3d Furniture Bed CAD Blocks Free DWG File consist of a soft, cushioned mattress on a bed frame, the mattress resting either on a solid base, often wood slats, or a sprung base. Many beds include a box spring inner-sprung base, which is a large mattress-sized box containing wood and springs that provide additional support and suspension for the mattress. Beds are available in many sizes, ranging from infant-sized bassinets and cribs, to small beds for a single person or adult, to large queen and king-size beds designed for two people. download free 3d bed isometric elevation design DWG file.