Patent Abstract:
Provided is a height-adjustable table configured such that a height adjustment member rotates in response to an operation of an actuation unit, thereby being released from a locked state, and when an upper plate of the table is vertically lifted to a desired level, the operation of the actuation unit is stopped, and the height of the upper plate is adjusted step by step. Optimal space utility and a simple inner structure of the height-adjustable table can be accomplished, thereby reducing manufacturing cost and increasing user convenience.

Full Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Korean Patent Application No. 10-2015-0028346, filed Feb. 27, 2015, the entire contents of which is incorporated herein for all purposes by this reference. 
     BACKGROUND OF THE INVENTION 
     1 . Field of the Invention 
     The present invention generally relates to a height-adjustable table. More particularly, the present invention relates to a height-adjustable table configured such that a height adjustment member rotates in response to an operation of an actuation unit, thereby being released from a locked state, and when an upper plate of the table is vertically lifted to a desired level, the operation of the actuation unit is stopped, and the height of the upper plate is adjusted step by step. Accordingly, the present invention realizes the optimal space utility and a simple inner structure of the height-adjustable table, thereby reducing manufacturing cost and increasing user convenience. 
     2 . Description of the Related Art 
     Generally, a table is manufactured in various sizes and shapes according to its intended use. When manufacturing a table for children, the table is small and light, but when manufacturing a table for a home or an office, the table requires durable and robust for its use, and thus it is big and heavy. 
     The table is typically made up of an upper plate and a plurality of support legs, and when used, the table is used with the support legs spread, but when unused, the table is stored with the support legs folded. 
     However, the conventional table has a problem in that when the support legs of the table are spread from the upper plate, the table is fixed to a single predetermined height for use, and it is impossible to adjust the height of the upper plate, thus the utility of the table is low. 
     To address the issue, a table constructed in a folding manner to be conveniently used is on the market. When the upper plate of the folding table is lifted, the folded upper plate is lifted up diagonally while describing a parabola. Accordingly, the folding table has a problem in that it requires a larger space for use, and thus space utility is low. 
     In recent years, to solve the problem, a table height-adjustment device has been proposed as disclosed in Korean Patent No. 10-0330661. 
     The invention of the related art includes: first longitudinal guide holes provided at two opposite sides of an upper plate of a table; second longitudinal guide holes provided at sides of supporting plates securely placed inside supporting poles; folding links movably combined with the first and second longitudinal guide holes; a moving unit connected with lower pins to stretch the folding links; a threaded shaft moving the moving unit forward and backward within the range of the second longitudinal guide holes; and rotating means to rotate the threaded shaft. Accordingly, the table of the related art can adjust the height of the table unlike the existing tables, and thus it can be used conveniently and comfortably. 
     However, in the invention of the related art, if a decelerating motor or a handle is rotated to adjust the height of the table, the threaded shaft rotates to close or open the folding links, thereby lifting or lowering the upper plate. Accordingly, since the inner structure of the table of the related art is complex, the table is difficult to fabricate, thereby increasing manufacturing cost and often causing malfunctions. 
     The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art. 
     3 . Documents of Related Art 
     (Patent Document 1) Korean Patent No. 10-0330661. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and the present invention is intended to propose a height-adjustable table configured in such a manner that a height adjustment member rotates in response to the operation of an actuation unit, thereby being released from a locked state, and when an upper plate is vertically lifted to a desired height, the operation of the actuation unit is stopped, and the height of the upper plate is adjusted step by step. Accordingly, the present invention realizes the optimal space utility and simple inner structure of the height-adjustable table, thereby reducing manufacturing cost and increasing user convenience. 
     In order to achieve the above object, according to one aspect of the present invention, there is provided a height-adjustable table including: 
     an upper plate; 
     a leg unit mounted to a lower surface of the upper plate and having a lifting unit provided in such a manner that when an actuation unit is operated, the lifting unit is lifted or lowered while a locking protrusion of the lifting unit is locked in one of a plurality of height adjustment holes of a height adjustment member; 
     the actuation unit including:
         an actuation lever rotatably combined with a fixed mount to rotate based on a shaft pin, the fixed mount being fixed to the lower surface of the upper plate; and   a pressure member pressurizing a height adjustment unit while the actuation lever is operated,   wherein when the actuation lever is operated, the locking protrusion of the leg unit is released from or locked in one of the height adjustment holes of the height adjustment member while the pressure member applies a pressure to the height adjustment member or removes the pressure therefrom; and       

     the height adjustment unit provided in such a manner that while the actuation unit is operated, the locking protrusion is released from or locked in one of the height adjustment holes to progressively adjust the height of the leg unit while the height adjustment member rotates based on a shaft thereof, the height adjustment unit being combined with an inner side of an upper bracket of the leg unit. 
