Patent ID: 7784816

Claim:
A flat platform cart with collapsible casters, comprising a supporting section, a push-pull section and a caster section connected thereto by a linkage means, and an extension positioning means which enables the push-pull section and the caster section to be maintained in an extending state, wherein the supporting section comprises a supporting frame ( 2 ), supporting bases ( 22 ) and a load supporting platform ( 1 ) which are interconnected together, the push-pull section has two supporting bars ( 4 ) which are hinged onto the supporting bases ( 22 ) respectively by means of a base bracket ( 41 ); the caster section comprises casters ( 3 ), connecting bars ( 13 ) each connecting two or more casters ( 3 ) and caster sleeves ( 31 ), the caster sleeves are engaged onto the supporting frame ( 2 ), characterized in that the extension positioning means comprises a vertical positioning means which simultaneously locks the push-pull section and the caster section in position and a horizontal positioning means disposed between the load supporting platform ( 1 ) and the supporting bases ( 22 ) which horizontally locks the push-pull section in position; the vertical positioning means comprises a left and a right connecting means ( 9 ) which are disposed at a rear end of the load supporting platform ( 1 ) and correspond to the two supporting bars ( 4 ) respectively, each of the left and the right connecting means ( 9 ) is disposed with an upper latching pin ( 91 a ) and a lower latching pin ( 91 b ) which are in parallel to each other, the two supporting bars ( 4 ) and/or the base brackets ( 41 ) are respectively disposed with positioning apertures corresponding to the upper latching pins ( 91 a ), the lower latching pins ( 91 b ) are in rectangular shape, the connecting bars ( 13 ) of the caster section each has an inner wall which correspond to the lower latching pin ( 91 b ), the lower latching pins ( 91 b ) are latched into the connecting bars ( 13 ) of the caster section after passing through rectangular apertures ( 22 a ) of the supporting bases ( 22 ) respectively.