| 摘要 |
<p>An underside recess is made in each rafter for form-locking onto the abutment which is secured on the rafter ends with fishplates, in preparing rafters for erection of roof support structures. The groove-shaped recess (18) is made as a saw cut aligned at right angles to the ends of the rafter (7) and its underside. The abutment front plate is then driven into this with one of its end edges, with form-locking with this plate effected, each fishplate is thrust onto the plate and then secured on the rafter ends. Saw cuts may be made on several rafters at once.</p> |
