Patent ID: 8500098

Claim:
An elevation mechanism comprising: a platform; a base assembly comprising a threaded rod, two threaded members, and two sliding members fixed to the corresponding threaded members, the threaded rod comprising two threaded portions threadedly engaging with the corresponding threaded members, wherein directions of rotation of the two threaded portions are opposite; a scissor lift assembly having a lower end and an upper end; and a sliding assembly comprising two fixing members, a sliding rod fixed between the two fixing members, and two sliding members sleeving the sliding rod, wherein the two fixing members are fixed to the platform; the two sliding members of the sliding assembly are pivotedly connected to the upper end of the scissor lift assembly; and the two threaded members are pivotedly connected to the lower end of the scissor lift assembly via the corresponding sliding members; the scissor lift assembly comprises a plurality of articulated first scissor legs, a plurality of articulated second scissor legs pivotedly coupled to the respective first scissor legs via a plurality of pivotal shafts, two first connecting members pivotedly connected to free ends of the outermost first scissor legs of the scissor lift assembly, two second connecting members pivotedly connected to free ends of the outermost second scissor legs of the scissor lift assembly, two fixing members, and two springs; one of the two first connecting members and one of the two fixing members of the scissor lift assembly are fixed to one of the two sliding members of the base assembly, and one of the two springs is positioned between and resists against the one of the two first connecting members and the one of the two fixing members of the scissor lift assembly; and one of the two second connecting members and the other of the two fixing members of the scissor lift assembly are fixed to the other sliding member of the base assembly, and the other of the two springs is placed between and resists against the one of the two second connecting members and the other of the two fixing members of the scissor lift assembly.