

invention, the conventional table 10 comprises: a table top 12; a pair of

retractable and extensible telescoping legs having first legs 14a connected

to the table top 10, and second legs 14b which is telescoped into the first

legs 14a such that the first legs 14a can ascend and descend; a

counterbalance mechanism 16 comprising weight means (not illustrated),

disposed between and attached to said pair of telescoping legs; and a pair of

pedestals 18 provided to the lower portion of the second legs 14b of the

legs 14.

However, this table uses the counterbalance mechanism having

weight means comprising a rack, a pinion, a chain and so on for adjusting

the height of the table top. Thus, the productivity becomes lower and the

mass production is difficult due to its complex structure. In addition,

since it is impossible to adjust the height of the footrest 19 in the pedestals

of the table, it is inconvenient for users having various body shapes.

Next, Korean Utility Model No. 20-0355945, which was allowed to Livart

Furniture, Co., Ltd. on July 1, 2004, discloses a device for adjusting table

height. Fig. 10 of the present application shows another example of the

conventional adjustable height table. As shown in Fig. 10, the

conventional device for adjusting the table height 20 comprises: a table 22;

a pair of movable columns 24 projected downward from the lower surface

of the table top 22; main columns 26having a hollow hole inside into which

the movable columns 24 are fitted to be slidingly guided; and pedestals 28

connected at a rectangular angle to the lower portion of the main coulmns

26.

At this time, a plurality of fixing holes 24a are formed at a regular

distance along the longitudinal direction of one side of the movable

coulmns 24; a through hole 26a corresponding to one of the plurality of

fixing holes 24a is formed on one side of the main columns 26; and a fixing

knob 29 connected by a fixing belt 29a is combined with the fixing hole

24a through the through holes 26a on one side of the main columns 26.

However, the conventional art is configured that the fixing knob is taken

off from the fixing hole of the movable supports and the through holes of

the main support. Accordingly, there is a problem in combining the fixing

knob again. In addition, it does not disclose the constitution of the

footrest, which can support the feet of the user.

DISCLOSURE OF INVENTION

Accordingly, in order to resolve the above-mentioned problems, an

object of the present invention is to provide an adjustable height table

which can easily adjust the height of a table top with a simple operation of

a control knob and without completely taking off the control knob which is

fitted into a second leg to thereby obtain an operational convenience.

Another object of the present invention is to provide an adjustable

height table for a user's convenience by installing an adjustable height

footrest on pedestals so that the user can conveniently adjust the height

according to the user's body shape.

In order to achieve the above objects, the present invention

comprises:

a table top;

a leg having a first leg connected to the table top, and a second leg

for supporting the table top to be flat, which is fitted into the first leg or

into which the first leg is fitted so as to contract and extend in a

longitudinal direction, wherein an adjusting hole is provided to one of the

first leg and the second leg, and a plurality of adjusting grooves are

successively provided to the other leg; and

a movable control member comprising: a nut provided to the

adjusting hole; a hollow fixing key which is fitted into the adjusting hole

opposite to the nut to fixedly contact to the first leg and the second leg and

forms a receiving groove on the inner wall of its one side; a compressed

spring fitted into the receiving groove of the fixing key to press the fixing

key; and a control knob having a bolting part, which passes through the

fixing key from the through hole to be screwed on the nut so that the distal

end may not be released from the nut, and a handle which a user can grip

by hands and rotate, wherein the fixing key overcomes the elasticity of the

compressed spring and moves back to contract and extend the length of the

leg when the control knob is spaced away from the leg at its maximum, and

the movement of the fixing key is restricted by the control knob to fix the

leg when the control knob approaches the leg at its maximum.

Preferably, the distal end of the bolting part of the control knob is

fixed by a fixing pin so that it is not released from the nut.

In order to achieve another object, the present invention comprises:

a table top; a pair of intermediate supporting means connected to the table

top; a pair of retractable and extensible legs having a first leg connected to

each of the intermediate supporting means, and a second leg into which the

first leg is ascendibly and descendibly fitted; a pair of pedestals connected

to the lower portion of the leg; a movable control member combined

integrally with the part of the adjusting hole formed on the second leg of

the leg so as not to be separated to thereby control the ascending and the

descending of the first leg; and a footrest capable of adjusting the height

between the pedestals.

Preferably, in order to adjust the height of the footrest, a supporting

frame is installed between the pedestals; a free end of the supporting frame

160 is bent on a slant toward the second leg of the leg; a multistage

clamping device having a plurality of clamping grooves is combined with

the free end of the supporting frame; a connecting part having a fixing hole

is integrated with both ends of the footrest to be located in one of the

clamping grooves of the multistage clamping device.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The aforesaid objects and advantages of the present invention will

become apparent from the following description of the preferred

embodiments taken in conjunction with the accompanying drawings.

