Pulse generator for intermittently energizing an actuating coil of a spray nozzle or the like
US4142684A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 26, 1977 |
| Grant date | Mar 6, 1979 |
| Priority date | — |
| Expiry date | May 26, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/64
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A substrate to be patterned, such as a textile web, is moved past an array of nozzles with discharge orifices closely spaced from its surface, the substrate being firmly backed at locations confronting the nozzles by being drawn against a supporting conveyor or by being led around rollers. The nozzles are electromagnetically operated by needle valves, the valve needles being carried by membranes under substantially balanced pressures from the printing liquor and from a fluid such as compressed air. The electromagnetic coils are intermittantly energized by a programmed pulse generator with a large but brief driving current followed by a low holding current, the pulse generator including two complementary power transistors in series with a coil winding. A dyestuff applicator carrying one or more of such nozzles may be transversely displaceable across the substrate, under the control of a programmer, between intermittent advances of the substrate in its longitudinal direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.