| 摘要 |
The auxiliary equipment is for the correct installation of bolts between arresting battens, rafters and spars in a sloping roof. It consists of a drilling jig (10) positioned on the batten (8), and containing a large number of guide apertures (12) for the drill bit, and at intervals in its lengthwise direction. It can be in the form of an oblong plate, with a right-angled positioning edge along the side towards the roof ridge. There can be flanges at either side, one fixed and the other adjustable, their undersides being smooth so as to fit against the batten. ADVANTAGE - Easy installation by the unskilled.
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