Patent ID: 6948696
Filing Date: 2005-09-27
Classification: F16K

Abstract:
1. A pinch valve comprising: a valve casing extending longitudinally between opposite ends; a flexible tubular valve member within the valve casing, the valve member extending longitudinally between opposite ends such that each of the opposite ends of the valve member is juxtaposed with a corresponding opposite end of the casing; the flexible tubular valve member having a longitudinal passage for conducting a fluid from one to the other of the opposite ends of the valve member, and a wall extending longitudinally between the opposite ends of the valve member and circumferentially around the passage, the passage including a prescribed lateral extent, and the wall extending circumferentially around the lateral extent of the passage; at least one fold in the wall of the valve member, the fold, when in a folded configuration, including overlying legs extending along the tubular valve member in an essentially longitudinal direction so as to overlie the wall and have a prescribed longitudinal extent; and a valve operator for selectively exerting a lateral force upon the wall of the valve member to unfold the at least one fold and move the legs of the fold laterally, the relative dimensions of the longitudinal extent of the legs of the fold and the lateral extent of the passage enabling the unfolding of the at least one fold and the lateral movement of the legs of the fold to restrict the flow of fluid from one end to the other end of the valve member with only minimum forces upon the valve member in directions tending to establish tensile stresses in the valve member.