Powder sprayer with automatic powder supply system

A printing press power sprayer for directing powder onto sheets passing through the printing press comprising

• a housing for containing a quantity of powder
• selectively operable means for discharging powder from said housing,
• a powder supply hopper,
• means for transferring powder from said hopper to said housing,
• and means for automatically operating said powder transferring means in timed intervals in response to and as determined by the operating time of said powder discharging means.

In a printing press having means for transferring sheet material along a predetermined path, a powder sprayer for directing anti-offset powder onto said sheet material, said powder sprayer comprising

• a housing for containing a quantity of powder, said housing having an elongated, substantially horizontally disposed discharge opening,
• a rotatable roller disposed within said opening for metering the discharge of powder from said housing through said discharge opening,
• a powder supply hopper remote from said housing,
• first and second conduits connecting said powder supply hopper and housing, said first conduit communicating with said sprayer housing adjacent one end of said discharge opening and said second conduit communicating with said sprayer housing adjacent an opposite end of said discharge opening,
• means for generating a pressurized air flow in said first conduit for drawing powder from said hopper and directing it through said first conduit and into said housing at a location adjacent said one end of said discharge opening, said first conduit air generating and directing means including first venturi means having a central air passageway with an inlet coupled to said hopper and an outlet coupled to said sprayer housing, said first venturi means having radial inlet passage means through which a pressurized air flow stream is directed for generating an air flow through said central passageway and first conduit, and
• means for generating a pressurized air flow in said second conduit for drawing excess powder from said housing at a location adjacent the opposite end of said discharge opening and directing it through said second conduit for return to said hopper, said second conduit air generating and directing means including second venturi means having a central passageway with an inlet coupled to said sprayer housing and an outlet coupled to said hopper, said second venturi means having radial inlet passage means through which a pressurized airflow stream is directed for generating an airflow through said central passageway and second conduit.

A powder sprayer comprising

• a housing for containing a quantity of powder, said housing having an elongated discharge opening,
• a rotatable roller disposed within said opening for metering the discharge of powder from said housing through said discharge opening,
• a powder supply hopper remote from said housing,
• first and second conduits connecting said powder supply hopper and housing,
• means for generating a pressurized air flow in said first conduit for drawing powder from said hopper and directing it through said first conduit and into said housing,
• means for generating a pressurized air flow in said second conduit for drawing excess powder from said housing and directing it through said second conduit for return to said hopper,
• said second conduit air generating and directing means being operable for generating a greater air flow than said first conduit air generating and directing means,
• said hopper including a removable lid having an air passage opening therein, and
• filter means contained in said lid for filtering air directed through said second conduit into said hopper and through said air passage opening.

A powder sprayer comprising

• a housing for containing a quantity of powder, said housing having an elongated discharge opening,
• a rotatable roller disposed within said opening for metering the discharge of powder from said housing through said discharge opening,
• a powder supply hopper remote from said housing,
• first and second conduits connecting said powder supply hopper and housing,
• means for generating a pressurized air flow in said first conduit for drawing powder from said hopper and directing it through said first conduit and into said housing,
• means for generating a pressurized air flow in said second conduit for drawing excess powder from said housing and directing it through said second conduit for return to said hopper,
• said first and second conduit airflow generating means including a pressurized air source,
• selectively operable control means for automatically communicating said pressurized air source to said first and second conduit airflow generating means in predetermined timed intervals, said control means including timer means operated in response to operation of said roller, and
• means responsive to operation of said timer means for a predetermined period for enabling communication of said pressurized air source to said first and second conduit airflow generating means.

