Abstract:
Electrostatic coating blade (11) for coating objects with a liquid. The blade consisting of two halves (12a, and 12b) held together by bolts (15). A central passage (14) is provided that receives liquid from a reservoir (not shown) and a narrow channel (16) can conduct liquid to a discharge edge (17). The blade can be used either horizontally (as is customary with electrostatic coating blades) or vertically. The blades (11) are particularly useful when vertically disposed to coat oil onto the edge of coils of sheet metal.
Abstract:
A mercury dispenser for electric discharge lamps consists of welding a small metallic member (16) in the form of a «patch», to a portion of the surface of the cathode disintegration shield (10) and trapping a predetermined volume of mercury under the «patch». A dimple (17) may be formed in the shield (10) or in the member (16). The shield (10) may be formed from a continuous strip which is dimpled at a predetermined pitch, the dimples filled with mercury and the «patches» (16) welded over the dimples. The strip can then be cut into discrete «patched» sections to be bent into shields and assembled with the cathode structure. The mercury is liberated from unter the «patch» by heating and vaporisation, the vapour pressure forcing the «patch» open.
Abstract:
A rotary atomizer (10) for coating workpieces with a fine layer of liquid material fed at very low flow rates includes a bell-type rotatable atomizing device (12) for dispensing the liquid from an edge (17) in an atomized condition under the effect of centripetal forces. The liquid fed into a tube (21) having an outlet (20) within the bell (12) appears as discontinuous drops (40) at the outlet (20). Air is also fed into the bell (12) via a tube (25) having an outlet (26) disposed adjacent the liquid outlet (20) such that the air jet (41) breaks up the drops (40) and forms a spray (42) directed at the internal wall of the bell (12). The spray (42) coalesces into a continuous film of liquid as it travels on the internal wall of the bell (12) to the discharge edge (17).
Abstract:
An electrostatic blade is disclosed having a slot (16) extending the length of the blade and leading from a central duct (14) to an outlet (18). A surface (20) made of non-conductive material extends in front of the outlet (18) and terminates in a discharge edge (22) which is spaced 0.05 to 4mm from the slot outlet (18). In use, liquid is passed from the duct (14) along the slot (16) to the outlet (18) where it collects as a bead. An electrostatic field is applied between the liquid at the slot outlet (19) and the object to be coated which draws liquid along the non-conductive surface (20) in a tapering stream and further causing the liquid to be discharged from the edge (22). Because the stream of liquid reaching the discharge edge is very thin, very low liquid discharge rates can be achieved while still maintaining a uniform coating on the target object.
Abstract:
An electrostatic coating apparatus is described comprising an applicator, means for supplying liquid to the applicator at a controlled rate, means for establishing an electrostatic field between the applicator and a target substrate to be coated and control means providing an output signal to the liquid supply means for setting the rate at which liquid is supplied to the applicator, the said control means also providing an output signal to the field establishing means which, in operation, sets the magnitude of the applied field, the said output signals being such that the applied field is varied in accordance with any change in the rate of supply of liquid to the applicator.