Pantograph
A pantograph is a 4-bar/4-pivot mechanical linkage that is used to copy designs, sometimes in different sizes. 2 of the corners are fixed, the tracing point is on one of the movable corners and the engraver is on the other. If the 4 arms are all the same length, the copy is the same size as the stencil, but by varying the arm length you can make a pantograph enlarge or reduce graphics.
A pantograph with an engraving tool is commonly used to engrave names in bicycle parts. High-end bikes, particularly Italian ones, sometimes have the frame builder's name "pantographed" on the handlebar stem, cranks/chainrings, lugs, etc.
i cant be the only one without a clue what you lot were on about!