An injection molding apparatus (5) comprising: an actuator (10) comprising a thermally conductive housing body (12) mounted in direct heat or thermally conductive contact with one or more mounts (60, 50, 803) that are in turn mounted in direct heat conductive contact or communication with the manifold (20), the cooling device (500, 800) comprising a heat transmitter comprised of an arm, member (502) or leg (800I) that is either: disposed in direct or integral thermal contact with a complementary surface (12Is) of the actuator (10) or, configured to have compressible spring joints (800s).