Abstract: A safety braking device (1) for doors, which is arranged between a door board (21) and a permanent seat (22) of the door board, comprises a seat body (11) and a one-way locking mechanism. The seat body (11) is arranged in the door board (21). The one-way locking mechanism comprises a lock position element (12) and a connecting rod element (13). The lock position element (12) is arranged in the seat body (11) and can be switched between a locked position and an unlocked position. One end of the connecting rod element (13) is fixed onto the permanent seat (22) of the door board, and the other end thereof extends into the seat body (11) and corresponds to the lock position element (12).

Abstract: A safety braking device (1) for doors, which is arranged between a door board (21) and a permanent seat (22) of the door board, comprises a seat body (11) and a one-way locking mechanism. The seat body (11) is arranged in the door board (21). The one-way locking mechanism comprises a lock position element (12) and a connecting rod element (13). The lock position element (12) is arranged in the seat body (11) and can be switched between a locked position and an unlocked position. One end of the connecting rod element (13) is fixed onto the permanent seat (22) of the door board, and the other end thereof extends into the seat body (11) and corresponds to the lock position element (12).

Abstract: A transparent powder-proof housing covers the heater block of a PECVD reactor chamber tightly, thereby to prevent from powder pollution while cleaning the interior of the reactor chamber. The transparent powder-proof housing has two outlets, one for connecting to a vacuum cleaner and the other for human operation inside the reactor chamber. The vacuum cleaner vacuums the powder dust out of the transparent powder-proof housing, thereby to largely reduce the powder pollution in a clean room and the chances to jeopardize human health.