Abstract: A central vacuum cleaning system has a tube having a nozzle at an inlet of the tube for sucking air containing dust, a filter carrier connected with an outlet of the tube by an inlet of the filter carrier for filtering the sucked air, an intake hose connecting with an outlet of the filter carrier by an inlet of the intake hose for serving as a passage of the filtered air, an air intake box installed at a place to be cleaned and an outlet of the intake hose detachably connected with the air intake box, and a machine unit having a motor for forcedly sucking air through the air intake box. The inet of the intake hose is swivelly connected with the filter carrier.

Abstract: An apparatus and method for automatically producing door panels in a single line in order to enable continuous production are provided. In the apparatus, a first uncoiler supplies the wound inner plate material. A first leveler regulates a flatness of the inner plate material. A press forms a pattern on the inner plate material. A marking device marks a cutting position on the inner plate material from the presser. A bend controller controls a bend of the inner plate material from the marking device. A second uncoiler supplies an outer plate material. A second leveler regulates a flatness of the outer plate material supplied from the second uncoiler. A roll forming device roll-forms both edges of the inner and outer plate materials. A heater preheats the inner and the outer plate materials. An injector injects insulated material between the inner and outer plate materials. A marking sensor senses the mark on the inner plate material and outputs a sensing signal.