Computer driven printer with a stripper roller and latching assembly

• US 6,267,521 B1
• Filed: 11/01/1999
• Issued: 07/31/2001
• Est. Priority Date: 09/22/1995
• Status: Expired due to Term

• Current Assignee: Zebra Technologies Corporation
• Original Assignee: Eltron International, Inc. (Zebra Technologies Corporation)
• Inventors: Lodwig, Dean H., Bryer, Philip Stuart, Harb, Douglas LeRoy
• Primary Examiner(s): COLILLA, DANIEL JAMES
• Application Number:
  US09/431,010
• Time in Patent Office: 638 Days
• Field of Search: 101/288, 400/120.01, 400/207, 400/208, 400/691, 400/693, 400/693.1, 347/222
• US Class Current: 400/693.1
• CPC Class Codes: B41J 17/24 Webs supplied from reels or spools attached to the machine
• CPC Class Codes: B41J 17/36 Alarms, indicators, or feed-disabling devices responsible to material breakage or exhaustion
• CPC Class Codes: B41J 33/14 Ribbon-feed devices or mechanisms
• CPC Class Codes: B41J 35/08 with tensioning arrangements

Abstract

Apparatus for maintaining tension on a ribbon in a printer used for transferring an image, e.g., thermally, from a print head through the ribbon to a print medium. By maintaining ribbon tension and thus keeping the ribbon essentially without wrinkles, print quality is enhanced. This tension maintenance apparatus uses a pair of torqued reel subassemblies with the ribbon extending between and is of particular significance when used in conjunction with a label stock as a printer medium when the printer mechanism bidirectionally moves the label stock to assist removal of labels from its backing. These torqued reel assemblies are sufficiently loaded such that ribbon tension is maintained between these reel assemblies despite this bidirectional movement.

Claims

1. A printer for transferring an image to a print medium, said printer comprising:

first and second subassemblies rotatlibly coupled at a first end;

the first and second subassembly comprising a print head;

the second subassembly comprising a drive roller and a stripper roller; and

a latching assembly for detachably coupling said subassemblies at a second end, said subassemblies being adapted to press a print medium between said drive roller and said print head when said latching assembly is in a latched position, said latching assembly further comprising means for separating said print head from drive said drive roller and means for separating said stripper roller from said drive roller when said latching assembly is in an unlatched position.

2. The printer of claim 1, the print bead being positioned in said first subassembly, said

first subassembly further comprising:

a ribbon supply apparatus for moving ribbon along a ribbon path, said subassemblies being adapted to press a print medium and a ribbon between said print head and said drive roller.

3. The printer of claim 2, said second subassembly further comprising:

a print medium supply apparatus for providing print medium along a print medium path to selectively receive ink from a ribbon.

4. The printer of claim 3, further comprising a drive mechanism for driving said ribbon supply apparatus and said print medium supply apparatus when said first and second subassemblies are latched by said latching assembly.

5. The printer of claim 1, the latching assembly comprising:

two bosses mounted on one of said subassemblies; and

two latches rotatably mounted on the other subassembly for engagement with the two bosses in a latched position and for disengagement with the two bosses in an unlatched position.

6. The printer of claim 5, wherein a total force of 8 pounds is needed to disengage said latches from said bosses.

16. The printer of claim 1, 7, 8, 11, or 15, wherein said print medium is label stock comprised of a plurality of labels removable from a label backing.

17. The printer of claim 16, further comprising:

a stripper bar coupled to at least one of said subassemblies for separating said labels from said label backing.

18. The printer of claim 1, 7, 8, 9, or 11, the latching assembly comprising:

at least one boss mounted on one of said subassemblies;

at least one latch rotatably mounted can one of said subassemnblies for engagement with the at least one boss in a latched position and for disengagement with the at least one boss in an unlatched position; and

cam means coupled to said latch for positioning said stripper roller in spaced relationship to said drive roller when said latch is in said unlatched position and for placing said stripper roller in contact with said drive roller when said latch is in said latched position.

7. A printer for transferring an image to a print medium, said printer comprising:

first and second subassemblies rotatably coupled at a first end;

said first subassembly comprising a print head and a ribbon supply apparatus for moving ribbon along a ribbon path;

said second subassembly comprising a print medium supply apparatus for providing print medium along a print medium path to selectively receive ink from a ribbon;

a drive roller for driving a print medium;

a latching assembly for detachably coupling said subassemblies at a second end,

wherein said subassemblies comprise means for pressing a print medium and a ribbon between said drive roller and said print head when said latching assembly is in a latched position and means for separating said print bead from said drive roller when said latching assembly is in an unlatched positions;

a stripper roller driven by said drive mechanism; and

,

said subassemblies further comprising means for separating said stripper roller from said drive roller to facilitate loading of a print medium between said stripper roller and said drive roller when said latching assembly is in an unlatched position.

