Patent ID: 8292040

Claim:
A double screw elevator, comprising: a double screw driving unit including a driving shaft assembly connected to a rotation power source, the driving shaft assembly being provided on an outer surface thereof with a first helical thread and a second helical thread in such a manner that the first helical thread and the second helical thread extend in opposite helical directions, the rotation power source is connected to the driving shaft assembly for driving the driving shaft assembly to rotate; a limit rail disposed in parallel to the driving shaft assembly; a carrying unit including a nut fixed to one side of a carrying seat, the nut being screwed with the first thread, while another side of the carrying seat being slidably received in the limit rail; an elevator car detachably disposed on the carrying seat of the carrying unit; a suspension unit including another nut fixed to one side of a suspension rack, the another nut of the suspension unit being screwed with the second thread, and another side of the suspension rack being slidably received in the limit rail; and an assembling device; including an upper assembling member, a lower assembling member and a power source assembly, the upper assembling member being fixed to the suspension rack, the lower assembling member being fixed to the elevator car and located under the upper assembling member; wherein the power source assembly includes a power source which includes a retractable central shaft with one end connected to an assembling portion, the assembling portion includes a first shaft and a second shaft, the upper assembling member is formed with a first inserting hole for insertion of the first shaft, while the lower assembling member is formed with a second inserting hole for insertion of the second shaft, when the power source pushes the retractable central shaft to an extended position, the first shaft and the second shaft will be inserted into the first and second inserting holes, respectively, so as to connect the elevator car to the suspension rack.