A balance system used with a door of a cupboard comprises a transmission shaft, a first pulley on the transmission shaft, and a balance component. The first pulley is connected to a door belt, one end of the door belt is secured to the first pulley, and the other end of the belt is connected to the door. The balance component comprises a balancing member, a balancing belt and a second pulley on the transmission shaft. One end of the balancing belt is connected to the second pulley, and the other end of the balancing belt is connected to the balancing member, such that the balancing member is hung on the second pulley. The first pulley and the second pulley rotate synchronously, and the door belt and the balancing belt are wound oppositely. With the balance system, a small driving force can open/close the door.

A motorized window blind includes a slotted motorized track member mounted to a vertical wall structure of a building and extending across the top of an opening in the wall. It also includes at least two panels mounted to the track and covering the wall opening while being in a position where the panels are parallel and coplanar with one another. The motorized track member has at least one motorized actuation system enabling one panel to move forward away from the opening thereby freeing the track for the second panel to laterally slide behind the first panel. The panels become stacked in a parallel superimposed position in relation with one another. In the stacked position, the panels cover a portion of one end of the opening while completely uncovering a potion at the other end of the opening.

A motorized window blind includes a slotted motorized track member mounted to a vertical wall structure of a building and extending across the top of an opening in the wall. It also includes at least two panels mounted to the track and covering the wall opening while being in a position where the panels are parallel and coplanar with one another. The motorized track member has at least one motorized actuation system enabling one panel to move forward away from the opening thereby freeing the track for the second panel to laterally slide behind the first panel. The panels become stacked in a parallel superimposed position in relation with one another. In the stacked position, the panels cover a portion of one end of the opening while completely uncovering a potion at the other end of the opening.

A cupboard has a body and an up-down louvered door. The door comprises a plurality of louvers, and a pair of lift racks to which the louvers are attached. The cupboard also includes a motor transmission apparatus, and two belts. When people need to open the door, the motor is actuated, whereby the lift racks lift and fold up, causing the louvers to fold up, and thus the door is opened. When people need to close the door, the motor is reversed, such that lift racks descend and extend, causing the louvers to extend, and thus the door is closed. The door can open adequately so as to facilitate taking out/putting in articles. No more space is occupied while opening the door, and the door is safe while closing. A small driving force can open/close the door.

A cupboard has a body and an up-down louvered door. The door comprises a plurality of louvers, and a pair of lift racks to which the louvers are attached. The cupboard also includes a motor transmission apparatus, and two belts. When people need to open the door, the motor is actuated, whereby the lift racks lift and fold up, causing the louvers to fold up, and thus the door is opened. When people need to close the door, the motor is reversed, such that lift racks descend and extend, causing the louvers to extend, and thus the door is closed. The door can open adequately so as to facilitate taking out/putting in articles. No more space is occupied while opening the door, and the door is safe while closing. A small driving force can open/close the door.

A cupboard has an up-down louvered door. Wherein the door comprises a plurality of louvers, and a lift rack in which the louvers are configured. When people need to open the door, the lift rack lifts and folds up, causing the louvers to fold up, and thus the door is opened; and when people need to close the door, the lift rack descends and extends, causing the louvers to extend, and thus the door is closed. The door can open adequately so as to facilitate taking out/putting in articles. No more space is occupied while opening the door, and the door is safe when closing. A small driving force can open/close the door, and the cupboard features easy operation, long lifetime, low cost and good stability.

A cupboard has an up-down louvered door. Wherein the door comprises a plurality of louvers, and a lift rack in which the louvers are configured. When people need to open the door, the lift rack lifts and folds up, causing the louvers to fold up, and thus the door is opened; and when people need to close the door, the lift rack descends and extends, causing the louvers to extend, and thus the door is closed. The door can open adequately so as to facilitate taking out/putting in articles. No more space is occupied while opening the door, and the door is safe when closing. A small driving force can open/close the door, and the cupboard features easy operation, long lifetime, low cost and good stability.

A window ventilation arrangement includes a window assembly and a window insert arrangement. The window assembly includes a window frame and a slidable window. The frame includes an insert-receiving channel and is configured to provide an air-letting opening. The slidable window is displaceable within the window channel portion so as to provide the air-letting opening. The window insert arrangement includes a panel and a plurality of panel spacers. The panel has four corners, a first panel edge, a second panel edge, and a panel thickness. The panel spacers are attached to the panel at least at the four corners for providing an overall insert thickness equaling an insert channel width of an insert-receiving channel of the slidable window. The window insert arrangement is insertable into the insert-receiving channel of the slidable window and exposed portions of the panel providing a reduced, air-letting opening for reductively ventilating the room.