Patent ID: 7819654

Claim:
A valve-gated hot-runner system, comprising: an actuator plate; a valve stem of a valve actuator; a back-up pad; a manifold bushing; a first radial gap being located between the actuator plate and the valve stem of the valve actuator; a second radial gap being located between the back-up pad and the valve stem; a third radial gap being located between the manifold bushing and the valve stem; and a cooling system being positioned relative to the first radial gap, the second radial gap and the third radial gap, the cooling system being configured to freeze a drool being made to enter, under pressure, into the first radial gap, the second radial gap and the third radial gap, so that the drool that becomes frozen substantially reduces flow of the drool along the valve stem and toward the valve actuator, wherein: the back-up pad includes: a cold inner surface being located proximate to the valve stem, the cold inner surface being cooled by the cooling system, so that a portion of the drool becomes frozen once the portion of the drool touches the cold inner surface associated with the back-up pad, the back-up pad defines a drool-capturing chamber being configured to receive and to capture the drool, and once the drool that is received in the drool-capturing chamber touches the cold inner surface of the back-up pad, the drool solidifies so that the drool is prevented from entering the second radial gap.