A collapsible support frame has a front frame, a rear frame, and a locking mechanism connected to the front and rear frames. The locking mechanism has a lever and a base member. In the locked position, the lever and the base member engage to pull the front and rear frames towards each other. This places tension on the front and rear frames and holds the frame structure in an open or unfolded position for use. In the unlocked position, the lever and the base member separate from each other. This releases the tension placed on the front and rear frames and allows the frame structure to collapse or fold in on itself for storage.