Apparatus for removing dusting powder in offset presses

• US 4,082,037 A
• Filed: 10/28/1975
• Issued: 04/04/1978
• Est. Priority Date: 10/28/1975
• Status: Expired due to Term

• Current Assignee: Grindley C. Ronald, Larry G. Boyd
• Original Assignee: Grindley C. Ronald, Larry G. Boyd
• Inventors: Boyd, Larry G., Grindley, C. Ronald
• Primary Examiner(s): Mancene, Louis G.
• Assistant Examiner(s): Hirsch, Paul J.
• Application Number:
  US05/626,456
• Time in Patent Office: 889 Days
• Field of Search: 101/425, 101/409, 101/415.1, 101/246
• US Class Current: 101/425
• CPC Class Codes: B41F 23/002 cleaning devices for sheets or webs

Abstract

A cleaning roller having a soft fibrous surface (such as lamb'"'"'s wool roller) is disposed ahead of the blanket cylinder of an offset press, the surface presenting a nap which swells upon rotation of the roller to wipe particulate matter (dusting powder or residue particles) from the paper sheets before the same are printed. A trough containing water (in which the particles are soluble) extends parallel to the roller and receives the particles stripped from the roller by a doctor blade. The removed particles are directed from the blade to the trough by a guide surface continuous with the blade which is presented by a specially shaped sheet member extending from the blade into the trough. The water may be recirculated by a pump, or supplied and drained at a rate to prevent the particles from accumulating.

Claims

1. Apparatus for removing liquid-mixable, dry particulate matter from sheets under movement in a printing press, said apparatus comprising:

a cleaning roller having a dry, soft, fibrous surface adapted for wiping contact with said sheets;

means for supporting said roller adjacent said sheets;

drive means connected with said roller for rotating the latter to cause said surface thereof to wipe said sheets and collect said dry particulate matter;

a receiver spaced from said roller;

a doctor blade engaging said surface as the roller rotates for stripping the collected matter therefrom;

guide means for receiving the particulate matter stripped from said surface by said blade, and including a member extending from adjacent said blade to said receiver,

said member having a guide surface defining a flow path adjacent said guide surface along which the stripped matter flows under the centrifugal force of the rotating roller, whereby the stripped matter is directed into the receiver by the action of the roller, doctor blade and guide means; and

a quantity of liquid in which the stripped matter is mixable, said liquid being contained in said receiver for retaining the stripped matter directed thereinto, whereby the retained matter is carried away upon removal of the liquid from the receiver and resupply of liquid thereto.

2. The apparatus as claimed in claim 1, wherein said member is coextensive with said blade and said guide surface extends transversely outwardly from said blade.

3. The apparatus as claimed in claim 1, wherein said member comprises a sheet having a marginal portion joined to said blade, said sheet member presenting said guide surface continuous with the blade and extending transversely outwardly therefrom.

4. The apparatus as claimed in claim 3, wherein said receiver comprises a trough disposed in generally parallel relationship with the axis of rotation of said roller, said blade extending longitudinally of said roller, said member having an opposite marginal portion terminating within said trough.

5. The apparatus as claimed in claim 1, wherein means is provided communicating with said receiver for supplying said liquid thereto and draining matter-containing liquid therefrom.

6. The apparatus as claimed in claim 1, wherein said surface presents a nap and wherein said supporting means positions said roller with said surface thereof closely spaced from said sheets when the roller is stationary, and further wherein said drive means upon rotation of the roller causes said nap to extend radially outwardly under centrifugal force into light wiping contact with said sheets, said drive means limiting the speed of rotation of the roller such that the creation of significant peripheral air currents capable of lifting the sheets is prevented.

7. Apparatus for removing liquid-mixable, dry particulate matter from sheets under movement in a printing press, said apparatus comprising:

a cleaning roller having a cylindrical, dry, soft, fibrous surface presenting a nap;

support means for positioning said roller with said surface thereof closely spaced from said sheets when the roller is stationary;

drive means connected with said roller for rotating the latter to cause said nap to extend radially outwardly under centrifugal force and into light wiping contact with said sheets, whereby the surface of the roller collects said dry particulate matter,

said drive means limiting the speed of rotation of the roller such that the creation of significant peripheral air currents capable of lifting the sheets is prevented;

stripping means operably associated with said roller for removing the collected matter from said surface;

a receiver spaced from said roller;

guide means operably associated with said stripping means for defining a flow path from the surface to the receiver along which the stripped matter flows under the centrifugal force of the rotating roller; and

a quantity of liquid in which the stripped matter is mixable, said liquid being contained in said receiver for retaining the stripped matter directed thereinto, whereby the retained matter is carried away upon removal of the liquid from the receiver and resupply of liquid thereto.

8. The apparatus as claimed in claim 7, wherein said roller is provided with an axle projecting from opposite ends thereof, and wherein said support means includes a pair of spaced end supports having bearing means receiving said axle, a pair of parallel tracks receiving corresponding end supports for movement therealong in directions causing said surface of the roller to move toward or away from said sheets, and adjustable means for shifting said end supports along said tracks to a selected position that provides the desired spacing between said sheets and the surface of the roller when stationary.

9. The apparatus as claimed in claim 7, wherein said sheets are under movement on an impression cylinder of said printing press having grippers that engage the sheets, and wherein a shield is provided on said cylinder for preventing the grippers from grooving said surface of the roller when the latter is rotating and the nap is radially extended.

10. A method for removing dry particulate matter from sheets under movement in a printing press, said method comprising the steps of:

providing a cleaning roller having a cylindrical, dry, soft fibrous surface presenting a nap;

positioning said roller with said surface thereof closely spaced from said sheets when the roller is stationary;

rotating the roller to cause said nap to extend radially outwardly under centrifugal force and into light wiping contact with said sheets, whereby the surface of the roller collects said dry particulate matter;

limiting the speed of rotation of the roller such that the creation of significant peripheral air currents capable of lifting the sheets is prevented;

stripping the collected matter from the surface of the roller; and

guiding the stripped matter away from the roller to a receiver therefor, by providing a flow path along which the stripped matter flows under the centrifugal force of the rotating roller.