Fig. 1 is a partial exploded perspective view of an adjustable height

table according to a preferred embodiment of the present invention;

Fig. 2 is a perspective view of the adjustable height table of Fig. 1

assembled together;

Fig. 3 is a cross-sectional view showing the adjustable height table of

Fig. 1 ;

Fig. 4 is an enlarged partial view of the part "A" in Fig. 3, showing a

locking state of a first leg of the leg;

Fig. 5 is an enlarged partial view of the part "A" in Fig. 3, showing

an unlocking state of a first leg of the leg;

Fig. 6 is an enlarged partial view of the part "A" in Fig. 3, showing a

retractable and extensible leg;

Fig. 7 is a side cross-sectional view taken along the line B-B of Fig.

2, showing a state of a heightened a table top and footrest of the table;

Fig. 8 is a side cross-sectional view taken along the line B-B of Fig.

2, showing a state of a lowered table top and a footrest of the table;

Fig. 9 is a perspective view showing an example of the conventional

adjustable height table; and

Fig. 10 is a perspective view showing another example of the

conventional adjustable height table.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, an adjustable height table according to the preferred

embodiments will be explained with reference to the accompanying

drawings.

Fig. 1 shows an adjustable height table according to a preferred

embodiment of the present invention. Fig. 2 shows the adjustable height

table of Fig. 1 assembled together. Fig. 3 is a cross-sectional view

showing the adjustable height table of Fig. 1. Fig. 4 is an enlarged partial

view of the part "A" in Fig. 3, showing a locked state of a first leg of the

leg. Fig. 5 is an enlarged partial view of the part "A" in Fig. 3, showing

an unlocked state of a first leg of the leg. Fig. 6 is a partial expanded view

of the part "A" in Fig. 3, showing a retractable and extensible leg.

Referring to Figs. 1-6, an adjustable height table 100 of the present

invention comprises: a table top 110; a pair of intermediate supporting

means 120 connected to the lower surface of the table top in a vertical

down direction; a plurality of retractable and extensible legs provided in a

vertical down direction of the bottom of the intermediate supporting means

120 so as to adjust the height; and a plurality of pedestals 140 installed at

the bottom of each leg 130.

More particularly, the table top 110 preferably has a substantially flat

surface.

Each of the intermediate supporting means 120 is provided on the

both sides of the lower surface of the table top 10 in a vertical down

direction. Since each of the intermediate supporting means 120 is spaced

away from one another, it is preferable to connect the middle point by an

upper connecting rod 122.

The leg 130 comprises a pair of first legs 132 provided in a vertical

down direction of each intermediate supporting means 120, and a pair of

second legs 136 into which the first legs 132 are ascendibly and

descendibly fitted. The first legs 132 preferably have a plurality of

suspending grooves 134 at a predetermined interval along its

circumferential surface. The suspending grooves 134 are arranged at a

regular interval, but it is possible to arrange them at an irregular interval if

required. A pair of the first legs 132 can be formed as one group. The

first legs 132 are spaced away from one another at a predetermined interval.

The suspending grooves 134 formed at the first legs 132 are located

opposite to one another.

A hollow hole with the upper surface open is provided to the inside

of the second legs 136. The first legs 132 are fitted into the hollow hole

of the second legs to be vertically ascended or descended. At least one

adjusting hole 136a corresponding to one of the suspending grooves 134 of

the first legs 132 is provided to the second legs 136. The adjusting hole

136a completely passes through one side to the other side of the outer

circumferential surface of the second legs 136. A lower connecting rod

138 is provided between each of the second legs 136. A hole for installing

the fixing pin 158 and means for closing up the hole can be provided to one

side of the lower connecting rod 138. Also, the lower connecting rod 138

can be applied to the other parts of the second legs 136.

Referring to Figs. 4 and 6, a movable control member for controlling

the ascending and the descending operation of the first legs 132 is provided

to the adjusting hole 136a of the second legs 136. The movable control

member comprises: a nut 150 integrated in the adjusting hole 136a

contacted to the both ends of the lower connecting rod 138; a hollow fixing

key 152 fitted into the adjusting hole 136a of the second leg 136 to be fitted

into one of the suspending grooves 134 of the first legs 132 and forming a

receiving groove 152a on its inside wall; a compressed spring 154 fitted

into the receiving groove 152a of the fixing key 152 to provide elasticity

for pushing the fixing key 152; a bolting part 156a passing through the

fixing key 152 from the adjusting hole 136 of the second legs 136 and

screwed its end with the nut 150; and a control knob 156 having a handle

156b which a user can grab to rotate. Herein, the end of the bolting part

156a of the control knob is fixed by the fixing pin 158 so that it is not

released from the nut 150. The strength of the compressed spring 154 is

preferably controlled in order to prevent a sudden descending of the table

top by its weight.

