There is an earlier straight-line mechanism, whose history is not well known, called Sarrus linkage (often misspelled Sarrut), consisting of a series of hinged rectangular plates, two of which remain parallel but can be moved normally to each other.
There is an earlier straight-line mechanism, whose history is not well known, called Sarrus linkage. This linkage predates the Peaucellier-Lipkin linkage by 11 years and consists of a series of hinged rectangular plates, two of which remain parallel but can be moved normally to each other.