US2384843A - Printing - Google Patents

Description

Sept. 18, 1945. J LOWE 2,384,843

PRINTING Filed May 15, 1943 5 Sheets-Sheet 1 E D F 1 1 N vz/v TOI? JAMES Moo/e5 Lo WE ITTORNEY J. M. LOWE PRINTING Sept. 18, 1945.

Filed May 15, 1943 3 Sheets$heet 2 N VEN T01? Jew/5s- M0 025 Lowz flrraRA/EY J. M. LOWE Sept. 18, 1945.

PRINTING Filed May 15, 1943 3 Sheets-Sheet 3 VENTOR JAMES MOORE Lows NON Patented Sept. 18, 1945 UNITED STATES PATENT OFFICE PRINTING James Moore Lowe, Valleyfleld, Quebec, Canada Application May 15, 1943, Serial No. 487,167 In Canada March 25, 1943 Introduction This invention relates to a textile offset lithographing or printing method and apparatus.

The great difliculty in printing continuous webs of material from lithographic plates is that these plates are not continuous on the roller. They are thin metal strips, each end of which is attached to a, groove in the roller, thus leaving a gap on the circumference of the roller. Thus, if the roller were to be continuously run in contact with the work, a space would occur between each repeat of the pattern. In printing textiles, naturally, it is desirable to obtain long rolls of fabric with the pattern repeating continuously.

The present invention has for a main object the provision of means whereby a continuous series of repeats can be applied lithographically to a textile fabric, paper or other sheet material. A further object of the invention is to provide a method of this nature in which the fabric may be printed in a, number of different colours. Still further objects are to provide a relatively simple and economical method, an apparatus which is simple to construct and to operate, and a method and apparatus, which employs to a large extent existing lithographic printing mechanism.

These objects may be performed in a series of operations in which the repeat is printed with the fabric stationary, the fabric being moved forward for each repeat. Generally, the arrangement is such that printing rolls and a feeding device for the fabric are synchronized. A series of offset printing rolls, each for printing a different colour, are successively brought into contact with respective inking plates and then with the fabric. Means is provided for maintaining the synchrony of the rolls and for moving them in synchrony. Means is also provided for lifting the rolls clear of inking plates which it is not desired that they should touch and for the return run.

More specifically, according to a preferred embodiment of the invention the apparatus includes a flat bed and frame adapted to carry the entire mechanism, impression plates, a pair of parallel offset printing rollers, spaced apart and adapted to traverse the bed over which the fabric is adapted to pass into position for printing. In conjunction with the rollers, mounted on the bed frame, is a feeding and take-up mechanism for the fabric whereby the latter may be fed into position for the printing of successive repeats. The frame also includes a rack-rail running along each side, and adjacent to the rack-rail a shifting rail which can be raised or lowered for 9 Claims. (Cl. 101-135) purposes to be described. Adapted to run along the bed frame isa carriage connected to the main printing rollers which include peripheral toothed portions adapted to run along the rack-rail to rotate the rollers in synchrony, and smooth peripheral portions adapted to be engaged by the shifting rail to lift the rollers to inoperative level on the return run. The carriage also carries the usual dampening and inking arrangement. In conjunction with the fabric feeding device and the lifting rail are mechanisms operable by the movement of the carriage to initiate action of the fabric feeding mechanism, and also to trip the mechanism to move the shifting rail. Additional rails are provided on the bed for engaging the respective rollers on the positive run and for lifting them clear of the impression plates with which they are not designed to come into contact.

In the method carried out according to this arrangement the carriage is advanced from one end to the other on the positive run, the rollers coming into contact with their respective impression inking plates and being inked thereby and avoiding contact with the other inking plates. The rollers are then successively passed over the work to complete the printing of one repeat. When this has been accomplished, the

movement of the carriage trips the mechanism for lifting the rollers to clear the fabric and the inking plates on the return run, and also sets in motion the mechanism for advancing the fabric for the printing of another repeat.

Detailed description The invention will be more fully understood by reference to the accompanying drawings illustrating a particular preferred embodiment and in which:

Figure l is a schematic diagram showing the arrangement of the apparatus in general.

Figure 2 is a fragmentary perspective view showing the apparatus of Figure 1 on a larger scale, certain of the structure having been omitted for the sake of clarity.

Figure 3 is an enlarged fragmentary side elevation showing the fabric feeding mechanism in more detail.

Figure 4 is a further enlarged fragmentary side elevation of a portion of the mechanism shown in Figure 3.

