folding boards

folding boards

[′fōld·iŋ ‚bȯrdz]
(mining engineering)
A shifting frame on which the cage rests in a mine. Also known as chairs; dogs; keeps; keps.
References in periodicals archive ?
Note that when multiple flex layers are used on folding boards, allowance must be made for the inner flexible layer to kink when the board is folded.