Doctor blade assembly with rotary end seals and interchangeable heads

A doctor blade assembly adapted for applying a liquid uniformly to a rotating transfer roller, comprising;

• a longitudinally extending doctor blade head having a channel-like cavity formed therein and oriented parallel to the transfer roller, a pair of doctor blades disposed on opposed sides of said cavity and extending the length thereof and adapted to impinge on the transfer roller,
• a pair of end seal assemblies secured to said doctor blade head and disposed at opposite ends of said cavity, each end seal assembly including means for establishing a liquid seal with a rotating peripheral surface portion of the transfer roller at a respective end of a transfer roller,
• means for supporting said doctor blade head and removably positioning said doctor blade head so that said doctor blades may be moved into and out of engagement with the transfer roller,
• a plurality of said doctor blade heads, said means for supporting said doctor blade head including means for interchangeably removing and securing any one of said plurality of doctor blade heads in substantially identical alignment with respect to the transfer roller,
• said means for supporting said doctor blade heads including a plurality of mounting lugs extending from each of said doctor blade heads, a like plurality of mounting blocks, a plurality of slots, each extending into one of said mounting blocks and dimensioned to receive one of said mounting lugs in close fit, and support arm means connected to said mounting blocks,
• said support arm means including a pivot shaft extending generally parallel to the transfer roller, and a like plurality of support arms extending fixedly from said pivot shaft in parallel alignment each to the other, and
• means for joining each of said mounting blocks to one of said support arms, including a stub shaft extending from each of said support arms and pivotally received in a respective mounting block, said stub shaft extending generally parallel to said pivot shaft and said transfer roller.

A doctor blade assembly adapted for applying a liquid uniformly to a rotating transfer roller, comprising;

• a longitudinally extending doctor blade head having a channel-like cavity formed therein and oriented parallel to the transfer roller, a pair of doctor blades disposed on opposed sides of said cavity and extending the length thereof and adapted to impinge on the transfer roller,
• a pair of end seal assemblies secured to said doctor blade head and disposed at opposite ends of said cavity, each end seal assembly including means for establishing a liquid seal with a rotating peripheral surface portion of the transfer roller at a respective end of the transfer roller,
• means for supporting said doctor blade head and removably positioning said doctor blade head so that said doctor blades may be moved into and out of engagement with the transfer roller,
• said end seal assemblies each including an end plate removably secured to a longitudinally opposed end of said doctor blade head and having a proximal end portion dimensioned to extend across one end of said channel-like cavity in sealing fashion, said end plate further including a distal end portion disposed to impinge on the end surface of the transfer roller,
• each of said distal portions of said end plates including a planar surface portion adapted to impinge on the end of said transfer roll, and further including a second surface opposed to said planar surface portion, and groove means extending in said second surface to provide enhanced resilient engagement of said distal end portion against the end surface of said transfer roller.

A doctor blade assembly adapted for applying a liquid uniformly to a rotating transfer roller, comprising;

• a longitudinally extending doctor blade head having a channel-like cavity formed therein and oriented parallel to the transfer roller, a pair of doctor blades disposed on opposed sides of said cavity and extending the length thereof and adapted to impinge on the transfer roller,
• said pair of doctor blades extending parallel to the transfer roller and converging as they extend from said opposed sides of said cavity toward the transfer roller,
• a pair of end seal assemblies secured to said doctor blade head and disposed at opposite ends of said cavity, each end seal assembly including means for establishing a high pressure liquid seal with a rotating peripheral surface portion of the transfer roller at a respective end of the transfer roller and means for overlapping the respective end surface of the transfer roller, and
• means for supporting said doctor blade head and removably positioning said doctor blade head so that said doctor blades may be moved into and out of engagement with the transfer roller.