Abstract: A control apparatus comprising a cylinder including therein a piston non-stepwise controllable in terms of the amount of piston portion protruded and the speed of its protruding movement. The amount of piston portion protruded is controlled by an attachment position at which the cylinder is attached to an adaptor for fastening the control apparatus to a device desired to be controlled and the position of a bar extended into the cylinder through one end portion thereof to abut against a piston head. The speed of protruding movement of the piston is controlled by a control fluid fed into and discharged from a cylinder chamber divided by the piston head into two parts.

Abstract: A control apparatus comprising a cylinder including therein a piston non-stepwise controllable in terms of the amount of piston portion protruded and the speed of its protruding movement. The amount of piston portion protruded is controlled by an attachment position at which the cylinder is attached to an adaptor for fastening the control apparatus to a device desired to be controlled and the position of a bar extended into the cylinder through one end portion thereof to abut against a piston head. The speed of protruding movement of the piston is controlled by a control fluid fed into and discharged from a cylinder chamber divided by the piston head into two parts.

Abstract: A hot runner mold provided with a runner pipe instead of a runner block wherein the walls of both end portions of the runner pipe are formed progressively thinner toward the tip of both end portions so as to cause the inner diameter of the walls to approximate to the outer diameter. One end portion of the runner pipe is made engageable with a hole formed in one side wall of a nozzle assembly and the other end portion is made engageable with a hole bored in a sprue bush. The runner pipe is laid between the nozzle assembly and sprue bush in a state inserted at both ends into said holes with a clearance provided therein in the axial directon of the runner pipe. Upon application of injection pressure, the thin walls of both end portions of the runner pipe expand outward in the radial direction for tight attachment to the inner walls of the holes, thereby presenting a sealing effect.

Abstract: Provided is an injection unit for the hot runner molding including a heating cylinder having passageways for fused plastic longitudinally formed therethrough and a nozzle member attached to one end of the cylinder and having an injection nozzle. Within the cylinder is fixably disposed a torpedo, which has a central blind hole formed therethrough in a manner spaced from and parallel with said plastic passageways of the cylinder. Within the central blind hole is disposed a spring assembly, which always biases a pin member abutting against the spring assembly. The pin member is provided with a valve and both are integrally operated. Where a prescribed level of plastic pressure acts on the valve, the valve is separated from the nozzle member to permit the plastic to be injected through the injection nozzle. Where the prescribed plastic pressure does not act on the valve, the valve is made to abut the nozzle member by the bias force of the spring assembly to close the injection nozzle.