Importance

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Abstract

A span lock system for a double-leaf drawbridge. A guide housing mounted at the tip of one leaf includes an opening with vertically opposed cushioned shoes slidably supporting an elongate lock bar reciprocative lengthwise in a direction along the length of the drawbridge. A receiver housing mounted at the tip of the other leaf is positioned to interlock with the guide housing and includes a like opening slidably receiving the lock bar between vertically opposed cushioned shoes. A pair of vertical guide columns project from both side of the guide housing opening with the upper and lower edges of the distal sides beveled inwardly, and another pair of vertical guide columns project from both side of the receiver housing opening with the upper and lower edges of the proximal sides beveled outwardly. Within a specified maximum limit of misalignment, the guide and receiver columns interengage causing their openings to closely align and facilitate insertion of the lock bar into the opening of the receiver housing with limited horizontal bending and shear. The distance between the proximal sides of the receiver housing exceeds the distance between the distal sides of the guide housing by an amount corresponding to the specified maximum misalignment for a particular bridge design. The housings are secured to the bridge trusses by vertical columns of bolts and the cushioned shoes are biased by disc springs mounted on guide pins.

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First Claim