Figure 5 is a side elevation of an alternative form of fabric feeding mechanism;

Figures 6 and 7 are fragmentary side views and end elevations, respectively, of the printing rollers.

General arrangement Bed frame mechanism The bed frame A supports a pair of elongated parallel side beams II running the length of the apparatus and cross beams I5. Each beam II carries a toothed rack I? also running the length of the apparatus. Alongside each beam II and mounted on the frame for slight reciprocal vertical movement is a rail 20. On the frame beneath each rail 2|! and in contacting relation thereto are mounted several cams 30, each connected to an actuating bar 35. The arrangement is such that when the bar is moved from left to right of Figure 2 the cams are rotated to exert upward pressure to raise the rail 20 and when the bar is moved to the right, the upward pressure is released, allowing the rail to gravitate into a lower position at which its top edge is substantially level with the top surface of the beam I I. Brackets 38 connect the bars 35 at one end of the machine with a lever all pinned to the beam II as at 4|. Movement of the lever to about the pin M will thus move the bar 35 in one direction or the other for the purposes to be described. At the other end of the machine, the bar 35 is connected by a bracket to a lever 35, pinned to the frame as at 35. There is a rail 26 and associated lever mechanism at each side of the frame A.

Mounted on each beam I I just inside the rack are upstanding fixed rails 50 and 5|, respectively. Each extends a portion of the length of the apparatus for the purpose of lifting particular printing rollers clear of impression plates, as will be explained.

Also mounted on the frame A are the impression plates CI, C2, and C3, usually made of metal, each of these plates adapted to be inked with a different colour and each to transmit this colour to one of the offset rollers. Each plate is adjustable in the bed by thumb screws 60 in a manner which will be familiar to one skilled in this art. Aso mounted on the frame A is a bearing plate 65 adapted to support the fabric in position for printing. On each side of the plate 65 having parallel axes and adapted for carrying the fabric into position over the plate 65 in a manner to :be described are rollers 66 and 61.

Carriage mechanism The carriage D includes a frame work having longitudinally extending beams and cross beams '73. On extensions of each end of the beams III are handles I5 for moving the carriage. For these may be substituted a mechanism for moving the carriage mechanically.

Extending from side to side of the carriage D and journalled in suitable bearings are the printing rollers El, E2, and E3, each equipped with conventional ofiset blankets of rubber or other suitable material, held in place in a conventional manner. The bearings on which the rollers EI and E3 are mounted are arranged for adjustment longitudinally of the frame so as to enable adjustment of the spacing between the offset rollers and thus to arrange for a register of the different colours. Each roller E is provided at both ends with an annular-toothed portion 9|, 92 and 93 respectively, adapted at all times to engage the rack II. Each roller E is also equipped adjacent both ends with grooves adapting the rollers to remain at bed level or to be lifted by the rails 50 and 5|. The roller E3 includes a groove I03 extending the width of both the rails 50 and SI and thus allowing the roller to be unaffected by the latter, since this roller always remains at bed level, on the positive run of the carriage, that is, towards the right of the figure. The roller E2 includes a narrower groove I02 adapted only to clear the rail 5| so that in the positive run of the carriage the roller E2 comes into contact with its printing bed, but is then lifted by the rail 50 so that it clears the bed C3. The roller EI has no annular groove 50 that this roller is, on the positive run of the carriage, lifted clear of .both beds C2 and C3 by the rails 50 and SI. In brief, the structure of the rollers E, and the positioning of the rails 50 and SI adapts these rails to lift the rollers selectively, to clear the impression beds C which they are not designed to contact.

The rollers-also include annular running surfaces BI, 82 and 83 adapted for contact with the shifting rail 20 when the latter is in its upper postiion, in which position, on the return run of the carriage, it lifts the rollers clear of all the beds. The carriage also includes the series of inking rollers F (which are shown schematically in Figure 1), as will be well understood by one skilled in the art. For the sake of clarity the inking arrangement has been omitted from Figure 2. The carriage may also, as illustrated, include small auxiliary rollers as well as the offset rollers to assist in supporting its weight, these rollers running on the bed frame.

