Abstract: A vibratory separator for separating components of material introduced to the vibratory separator, the vibratory separator in one particular aspect being a shale shaker, the vibratory separator including a basket for holding screening apparatus, the basket having two sides spaced-apart by a first end at which the material is introduced into the basket and a second end spaced-apart from the first end, components separated from the material exiting the basket from the second end, vibrating apparatus connected to the basket for vibrating the basket, screening apparatus mounted in the basket, the screening apparatus having at least a first portion and a second portion, the first portion at the first end of the screen and the first portion lower in the basket than the second portion, receptacle apparatus below the screening apparatus for receiving material components flowing through the screening apparatus, maintenance apparatus for maintaining height of a portion of the screening apparatus, and a pool of the mate

Abstract: A vibratory separator for separating components of material introduced to the vibratory separator, the vibratory separator in one particular aspect being a shale shaker, the vibratory separator including a basket for holding screening apparatus, the basket having two sides spaced-apart by a first end at which the material is introduced into the basket and a second end spaced-apart from the first end, components separated from the material exiting the basket from the second end, vibrating apparatus connected to the basket for vibrating the basket, screening apparatus mounted in the basket, the screening apparatus having at least a first portion and a second portion, the first portion at the first end of the screen and the first portion lower in the basket than the second portion, receptacle apparatus below the screening apparatus for receiving material components flowing through the screening apparatus, maintenance apparatus for maintaining height of a portion of the screening apparatus, and a pool of the mate

Abstract: A variable ratio power transmission in the form of a gear box is described, in which the gear ratio of the input and output shafts can be varied continuously between a maximum and a minimum. The power transmission comprises a first bevel wheel (40) rotatably mounted in connection with a U-shaped member (32) on a first axis (34). The U-shaped member (32) is pivotable about the axis (34) and is coupled to the bevel wheel (44) via a sprag clutch (36). Hence, pivoting movement of the U-shaped member (32) in a first direction about the axis (34) results in a torque being applied via the sprag clutch (36) to the bevel wheel (44), whereas pivoting movements of the U-shaped member (32) in the opposite direction has no effect via the sprag clutch (36) on rotation of the bevel wheel (44). A second bevel wheel (50) is also coupled to the U-shaped member (32) via a second sprag clutch (38) which operates in the reverse direction to that of the first sprag clutch (36).