8. A printer for transferring an image to a print medium, said printer comprising:

first and second subassemblies rotataibly coupled at a first end;

a latching assembly for detachably coupling said subassemblies at a second end;

a print head;

a drive roller;

a drive mechanism for driving a ribbon supply apparatus and a print medium supply apparatus when said first and second subassemblies axe latched by said latching assembly; and

a stripper roller driven by said drive mechanism,

said subassemblies farther comprising means for pressing a print medium and a ribbon between said drive roller and said print head when said latching assembly is in position and means for separating said print head from said drive roller and for separating said stripper roller from said drive roller when said latching assembly is in unlatched position.

9. A printer for transferring an image to a print medium, said printer comprising:

first and second subassemblies;

a stripper bar coupled to at least one of said subassemblies;

a first subassembly comprising;

a print head; and

a ribbon supply apparatus for moving ribbon along a ribbon path;

a second subassembly comprising;

a drive rollers;

a stripper roller;

a drive mechanism for rotating said drive roller; and

a print medium supply apparatus defining a print medium path extending past said drive roller, around said stripper bar, and between said drive roller and said stripper roller;

means mounting said first subassembly to said second subassembly at a first end for relative rotation with respect to said second subassembly, said relative rotation being between an open inoperative condition and a closed operative condition; and

a latching assembly coupled to said subassemblies at a second end, said latching assembly being adapted to unlatch said subassemblies for said open inoperative position and to latch said subassemblies for said closed operative condition,

said subassemblies being adapted to press a ribbon and a print medium between said drive roller and said print head when said latching assembly is in a latched position and to separate said print head from sad drive roller when said latching assembly is in an unlatched position, said latching assembly further being adapted to position said stripper roller in spaced relationship to said drive roller when said latching assembly is in said unlatched position and to position said stripper roller in contact with said drive roller when said latching assembly is in said latched position.

10. The printer of claim 9, wherein said print medium is label stock comprised of a plurality of removable labels from a label backing.

11. A printer for transferring an image to a print medium, said printer comprising:

a first subassembly;

a second subassembly;

means for mounting said first subassembly to said second subassembly at a first end for relative rotation with respect to the second subassembly about a pivot axis, said relative rotation being between an open inoperative position and a closed operative position;

a print head;

a drive roller;

a stripper roller; and

a latching assembly coupled to said subassemblies at a second end, said latching assembly being adapted to unlatch said subassemblies for said open inoperative position and to latch said subassemblies for said closed operative condition,

said subassemblies being adapted to press a print medium between said rive roller and said print head when said latching assembly is in a latched position and to separate said print head from said drive roller when said latching assembly is in an unlatched position, said latching assembly further being adapted to position said stripper roller in spaced relationship to said drive roller when said latching assembly is in said unlatched position and to position said stripper roller in contact with said drive roller when said latching assembly is in said latched position.

12. The printer of claim 11, wherein said printer further comprises a stripper bar positioned adjacent to said drive roller.

13. The printer of claim 11, wherein said print head is positioned within said first subassembly and said first subassembly further comprising:

a ribbon supply apparatus defining a ribbon path extending past said print head, herein said first subassembly is also adapted to press a ribbon between said print head and said drive roller.

14. The printer of claim 11, wherein said drive roller and said stripper roller are positioned within said second subassembly, the second subassembly further comprising:

a drive mechanism for rotating said drive roller; and

a print medium supply apparatus defining a print medium path extending past said drive roller.

15. A printer for transferring an image to a print medium, said printer comprising:

a first subassembly comprising;

a print head; and

a ribbon supply apparatus for moving ribbon along a ribbon path;

a second subassembly rotatably attached to said first subassembly at a first end;

a latching assembly for detachably coupling said subasemblies at a second end;

said second subassembly comprising;

a drive roller;

a drive mechanism for rotating said drive roller; and

a print medium supply apparatus defining a print medium path extending past said drive roller;

said subassemblies being adapted to press a ribbon and a print medium between said drive roller and said print head when said latching assembly is in a latched position and to separate said print bead from said drive roller when said latching assembly is in an unlatched position;

a stripper roller; and

said latching assembly having

a latch; and

cam means coupled to said latch for rotatably positioning said stripper roller in relationship to said drive roller.