Feeding mechanism Used in conjunction with the feeding rollers in one form of feeding mechanism are feed and take-up drums H0 and II2 respectively, about which the fabric is adapted to travel to and from the rollers 66 and 57. These drums are mounted on parallel axes, their rotation being synchronized by a belt III, passing about respective pulleys H5, H5. To the axis of the drum H5 is connected a toothed driving wheel I20 which is fitted with a fine rachet I23 to prevent backslip. The wheel I20 meshes with a worm I36 on a connecting shaft I32. On the other end of the shaft I32 is a worm I 35 held in suitable bearings (not shown). With the worm I35 meshes a gearwheel I31. A belt I36 passes about another portion of the wheel I31 and also about pulleys I38 and I39 having axes in triangular relationship as indicated. The pulley I38 is mounted on a bearing block Hill which is slidably mounted, for movement longitudinally of the bed A, on a slide M2. A worm screw I43 operated by a handle I 44 acts on the block I40 for moving it to right or left of the figure in the bracket, thus serving to position the pulley I38. The pulley I39 is mounted on vertically adjustable bearings I50 and is normally urged towards its downward position by a strong compression spring I52, thus constantly exerting tension on the belt I36. The belt I36 is provided with a serrated surface, which is adapted to be engaged by a peg I6" mounted on the carriage D. That is to say, the belt carries upstanding spaced apart projections engageable by a member projecting from the carriage. In this way. movement of the carriage from left to right of the bed causes predetermined clockwise travel of the belt I38 and thus rotation of the pulley I81 and eventually of the drum II8, thereby pulling the cloth forward to the extent of movement of the belt.

Operation Positive run The operation starts with the carriage D at the extreme left-hand end of the frame A when the fabric is in position for printing the first repeat. The carriage i moved on the positive run (from left to right of the bed as viewed in the figure). Simultaneously the inking rollers associated with the respective offset rollers E, respectively run over the plates C3, C2 and Cl respectively, thus inking these plates. Then the offset rollers E run over the plates C, respectively receiving an impression therefrom. Th offset rollers E are rotated as the carriage moves, by the engagement of their respective toothed portions SI, 92 and 93 with the rack ll. Then the offset roller E3 runs over the fabric in place on the support 68, applying its impression thereto. At the same time, the rollers E2 and El, and respective inking mechanisms are lifted clear of the plates C3 and C2 'by the rails 58 and El as has been described. Immediately the rolls have passed over these rails, however, they are allowed to descend to bed-level and first the roller E2 and then the roller El contacts the fabric and passes its impression thereto. Thus three separate colours are applied in register to the fabric.

Return run When all three rollers have passed the work and the carriage reaches the end of its positive run it comes into contact with the end of the frame and moves the levers 45. This immediately moves the 'bars 35 from right to left and raises the rail 28 to its upper position. In this position, the rail contacts the running surfaces 8I, 82 and 83, respectively, thus lifting all the rollers E into inoperative position so that they will clear the fabric and the printing beds on the return run of the carriage. The carriage is then moved from right to left of the bed in its return run clearing the fabric and the printing beds and it eventually reaches the extreme left-hand end of the .bed frame A, where its contacts the lever 48, which moves the bars 35 from left to right of the frame, allowing the rail 28 to return to its lower level and permitting all the, rollers to return to contact level. At all times the toothed portions 88 engage he rack I1, thus rotating the rollers E in synchrony.

Fabric-feeding ward, the distance of one repeat between eachrun of the carriage. On the return run, the carriage is lifted sufllciently that thepeg I88 clears the belt I38. The fabric is then in position for a further printing cycle as described above.

Alternatively, the fabric may be fed in other ways,- for instance by the mechanism shown in Figure 5 as follows. As the carriage D passes from left to right of the bed near the end of the printing operation a Dec 288 engages a switch lever 2I8 making electrical contact with a switch 282, (switch not shown). This starts an electric motor I89. The motor rotates a shaft I88 on which is mounted a gear I8! ngaging a toothedwheel I88 mounted on the shaft I83. Rotation of this wheel rotates the pulley I92, thus raising the block I94 until it contacts a lever I88. Upward movement of the block I84 allows a corresponding movement of the wire I88 from which it its suspended, which in turn allows a registration control block I8I to pass back to starting position where it contacts a terminal I83. This also permits counter-revolution of the ratchet gear wheel II8 to starting position by the urge of a weight I12 operating by gravity from its suspension on a wire I18 over the pulley I1 I.

When the block I84 has reached the upper limit of its travel it raises the lever I88 which operates an electrical cut-off switch. at I81, stopping the motor I89. This releases the block I84, which, being considerably heavier than the counterbalancing weight I12, immediately falls to the lower limit of its travel. The distance of this travel is controlled by the position of the variable stop I84 adjustable manually to various positions along the rails I82. This controls the distance of travel of the block I8I. The distance between the blocks I83 and I84 is th distance through which the block I8| moves. The cloth is moved a relative amount in each cycle of operation.

