Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
  • B41J2/01—Ink jet
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J15/00—Devices or arrangements of selective printing mechanisms, e.g. ink-jet printers or thermal printers, specially adapted for supporting or handling copy material in continuous form, e.g. webs
  • B41J15/16—Means for tensioning or winding the web
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J3/00—Typewriters or selective printing or marking mechanisms characterised by the purpose for which they are constructed
  • B41J3/407—Typewriters or selective printing or marking mechanisms characterised by the purpose for which they are constructed for marking on special material
  • B41J3/4078—Printing on textile

Definitions

• the present invention relates to the technical field concerning apparatuses for printing of digitised drawings (plotters) .
• the present invention relates to an improved ink-jet vertical plotter, fit to trace shapes, particularly designed to be used for cloths cutting, on a paper medium or on a similar support.
• Ink-jet plotters of such type carry out the shape tracing by means of a print head which slides horizontally and crosswise with respect to the paper ribbon, very close to a face thereof. Said head is operated for reciprocally crossing the ribbon along its width, printing the dots which define the shapes outline.
• the ribbon is supported by a motor driven supporting and dragging roller, which is part of a complex, step driven paper dragging system, operated during the print head stops.
• a motor driven supporting and dragging roller which is part of a complex, step driven paper dragging system, operated during the print head stops.
• Each feeding step width is equal to the head printing width, and it is defined by an encoder, which detects the supporting roller rotation.
• the dragging system in addition to said dragging roller, usually comprises: a feeding free roller, fit to receive a web of paper or any other suitably medium wherein shapes can be traced, placed downstream of said dragging roller, with respect to the feed direction of the ribbon; a counter-rotating roller, parallel and in contact with the same, cooperating therewith for dragging the ribbon; a motor driven ribbon rewind roller, placed downstream of the aforesaid dragging roller and print head, fit to rewind the paper ribbon after the shapes have been traced.
• the above described plotters require that the ribbon tension during the dragging step is as constant as possible, in order to guarantee a correct and accurate shape tracing. Since the ribbon feeding step comes suddenly, the same ribbon is subject to fast accelerations, and its tension tends to lower, even because of the feeding web inertia. This can lead to variable ribbon feeding steps, as well as to some possible ribbon breaking.
• the known paper dragging systems in order to avoid the aforesaid drawbacks, are provided with a ribbon tension stabiliser, usually consisting of a "lung”, comprising a plurality of free rotating rollers, interposed between the feeding roller and the dragging roller, placed parallel thereof and at different heights, around which wraps the ribbon.
• At least one of the free rollers is vertically slidable along a guide made in the plotter frame. Said roller is fit to damp the stretch exerted on the ribbon by the dragging roller during the feeding steps, and to exert in turn a stretch on the ribbon during the stop periods, thus stabilising the ribbon tension.
• the ribbon tension stabilisers as the one above described are usually complex, expensive and not easy to use. Substituting the feeding web is normally very complex and requires a long execution time.
• a further object of the present invention is to propose a device for stabilising the ribbon tension, which moreover allows to simplify the feeding web substitution operations, and which is also reliable and easy to maintain.
• a tension stabilising device which consists of an oscillating tensioning roller, interposed between a feeding web of a continuous ribbon, and a roller for supporting and dragging said ribbon, said tensioning roller being supported by the upper face of said ribbon, being also hinged to a pair of oscillating arms, and being fit to exert on said ribbon a substantially constant force, against the dragging force exerted by said support and dragging roller.
• FIG. 1 shows a schematic, perspective view of a paper dragging system in a plotter for tracing of shapes for cloths, provided with a tension stabilising device according to the present invention
