System for selectively closing a fluid channel

A system for selectively closing a fluid flow channel, the system comprising:

• a gate apparatus for selectively closing off flow in the fluid flow channel, the gate apparatus comprising:
• a gate structure and a guide frame assembly guiding movement of the gate structure between a closed position and an open position, the guide frame assembly defining a passage opening through which fluid in the fluid flow channel is selectively permitted to flow;
• wherein the guide frame assembly forms an elongated track guiding movement of the gate structure along a guide path of movement between the closed and open positions, the guide frame assembly including a gate threshold located toward a bottom end of the guide frame assembly, the gate threshold including a threshold plate defining the passage opening, the threshold plate having an opening perimeter forming the passage opening, the opening perimeter being formed by an edge of the threshold plate, the opening perimeter having a lower perimeter portion;
• wherein the gate structure includes a gate plate having a perimeter edge having a lower edge portion and a gate stem extending from the gate plate along at least a portion of the track;
• wherein the lower edge portion of the perimeter edge of the gate plate bypasses the lower perimeter portion of the edge of the threshold plate forming the opening perimeter when the gate structure moves toward the closed position to form a first shear point to shear any plant material extending through the passage opening when the gate structure is moved toward the closed position;
• a gate operator assembly configured to control movement of the gate structure along the track formed by the guide frame assembly, the gate operator assembly being configured to lift the gate structure from the closed position toward the open position and to release the gate structure to fall under the influence of gravity to the closed position;
• wherein the gate operator assembly comprises:
• a toothed wheel rotatably mounted on the guide frame assembly, the toothed wheel having a plurality of teeth;
• a ratchet gear rotatable as a unit with the toothed wheel, the ratchet gear having a plurality of ratchet teeth;
• a pawl member mounted on the guide frame assembly and engaging the ratchet gear to permit rotation of the ratchet gear and the toothed wheel in a first rotational direction and resist rotation in a second rotational direction, the first rotational direction corresponding to the operator assembly moving the gate structure toward the open position, the second rotational direction corresponding to the operator assembly permitting the gate structure to move toward the closed position;
• and
• wherein the gate stem is elongated in a longitudinal direction of the stem, the gate stem defining a plurality of slots arrayed in a longitudinal direction of the stem with the slots each extending perpendicular to the longitudinal direction to be engaged by the teeth of the toothed wheel.

A system for selectively closing a fluid flow channel, the system comprising:

• a gate apparatus for selectively closing off flow in the fluid flow channel, the gate apparatus comprising:
• a gate structure and a guide frame assembly guiding movement of the gate structure between a closed position and an open position, the guide frame assembly defining a passage opening through which fluid in the fluid flow channel is selectively permitted to flow;
• wherein the guide frame assembly forms an elongated track guiding movement of the gate structure along a guide path of movement between the closed and open positions, the guide frame assembly including a gate threshold located toward a bottom end of the guide frame assembly, the gate threshold including a threshold plate defining the passage opening, the threshold plate having an opening perimeter forming the passage opening, the opening perimeter being formed by an edge of the threshold plate, the opening perimeter having a lower perimeter portion;
• wherein the gate structure includes a gate plate having a perimeter edge having a lower edge portion and a gate stem extending from the gate plate along at least a portion of the track;
• wherein the lower edge portion of the perimeter edge of the gate plate bypasses the lower perimeter portion of the edge of the threshold plate forming the opening perimeter when the gate structure moves toward the closed position to form a first shear point to shear any plant material extending through the passage opening when the gate structure is moved toward the closed position;
• a positioning structure comprising a positioning plate configured to be positioned in abutment against the gate plate when the gate structure is in the closed position, the positioning plate being spaced from the threshold plate to form a plate gap for receiving a portion of the gate plate when the gate structure is positioned in the closed position;
• wherein the gate plate and the positioning plate form a second shear point therebetween to facilitate shearing of plant material extending through the passage opening when the gate structure is moved toward the closed position;
• and
• wherein the positioning structure comprises a spacer plate positioned between the positioning plate and the threshold plate, the spacer plate forming a stop for the lower edge portion of the gate plate when the gate structure is in the closed position.