GB1589266A - Printing machines - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO PRINTING MACHINES (71) We, BENNETT-DEAN DESIGN LIMI TED a British Company of Hill Street, Ashtonunder-Lyne, Lancashire OL7 0PZ, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement : This invention concerns printing machines, and in particular printing machines of the kind used to print multi-coloured patterns on paper and the like. In this specification the term 'patterns" should be understood to include letters, numbers and other indicia in addition to pictorial and illustrative printed designs.

Known machines for printing, for example, wallpaper, include a cylinder around which the paper to be printed is passed. Around part of the periphery of the cylinder and at spaced intervals are provided colour trays and printing rollers. In such a printing machine the trays contain colouring liquids (herein referred to as 'ink') and the printing rollers are engraved such that each roller will generally apply colour to only part of the total pattern to be produced. Thus, only after the paper passes the last roller will the pattern be complete. Such a process is generally referred to as surface printing. There are of course other kinds of printing process such as flexographic printing, that is, printing using an ink applying roller having a flexible surface, such roller being fed with ink by means of an etched (or analux) roller; and rotogravure (or intaglio) printing, that is, printing with an engraved roller which is wiped by a doctor blade to remove surplus ink. Generally printing machines are constructed to enable one known process to be carried out.

A machine of the sieveless type in which a contoured ink applying roller is fed with ink by a flexible surfaced roller itself fed by a grooved roller has been described in our application for Letters Patent No. 19268/75 (1526271) and it is primarily, though not exclusively, with this type of machine that the present invention is concerned.

Thus according to the present invention a printing machine comprises a cylinder, a plurality of printing units each comprising a colour applying roller and associated colour tray mounted in a frame, the frames being removably mounted or mountable on the machine and when mounted adapted to be movable relative to the machine frame whereby printing units for carrying out different types of printing process can selectively be mounted and rendered operative or inoperative on the machine as required.

The invention will now be described further, by way of example only, with reference to one practical form thereof and the accompanying drawing which illustrates part of a sieveless printing machine.

In a printing machine made in accordance with this invention there is provided a rotatable sheet material transport cylinder 10 mounted between end frames 11 part only of one of which is shown. Web guide rollers (not shown) are provided, in known manner to ;guide a web 12 to be printed onto and off the the cylinder 10. Generally the contact arc of the web 12 over the cylinder 10 will be of the order of 270 280 and a number, for example, eight, of printing ink applying rollers 13 are located at spaced intervals around the cylinder 10 within this arc. In the machine being described there would be four such printing rollers 13 at each side of the cylinder 10.

At positions corresponding to the printing stations the end frames 11 of the machine are provided with outwardly projecting rods 14, conveniently of circular cross-section, and these rods 14 serve as carriers for a printing unit (referred to below) comprising a set of rollers and an ink tray 15. Conveniently a removable end cap 14a of larger diameter than the rod 14 is provided on each rod 14 to ensure that even if the printing unit should have to be moved from a printing position, for example for servicing, it cannot inadvertently be pulled off the rods 14. When it is required to change one printing unit - for another the first step in the operation is, of course, to remove the end caps or stops 14a from the rods 14. The set of rollers, that is to say the actual printing roller 13 and a transferring roller 16, an ink take-up roller 1 6a and the tray 15 are themselves mounted in end frames 17 which are provided, at their upper extremities, with upwardly extending arms 18 adapted to receive the outwardly projecting rods 14 of the machine end frames 11. The group or rollers and ink tray 15, herein called a 'printing unit', can be located at any desired printing station by locating the end frames 17 on the requisite pair of rods 14.

When the printing units are correctly positioned relative to the cylinder 10 they are locked in position on the rods 14. One means for locating and locking the printing units in position includes a locating peg 18a projecting from each machine end frame 11 and having thereon a spacer collar 19. In addition, fixed to each machine end frame 11, adjacent the peg 18a is a pivot block 20 having pivotally mounted therein a clamp bolt 21 carrying a clamp nut 22. Mounted on each of the printing unit end frames 17 is a channeled clamp bolt receiving block 23 in the channel of which the bolt 21 is located with its clamp nut 22 at that side of the block 23 remote from the pivot block 20. The printing unit end frames can thus be clamped up by the nuts 22 until they are held against the spacer collars 19 of the pegs 18a.

The cylinder 10 carries, at each end, a drive gear. At one end of the machine the drive gear meshes with a drive pinion 25 adapted, via meshing pinions 26 and 27, to drive the ink take-up roller 16a. The ink take-up roller 16a is provided with a drive shaft 28 upon which the pinion 27 is mounted. A further drive pinion 29 on the shaft 28 meshes with a drive pinion (not shown) on the shaft 30 of the ink transferring roller 16 to drive this roller. The roller 13 is driven via a gear system (not shown) from the drive gear mounted on the cylinder at the other side of the machine.

The speed or rotation of the ink rollers 13, 16, 1 6a can be varied by the substitution of one set of drive pinions by another.

An advantage of the printing machine described above lies in the fact that, since the groups of rollers and colour (or ink) bath are assembled in their own frames 17 to form a sub-unit of the printing machine as a whole, a roller arrangement of, for example, the sieveless type referred to above may be substituted by a printing unit of the intaglio, letterpress, flexographic or any other type and thus a single basic printing machine can be used for carrying out any one of the various printing processes now carried out on machines specifically designed for a particular process.