As the block I94 falls it operates by means of the wires I88 and I88 and through the rachetgeared wheel I88. The cloth-carrying drum II8 causes a definitely predetermined length of cloth to be moved over the printing bed 85 at each cycle of operation. The cloth-carrying drum is geared to the other cloth-carrying drum II! by a shaft and bevel gearing (not shown in the drawings).

As the block I8I reaches the limit of its movement it rests against the inner face of the block I84 until the commencement of the next cycle of operation. It is held tightly in position by the gravitational pull of the block I84. This pull also holds the cloth steadily in position on the printing bed, preventing its movement during the printing operation.

This cycle of cloth-moving operations cannot be repeated until the electrical switch at 282 is reset by the resetting switch 285. The switch at 285 (switch not shown) is actuated by the carriage D on its trip back to the starting end of the machine, the peg 288 contacting and deflecting the switch lever 284, Each lever 2I8 and 284 is, after having performed its fnuction, brought back into operative position by means of weights 2 and 2I2, respectively, attached to its lower end.

Advantages This method and apparatus has several advantages. In the first place, the printing of a continuous textile web in several colours can be accomplished lithographically. The method and apparttus is simple and convenient. A flat bed press can be equipped according to the invention to do continuous printing. The work accomplished is accurate and comparable with that pro duced by a roll printing press. Other advantages will become apparent to those skilled in the art.

It will be understood that, without departing from the spirit of the invention or the scope of the claims, various modifications may be made in the specific expedients described. The latter are illustrative only and not offered in a restricting sense, it being desired that only such limitations shall be placed thereon as may be required by the state of the prior art.

The sub-titles used throughout the specification are merely to simplify reference thereto and should otherwise be disregarded.

I claim:

1. A method of lithographically printing a fabric web in a number of different colours, com-. prising the steps of, applying to -several non-continuous offset printing rollers aligned in a substantially horizontal plane respective impressions to appear register in a pattern, positioning a portion of a fabric web in a horizontal plane parallel to the direction of travel of said rollers, causing relative movement between said rollers and said web whereby said impressions are transferred thereto in register to print a repeat, moving said web forward to a position for printing another repeat, and again passing said rollers over the web to apply a further such repeat thereto in register with the first repeat, and soon whereby the web has applied to it a plurality of registering repeats.

2. A lithographic printing mechanism, comprising in combination, an elongated printing bed, several impression plates carried by said bed, a fiat support carried by said bed for positioning a web of fabric for printing, said plates and said support being in a substantially horizontal plane, a carriage adapted to move across said bed over said plates, several printing rollers carried by said carriage and held thereby in fixed spaced apart relationship, each roller adapted to receive an impression from one of said plates, fabric feeding means associated with said fabric positioning means adapted to feed a web of fabric into position for printing, a rack on said bed and an annular toothed portion on each of said rollers adapted always to engage said rack whereby the rollers are rotated in synchrony when the carriage is moved relatively to the bed, an annular track on each roller and horizontal tracks on said bed causing each roller on the positive run of the carriage to contact its respective impression plate and to clear the other impression plates, shift means operable by the movement of said carriage causing said rollers on the return run to be lifted clear of said fabric positioning means engageable by the carriage and all said impression beds, means operable by the movement thereof to cause said feeding means to move the fabric forward to a predetermined extent between each positive run of the carriage.

3. A lithographic printing mechanism for fabric webs, comprising in combination, a bed, a plurality of impression plates mounted in series on said bed, a carriage adapted to reciprocate across said bed frame in positive and return runs, a plurality of non-continuous lithographic printing rollers connected to said carriage and adapted on the positive run of the carriage to transfer respectively different colours from the impression plates to the fabric, a fabric web support mounted in horizontal alignment with said plates,

ass-seas fabric web feeding means associated with said support. means associated with said impression plates for lifting said printing rollers out of operative position as it passes over the plates corresponding to the other rollers on the positive run, a track on the bed and an annular geared portion on each roller for synchronizing the rotation of said rollers during all movements of the carriage, shift means for lifting all said printing rollers out of operative position on the return run of the carriage, means associated with said feeding means for operation by the movement of said carriage whereby the fabric web is moved forward one repeat on each movement of the carriage across the frame, means operable by the movement of said carriage for moving said shift means i into lifting position on each positive run of the carriage, and means operable by the return movement of the carriage for moving said shift means into inoperative position.

