  We introduce two coloured operads in sets -- the lattice path operad and a
cyclic extension of it -- closely related to iterated loop spaces and to
universal operations on cochains. As main application we present a formal
construction of an $E_2$-action (resp. framed $E_2$-action) on the Hochschild
cochain complex of an associative (resp. symmetric Frobenius) algebra.
