Structure for folding shopping carts, laundry carts and the like

In a folding cart assembly having a back cross frame of centrally pivoted rigid members, a bottom cross frame of centrally pivoted rigid members, pivotal connection means attaching one of each of the bottom frame members to one of each of the back frame members at each of two corners of said cross frames to permit the members of each cross frame to pivot with respect to each other and to permit said cross frames to pivot with respect to each other, and releasable means for holding the members of at least one of the cross frames in an extended position when the assembly is unfolded, the improvement comprising:

• a. a first pair of members pivotally attached at first ends thereof to the bottom cross frame near the other two corners of the bottom cross frame, respectively;
• b. a second pair of members pivotally attached at first ends thereof to the back cross frame near the other two corners of the back cross frame, respectively;
• c. two 270.degree. knuckle joints, each connecting a second end of one of said first pair of members to a second end of one of said second pair of members, for holding the first pair of members in a vertical position and the second pair of members in a generally horizontal position when the assembly is unfolded and said at least one of the cross frames is held in an extended position by said releasable means;
• and,
• d. a generally box-shaped fabric sack open at the top thereof and fixedly attached along its opposed upper side edges to said second pair of members for holding said second pair of members in parallel relationship with predetermined spacing therebetween against forces urging them apart which are developed in the assembly when it is unfolded with said at least one of the cross frames in said extended position.