Referring back to Figs. 1-3, the pedestals 140 are arranged in the

horizontal direction at the bottom of the second legs 136. That is, the

pedestals 140 are preferably arranged at a right angle with respect to the

second legs 136 standing upright. The pedestals 140 maintain the standing

state of the table 100 by contacting the ground or the other surface of work

stations.

In addition, a footrest capable of adjusting the height step by step can

be further installed between each of the pedestals 140. The footrest

element comprises: a supporting frame 160 provided between each pedestal

140 and in which its free end is bent on a slant toward the second leg 136

of the leg 130; a multistage clamping device 162 combined with the bent

free end of the supporting frame 160 and providing a plurality of clamping

grooves 162a stepwise; and a footrest 164 fitted into the multistage

clamping device 162 and capable of adjusting the height step by step.

Especially, the footrest 164 is integrally extended with foot supporting

means 166 for being put on and contacted with the user's feet, and a

connecting part 168 having clamping holes 166 on the both sides of the

foot supporting means 166. A plurality of grooves can be formed on the

top surface of the foot supporting means 166 to prevent slipping of the feet

contacted to the top surface. After passing through the clamping hole

168a formed in the connecting part 168 of the footrest, the connecting part

168 is fixedly clamped with one of the clamping grooves 162a of the

multistage clamping device 162 to be fixed.

The operation of the adjustable height table configured as mentioned

above is explained with reference to the accompanying Figs. 7 and 8.

Fig. 7 is a side sectional view taken along the line B-B of Fig. 2, showing a

state of a heightened table top and footrest of the table. Fig. 8 is a side

cross-sectional view taken along the line B-B of Fig. 2, showing a state of a

lowered a table top and a footrest of the table.

Referring to Fig. 7, if the figure of the user of the table 100 is big, if

the control knob 156 is rotated in a clock- wise direction or in a counter

clock-wise direction, the handle 156b of the control knob 156 releases the

compression state of the compressed spring 154, while spaced away from

the fixing key 152 which were pushing the handle 156b to be fixed.

Thereafter, the fixing key 152 moves back toward the handle 156b by an

external force, that is, the moving force of the first leg 132. At this time,

the moving force of the first leg 132 becomes bigger than the elasticity of

the compressed spring 154. Thus, the fixing key 152 is released from the

suspending groove 134 of the first leg 154. At this time, the pushing force

by the handle 156b of the control knob 156 disappears but still the elasticity

of the compressed spring 154 pushing the fixing key 152 toward the

suspending groove 143 of the first leg 132 (please refer to Figs. 5 and 6)

exists. Then, the height of the table top 110 can be easily adjusted even

by the user's weak power. At this stage, the user can pull the table top

110 high to adjust the height so that the table can suit the user's body shape.

Next, the control knob 156 is rotated in opposite to the above process.

Then, the handle 156b of the control knob 156 pushes the compressed

spring 154 to eventually fix the fitting state of the fixing key 152 into the

fixing groove 134 of the first leg 132. Therefore, the first leg 132 is fixed

in the second leg 136.

In addition, as shown in Fig. 7, the footrest 164 is moved from the

clamping groove 162a of the lowest portion (shown in solid line) of the

multistage clamping device 162 to the highest portion (shown in solid line).

For this process, the user performs a simple operation which takes out the

footrest 164 from the clamping groove 162a of the lowest portion and fits it

to the highest portion to combine it.

Conversely to the above operation, referring to Fig. 8, if the user's

body shape is small, as already mentioned above, after releasing the

locking state of the first leg 132 by the rotation of the control knob, the user

can lower the table top to the required height. Thereafter, the first leg 132

becomes the locking state by the rotation of the control knob 156 to fix the

table top 110.

Also, the footrest 164 can be moved from the highest position

(shown in dotted line) to the lowest position (shown in solid line) to fit the

user's figure.

INDUSTRIAL APPLICABILITY

As mentioned above, the adjustable height table according to the

preferred embodiments of the present invention, forms a plurality of fixing

grooves on the first leg connected to the table top; arranges the first legs in

the hollow hole of the second legs ascendibly and descendibly; and enables

up and down adjustment of the first legs by the fixing element provided to

the second legs. Thus, the present invention has an effect of raising and

lowering the table top by a simple rotation of the control knob according to

the user's figure. Especially, since the control knob is not released from

the second legs, it is convenient to adjust the height.

In addition, the present invention provides the supporting frame

having a multistage clamping device on the pedestals of the leg, and

selectively fits the footrest into a plurality of clamping grooves formed on

the multistage clamping device. Thus, the user can adjust the height of

the table vertically by a simple operation of selecting one of the clamping

grooves of the multistage clamping device according to the user's body

shape and fitting or taking out the footrest.

Although the invention has been shown and described with respect to

the preferred embodiments, it will be understood by those skilled in the art

that various changes and modifications may be made without departing

from the spirit and scope of the invention as defined in the following claims.