     The present invention has an advantage in that the height adjustment member rotates in response to the operation of the actuation unit of the present invention, thereby being released from a locked state, and when the upper plate is vertically lifted to a desired height, the operation of the actuation unit is stopped, and the height of the upper plate is adjusted step by step. Accordingly, the present invention realizes optimal space utility and a simple inner structure of the height-adjustable table, thereby reducing manufacturing cost and increasing users&#39; convenience. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a front sectional view of the present invention; 
         FIG. 2  is a side sectional view of the present invention; 
         FIGS. 3 to 7  are views showing the operation of the present invention; and 
         FIGS. 8 and 9  are views showing the use of a table put in a table receiving space. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinbelow, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. Throughout the drawings, the same reference numerals will refer to the same or like parts. 
     The height-adjustable table  100  of the present invention includes: an upper plate  110 ; a leg unit  120  mounted to a lower surface of the upper plate  110  and having a lifting unit  122  provided in such a manner that when an actuation unit  130  is operated, the lifting unit  122  is lifted or lowered while a locking protrusion  122   b ′ of the lifting unit  122  is engaged with one of a plurality of height adjustment holes  142   c  of a height adjustment member  142 ; the actuation unit  130  including: an actuation lever  131  rotatably combined with a fixed mount  131   a  to rotate based on a shaft pin  131   b , the fixed mount  131   a  being fixed to the lower surface of the upper plate  110 ; and a pressure member  132  pressurizing a height adjustment unit  140  while the actuation lever  131  is operated, wherein when the actuation lever  131  is operated, the locking protrusion  122   b ′ of the leg unit  120  is released from or engaged with one of the height adjustment holes  142   c  of the height adjustment member  142  while the pressure member  132  applies a pressure to the height adjustment member  142  or removes the pressure therefrom; and the height adjustment unit  140  provided in such a manner that while the actuation unit  130  is operated, the locking protrusion  122   b ′ is released from or locked in one of the height adjustment holes  142   c  to progressively adjust the height of the leg unit  120  while the height adjustment member  142  rotates based on a shaft  142   a ′ thereof, the height adjustment unit  140  being combined with an inner side of an upper bracket  121  of the leg unit  120 . The above description will be described in more detail. 
     In the height-adjustable table  100 , the leg unit  120  includes: upper and lower brackets  121  and  121 ′ each having a longitudinal guide hole  121   a  with which the lifting unit  122  is combined, the upper and lower brackets  121  and  121 ′ being fixed at locations under the upper plate  110 ; the lifting unit  122  including a plurality of lifting members mounted to the upper and lower brackets  121  and  121 ′ in a scissor type, wherein a first end of each of the lifting members is held by a rotation guide shaft  122   a , and a second end thereof is combined with a guide roller  122   b  to guide a movement of the lifting member along the longitudinal guide hole  121   a , the guide roller  122   b  having the locking protrusion  122   b ′ protruding therefrom; and an elastic member  123  provided between the lifting members, thereby preventing the lifting unit  122  from being lowered too rapidly. 
     The elastic member  123  includes two springs having different diameters. 
     The leg unit  120  further includes: an auxiliary spring  124  provided to elastically lift or lower the lifting unit  122 , the auxiliary spring  124  being combined with the rotation guide shaft  122   a  of the lifting unit  122 . 
     The height adjustment unit  140  includes: a fixed member  141  fixed to the inner side of the upper bracket  121  of the leg unit  120 ; the height adjustment member  142  combined with the fixed member  141  and adjusting the height of the leg unit  120  while rotating based on the shaft  142   a ′ thereof when the actuation unit  130  is operated; and a restoration member  143  provided between the fixed member  141  and the height adjustment member  142 , and restoring the height adjustment member  142  to the initial position thereof. 
