| 摘要 |
<p>A method of forming an opening in an existing brick wall comprises inserting at least one expandable element in the course of bricks above the top of the intended opening, to and expanding the element or elements to exert a horizontal force in the course of bricks. The tool comprises a pair of parallel pressure plates (20) and (21), a cam element (22) between the plates, ratchet lever means (25) for rotating the cam element, and ratchet and pawl means (24,27) for latching the cam element. Expansion plates (34) maybe used for wide joints.</p> |
