Metal crib bedstead

1. A metal crib bedstead, comprising:

a pair of symmetrical widthwise frames each including an U-shaped tube, an upper transverse tube and a lower transverse tube that are connected to two ends of the U-shaped tube by welding and opposite to each other, and a plurality of first longitudinal tubes connected with the upper transverse tube and the lower transverse tube, each of the two ends of the U-shaped tube including two wedge holes formed at an inner side thereof, two apertures formed at an outer side thereof corresponding to the two wedge holes, and a plurality of adjustment holes formed between the two wedge holes, the upper transverse tube and the lower transverse tube respectively including a plurality of first upper wedge holes and a plurality of first lower wedge holes for receiving the plurality of first longitudinal tubes by wedging and allowing the plurality of first longitudinal tubes to fasten to the upper transverse tube and the lower transverse tube by welding

a pair of symmetrical longitudinal frames each including an upper transverse frame tube and a lower transverse frame tube that are opposite to each other, and a plurality of second longitudinal tubes connected with the upper transverse frame tube and the lower transverse frame tube by welding, the upper transverse frame tube and the lower transverse frame tube wedged respectively in the wedge holes of the U-shaped tubes through screw nuts that are respectively held in two ends of the upper transverse frame tube and the lower transverse frame tube and through screws that pass through the apertures to fasten to the screw nuts, each of the screw nuts including an arched surface at one end thereof abutting against the inner surface of the U -shaped tube and corresponding to the aperture, the upper transverse frame tube and the lower transverse frame tube also including respectively a plurality of second upper wedge holes and a plurality of second lower wedge holes for receiving the plurality of second longitudinal tubes by wedging and allowing the plurality of second longitudinal tubes to fasten to the upper transverse frame tube and the lower transverse frame tube by welding; and

a mattress support frame which is located at bottoms of the pair of widthwise frames and the pair of longitudinal frames and includes an outer frame, a plurality of springs and a mesh frame, the outer frame including four transverse anchor holes respectively at two opposite width sides thereof and a plurality of first latch holes at four sides thereof facing upwards, each of the plurality of springs including two flat extension portions respectively extended outwards from two ends thereof, a first hook extended from one flat extension portion to latch in one of the first latch holes, a second hook extended from another flat extension portion to latch on a rim of the mesh frame, and two inverse hooks respectively extended from the first hook and the second hook, the first hook and the second hook being formed respectively at a length smaller than the diameter of the spring; and

four elongated anchor planks each including a positioning hole at an upper end thereof corresponding to one of the adjustment holes of the U-shaped tube to receive a screw for fastening, and a fastening hole at a lower end thereof corresponding to the transverse anchor hole of the outer frame to receive another screw for fastening.

2. The metal crib bedstead of claim 1 , wherein the arched surface of the screw nut matches the curve of the inner surface of the U -shaped tube.

3. The metal crib bedstead of claim 1 , wherein the outer frame includes four anchor struts respectively at an outer side of the four transverse anchor holes for the four elongated anchor planks to rest.

4. The metal crib bedstead of claim 3 , wherein the four anchor strut are screws fastened to screw holes respectively formed at the outer side of the four transverse anchor holes.