Positive grip lifting mechanism

A grab assembly for lifting articles such as aluminum or steel ingots and the like comprising

• a support frame,
• a first pair of vertically projecting horizontally movable opposed complemental tongs depending from and extending beneath said frame,
• means for moving said first pair of tongs horizontally inward and outward,
• a second pair of vertically projecting horizontally movable opposed complemental tongs depending from and extending beneath said frame, said second pair of tongs being disposed in spaced parallel relationship to said first pair of tongs,
• means for moving said second pair of tongs horizontally inward and outward,
• each of said tongs including a vertically elongated leg, a pivot member fixedly attached to and depending from said leg, said pivot member having an upper and a lower portion, a tong bit having an upper and a lower portion, said upper portion of said tong bit being attached to said upper portion of said pivot member by an upper link member, said upper link member being pivotally attached to said upper portion of said pivot member by first upper pin means, said upper link member being pivotally attached to said upper portion of said tong bit by second upper pin means, said second upper pin means being positioned outwardly of said first upper pin means, said lower portion of said tong bit being attached to the lower portion of said pivot member by a lower link member, said lower link member being pivotally attached to said lower portion of said pivot member by first lower pin means, said lower link member being pivotally attached to said lower portion of said tong bit by second lower pin means, said second lower pin means being positioned outwardly of said first lower pin means, said lower portion of said tong bit extending under said pivot member and having an innermost end projecting inwardly of said pivot member, said innermost end including means for penetratingly engaging a side of the article to be lifted, and means for resiliently restraining said tong bit against said pivot member.

A crane for transporting articles such as aluminum or steel ingots and the like comprising

• a bridge,
• a plurality of ropefalls depending from said bridge,
• a support frame suspended by said ropefalls,
• a first pair of vertically elongated horizontally movable opposed complemental tongs depending from and projecting below said support frame,
• means for moving said first pair of tongs inwardly and outwardly,
• a second pair of vertically elongated horizontally movable opposed complemental tongs depending from and projecting below said support frame, said second pair of tongs being disposed in spaced parallel relationship to said first pair of tongs,
• means for moving said second pair of tongs inwardly and outwardly,
• each of said tongs including a vertically elongated leg, a pivot member fixedly attached to and depending from said leg, said pivot member having an upper and a lower portion, a tong bit having an upper and a lower portion, said upper portion of said tong bit being attached to said upper portion of said pivot member by an upper link member, said upper link member being pivotally attached to said upper portion of said pivot member by first upper pin means, said upper link member being pivotally attached to said upper portion of said tong bit by second upper pin means, said second upper pin means being positioned outwardly of said first upper pin means, said lower portion of said tong bit being attached to the lower portion of said pivot member by a lower link member, said lower link member being pivotally attached to said lower portion of said pivot member by first lower pin means, said lower link member being pivotally attached to said lower portion of said tong bit by second lower pin means, said second lower pin means being positioned outwardly of said first lower pin means, said lower portion of said tong bit extending under said pivot member and having an innermost end projecting inwardly of said pivot member, said innermost end including means for penetratingly engaging a side of the article to be lifted, and means for resiliently restraining said tong bit against said pivot member.