4. A printing mechanism, comprising in combination, a bed frame, a plurality of impression beds mounted on said frame, each adapted to receive a different colour, a flat fabric support mounted on said frame to support a run of the fabric substantially parallel to said beds, a carriage, a plurality of non-continuous lithographic printing rollers mounted on said carriage and each adapt ed to receive an impression from one of said beds and to tranmit it to the fabric, a rack on said frame and a geared portion on each roller for engagement therewith whereby the rollers are rotated in synchrony on movement of said carriage, a track mounted on said frame for limited vertical movement, said track running substantlally the length of the frame and being adapted in operative position to engage a portion of each roller and thus to raise it from printing position, means for lifting said track, said track-lifting means being operable by movement of said carriage to move the track into operative and inoperative positions, means for feeding fabric into position on said support repeat by repeat, said feeding means being operable by movement of said carriage whereby the fabric is fed forward one repeat with each reciprocation of the carriage across the bed before the rollers come into printing contact therewith.

5. In a printing apparatus including a, bed, a flat support for a portion of a web of fabric to be printed mounted on said bed, a plurality of impression plates for respectively different colours mounted on said bed in alignment with said fabric support, a plurality of non-continuous rollers adapted to pass across said plates and across the fabric and to return out of contact therewith and a frame connecting said rollers and moving therewith, feeding mechanism, a feed drum and a take-up drum for the fabric, a belt extending about pulleys and having a portion of its length parallel with the bed, belt engaging means on said carriage for engaging said belt whereby it is moved forward a predetermined distance for each run of the carriage, means for transmitting the movement of said belt to said take-up drum whereby the fabric is moved forward for each movement of the belt, and means for causing said belt engaging means to clear the belt on each return run of the carriage.

6. A printing apparatus including a support for a web of fabric to be printed, a plurality of impression plates adapted to be inked with respectively different colours, a plurality of noncontinuous offset printing rolls each adapted to receive an impression from one of said plates.

operating means for moving said rollers across said plates and acros the portion of fabric in printing position and to return said rolls out of contact with the fabric and plates comprising, feeding means for the fabric web, an actuating member connected to said feeding means, said actuating member being advanced by the movement of said rolls whereby the feeding means is moved with each complete movement of said rolls to advance the web one repeat.

7. A lithographic printing apparatus including a fiat support for a fabric web to be printed, a plurality of impression plates mounted in the same plane as the web support and adapted to receive respectively different colours, a plurality of offset printing rollers each adapted to receive an impression from one of said plates, means for moving said printing rollers selectively into contact with said plates and with said fabric, comprising, feeding means for moving said fabric forward, a runner connected to said feeding means and adapted for moving a distance equivalent to a repeat of said pattern and returning to starting position, actuating means connected to said runner for advancing it by one repeat, means engageable by the carriage for advancing said runner, means engageable by the carriage for returning said runner to starting position, and so on.

8. A lithographic printing apparatus including a flat support for a fabric web to be printed, a plurality of impression plates in alignment with said support and adapted to receive respectively different colours, a plurality of non-continuous offset printing rollers, each adapted to receive an impression from one of said plates, means for moving said printing rollers selectively into contact with said plates and with said fabric, comprising, feeding means for moving said fabric forward, a runner connected to said feeding means, fabric-advancing means urging said runner in one direction, setting means urging the runner in the other direction, and means actuated by the movement of said printing rollers to control the action of said advancing means and said setting means whereby said runner is moved through an advancing stroke and returned to starting position during each run of the carriage.

9. A lithographic printing mechanism, comprising in combination, a frame, several impression plates, means for positioning in substantially the same'plane to said plates a web of fabric for printing, several non-continuous printing rolls each adapted to receive an impression from one of said plates and to transfer it to said web, fabric feeding means adapted to feed said web into position on said fabric positioning means for printing repeat-by-repeat, means connecting said rollers whereby they are maintained in accurately spaced-apart relationship, said frame including a rack, each of said rollers including an annular toothed portion engageable with said rack whereby the rollers are rotated in synchrony by relative movement between the rollers and the frame, the rollers being so related to the printing plates and web that relative movement therebetween on a positive run causes each roller to pick up an impression from its respective impression plate and to transfer said impression from said plate to said web, a track on said frame cooperating with an annular portion of each roller causing said roller to avoid contact with the impression plates of the other rollers, feeding means actuated by the movement between the rollers and the frame whereby the fabric is advanced a repeat after each repeat is printed and a member which in operative position increases the space between the rollers and the frame whereby the rollers clear the web and impression plates, and means operated by the relative movement between the rollers and the frame to move said member into operative position after a repeat ha been printed and to move it into inoperative position prior to the printing of the next repeat.

JAMES M. LOWE.

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