This is a very interesting item.
It is a swift or yarn winder.
I am not exactly sure how this worked but the top is expandable wooden sticks and the base is a removable clamp to attach to a table.
The sticks are riveted and there is also a key that turns at the top.
The clamp fits in with a metal post and there is post at the top for attaching the yarn, I presume.
Condition: There are some losses to the wooden sticks, but they still expand perfectly. Otherwise, very good. Patina is lovely.
Size: 12 inches top to bottom.
19th Century Wooden Sewing Swift or Yarn Winder