A powder sprayer comprising

• a housing for containing a quantity of powder, said housing having an elongated, substantially horizontally disposed discharge opening,
• a rotatable roller disposed within said opening for metering the discharge of powder from said housing through said discharge opening,
• a powder supply hopper remote from said housing,
• first and second conduits connecting said powder supply hopper and housing, said first conduit communicating with said sprayer housing on one end of said discharge opening and said second conduit communicating with said sprayer housing on an opposite end of said discharge opening,
• means for generating a pressurized air flow in said first conduit for drawing powder from said hopper and directing it through said first conduit and into said housing at said one end of said discharge opening, and
• means for generating a pressurized air flow in said second conduit for drawing excess powder in said housing from said opposite end of said discharge opening and directing it through said second conduit for return to said hopper.

A powder sprayer comprising

• a housing for containing a quantity of powder, said housing having an elongated discharge opening,
• a rotatable roller disposed within said opening for metering the discharge of powder from said housing through said discharge opening,
• a powder supply hopper remote from said housing,
• first and second conduits connecting said powder supply hopper and housing, said first and second conduits being connected to a common end of said sprayer housing, one of said conduits communicating directly with the interior of said sprayer housing adjacent said one end, and the other of said conduits having an extension tube extending substantially the length of said housing with the end of the tube communicating with the interior of said housing at the other end thereof;
• means for generating a pressurized air flow in said first conduit for drawing powder from said hopper and directing it through said first conduit and into said housing, and
• means for generating a pressurized air flow in said second conduit for drawing excess powder from said housing and directing it through said second conduit for return to said hopper.

In a printing press having means for transferring sheet material along a predetermined path, a powder sprayer for directing anti-offset powder onto said sheet material, said powder sprayer comprising

• a housing for containing a quantity of powder, said housing having an elongated discharge opening,
• a rotatable roller disposed within said opening for metering the discharge of powder from said housing through said discharge opening,
• a powder supply hopper remote from said housing,
• first and second conduits connecting said powder supply hopper and housing,
• first means for generating a pressurized air flow in said first conduit for drawing powder from said hopper and directing it through said first conduit and into said housing,
• second means separate from said first pressurized airflow generating and directing means for generating a pressurized air flow in said second conduit for drawing excess powder from said housing and directing it through said second conduit for return to said hopper, and
• said second conduit air generating and directing means being operable for generating a greater air flow than said first conduit air generating and directing means.

In a printing press having means for transferring sheet material along a predetermined path, a powder sprayer for directing anti-offset powder onto said sheet material, said powder sprayer comprising

• a housing for containing a quantity of powder, said housing having an elongated discharge opening,
• a rotatable roller disposed within said opening for metering the discharge of powder from said housing through said discharge opening,
• a powder supply hopper remote from said housing,
• first and second conduits connecting said powder supply hopper and housing,
• first means for generating a pressurized air flow in said first conduit for drawing powder from said hopper and directing it through said first conduit and into said housing,
• second means separate from said first pressurized airflow generating and directing means for generating a pressurized air flow in said second conduit for drawing excess powder from said housing and directing it through said second conduit for return to said hopper,
• said first and second conduit air generating and directing means being selectively operable, and
• means for automatically operating said first and second conduit air generating and directing means in timed intervals in response to and as determined by the operating time of said roller.

In a printing press having means for transferring sheet material along a predetermined path, a powder sprayer for directing anti-offset powder onto said sheet material, said powder sprayer comprising

• a housing for containing a quantity of powder, said housing having an elongated discharge opening,
• a rotatable roller disposed within said opening for metering the discharge of powder from said housing through said discharge opening,
• a powder supply hopper remote from said housing,
• first and second conduits connecting said powder supply hopper and housing,
• first means for generating a pressurized air flow in said first conduit for drawing powder from said hopper and directing it through said first conduit and into said housing,
• second means separate from said first pressurized airflow generating and directing means for generating a pressurized air flow in aid second conduit for drawing excess powder from said housing and directing it through said second conduit for return to said hopper,
• said first and second conduit air flow generating means
• including a pressurized air source, and
• selectively operable control means for automatically communicating said pressurized air source to said first and second conduit airflow generating means in predetermined timed intervals.