Abstract: Apparatus for controlling fluid flow through a gate opening includes frame means that define the opening, and guide means which are adapted to retain a gate disc in slidable relation with the opening. Drawing means for laterally displacing the disc relative to the opening are pivotably connected to lever means having long and short ends. A fulcrum between the ends is pivotably connected to the disc. The short end is disposed to bear against a fixed portion of the guide means when the disc is closed, and the long end is connected to the drawing means to obtain a mechanical advantage in drawing pressure when displacing the disc to a partially open position. The lever means may be a single lever, but a preferred embodiment discloses a pair of levers to apply a uniform drawing pressure on the disc via a hydraulic cylinder that is anchored in a wall of a closed tank which contains the apparatus.

Abstract: Apparatus having radially disposed adjustable pitch fan blades embodies a split hub that is adapted to retain the blades in the plane of the hub. One portion of the hub includes an annular base with concentric upstanding inner and outer walls that define a channel. The outer wall includes a plurality of openings in which the blades are rotatably journalled with a cam portion of each blade extending into the channel. Cam follower means are slidably disposed in the channel and interlink adjacent cam portions so that rotation of any one blade will correspondingly adjust the pitch of each of the other blades. The blades are locked to a predetermined pitch setting by fastening the hub portions together. Another embodiment includes the fan blades and split hub which is bushed and secured to a shaft of a reversible drive motor.

Abstract: An ice cube tray comprising a body of plastic or pressure die cast material or sheet metal having generally relatively thin uniform thickness throughout, and a top wall with at least the central portion thereof having a flat top surface. The flap top surface has a plurality of longitudinally spaced openings and a bottom wall and side walls extending downwardly from the edges of each opening to define a cavity. Each bottom wall is arcuate in a transverse direction. Depressions are provided in the top wall at the juncture of the bottom walls or side walls to form water level control surfaces to maintain the water level to form an ice cube whose top surface is at or below the center line forming the said arcurate wall.