Patent ID: 7887279

Claim:
An automated storage and retrieval system, comprising: a mast, at least one rack including a plurality of shelves, at least two elevation frames which are independently elevated and lowered along said mast, and at least two transfer apparatuses for transfer of articles to and from said rack, wherein a first one of said at least two transfer apparatuses is provided on a first one of said at least two elevation frames, wherein a second one of said at least two transfer apparatuses is provided on a second one of said at least two elevation frames, wherein in said first one of said at least two transfer apparatuses, a first plurality of vertically overlapped arms are arranged from the proximal side to the distal side such that more a distal arm is disposed above a more proximal arm, wherein in said second one of said at least two transfer apparatuses, a second plurality of vertically overlapped arms are arranged from the proximal side to the distal side such that a more proximal arm is disposed above a more distal arm, wherein said first one of said at least two transfer apparatuses is capable of storing articles on, and retrieving articles from, a shelf at the highest level, and wherein said second one of said at least two transfer apparatuses is capable of storing articles on, and retrieving articles from, a shelf at the lowest level.