Wikipedia
Tracing wheel
A tracing wheel, also known as a pattern wheel, pounce wheel, and dart wheel, is an instrument with multiple teeth on a wheel attached to a handle. The teeth can be either serrated or smooth. It is used to transfer markings from patterns onto fabric with or without tracing paper, this sewing tool also makes slotted perforations. Such markings might include pleats, darts, buttonholes, notches or placement lines for appliques or pockets. A search on commercial establishments using a "pattern makers pinwheel" yields only pinwheels.