| 摘要 |
The present invention comprises apparatus (1) for opening and closing a sash window (4), the apparatus comprising a cord (5); and a series of pulleys (6, 7, 8); wherein, at least one of the pulleys is a drive pulley which is able to positively grip the cord for allowing, in use, the cord to be driven in a first direction to open a window and' in a second direction to close a window. |
