| 摘要 |
A self-opening cuff comprising a fixed member, to which a cylindrically curved cuff is pivoted for swinging movement in a vertical plane. The fixed member is rigidly attached to the crutch tubing, and has two laterally projecting, angularly spaced side arms with an included angle of approximately 90 DEG between them. The two side arms have a cylindrically curved inner surface with the same radius of curvature as the cuff, and this curved surface is interrupted at its midpoint by a vertical slot. Disposed within the slot and swingably connected to the fixed member by a pivot bolt is a lug which is provided on the outside of the cuff. The top portion of the cylindrically curved surface is smoothly rounded with a curvature having its center at the pivot bolt axis, forming a ramp that the outer surface of the cuff rides on as it swings upwardly. The cuff is a split cylinder having a larger fixed section that is rigidly fixed to the lug, and a smaller section that is hinged closely adjacent the lug and swingable toward and away from the fixed section. When the cuff is positioned between the side arms, both the larger section and smaller sections are backed up by the side arms, locking the cuff in the closed position. When the cuff is swung up to its raised position, both sections slide up over the ramp until they are clear of the side arms, at which point the smaller hinged section drops open by gravity, opening the cuff so that the user can insert his forearm sideways into the same.
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