Antique Victorian quilting clamps Primitive  Cast Iron Quilt Frame Sewing Nice!

I thought these were antique C clamps at first glance, then I saw the label marked Clamps for quilting frames. One is marked: STEARNS PAT. They seem usable, not frozen or stuck. The three open up to about 3 7/8. The Stearns clamp opens to about 2 1/2 inches. Any questions, please use the conact seller feature. Thank you for your interest in my item.