An injection molding apparatus (5) comprising a clamp plate (80), a heated manifold (20), an actuator (10) interconnected to a valve pin (17) drivable along an axis (A), a mold (300) and a cooling device (500) that cools the actuator,
the actuator (10) comprising a thermally conductive housing body (12) that is mounted in direct heat or thermally conductive contact with one or more insulators (60, 50) that are in turn mounted in direct heat conductive contact or communication with the manifold (20),
the cooling device (500) comprising a heat transmitter comprised of an arm (502) comprised of a thermally conductive material having a distal end surface (502s) for making thermally conductive contact with the clamp plate (80),
the proximal surface (502b) of the arm (502) being slidably engageable against a complementary surface (12ls) of the actuator that is spaced laterally (12ld) from the valve pin axis (A) for transmitting heat from the housing body (12) to the proximal surface (502b) and in turn to the distal end surface (502s) of the arm (502).