Printing drum assembly for a stencil printing device

• US 5,443,557 A
• Filed: 05/16/1994
• Issued: 08/22/1995
• Est. Priority Date: 05/25/1993
• Status: Expired due to Fees

• Current Assignee: RISO Kagaku Corporation
• Original Assignee: RISO Kagaku Corporation
• Inventors: Hasegawa, Takanori
• Primary Examiner(s): Burr, Edgar S.
• Assistant Examiner(s): FEILD, LYNN DIANA
• Application Number:
  US08/242,986
• Time in Patent Office: 463 Days
• Field of Search: 101/116, 101/119, 101/120, 101/123, 101/129
• US Class Current: 101/119
• CPC Class Codes: B41L 13/06 with a single cylinder carrying the stencil

Abstract

A printing drum is rotatable supported by a fixed hollow cylindrical member at two axially spaced positions thereof so that the printing drum may be supported in a highly stable fashion and any mis-alignment of the printing drum can be avoided. Also, the interior of the fixed hollow cylindrical member provides an easily accessible space for accommodating a printing ink container and a pump for supplying printing ink. In particular, by using a squeegee blade instead of a squeegee roller, a particularly advantage can be obtained because the diameter of the fixed hollow cylindrical member can be such that an annular chamber defined between the fixed hollow cylindrical member and the inner circumferential surface of the printing drum is barely sufficient to accommodate the squeegee blade in the annular chamber, and the fixed hollow cylindrical member can provide a highly rigid support structure.

Claims

1. A printing drum assembly for a stencil printing device, comprising:

a frame of a stencil printing device;

a hollow cylindrical member fixed to and supported by said frame;

a printing drum having an inner circumferential surface rotatably supported by said hollow cylindrical member at two axially spaced positions thereof, said printing drum including an ink permeable outer shell;

a printing ink container disposed inside said hollow cylindrical member; and

printing ink supplying means for feeding printing ink from said printing ink container to said inner circumferential surface of said printing drum.

2. A printing drum assembly according to claim 1, wherein said hollow cylindrical member is fixedly secured to said frame at two axial ends thereof.

3. A printing drum assembly according to claim 1, wherein said hollow cylindrical member has an open end at a first axial end and a closed end at a second axial end.

4. A printing drum assembly according to claim 1, further comprising a squeegee blade supported by said hollow cylindrical member and engaging said inner circumferential surface of said printing drum.

5. A printing drum assembly according to claim 4, wherein an annular chamber defined between said hollow cylindrical member and said inner circumferential surface of said printing drum is barely sufficient to accommodate said squeegee blade in said annular chamber.

6. A printing drum assembly according to claim 4, including an adjust screw threadably passed through a wall of said hollow cylindrical member and a member supporting said squeegee blade, said adjust screw having a free end which abuts said member supporting said squeegee blade.

8. A printing drum assembly according to claim 1, wherein said printing ink supplying means comprises a pump for feeding printing ink received in said container to said inner circumferential surface of said printing drum.

9. A printing drum assembly according to claim 1, including an annular chamber defined between said hollow cylindrical member and said inner circumferential surface of said printing drum wherein said printing ink supplying means comprises a solenoid valve provided on an opening provided in said hollow cylindrical member for selective communication between said container for printing ink and said annular chamber.

10. A printing drum assembly according to claim 1, wherein said hollow cylindrical member is fixedly secured to said frame at an axial end thereof in the manner of a cantilever.

7. A printing drum assembly for a stencil printing device comprising:

a frame of a stencil printing device;

a hollow cylindrical member fixed to and supported by said frame;

said hollow cylindrical member serving as a container for printing ink;

a printing drum having an inner circumferential surface rotatably supported by said hollow cylindrical member at two axially spaced positions thereof, said printing drum including an ink permeable outer shell; and

printing ink supplying means for feeding printing ink from said printing ink container to said inner circumferential surface of said printing drum.