Vibrating screen control arrangements

A vibratory screening apparatus including a static section;

• a dynamic section including a screening deck;
• at least three rotary motion exciter cells mounted to said dynamic section whereby rotation of said rotary motion exciter cells imposes a vibratory motion on said dynamic section relative to said static section;
• drive means for rotationally driving each of said rotary motion exciter cells;
• and mechanical synchronisation means mechanically linking rotation of a first one of said rotary motion exciter cells to at least a second one of said rotary motion exciter cells with at least a third one of said rotary motion exciter cells not being linked by said mechanical synchronisation means, whereby rotation of at least said first and said second rotary motion exciter cells occur in a common rotational direction and are synchronised together.

A method of operating a vibratory screening apparatus having a static section, a dynamic section including a screening deck, at least three rotary motion exciter cells mounted to said dynamic section whereby rotation of said rotary motion exciter cells impose a vibratory motion on said dynamic section relative to said static section, and drive means being arranged to rotationally drive each of said rotary motion exciter cells;

• said method including providing:
• mechanical synchronisation means for mechanically linking rotation of a first one of said rotary motion exciter cells to at least a second one of said rotary motion exciter cells whereby rotation of at least said first and said second rotary motion exciter cells occur in a common rotational direction;
• and
• control means controlling at least direction of rotation of a third one of said rotary motion exciter cells, said method further including carrying out screening of ore particulate material on said screening deck while rotating at least said third one of said rotary motion exciter cells in a direction counter to said common rotational direction of at least said first and said second rotary motion exciter cells.