San Francisco : Architect and Engineer, Inc · leaf 391
type. Multi-leaf electric operators will closeand open the six sections of the doors at thetouch of a button. The leaves are 120 feethigh and are supported laterally by guide rails … Flame-proofed wood sheathing is nailed fo pHrlins on asteel door leaf. at the top. They roll on flanged steel wheelsover railroad - type tracks. The operatingmechanism is so engineered as to move theseveral segments, or leaves, at different ratesof speed—the second traveling twice as fastas the…
Architecture · Building
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