Container handling apparatus

A container handling apparatus comprising:

• a parallel pair of elongated side frames;
• a cross frame connecting the side frames at one end;
• the side frames being normally disconnected at the other end so a container can be received between the two side frames;
• a plurality of wheels supporting the side frames and the cross frames;
• four lift mechanisms for attachment to a container, each mechanism having a tab for insertion into a slot on the container and means for rotating the tab to lock the tab into the slot;
• four secondary lift arms, two of the secondary lift arms mounted to each of the side frames, each of the two secondary lift arms mounted to the same side frame having an upper end pivotally connected to a corresponding one of the lift mechanisms for movement in the same vertical plane as the upper end of another secondary lift arm;
• each secondary lift arm having a lower end that is laterally offset from its upper end for movement in a vertical plane parallel to and overlapping the vertical plane traveled by the lower end of said other secondary lift arm mounted on the same side frame;
• four primary lift arms, each having one end pivotally connected to the midpoint of one of the secondary lift arms and the other end pivotally connected to one of the side frames, each secondary lift arm having a length twice that of each primary lift arm;
• a cam follower mounted on the lower end of each of the secondary lift arms;
• a plurality of cams for guiding each of the cam followers along the side frames in said parallel overlapping paths;
• and
• power means for rotating the primary lift arms about the pivot connections to the side frames to cause the upper ends of the secondary lift arms to move vertically to raise and lower the lift mechanisms and the container.

A container handling apparatus comprising:

• a parallel pair of elongated side frames;
• a cross frame connecting the side frames at one end;
• the side frames being normally disconnected at the other end so a container can be received between the two side frames;
• a plurality of wheels supporting the side frames and the cross frames;
• four lift mechanisms for attachment to a container, each mechanism having a tab for insertion into a slot on the container and means for rotating the tab to lock the tab into the slot;
• four secondary lift arms, two of the secondary lift arms mounted to each of the side frames, each of the two secondary lift arms mounted to the same side frame having an upper end pivotally connected to a corresponding one of the lift mechanisms for movement in the same vertical plane as the upper end of another secondary lift arm, each secondary lift arm having a lower end that is laterally offset from its upper end for movement in a vertical plane parallel to and overlapping the vertical plane traveled by the lower end of said other secondary lift arm mounted on the same side frame;
• four primary lift arms, each having one end pivotally connected to the midpoint of one of the secondary lift arms and the other end pivotally connected to one of the side frames, each secondary lift arm having a length twice that of each primary lift arm;
• a cam follower mounted on the lower end of each of the secondary lift arms;
• a plurality of cams for guiding each of the cam followers along the side frames in said parallel overlapping paths;
• power means for rotating the primary lift arms about the pivot connections to the side frames to cause the upper ends of the secondary lift arms to move vertically to raise and lower the lift mechanisms and the container;
• and equalizing means for determining the position of each primary lift arm and automatically keeping the positions of the four lift mechanisms at the same height.