| 摘要 |
A crutch of tubular construction has two crutch bows with straight parallel lower ends, between which is a leg carrier tube held by an upper fastener and lower rivets, and a crutch leg telescoped in the carrier tube. Weak points are avoided by gradually flattening the bows from a cylindrical cross section at the upper fastener through intermediate partially flattened bow portions to fully flattened bow ends at the lower rivets.
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