• FIG. 1 shows a schematic, cross sectional view of the dragging system of Figure 1.
• numeral 30 indicates a stabilising device for stabilising the tension of a paper ribbon, or other similar support medium, in an ink-jet, vertical plotter for tracing shapes for cloths.
• Said plotter is provided with a paper dragging system 1, fit to take a paper ribbon 2 from a web 3, and to route it as far as a printing head 4, of known type.
• a paper dragging system 1 fit to take a paper ribbon 2 from a web 3, and to route it as far as a printing head 4, of known type.
• Head 4 is reciprocally operated, and it is fit to trace on the ribbon 2, according to known techniques, shapes 6 for cloths cutting.
• the paper dragging system 1 comprises a feeding roller 10, a motor driven support and dragging roller 11, provided with a respective counter-rotating roller 12, and a rewind roller 13, all arranged upstream to downstream with respect of a feed direction W of the ribbon 2.
• Said rollers are horizontally placed inside the vertical plotter, according to known arrangements, which are designed for optimising the plotter size and the ribbon 2 path.
• the feeding roller 10 can freely rotate about its axis, and it carries the web 3.
• the supporting and dragging roller 11 supports and drags the ribbon 2, in cooperation with the counter-rotating roller 12, along the feed direction W, and routes it up to a printing position just underneath the head 4.
• the supporting and dragging roller 11 is step operated, in a phase relationship with the motion of the head 4. More precisely, it is operated during the head 4 stops, occurring during its motion reversals.
• the rewind roller 13, also motor driven and rotating in a phase relationship with the supporting and dragging roller 11, is approximately placed on the same vertical plane as this latter, underneath of it, and receives the ribbon 2 downstream of the head 4.
• the tension stabilising device 30 is interposed between the web 3 and the support and dragging roller 11; it consists of an oscillating tensioning means, supported by the upper face 2a of the ribbon 2. It is fit to apply a substantially constant force to the ribbon 2, against the dragging force applied by the supporting and dragging roller 11. Since its weight is applied to the ribbon 2, the tensioning means tends to form a bend in the portion thereof comprised between the web 3 and the supporting and dragging roller 11.
• the tension stabilising device 30 comprises a tensioning roller 33, placed on the upper face 2a of the ribbon 2 and parallel with respect to the dragging roller
• the tensioning roller 33 is coupled at its ends to respective ends 35a, 35b of a pair of swinging arms
• 34a, 34b are placed sideways and above the web 3, and they are hinged at their opposite ends 36a, 36b, which lay on the same vertical plane of the feeding roller 10.
• Arms 34a, 34b cooperate to keep the tensioning roller 33 parallel to the supporting and dragging roller 11, and to allow the tensioning roller 33 to move along an arc of the circle L whose radius is equal to the length of arms
• the tensioning roller 33 is preferably fixed to the arms 34a, 34b, but it can be advantageously made free to rotate about its axis, in order to help sliding the ribbon 2.
• the advantages of the present invention mainly consist of stabilising the ribbon 2 tension by means of a simple device, made with a single tensioning roller 33, and thus being extremely reliable and cheap.
• a further advantage is to obtain, together with a easy operating device, a great simplification in the plotter maintenance and in the web changing operations.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Treatment Of Fiber Materials (AREA)
• Handling Of Continuous Sheets Of Paper (AREA)
• Particle Formation And Scattering Control In Inkjet Printers (AREA)
• Recording Measured Values (AREA)
• Ink Jet (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=11341647

Family Applications (1)

Country Status (6)

Cited By (3)

Families Citing this family (2)

Citations (2)

Family Cites Families (2)

• 1996
  • 1996-10-15 IT IT96BO000514A patent/IT1286730B1/it active IP Right Grant
• 1997
  • 1997-10-14 EP EP97943088A patent/EP0944478B1/en not_active Expired - Lifetime
  • 1997-10-14 AU AU44695/97A patent/AU4469597A/en not_active Abandoned
  • 1997-10-14 AT AT97943088T patent/ATE213698T1/de active
  • 1997-10-14 WO PCT/IB1997/001278 patent/WO1998016394A1/en active IP Right Grant
  • 1997-10-14 DE DE69710770T patent/DE69710770T2/de not_active Expired - Fee Related

Patent Citations (2)

Non-Patent Citations (3)

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