Height-adjustable table

A height-adjustable table, comprising:

• a table top comprising two support block units located on a bottom surface thereof and respectively extended along two opposite short sides thereof in a parallel manner, each said support block unit comprising a position-limiting rail block having a sliding open chamber defined therein, a first pivot holder and a second pivot holder respectively located at opposing front and rear sides in a diagonal relationship;
• a linkage mechanism comprising two first linkages and two second linkages respectively and pivotally connected to said first pivot holders and said second pivot holders of said support block units, each said first linkage comprising a first leg, each said second linkage comprising a second leg;
• and
• a lifting control mechanism comprising two first sliding tooth racks and two second sliding tooth racks respectively slidably mounted in said sliding open chamber of said two support block unit and respectively pivotally coupled to said first leg and said second leg, two lock mechanisms respectively mounted between said two first sliding tooth racks and said two second sliding tooth racks and an operating handle mounted at each said lock mechanism, each said lock mechanism comprising a base frame and a center gear rotatably mounted in said base frame and meshed with one said first sliding tooth rack and one said second sliding tooth rack, each said operating handle comprising a grip suspending outside one respective said support block unit, a shank perpendicularly extended from one end of said grip and pivotally coupled to said base frame of one respective said lock mechanism and a locking member fastened to a distal end of said shank remote from said grip and adapted for locking said center gear, said grip being operable to bias said locking member in direction away from said center gear for allowing said table top to be moved upward or downward by an external force in extending out or collapsing said first linkages and said second linkages so that said center gears are rotated to move said first sliding tooth racks and said second sliding tooth racks in the respective position-limiting rail blocks in reversed directions,
• wherein said position-limiting rail block of each said support block unit comprises a top panel, two side panels respectively downwardly extended from two opposite lateral sides of said top panel, said first pivot holder and said second pivot holder respectively located at said two side panels at opposing front and rear sides in a diagonal relationship, and a first sliding slot and a second sliding slot respectively located at said two side panels and respectively disposed remote from said first pivot holder and said second pivot holder in a diagonal relationship;
• said first sliding tooth racks of said lifting control mechanism each comprise a first guide rod and said second sliding tooth racks of said lifting control mechanism each comprise a second guide rod respectively, said first guide rods and said second guide rods of said lifting control mechanism being respectively slidably inserted through said first sliding slots and said second sliding slots of said position-limiting rail blocks of the respective support block units.