| 摘要 |
A sash window comprising: a frame containing first and second window sashes disposed parallel to a window plane, the first sash being slidable relative to the second window sash; a pulley 45 attached to the frame; and resilient means 50 such as a spring, wherein the first sash is connected to resilient means via the pulley. Preferably the resilient means is a torsion spring fixed at 51 and rotationally coupled to a helical bar 56 which is mounted via guide block 58 for sliding movement; the helical bar is prevented from rotational movement such that axial sliding of the helical bar in response to opening and closing the window rotates the spring. |
