Pressure actuated nozzle valve for injection molding units

An injection unit for a hot runner molding comprising a heating cylinder having plastic passageways formed therethrough in the longitudinal direction, a torpedo member having a central blind hole formed therethrough in a manner spaced from and parallel with said plastic passageways of the cylinder and disposed fixed within the cylinder, nozzle means attached to one end of said cylinder at the opening side of the central blind hole of the torpedo member and provided with an injection nozzle communicating with the plastic passageways of the cylinder, said heating cylinder having elastically wide operable blind heater holding holes bored at the other cylinder end in a manner substantially equiangularly spaced from one another, valve means having a slidable pin member disposed within the central hole of the torpedo and a valve member connected to the pin member and disposed within the nozzle means, and resilient biasing means so disposed within the central hole of the torpedo as to bias the pin member thereby causing the injection nozzle of the nozzle means to be closed by the valve member.