Base of a collapsible baby playing bed

A base of a collapsible baby playing bed, in combination:

• four corner supports, each corner support being connected with a corner rod of said bed and having a connecting end;
• first and second connecting elements, each connecting element having a connecting portion, an opening and a through hole;
• two pivotal rods, each pivotal rod having a turned portion and an elongate hole, each turned portion being passed into and pivoted to a respective one of said openings of said connecting elements;
• first and second holders, each holder having a hole and a U-shaped recessed part;
• first and second mediate supports provided for supporting said base, each mediate support having a connecting opening and a connecting hole;
• each elongate hole of said pivotal rods being received within, and pivoted to, a respective said connecting opening;
• first and second mediate rods, each mediate rod having a bored end pivoted to a respective said U-shaped recessed part of said holders and being connected to a respective said connecting hole of said mediate support;
• a first support rod pivoted to said connecting end of said first corner support at a first end said first support rod being passed through said through hole of said first connecting element and connected to said hole of said first holder at one end opposite said first end thereof;
• a second support rod, said second support rod being substantially parallel to said first support rod and being pivoted to said connecting end of
• said second corner support at a first end thereof, passed through, and pivoted to, said through hole of said second connecting element and connected to said hole of said second holder at one end opposite said first end thereof;
• a third support rod pivoted to said connecting end of said third corner support at one end thereof, said third support rod being connected to said connecting portion of said first connecting element at one end opposite said first end thereof;
• a forth support rod, said forth support rod being substantially parallel to said third support rod and being pivoted to said connecting end of said forth corner support at one end thereof and connected to said connecting portion of said second connecting element at one end opposite said first end thereof.