Wetting apparatus

Patent metadata

Field	Value
Publication number	US-11472174-B2
Application number	US-201716605873-A
Country	US
Kind code	B2
Filing date	Dec 14, 2017
Priority date	Dec 14, 2017
Publication date	Oct 18, 2022
Grant date	Oct 18, 2022

Abstract

There is disclosed apparatus for wetting a roller of a printing system comprising an applicator unit comprising a liquid agent chamber. Upper and lower walls extend from the liquid agent chamber to define a slit therebetween. The upper wall extends beyond a lip of the lower wall to a transfer lip. A flow restrictor is received in the slit to prevent flow of liquid agent to a respective portion of the transfer lip, thereby defining a restricted portion of the slit and an adjacent unrestricted portion of the slit. The flow restrictor fits in the restricted portion with a clearance that permits liquid agent flow at a reduced velocity relative flow through the unrestricted portion, such that liquid agent along the restricted portion is discharged from the lower wall. A method of installing a flow restrictor is also disclosed.

First claim

The invention claimed is:

1. Apparatus for wetting a roller of a printing system, the apparatus comprising:
an applicator unit comprising:
a liquid agent chamber;
upper and lower walls extending from the liquid agent chamber to define a slit between them for conveying liquid agent, the slit having a width along a lateral direction;
wherein the upper wall extends beyond a lip of the lower wall and terminates at a laterally extending transfer lip to transfer liquid agent conveyed thereto to a roller;
a flow restrictor received in the slit to prevent flow of liquid agent to a respective lateral portion of the transfer lip, thereby defining a restricted portion of the slit and an adjacent unrestricted portion of the slit;
wherein there is a clearance between the flow restrictor and the slit which permits liquid agent to flow along the restricted portion at a reduced velocity relative a flow of liquid agent through the unrestricted portion, such that liquid agent flowing along the restricted portion is discharged from the lip of the lower wall.

2. Apparatus according to claim 1 , wherein the flow restrictor comprises a boundary guide adjacent the transfer lip to define a lateral boundary of a wetted zone on a roller;
wherein the boundary guide comprises a boundary surface to receive liquid agent, the boundary surface extending along the lateral direction and a guide direction perpendicular to the lateral direction to oppose a roller; and
wherein the boundary surface terminates at a boundary edge extending perpendicular to the lateral direction to prevent lateral migration of liquid agent on the boundary surface beyond the boundary edge and thereby define a lateral boundary of a wetted zone on the roller.

3. Apparatus according to claim 2 , wherein the boundary guide comprises two boundary surfaces terminating at respective boundary edges laterally spaced apart by a void to prevent lateral migration of liquid agent on the boundary surfaces beyond the boundary edges, and thereby define an un-wetted zone on the roller corresponding to the void.

4. Apparatus according to claim 3 , wherein the boundary guide comprises an intermediate portion laterally between the two boundary surfaces, the two boundary surfaces being disposed forward of the intermediate portion with respect to an application direction from the slit to a roller;
wherein the intermediate portion comprises a locating formation to cooperate with a corresponding locating feature of an apparatus for placement of the flow restrictor.

5. Apparatus according to claim 4 , wherein a portion of the boundary guide extends above the transfer lip and in front of the transfer lip with respect to the application direction.

6. Apparatus according to claim 4 ;
wherein the boundary guide comprises two rails defining the boundary surfaces, the rails extending from a lip portion of the boundary guide adjacent the lip to a distal support portion;
wherein the distal support portion is to rest against a support structure of the apparatus; and
wherein the rails are profiled so that the boundary surfaces are disposed forward of the intermediate portion; and
wherein the intermediate portion is integral with the support portion and affixed to the lip portion.

7. Apparatus according to claim 2 , wherein the flow restrictor comprises a slit portion received in the slit; and
wherein the slit portion and the boundary guide are integrally formed.

8. Apparatus according to claim 7 ,
wherein the boundary guide comprises two rails defining the boundary surfaces, the rails extending from a lip portion of the boundary guide adjacent the lip to a distal support portion;
wherein the distal support portion is to rest against a support structure of the apparatus; and
wherein the rails are profiled so that the boundary surfaces are disposed forward of an intermediate portion; and
wherein the intermediate portion is integral with the support portion and affixed to the lip portion.

9. Apparatus according to claim 1 , wherein the flow restrictor is a format limiter to prevent flow of liquid agent to an end portion of the transfer lip, thereby defining a lateral boundary of a total wetted zone on a roller.

10. Apparatus according to claim 9 , wherein the format limiter comprises:
an arm portion extending laterally into the slit from a lateral end of the slit; and
a tab portion extending from the arm portion towards the transfer lip,
whereby the arm portion and the tab portion define a corresponding restricted portion of the slit; and
wherein the apparatus further comprises a drive for laterally moving the format limiter to vary the boundary of the total wetted zone.

11. Apparatus according to claim 10 ,
further comprising a seal; and
wherein the drive is disposed outside of the chamber and outside of the slit, and wherein the arm portion extends through the seal to engage the drive.

12. Apparatus according to claim 1 , wherein the flow restrictor is a lane insert to prevent flow of liquid agent to an intermediate dry portion of the transfer lip, to thereby form a corresponding dry lane on a roller.

13. Apparatus according to claim 12 , wherein the lane insert comprises an insert portion received in the slit which is biased away from a planar configuration for retention in the slit.

14. A method of installing a flow restrictor in a wetting apparatus comprising:
an applicator unit having a liquid agent chamber, upper and lower walls extending from the liquid agent chamber to define a slit between them for conveying liquid agent, the slit having a width along a lateral direction; wherein the upper wall extends beyond a lip of the lower wall and terminates at a laterally extending transfer lip to transfer liquid agent conveyed along the upper wall from the slit to a roller;
the method comprising:
installing a flow restrictor in the slit to prevent flow of liquid agent to a respective lateral portion of the transfer lip, thereby defining a restricted portion of the slit and an adjacent unrestricted portion of the slit;
wherein there is a clearance between the flow restrictor and the slit which permits liquid agent to flow along the restricted portion at a reduced velocity relative a flow of liquid agent through the unrestricted portion, such that liquid agent flowing along the restricted portion is discharged from the lip of the lower wall.

15. A method according to claim 14 , further comprising aligning the flow restrictor with the slit using an insert jig by:
engaging cooperating locating features on the flow restrictor and a restrictor guide of the insert jig;
sliding the restrictor guide to align the flow restrictor relative the insert jig; and

aligning the insert jig with the applicator unit.

Assignees

• Hewlett Packard Development Co

Inventors

• Feygelman Alex
• Arenson Mordechai
• Richter Marko
• Yaacobov Yossi

Classifications

• B41F31/28 Primary

  Spray apparatus · CPC title

• B05C1/0813

  characterised by means for supplying liquid or other fluent material to the roller · CPC title

• B41F31/04 Primary

  with duct-blades or like metering devices · CPC title