Universal rack assembly

A universal rack assembly comprising:

• multiple connecting heads disposed at spaced intervals, and each one of the multiple connecting heads having
• a body having multiple side surfaces respectively facing different directions;
• and
• multiple insert structures, each protruding from one of the multiple side surfaces;
• at least one framework having
• multiple support tubes, each end portion of each one of the multiple support tubes configured for said insert structure to be inserted into, wherein part of the multiple support tubes are
• multiple extruded tubes disposed along a height direction of the universal rack assembly and each having
• at least one slide rail extending along the height direction to two opposite ends of said extruded tube;
• multiple shelf supports respectively mounted on the multiple extruded tubes, and each one of the multiple shelf supports having
• a slider mounted in said slide rail of the corresponding extruded tube and configured to slide along the height direction in said slide rail;
• and
• a support seat connected to the slider and located outside said slide rail;
• and
• multiple positioning units, each one of the multiple positioning units configured to be screwed with and mounted through the slider of a respective one of the multiple shelf supports to abut against said slide rail of a respective one of the multiple extruded tubes for positioning the corresponding shelf support on the corresponding extruded tube.