The fact that a Yang-Baxter operator defines tensor representations of
the Artin braid group has been used to construct knot invariants. The
main purpose of this note is to extend the tensor representations of
the Artin braid group to representations of the braid group ZB(k) asso
ciated to the Coxeter graph B-k. This extension is based on some funda
mental identities for the standard R-matrices of quantum Lie theory, h
ere called four braid relations. As an application, tensor representat
ions of knot algebras of type B (Hecke, Temperley-Lieb, Birman-Wenzl-M
urakami) are derived.