| 摘要 |
<p>A brick wall has an aperture with side edges for installation of an outer door frame. The door frame is presented and located in position where it is held by a jig (1) while secured by. e.g. a foam bonding agent or fixtures. The jig has one or more transverse beams, each terminating in a suction pad (3, 4) held against the frame under negative pressure by a vacuum.</p> |