It is also to be borne in mind that the mounting rods 14 of the machine frame 11 are of such a length as to allow for movement of the printing unit relative to the cylinder 10 so that accessibility to the rollers and other parts of the unit, for example for servicing, is facilitated. In addition, of course, simply by sliding a unit out of a printing position, without removing it completely from the rods 14 will render it inoperative and yet capable of being easily returned to an operative position when required. Thus a machine having the capability of having, for example, eight printing units around its cylinder can be used for printing any number of colours between one and eight. If the machine is required to print between one and four colours then the units at one side only of the cylinder will normally be used, and thus, even with the machine running, the units at the other side of the machine may be prepared for printing, when required. Down-time is thus minimised and the change over from one set of units to the other is achieved simply by moving the operative units into an inoperative position and locating the hitherto inoperative units in an operative position.

It will be appreciated that there has been described a printing machine which can be simply and relatively quickly be adapted to print, as desired, for example sieve less rotogravure or flexographic.

WHAT WE CLAIM IS: 1. A printing machine comprising a cylinder, a plurality of printing units each comprising a colour applying roller and associated colour tray mounted in a frame, the frames being removably mounted or mountable on the machine and when mounted adapted to be movable relative to the machine frame whereby printing units for carrying out different types of printing process can selectively be mounted and rendered operative or inoperative on the machine as required.

2. A printing machine as claimed in claim 1, in which each frame is adapted to be mounted at a selected one of a plurality of positions angularly spaced with respect to the cylinder.

3. A printing machine as claimed in claim 1 or claim 2, in which, for mounting each printing unit there is provided a pair of mounting rods extending from the printing machine frame, the printing unit frame having formations thereon adapted slidably to locate on the rods.

4. A printing machine as claimed in claim 3, in which the printing unit mounting rods are provided with removable end stops.

5. A printing machine as claimed in any one of claims 1 to 4, in which means are provided on the printing unit frames and the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. from the rods 14. The set of rollers, that is to say the actual printing roller 13 and a transferring roller 16, an ink take-up roller 1 6a and the tray 15 are themselves mounted in end frames 17 which are provided, at their upper extremities, with upwardly extending arms 18 adapted to receive the outwardly projecting rods 14 of the machine end frames 11. The group or rollers and ink tray 15, herein called a 'printing unit', can be located at any desired printing station by locating the end frames 17 on the requisite pair of rods 14. When the printing units are correctly positioned relative to the cylinder 10 they are locked in position on the rods 14. One means for locating and locking the printing units in position includes a locating peg 18a projecting from each machine end frame 11 and having thereon a spacer collar 19. In addition, fixed to each machine end frame 11, adjacent the peg 18a is a pivot block 20 having pivotally mounted therein a clamp bolt 21 carrying a clamp nut 22. Mounted on each of the printing unit end frames 17 is a channeled clamp bolt receiving block 23 in the channel of which the bolt 21 is located with its clamp nut 22 at that side of the block 23 remote from the pivot block 20. The printing unit end frames can thus be clamped up by the nuts 22 until they are held against the spacer collars 19 of the pegs 18a. The cylinder 10 carries, at each end, a drive gear. At one end of the machine the drive gear meshes with a drive pinion 25 adapted, via meshing pinions 26 and 27, to drive the ink take-up roller 16a. The ink take-up roller 16a is provided with a drive shaft 28 upon which the pinion 27 is mounted. A further drive pinion 29 on the shaft 28 meshes with a drive pinion (not shown) on the shaft 30 of the ink transferring roller 16 to drive this roller. The roller 13 is driven via a gear system (not shown) from the drive gear mounted on the cylinder at the other side of the machine. The speed or rotation of the ink rollers 13, 16, 1 6a can be varied by the substitution of one set of drive pinions by another. An advantage of the printing machine described above lies in the fact that, since the groups of rollers and colour (or ink) bath are assembled in their own frames 17 to form a sub-unit of the printing machine as a whole, a roller arrangement of, for example, the sieveless type referred to above may be substituted by a printing unit of the intaglio, letterpress, flexographic or any other type and thus a single basic printing machine can be used for carrying out any one of the various printing processes now carried out on machines specifically designed for a particular process. It is also to be borne in mind that the mounting rods 14 of the machine frame 11 are of such a length as to allow for movement of the printing unit relative to the cylinder 10 so that accessibility to the rollers and other parts of the unit, for example for servicing, is facilitated. In addition, of course, simply by sliding a unit out of a printing position, without removing it completely from the rods 14 will render it inoperative and yet capable of being easily returned to an operative position when required. Thus a machine having the capability of having, for example, eight printing units around its cylinder can be used for printing any number of colours between one and eight. If the machine is required to print between one and four colours then the units at one side only of the cylinder will normally be used, and thus, even with the machine running, the units at the other side of the machine may be prepared for printing, when required. Down-time is thus minimised and the change over from one set of units to the other is achieved simply by moving the operative units into an inoperative position and locating the hitherto inoperative units in an operative position. It will be appreciated that there has been described a printing machine which can be simply and relatively quickly be adapted to print, as desired, for example sieve less rotogravure or flexographic. WHAT WE CLAIM IS:

1. A printing machine comprising a cylinder, a plurality of printing units each comprising a colour applying roller and associated colour tray mounted in a frame, the frames being removably mounted or mountable on the machine and when mounted adapted to be movable relative to the machine frame whereby printing units for carrying out different types of printing process can selectively be mounted and rendered operative or inoperative on the machine as required.

2. A printing machine as claimed in claim 1, in which each frame is adapted to be mounted at a selected one of a plurality of positions angularly spaced with respect to the cylinder.

3. A printing machine as claimed in claim 1 or claim 2, in which, for mounting each printing unit there is provided a pair of mounting rods extending from the printing machine frame, the printing unit frame having formations thereon adapted slidably to locate on the rods.

4. A printing machine as claimed in claim 3, in which the printing unit mounting rods are provided with removable end stops.

5. A printing machine as claimed in any one of claims 1 to 4, in which means are provided on the printing unit frames and the

machine frame for locating and locking the printing units in an operative position.

6. A printing machine substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.