I have heard these bobbin cases referred to as “banjo type” bobbin cases. It seems like there are two different designs of them. The White case is #836, and takes a #744 rotary bobbin.
ETA: The old style White bobbin case was the other design, and was a #741.
Free and New Home Rotary machines had one that looks similar, but has a solid center pin.
CD in Oklahoma
Last edited by ThayerRags; 09-20-2014 at 05:06 AM.