Sulzer-escher Wyss Ag

Itw Gema Ag

Gema Volstatic Ag

Gema Voltstatic Ag

Eugen Thomas Buhlmann

Wolf-Gunter Stotz

Mario Biondetti

The invention concerns powder spray coating equipment comprising an air divider (16) to adjustably divide a total-air flow (6, 14) into a conveying-air flow (54, 57, 70) and a supplemental-air flow (56, 84, 86) in such manner that, when adjusting for a larger flow of conveying air, the flow of supplemental air shall be reduced in a predetermined ratio, and vice versa; further comprising an injector (76) to aspirate and to pneumatically convey coating powder by means of the flow of conveying air; and a supplemental-air intake (89) into the air/powder path (76, 82). The conveying-air path (54, 57, 70) and the supplemental-air path (56, 84, 86) each are fitted with at least one throttling duct each constituted by at least one channel (40, 42) in a rotatable shaft (34, 36) and by a bearing surface (39) covering the channel. The channels (40, 42) run in the circumferential shaft direction and their cross-section decreases monotonely from a channel beginning (41, 43) as far as a channel end (45, 47) whereby, together with the bearing surface (39) they form an increasingly larger flow impedance. The total-air path (6, 12, 14) communicates with the channel beginnings (41, 43). A conveying-air discharge aperture (54) is present in the bearing surface (39) above the channel (40) of the conveying-air path, and a supplemental-air discharge aperture (56) is present above the channel (42) of the supplemental-air path in the bearing surface (39), said discharge apertures running only over a very short segment of the the length of the channels.

Powder spray coating equipment

A spray device and method for the coating of objects with powder coating material. A high voltage electrode or several electrodes are located on only one side of the coating material stream in the vicinity of a spray orifice for electrostatically charging the coating material. A first flow of compressed air is directed over the electrodes to keep the coating material from accumulating on the electrode and to shape the envelope of the sprayed coating material. A second stream of compressed air is directed at the stream of coating material to counteract the deflection of the stream by the first flow and by the effects of the high voltage. Better coating efficiency (reduced loss of sprayed powder) is achieved than with electrodes arranged on both sides of the coating material stream.

Spray device and method for powder coating material

An electrostatic spray device contains a tube-like spray element (3); at least one charging electrode (12) to transfer electrostatic charges to the powder; at least one counterelectrode (44) arranged in the vicinity of the charging electrode (12), which is connected to an electrical potential (20) different from the charging electrode (12), so that it takes up at least part of the free ions generated during electrical charging of the powder; at least one ring-shaped element (44; 68; 74) which forms or carries the counterelectrode (44; 64; 74, 76) and extends around the downstream segment (72) of the spray element (3), on which it is radially supported; at least one connection ridge (78) outside the spray element (3), which carries the ring-shaped element (74) at its downstream end (79) and can be attached to the spray element (3) by its upstream end; and an electrical connection between the electrical potential connection (20) and the counterelectrode (44) by way of the connection ridge (78).

Electrostatic spray device

The controlled deflection roll comprises a rotatable roll shell supported at a stationary support member by means of a plurality of hydrostatic pressure elements. The hydrostatic pressure elements are sealingly movably guided by guide structure, for example, bores, which define cylinder chambers. Each cylinder chamber is connected by a feed system comprising a feed channel to a source of a hydraulic pressure medium. Between each feed channel and the related hydrostatic pressure element, there is arranged a damping body provided with at least one throttle location, for example throttle bores, through which the hydraulic pressure medium can flow. The damping body defines essentially the only connection between the feed channel and the cylinder chamber. Possibly occurring oscillations or vibrations of the rotatable roll shell relative to the stationary support member are damped by these damping bodies and, accordingly, transmission of such oscillations or vibrations to the hydraulic pressure medium feed system is prevented.

Growing community of inventors

Gossau, Switzerland

Eugen Thomas Buhlmann