Abstract: A doctor blade head for coating a transfer roller includes a semi-cylindrical cavity to enable streamline fluid flow therethrough, and check plates at the inlet and outlet openings for permitting unidirectional flow into the inlet opening from said pump and out of the outlet opening toward the pump. An hydraulic accumulator acts as a fluid pressure and fluid velocity balancing device, and includes a rolling diaphragm piston moving in a cylinder that is connected to the inlet fluid path, with a spring impinging on the piston to absorb pressure surges and compensate pressure dropoffs.

Abstract: A doctor blade head for coating a transfer roller includes a semi-cylindrical cavity to enable streamline fluid flow therethrough, and check plates at the inlet and outlet openings for permitting unidirectional flow into the inlet opening from said pump and out of the outlet opening toward the pump. An hydraulic accumulator acts as a fluid pressure and fluid velocity balancing device, and includes a rolling diaphragm piston moving in a cylinder that is connected to the inlet fluid path, with a spring impinging on the piston to absorb pressure surges and compensate pressure dropoffs.

Abstract: A supply system for a chambered doctor blade assembly makes possible the sequential use of water-based and non-water-based liquid inks through automated functions programmed in a PLC that controls the system. A pair of pneumatically driven diaphragm pumps serve as supply pump and return pump between the doctor blade chamber and an ink reservoir A PLC controls the pulse rate of pneumatic pressure to the pumps to control the rate of flow of the liquid into, and out of the doctor blade chamber. A capacitive sensor detects a high liquid level in the ink reservoir. The PLC is programmed to modify the pulse rate of the supply pump and return pump to maintain the liquid level in the reservoir above the drain thereof and below the maximum level.

Abstract: A supply system for a chambered doctor blade assembly makes possible the sequential use of water-based and non-water-based coating materials through automated functions programmed in a PLC that controls the system. A pair of pneumatically driven diaphragm pumps serve as supply pump and return pump between the doctor blade chamber and a coating reservoir A PLC controls the pulse rate of pneumatic pressure to the pumps to control the rate of flow of the coating material into, and out of the doctor blade chamber. An ultrasonic sensor mounted detects the liquid level in the trough collection area. The PLC is programmed to modify the pulse rate of the supply pump and return pump to maintain the liquid level in the trough collection area above the drain thereof and below the maximum tolerance.