Reverse angle doctor blade assembly with stationary end seal

A liquid transfer apparatus of a type wherein liquid in a reservoir wets the surface of a rotating transfer roll which then applies liquid to a moving web or intermediate roll, the improvement comprising:

• a reservoir chamber having one open face;
• means for circulating a liquid through said reservoir chamber;
• a transfer roll disposed for rotation adjacent to said open face for receiving liquid from said reservoir chamber;
• at least one reverse angle doctor blade means having an edge oriented in a direction opposite the direction of rotation of said transfer roll for shearing excess liquid from the surface of the transfer roll;
• a seal support disposed at each end of said transfer roll, each seal support having a sealing surface coplanar with an adjacent abutting portion of the surface of said transfer roll;
• means for holding each seal support in stationary, sliding relation to its end of the transfer roll;
• and
• a resilient seal disposed at each end of the reservoir chamber, each seal having an edge for sealingly engaging said sealing surface of its adjacent seal support and an adjacent end of said blade means to provide a liquid seal at the ends of said transfer roll and said reservoir chamber.

A high speed liquid transfer apparatus, comprising:

• a transfer roll and means for rotating said transfer roll;
• a reservoir chamber for retaining liquid, said reservoir chamber having means for engaging in fluid communication with the surface of the transfer roll;
• reverse doctor blade means for metering liquid from said reservoir onto the surface of said transfer roll, said reverse doctor blade means having an edge extending along the length of said transfer roll and oriented opposite the direction of rotation of said transfer roll for shearing excess liquid from the surface of the transfer roll;
• seal support means mounted in stationary relation to said transfer roll;
• resilient seal means for engaging said seal support means and said reverse doctor blade means to provide a seal against said liquid at the ends of said reservoir chamber and transfer roll;
• and
• liquid deflecting means disposed in the liquid of said reservoir chamber for deflecting a cascade of sheared liquid from said reverse doctor blade means away from the back of said reservoir chamber to maintain the level of liquid within the reservoir chamber.

A liquid transfer apparatus, comprising:

• a transfer roll and means for rotating said transfer roll;
• a reservoir chamber for retaining liquid, said reservoir chamber having means for engaging in liquid communication with the surface of the transfer roll;
• reverse doctor blade means oriented opposite the direction of rotation of said transfer roll for shearing excess liquid from the surface of said transfer roll;
• sealing means for providing a liquid seal at the ends of said reservoir chamber and said transfer roll;
• and
• a groove formed in a back wall of said reservoir chamber for deflecting a cascade of sheared liquid from said reverse doctor blade means away from the back wall of said reservoir chamber to control the turbulence of liquid within the reservoir chamber and thereby maintain a relatively constant level of liquid within the reservoir chamber.

A liquid transfer apparatus, comprising:

• a reservoir chamber for retaining a liquid;
• a transfer roll disposed for rotation with at least a portion of its surface in liquid communication within the reservoir chamber to receive liquid from the reservoir chamber;
• means for circulating said liquid through said reservoir chamber;
• a first blade means for shearing excess liquid from the surface of said transfer roll when the transfer roll rotates in one direction and for retaining liquid in said reservoir chamber when the transfer roll rotates in an opposite direction;
• a second blade means for shearing excess liquid from the surface of said transfer roll when the transfer roll rotates in said opposite direction and for retaining liquid in said reservoir chamber when the transfer roll rotates in said one direction;
• two seal supports, the seal supports disposed at opposite ends of said transfer roll;
• means for holding each seal support in stationary sliding relation to its end of the transfer roll;
• a resilient seal disposed at each end of the reservoir chamber, each seal sealingly engaging an adjacent stationary seal support to provide a liquid seal at the ends of said transfer roll and said reservoir chamber;
• and
• deflector means disposed within said reservoir chamber for deflecting liquid sheared from at least one of said blade means away from a back wall of said reservoir chamber to control the turbulence of liquid within the reservoir chamber and thereby maintain a relatively constant level of liquid within the chamber.