| 摘要 |
A sash window restrictor (20) has a housing (22) which is to be let into a vertical frame member (10) of one sash (normally the upper, outer sash) of a window, at a position, say, 10 cm above the top rail of the lower sash when the windows are closed. A tab (24) is mounted in the housing and can be retracted into the housing or extended from the housing. A mechanism acts between the tab and the housing and allows the tab to be pressed into the housing and held in the housing for a period of time before the tab is released to allow the tab to extend. With the tab extended, the lower sash (12) can be lifted until it reaches the tab (24) but no further, so that a 10 cm gap will be opened at the bottom of the window. |
| 主权项 |
1. A restrictor, comprising:
a housing; a tab pivotally mounted on the housing; a pushing element; and a restraining element, the tab comprising a first arm and a second arm, the tab being pivotally movable relative to the housing between:
at least a first pivot position, in which the restraining element is in a disengaged arrangement and at least a portion of the first arm is on a first side of a first plane and an entirety of the second arm is on a second side of the first plane, anda second pivot position, in which:
the restraining element is engaged, and the restraining element prevents the tab from pivoting,an entirety of the first arm is on the second side of the first plane,at least a portion of the second arm is on the first side of the first plane, andat least a portion of the second arm protrudes from the housing, the pushing element biasing the tab to pivot toward the first pivot position, with the restraining element engaged, the restraining element can be disengaged by pressing the second arm, such that the pushing element causes the tab to pivot toward the first pivot position. |
