An injection molding apparatus comprising a clamp plate, a heated manifold, an actuator interconnected to a valve pin having an axis, a mold and a cooling device that cools the actuator wherein, when assembled, the clamp plate mounted upstream of the mold, the manifold being disposed between the clamp plate and the mold, wherein the actuator comprises a housing body that is mounted in thermally conductive contact along the axis to one or more actuator mounts (50, 60, 803) that are mounted downstream in heat conductive communication with or contact with or on the manifold along the axis, wherein the cooling device comprises: a heat transmitter comprising a proximal arm or member comprised of a heat conductive material and a distal arm or member comprised of a thermally conductive material, the distal arm or member or member being mounted by a spring loadable interconnection or engagement on or to the proximal base or member, the distal arm or member having a distal end surface for engaging the clamp plate (80, 80a) under a spring load and a proximal surface for transmitting heat from the proximal surface to the distal end surface, the housing body having a surface that is spaced laterally from the axis, the proximal surface being adapted to be engaged and slidable against a lateral surface of the housing body of the actuator such that heat thermally conducts between the housing body and the distal arm or member 502 and such that the distal base or member is spaced laterally apart from contact with the one or more actuator mounts (50, 60, 803) in an arrangement wherein the distal end surface of the distal arm or member is movable through the spring loadable interconnection toward and away from the actuator, the clamp plate, the mold, the manifold, the actuator and the heat transmitter being assemblable together in an arrangement wherein the spring loadable interconnection is loaded urging the distal end surface of the distal arm or member into compressed engagement with the clamp plate, at least when the manifold is heated to an elevated operating temperature. a heat transmitter comprising a proximal arm or member comprised of a heat conductive material and a distal arm or member comprised of a thermally conductive material, the distal arm or member or member being mounted by a spring loadable interconnection or engagement on or to the proximal base or member, the distal arm or member having a distal end surface for engaging the clamp plate (80, 80a) under a spring load and a proximal surface for transmitting heat from the proximal surface to the distal end surface, the housing body having a surface that is spaced laterally from the axis, the proximal surface being adapted to be engaged and slidable against a lateral surface of the housing body of the actuator such that heat thermally conducts between the housing body and the distal arm or member 502 and such that the distal base or member is spaced laterally apart from contact with the one or more actuator mounts (50, 60, 803) in an arrangement wherein the distal end surface of the distal arm or member is movable through the spring loadable interconnection toward and away from the actuator, the clamp plate, the mold, the manifold, the actuator and the heat transmitter being assemblable together in an arrangement wherein the spring loadable interconnection is loaded urging the distal end surface of the distal arm or member into compressed engagement with the clamp plate, at least when the manifold is heated to an elevated operating temperature.