When threads of silk, linen and cotton, were supplied in skeins, they had to be transferred to spools. Pairs of clamps with hollow winding frames revolving on a spindle were used with the threads stretched between them to wind into a more usable form
Prior to 1840's when manufacturers began to sell sewing thread ready for use, winding clamps and similar were needed to transform skeins of thread into a spool so it could be used without tangling
One of a pair of Bone Winding Clamps, carved base, decorated with birds. Topped by rotating cage with four uprights and central spindle, joining two discs. Top Finial missing lower bone screw
Clamp base decorated with birds
winding clamp