US 4,792,249 A · Vacuum paper transport system for printer

Abstract

A controlled paper transport arrangement utilizes a flexible belt which attracts the paper to its surface by the application of a reduced air pressure on the other side. In a preferred embodiment, the belt operates in a continuous loop and in combination with a vacuum feed roller, the belt and the vacuum feed roller being arranged on respective sides of a print strike bar. The presence of the paper against the flexible belt causes trip valves to change state such that the full force of the air pressure differential between the ambient air and the reduced air pressure, on either side of the flexible belt, is applied only in the vicinity of the paper to be printed. In some embodiments, the vacuum feed roller is sectored so that the reduced air pressure is applied only in the region which communicates with the paper to be printed. The flexible belt and its associated assembly is tiltable about its vacuum supply inlet for achieving compact storage and for delivering printed sheets to a storage bin. In operation, the flexible belt and the vacuum roller can be driven in reverse to allow reprinting.

Drawings

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Drawings

Claims40

Dependent claims

A paper transport arrangement for a printer, the paper transport arrangement being of the type wherein a sheet of paper is received from a supply and transported across a predetermined print zone where printing may occur, the paper transport arrangement comprising:

vacuum roller means for grasping the sheet of paper and transporting the sheet of paper across the predetermined print zone, said vacuum roller means having an axis of rotation and a plurality of apertures on a surface thereof, said vacuum roller means adapted to be coupled to a supply of reduced air pressure thereby to provide a reduced air pressure at said apertures which attracts and holds the sheet of paper;
flexible vacuum conveyor means arranged to transport the paper in a direction which is essentially orthogonal to said axis of rotation of said vacuum roller means, said flexible vacuum conveyor means adapted to be coupled to the supply of reduced air pressure and having a plurality of apertures on a surface thereof thereby to provide a reduced air pressure at said apertures which attracts the sheet of paper, said vacuum conveyor means being arranged on the other side of the predetermined print zone from said vacuum roller means;
printing support means for supporting the sheet of paper during printing arranged in said predetermined print zone;
and
vacuum chamber means arranged in the vicinity of said predetermined print zone and intermediate of said vacuum roller means and said flexible vacuum conveyor means, said vacuum chamber means adapted to be coupled to the supply of reduced air pressure and having a plurality of apertures on a surface thereof thereby to provide a reduced air pressure at said apertures which holds the sheet of paper in the vicinity of said predetermined print zone;
said flexible vacuum conveyor means further comprising a plurality of flexible cells arranged in a predetermined array configuration, said flexible cells being adapted to receive said reduced air pressure, each of said flexible cells being at least partially isolated pneumatically from others of said flexible cells, said flexible vacuum conveyor means comprising a base means having a closed loop configuration so as to form a belt, and further being adapted to hold said flexible cells in said predetermined array configuration, said flexible cells on said flexible conveyor base means being provided with respectively associated valve means for adjusting a pneumatic impedance through which said reduced air pressure is conducted to said apertures on said surface of said flexible vacuum conveyor means in response to the presence of the sheet of paper adjacent to said valve means, the presence of a sheet of paper reducing said pneumatic impedance to permit increased communication between said apertures and said reduced air pressure;
said vacuum chamber means being in vacuum communication with said vacuum roller means, and there further being provided first seal means on said vacuum chamber means for forming a seal which substantially prevents air leakage at said surface of said vacuum roller means.

4 more elements

In a printer, a paper feed and transport system for positioning paper for printing, the paper feed and transport system comprising:

strike bar means for providing a backing against which impact printing is performed and having a longitudinal axis;
roller means for transporting said paper from a paper supply location across said strike bar means, said paper being moved in a direction which is transverse to said longitudinal axis of said strike bar means;
flexible conveyor means for transporting said paper beyond said strike bar means, said flexible conveyor means being arranged in the vicinity of said strike bar means;
said roller means comprising a vacuum roller having a plurality of apertures distributed thereover, said vacuum roller further having sectoring means therein for applying a suction force corresponding to a low air pressure through said apertures only over a selectable axial segment of said vacuum roller;
said flexible conveyor means being arranged as a continuous loop having a plurality of selective valve means disposed thereon whereby a suction force of a predetermined magnitude is provided only through ones of said selective valve means which are covered by the paper, remaining ones of said selective valve means each providing a suction force having a lower magnitude than said predetermined magnitude, said valve means being provided in a predetermined array configuration on said continuous loop;
there being further provided tilt means for said flexible conveyor means for tilting said flexible conveyor means in a preselected direction and for depositing said paper at a preselected stacking location, said tilt means comprising first and second pivot couplings displaced from one another by a predetermined distance, said flexible conveyor means being pivotally movable about said first and second pivot couplings, and pivot coupling lock means for locking one of said first and second pivot couplings to limit pivotal motion thereabout by said flexible conveyor means.

