Rotary device for transmission of material in particulate form

An electrostatically controlled coating device comprising:

• a first rotary bell-shaped member having an axis of rotation and an internal shaping region arranged to project a conical curtain of particulate material towards a target surface;
• a supply system for conducting said material towards said first rotary bell-shaped member;
• and
• a distributor arrangement for distributing said material from said supply system onto said internal shaping region, said distributor arrangement comprising a second rotary bell-shaped member disposed inwardly of said first rotary bell-shaped member and coaxial therewith and a rotary disc associated with said second rotary bell-shaped member and defining at least one through-hole leading from an inner face of said disc which faces said second rotary bell-shaped member to an outer face of said second rotary bell-shaped member which faces away from said second rotary bell-shaped member, the arrangement being such that a first portion of said material from said supply system is distributed to said internal shaping region via an internal surface of said second rotary bell-shaped member and a second portion to said material from said supply system is distributed to said internal shaping region via said at least one through-hole and said external face, and wherein said first and second rotary bell-shaped members rotate differently such that at least a major part of said particulate material is subject to differing rotary forces imparted by said first and second rotary bell-shaped members.

In combination, a robot arm and an electrostatically controlled device for transmitting a beam of material in particulate form at a target surface to be coated, said device comprising:

• an outer bell-shaped member which is rotatable about a principal axis and arranged to project a conical curtain of small particles flowing generally towards said target surface;
• a supply system for supplying material from a reservoir source towards a peripheral internal shaping region of said outer bell-shaped member;
• an inner rotary bell-shaped member provided coaxially with said outer bell-shaped member and arranged to rotate differently to said outer bell-shaped member so that at least a major part of the material supplied by said supply system is subject to differing rotary forces imparted by the inner and outer rotary bell-shaped members;
• and
• a centrally located rotary diffuser disc for transmission of said material from said supply system to the inner rotary bell-shaped member, said disc having at least one aperture therethrough so that some of said material supplied by said supply system can pass through said aperture and onto an external face of said disc so as to be forced outwards centrifugally towards the outer bell-shaped member, and
• wherein said device is mounted on said robot arm.