Swivel wheel anti-wobbling device for cart

A suspension device for preventing swivel wheel wobbling of a cart over uneven terrain, said cart of the type including a rigid underframe to be directionally carried over ground by a pair of laterally opposite swivel wheels, said suspension device consisting of:

• a rigid elongated cross-member, to be fixedly mounted to said cart under frame, including a full web and two opposite downturned flanges;
• an elongated arm member, defining first and second opposite ends and consisting of pair of elongated lever arms each defining an outer end and an opposite inner end, the outer ends of both lever arms defining said first and second ends of said arm member;
• first mounting means, mounting said arm member underneath and in alignment with said cross-member for relative movement thereabout of said first and second ends thereof, said first mounting means including a shaft, therefrom, and a hinge member, rotatably mounted around said shaft and defining first and second hinge parts fixedly mounted to corresponding first and second lever arm inner ends whereby each said lever arm is freely movable relative to the other said lever arm;
• limit means, to restrain within a prescribed play said relative movement of said arm member first and second ends, whereby lateral stability of the cart is not compromised;
• and
• second mounting means, for rotatably mounting the two swivel wheels to corresponding said opposite first and second ends of said elongated arm member;
• wherein said relative movement of the arm member first and second ends is responsive to terrain irregularities, to keep both swivel wheels in constant contact with the terrain;
• said swivel wheels thus being able to enter into independent vertical motion around said shaft, the outer ends of said lever arms including corresponding abutment members, at a location opposite the corresponding said swivel wheels, both said abutment members, in an upper limit position of said lever arms, continuously abuttingly engaging said cross-member web under load from the cart over even terrain;
• and further including biasing means, biasing each said lever arm downwardly away from said cross-member web and said limit means includes a pair of stopper means carried by said web and spacedly extending under said lever arms when in said upper limit position.