     The height adjustment member  142  includes: a height adjustment body  142   a  rotated based on the shaft  142   a ′ of the height adjustment member  142  by the operation of the actuation unit  130 ; a pressure protrusion  142   b  provided on an upper part of the height adjustment body  142   a;  and the plurality of height adjustment holes  142   c  which are engaged with or released from the locking protrusion  122   b ′ of the leg unit  120 , the height adjustment holes  142   c  being provided on a lower part of the height adjustment body  142   a.    
     The height-adjustable table  100  further includes: a cooperation unit  150  provided between and combined with the height adjustment units  140  placed at opposite sides of the table and configured such that the height adjustment units  140  are operated simultaneously while the cooperation unit  150  cooperates with the pressure of the pressure member  132 . 
     The cooperation unit  150  includes: a cooperation guide member  152  rotating based on a central shaft  152 ′ thereof; and cooperation members  151  connected with two opposite ends of the cooperation guide member  152 , respectively, the cooperation members  151  cooperating with the cooperation guide member while rotating based on the cooperation guide member  152  when the actuation unit  130  is operated, the cooperation members  151  having respective combination notches  151 ′ combined with the pressure protrusions  142   b  provided in the height adjustment units  140 . 
     The fabrication process of the exemplary embodiment of the present invention constructed above will be described in detail below. 
     First, the upper plate  110  made of wood and formed to be flat as illustrated in  FIGS. 1 and 2  is turned over so that the lower surface of the upper plate  110  faces upward. 
     After the upper brackets  121  are arranged at opposite positions spaced at a predetermined distance on the lower surface of the upper plate  110  and are mounted thereto, while the fixed mount  131   a  is fixed to be adjacent to the outside of each of the upper brackets  121 , the actuation lever  131  is combined with the fixed mount  131   a  by using the shaft pin  131   b  so that the actuation lever  131  can rotate. 
     The pressure member  132  pressurizing the height adjustment member  142  is mounted to be in close contact with the inner surface of the actuation lever  131 . 
     In addition, the fixed member  141  of each of the height adjustment units  140  is fixed to the inner side of each of the upper brackets  121 , and the height adjustment member  142  having the height adjustment holes  142   c  is located between the upper bracket  121  and the fixed member  141 , and then the shaft  142   a ′ of the height adjustment member  142  is combined with the height adjustment member  142  toward the side of the height adjustment member  142  from the outside of the fixed member  141  so that the height adjustment member  142  can rotate. 
     In this case, the pressure member  132  of the actuation unit  130  is in close contact with the pressure protrusion  142   b  of the height adjustment member  142  so that when the pressure member  132  is pressurized, the height adjustment member  142  can rotate. 
     The restoration member  143  is mounted between the fixed member  141  and the height adjustment member  142 , wherein the first end of the restoration member  143  is mounted to one side of the height adjustment member  142  and the second end thereof is mounted to the inner surface of the fixed member  141 . 
     As described above, when the fabrication of the height adjustment units  140  is completed, the cooperation unit  150  simultaneously operating the height adjustment units  140  during the operation of the actuation unit  130  is provided between and combined with the height adjustment units  140 . After the combination notches  151 ′ formed on the cooperation members  151  of the cooperation unit  150  are combined with the pressure protrusions  142   b  of the height adjustment members  142 , opposing ends of the cooperation members  151  are connected with respective opposite ends of the cooperation guide member  152 . 
     The cooperation guide member  152  is mounted to rotate based on the central shaft  152 ′ thereof located between the height adjustment units  140 . 
     Additionally, a first end of each of the lifting members provided in a scissor type is held to the upper and lower brackets  121  and  121 ′ by the rotation guide shaft  122   a  so that the lifting members can rotate, and the guide roller  122   b  is mounted to a second end of each of the lifting members to be guided in rolling contact with the inner surfaces of the upper and lower brackets  121  and  121 ′. The locking protrusion  122   b ′ of the guide roller  122   b  is provided protruding toward the side of the longitudinal guide hole  121   a  to be combined with one of the height adjustment holes  142   c  of the height adjustment members  142 . 
     The elastic member  123  including a spring provided under the upper plate  110  and between the lifting members is connected with the lifting members to prevent the lifting unit  122  from being lowered too rapidly and to lift the lifting unit  122  elastically when the lifting members are lifted. 
