Recent Results in the NJL model with heavy quarks

We investigate the interplay of chiral and heavy quark symmetries by using the NJL quark model. Heavy quarks with finite masses m(Q) as well as the limit m(Q) to infinity are studied. We found large corrections to the heavy mass scaling law for the pseudoscalar decay constant. The influence of external momenta on the shape parameters of the Isgur-Wise form factor is discussed.