3 more elements

A flexible conveyor for transporting sheet material, the flexible conveyor having a belt-like base member which is arranged to be movable about first and second rotatable rollers, the flexible conveyor further being of the type which utilizes a suction force to hold the sheet material to an outer surface of the flexible conveyor, the flexible conveyor further comprising vacuum control means for controlling the application of the suction force to the surface of the flexible conveyor, the suction force being controlled to have a first magnitude over a first portion of the surface of the flexible conveyor, and a second magnitude over a second portion of the surface of the flexible conveyor, said second portion being substantially coextensive with the sheet material, said flexible conveyor being provided with a plurality of apertures on the outer surface thereof through which the suction force is applied to the sheet material, said vacuum control means further comprising a plurality of cell means disposed in a predetermined array in said flexible conveyor, each associated with at least one of said apertures on the outer surface of the flexible conveyor, and valve means disposed in said flexible conveyor for controlling the suction force applied to said apertures associated with respective ones of said cell means in response to whether the sheet material is arranged over at least a portion of said cell means, the cell means being arranged to form a plurality of columns of said cell means, said columns of said cell means being substantially parallel with respect to each other and to a direction of motion of the belt-like base member, there being further provided a plurality of divider means for producing a plurality of vacuum plenums which are pneumatically substantially isolated from each other extending in the direction of motion of the belt-like base member, said divider means being arranged so that respective ends thereof sealably contact the first and second rotatable rollers and are separated from one another by a distance which accommodates a column of said cell means, said column of said cell means being movable in the direction of motion of the belt-like base member with respect to said divider means.

A paper handling apparatus for a printer comprising:

a vacuum conveyor having at least a flexible belt portion with a plurality of apertures in an exterior surface thereof;
a vacuum source connected with the interior of said vacuum conveyor to draw a vacuum through said apertures whereby a paper to be printed is firmly held on said exterior surface of said vacuum conveyor;
vacuum feed roller means for engaging said paper to be printed and for moving said paper to a print zone;
vacuum print bar means for holding said paper securely in the vicinity of said print zone disposed between said vacuum feed roller means and said vacuum conveyor;
a plurality of sensing means disposed in said vacuum conveyor for sensing the presence of said paper in the vicinity of a predetermined portion of the exterior surface of said vacuum conveyor;
and
a plurality of pilot valve means responsive to said sensing means for controlling the vacuum drawn through the apertures in said predetermined portion of said exterior surface of said vacuum conveyor, said valve means being disposed in said flexible belt portion of said vacuum conveyor,
said vacuum print bar means being disposed in a vacuum chamber, said vacuum chamber being in vacuum communication with said vacuum feed roller means, and there further being provided first seal means on said vacuum chamber for forming a seal which substantially prevents air leakage at the surface of said vacuum feed roller means.

5 more elements

Dependencies are inferred from the claim text.

Description14,071 words

Summary3,711 words

#This disclosure is related to, and incorporates by reference, the following applications filed concurrently herewith:

#Rotary Printer With Off-Carriage Motor Drive, Ser. No. 570,737, now abandoned and refiled on 11/27/85 as Ser. No. 802,620, now abandoned.

#Shift System for Multi-Row Print Element Ser. No. 570,739, now abandoned.

Brief description of the drawings15 figures

#Comprehension of the invention is facilitated by reading the following detailed description in conjunction with the annexed drawings, in which:

#FIG. 1 is an isometric view of the exterior of a printer arrangement constructed in accordance with the invention showing the flexible conveyor in an upward position;

#FIG. 2 is a cross-sectional side view of the embodiment of FIG. 1 showing the flexible conveyor in a storage position;

Detailed description9,999 words

#FIG. 1 shows a serial printer which is generally designated 10 and has a tiltable housing 20 containing a vacuum platen 21 at the front and three sheet bins 22A, 22B, and 22C at the rear. Printer 10 is provided with an upper surface which bears two paper rails 26. Vacuum conveyor 21 can be pivoted forward from tiltable housing 20 so as to be substantially parallel with the uppermost surface of printer case 27. From this position, vacuum conveyor 21 discharges a finished printed page previously held thereto onto the space between paper rails 26. This space on printer case 27 and between paper rails 26 thus forms a storage receptacle for finished printed copy, popularly known as an "out basket."

#At the front of printer case 27 is provided a paper gage 28 which may operate as a commercially available digital micrometer. When a sheet of paper 31, or an envelope, which is intended for storage in sheet bins 22 is inserted into paper gage jaws 28, the thickness of paper 31 is determined. Each of sheet bins 22A, 22B, and 22C may be provided with a paper stack caliper, not shown in this drawing, which determines the thickness of the total stack of paper. The information pertaining to the thickness of the paper and the total thickness of the stack enables determination of the available paper supply. Additionally, the paper thickness information may be used to adjust correspondingly a vacuum suction force.

#FIG. 2 is a cross-sectional side view from the right side of printer 10, showing vacuum conveyor 21, paper bins 22A, 22B, and 22C, and housing 20 in a forward-pivoted position. As shown, tiltable housing 20 is radially displaced in a forward direction so that the front surface of tiltable housing 20 lies atop the upper face of printer case 27. This position is particularly adapted for storage of the printer. When tiltable housing 20 is in this storage position, a rear paper ledge 40 is tilted to lie flat over the upper surface of printer case 27, so as not to prevent vacuum platen 21 from lying on printer case 27 during storage.

Vacuum paper transport system for printer

Life of this patent

Vacuum paper transport system for printer

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims40

Description14,071 words

Drawings

Classification6 codes

Life of this patent

Description14,071 words