     In the elastic member  123 , the spring is a double spring in which a small diameter spring is inserted into a large diameter spring, and the elastic member  123  prevents the lifting unit  122  from being lifted and lowered too rapidly. 
     Furthermore, the auxiliary spring  124  is mounted to the rotation guide shaft  122   a  of the lifting unit  122  to help the lifting or lowering motion of the lifting unit  122 . 
     The operation of the exemplary embodiment of the present invention constructed as described above will be described in detail below. 
     First, as illustrated  FIGS. 3 to 7 , when it is required to lift a folded table to a predetermined height by closing the leg units  120 , a user holds and presses at least one of the actuation levers  131  of the actuation units  130 . 
     If the actuation lever  131  rotates based on the shaft pin  131   b  thereof, the pressure member  132  positioned at one end of the actuation lever  131  pressurizes one surface of the pressure protrusion  142   b  of the height adjustment member  142 . 
     Then, the height adjustment member  142  is rotated based on the shaft  142   a ′, and the cooperation members  151  of the cooperation unit  150  combined with the pressure protrusions  142   b  of the two height adjustment units  140  provided at opposite sides of the table rotate based on the cooperation guide member  152  to simultaneously rotate the height adjustment members  142 . 
     In this case, the locking protrusion  122   b ′ of the lifting unit  122  locked in one of the height adjustment holes  142   c  is released therefrom. 
     When the locking protrusion  122   b ′ is released from the height adjustment hole  142   c  of the height adjustment member  142  as described above, the user vertically lifts the upper plate  110  to the predetermined height while holding the actuation lever  131  of the actuation unit  130 . 
     When the upper plate  110  is lifted, the lifting members of the lifting unit  122  rotate based on a rotation shaft  122 ′, and the guide rollers  122   b  move in rolling contact with the upper and lower brackets  121  and  121 ′. During the movement of the rollers  122   b , the locking protrusions  122   b ′ of the guide rollers  122   b  are simultaneously guided along the longitudinal guide holes  121   a.    
     In this case, the movement of the locking protrusion  122   b ′ is not interrupted from the height adjustment hole  142   c  of the height adjustment member  142 . 
     When the upper plate  110  reaches a desired height, the user removes the pressure from the actuation lever  131 . 
     When the pressure of the actuation lever  131  is removed, the height adjustment member  142  rotates based on the shaft  142   a ′ by the elasticity of the restoration member  143  mounted between the height adjustment member  142  and the fixed member  141 , thereby restoring the position of the height adjustment member  142  to the initial position thereof. At the same time, the locking protrusion  122   b ′ of the lifting unit  122  is locked in one of the height adjustment holes  142   c  of the height adjustment member  142 , thereby realizing adjustment of the height of the leg unit  120 . 
     In this case, when the height adjustment member  142  rotates, the pressure member  132  pressurizing the pressure protrusion  142   b  is moved toward the actuation lever  131  by the restoring force of the height adjustment member  142 , thereby rotating the actuation lever  131  to the initial position thereof. 
     In addition, the cooperation members  151  combined with the pressure protrusions  142   b  of the height adjustment members  142  provided at the opposite sides of the table rotate based on the central shaft  152 ′ of the cooperation guide member  152 , thereby restoring the position of the cooperation member  151  to the initial position thereof. 
     To lift the height of the upper plate  110  higher after adjusting the height of the upper plate  110  as described above, the same process described above may be applied to adjust the height of the upper plate  110 . 
     Accordingly, as described above, the upper plate  110  is vertically lifted to progressively adjust the height thereof. 
     In addition, as illustrated in  FIGS. 8 and 9 , the height-adjustable table  100  having the above-mentioned construction may be used while being put in a table  100 ′ having a receiving space A. 
     Here, the height of the upper surface of the height-adjustable table  100  is equal to the height of the table  100 ′ having the receiving space A, so the height-adjustable table  100  put in the table  100 ′ may be used as a normal table. When it is required to lift the upper plate  110  of the height-adjustable table  100  to a predetermined level, the upper plate  110  may be lifted to the desired height by operating the actuation unit  130  in the same manner as described above. 
     All terms or words used in the specification and claims have the same meaning as commonly understood by one of ordinary skill in the art to which inventive concepts belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Technology Classification (CPC): 0