Abstract: Spring elements are described that are especially adapted for use in high temperature environments such as for example in sliding gate valves for metal pouring vessels. The spring elements include an expansable chamber defined in part by a bellows member and a thrust surface adapted to apply the spring force. The chamber is filled with a thermally expansive fluid operative to expand the chamber and thus apply the spring force when exposed to elevated temperatures and conversally, to effect retraction of the same when the elevated temperatures are removed.

Abstract: The toggle levers in a sliding gate valve operative to impart the compressive loading between the slide assembly housing and the teeming vessel are mechanically actuated to their engaged or released positions by the drive motor utilized to operate the slide frame. The toggle levers are attached to connecting rods which are, in turn, connected by a follower rod that extends across the path of travel of the slide frame. The follower rod can be positioned on one side of the slide frame or the other to alternatively engage or release the levers. During normal operation of the valve the follower rod is locked to the housing whereby the slide frame is free to move with respect to the toggle levers.