Patent ID: 9725288
Date: 2017-08-08
CPC Classifications: B65G,B66F

Claim:
1. A stacker crane that travels along a rail, comprising: a first mast and a second mast spaced apart from one another in a travelling direction and extending vertically; connecting plates including a plate-shaped first plate and a plate-shaped second plate mounted to a lower portion and both side surfaces, which face a crossing direction crossing the travelling direction, of the first mast, and a plate-shaped third plate and a plate-shaped fourth plate mounted to a lower portion and both side surfaces, which face the crossing direction, of the second mast, the first plate and the second plate each including an upper portion fixed to the first mast and a lower portion whose width in the travelling direction is greater than that of the upper portion, and the third plate and the fourth plate each including an upper portion fixed to the second mast and a lower portion whose width in the travelling direction is greater than that of the upper portion; and a first lower hollow frame and a second lower hollow frame including a pair of hollow members disposed on outer sides of the connecting plates in the crossing direction on both sides of the first mast and the second mast in the crossing direction and extending in the travelling direction, the first lower hollow frame including a first end fixed to an outer side surface of the lower portion of the first plate in the crossing direction and a second end fixed to an outer side surface of the lower portion of the third plate in the crossing direction, and the second lower hollow frame including a first end fixed to an outer side surface of the lower portion of the second plate in the crossing direction and a second end fixed to an outer side surface of the lower portion of the fourth plate in the crossing direction; a first travelling wheel unit including a first travelling wheel including both shaft ends rotatably supported by the first plate and the second plate, the first travelling wheel being configured to roll on an upper surface of the rail; a second travelling wheel unit including a second travelling wheel including both shaft ends rotatably supported by the third plate and the fourth plate, the second travelling wheel being configured to roll on the upper surface of the rail; and a drive wheel unit configured to contact a side surface of the rail.