Patent ID: 11969748
Assignee: NORDSON CORPORATION
Field: Surface technology, coating (Chemistry)
Classification: CPC B  F | IPC B  F

Claim 38:
39. A dispensing assembly for dispensing a liquid onto a substrate, the dispensing assembly comprising:
a dispensing portion having a liquid inlet and a liquid outlet, the dispensing portion defining a liquid chamber configured to receive the liquid therein from the liquid inlet;
a valve seat adjacent to the liquid outlet;
a valve stem disposed in the liquid chamber and configured to move within the liquid chamber;
a valve stem tip defined at a distal end of the valve stem and configured to selectively contact the valve seat and be spaced away from the valve seat;
an actuation portion having an air inlet configured to receive pressurized air therethrough, the actuation portion defining a first chamber and a second chamber that is separate from the first chamber;
a piston disposed in the actuation portion, the piston being movable by the pressurized air;
a control valve configured to direct the pressurized air selectively either to the first chamber or to the second chamber;
an exhaust passage configured to discharge the pressurized air therethrough from the dispensing assembly; and
a first channel that is disposed between the first chamber and the control valve, the first channel being in fluid communication with the first chamber, and the first channel being in fluid communication with the control valve when the control valve is in a first position; and
a second channel that is disposed between the second chamber and the control valve,
wherein the control valve has a first configuration and a second configuration, the control valve in the first configuration being configured to direct the pressurized air to the first chamber, the control valve in the second configuration being configured to direct the pressurized air to the second chamber,
wherein when the control valve is in the first configuration, the pressurized air in the first chamber acting on the valve stem is configured to act on the piston and configured to cause the piston to move in a first direction due to the pressurized air acting thereon, and
wherein when the control valve is in the second configuration, the exhaust passage is configured to receive the pressurized air therein and to discharge the pressurized air out of the dispensing assembly,
wherein when the control valve is in the first position, the control valve is configured to receive the pressurized air from a pressurized air source and to discharge the pressurized air into the first channel, whereby the control valve is configured to be in fluid communication with the first chamber and configured to direct the pressurized air to the first chamber,
wherein when the control valve is in a second position, the control valve is configured to be in fluid communication with a second chamber that is separate from the first chamber, and is further configured to direct the pressurized air from the first chamber to the second chamber via the second channel,
wherein the exhaust passage is configured to fluidly communicate with the second chamber, and
whereby when the control valve is in the second position, the pressurized air that is present in the first chamber is permitted to move through the first channel, through the control valve, through the second channel, and into the second chamber.