Scissor lift and mobile robot having the same

A mobile robot comprising:

• a main body configured to travel autonomously;
• and
• a scissor lift on an upper surface of the main body,
• wherein the scissor lift comprises:
• a fixed plate;
• a lifting plate above the fixed plate;
• a pair of scissor arms between the fixed plate and the lifting plate and having an X shape, the pair of scissor arms comprising a first scissor arm and a second scissor arm, each of the first scissor arm and the second scissor arm comprising a fixed end fixed to the fixed plate and a moving end configured to move linearly with respect to the fixed plate;
• a motor configured to move the moving end of the first scissor arm and the moving end of the second scissor arm;
• and
• a load reduction device configured to reduce a load applied to the motor in a case where the lifting plate descends, and
• wherein the load reduction device comprises a plurality of elastic bodies, the plurality of elastic bodies comprising a first elastic body and a second elastic body that are on the moving end of the first scissor arm and connected in series,
• wherein the load reduction device further comprises:
• a moving bracket connected to the moving end of the first scissor arm, wherein one end of the plurality of elastic bodies is connected to the moving bracket;
• a plurality of engaging plates at another end of the plurality of elastic bodies and between the plurality of elastic bodies;
• a plurality of stopping plates configured to selectively engage with the plurality of engaging plates;
• and
• a string winder adjacent to the fixed end of the first scissor arm and comprising a string connected to an engaging plate furthest from the moving bracket among the plurality of engaging plates.

A lift comprising:

• a fixed plate;
• a lifting plate above the fixed plate;
• a scissor arm between the fixed plate and the lifting plate and having an X shape, the scissor arm comprising a fixed end fixed to the fixed plate and a moving end configured to move linearly with respect to the fixed plate;
• a motor configured to move the moving end of the scissor arm;
• a load reduction device configured to reduce a load applied to the motor in a case where the lifting plate descends,
• wherein the load reduction device comprises a plurality of elastic bodies on the moving end of the scissor arm and connected in series, and
• wherein the load reduction device further comprises:
• a moving bracket connected to the moving end of the scissor arm, wherein one end of the plurality of elastic bodies is connected to the moving bracket;
• a plurality of engaging plates at another end of the plurality of elastic bodies and between the plurality of elastic bodies;
• a plurality of stopping plates configured to selectively engage with the plurality of engaging plates;
• and
• a string winder adjacent to the fixed end of the scissor arm and comprising a string connected to an engaging plate furthest from the moving bracket among the plurality of engaging plates.