Hah Hah. "Turn button"! I was trying turn toggle, turn knob, twiddle bit. The results for hatch dogs were pat flaps. That is exactly what I meant. Thank you.
Apologies if this is really obvious but I cannot think of the name for this and Google is no help.
I want the name for those little pieces of wood or metal that stop doors from opening by rotating ab out a screw. You get small ones on cupboards and big ones on containers. I thought they were...