Lifting device

A lifting device adapted for being connected between a seat body and a carrier, and drivable to move the carrier upward or downward relative to the seat body, said lifting device comprising:

• a guide unit adapted for being connected between the seat body and the carrier, being extendable and retractable along a top-bottom direction, and defining an inner space extending along the top-bottom direction;
• a support unit disposed in said inner space and including:
• a securing connector that is adapted for being fixed to the seat body and that is made of an elastic material,
• a support tube that has a bottom portion connected to said securing connector, and that extends along the top-bottom direction, and
• a support member that is disposed at a top portion of said support tube and that has a connecting hole which is spatially communicated with the inside of said support tube;
• and
• a lifting unit including:
• a first rod-actuating screw member that is disposed on said support member inside said inner space, and that has a first threaded hole aligned with said connecting hole, and
• a threaded rod unit that is adapted for being connected to the carrier and that includes a first threaded rod which extends through said first threaded hole into said support tube, and which is threadedly engaged with said first threaded hole of said first rod-actuating screw member in such a manner that said first threaded rod is rotatable by an external force and movable along the top-bottom direction, wherein:
• all of said first rod-actuating screw member, said support member, and said guide unit have identical cross sectional shapes which are non-circular;
• said first threaded rod of said threaded rod unit of said lifting unit is hollow and has an inner surface that defines a plurality of guiding grooves each extending along the top-bottom direction;
• said lifting unit further includes a second rod-actuating screw member fixed to a top portion of said first threaded rod and capable of permitting rotation of said first threaded rod, said second rod-actuating screw member having a second threaded hole;
• said threaded rod unit further includes:
• a second threaded rod that extends into said first threaded rod and threadedly engages said second threaded hole, and that has a top end adapted for being connected to the carrier, and
• a coupling member that is connected to a bottom end of said second threaded rod and that has a plurality of protruding blocks which are respectively and slidably engaged with said guiding grooves;
• said second threaded rod is drivable by the external force and rotatable to drive rotation of the coupling member, which in turn cause said first threaded rod to rotate, such that said first threaded rod and said second threaded rod move telescopically along the top-bottom direction;
• and
• said second rod-actuating screw member and said guide unit have identical cross sectional shapes.