Structure of foldable receiving bin

An improved structure of foldable receiving bin, said foldable receiving bin comprises a cover plate, an upper frame, a lower base plate, two foldable plates and two lateral side plates, wherein:

• said cover plate is comprised of a left cover plate and a right cover plate, and is pivotally connected to the top of said upper frame;
• said left and said right cover plates are connected by abutting and engaging, and are provided each on a lateral edge thereof with an engaging member in the form of a pusher piece, said engaging member is provided at one side of it with a plurality of round holes, and is provided beneath it with a hooking member which extends down and beneath said left cover plate or said right cover plate corresponding thereto;
• said upper frame is in the shape of a rectangle which is hollow centrally, the rear and the front sides thereof are pivotally connected respectively with said left cover plate and said right cover plate, and two lateral sides of said upper frame are provided each with an engaging hole, and a plurality of through holes are provided on both said lateral sides;
• said upper frame is provided on each of said two lateral sides thereof with an engaging piece having a protruding strip thereon;
• said two foldable plates are pivotally connected to said front and rear sides respectively of said upper frame, while said two lateral side plates are pivotally connected to said lateral sides of said upper frame;
• said two foldable plates are symmetrical with respect to each other, and are provided each in the middle thereof with a pivot, said two foldable plates thus are adapted to unfolding to their upright positions or folding to collapse. and are provided on both lateral sides thereof with hooks;
• the upper ends of said two lateral side plates are pivotally connected to the bottom side of said upper frame;
• said two lateral side plates are provided at the upper positions on the external surfaces thereof each with a lug, and are provided each at the front and rear sides thereof with recessed engaging slots, on the middle bottom edges thereof each with a protruding engaging piece;
• said two lateral side plates are further provided each at the lower portion near the front and rear sides thereof with two slide grooves which each has an engaging slide member therein, said engaging slide member is straddled at both sides thereof with an elastic engaging rod on which there are a plurality of concave portions to engage with a pair of protruding engaging portions provided on the wall of the corresponding one of said slide grooves for mutual engaging and positioning;
• when said foldable receiving bin is unfolded for use, said upper frame is lifted to render said two foldable plates upright, then said two lateral side plates are adjusted to their proper positions leftwards and rightwards, said upper cover plate on said foldable receiving bin has said left and the right cover plates fixed on said upper frame in assembling said foldable receiving bin.