US2054152A - Printing mechanism - Google Patents

Description

0. F. WOOD PRINTING MECHANISM Sept. 15, 1936.

Filed March 3, 1931 2 Sheets-Sheet l INVEN TOR. 0775 rT/Vaaa 9 ATTORNEY Sept. 15, 1936. 01F. woon PRINTING MECHANISM Filed March 3, 1931 2 Sheets-Sheet 2 'INVENTOR. flr/a 'f'l l qaa Patented Sept. 15, 1936 UNITED STATES PATENT OFFICE PRINTING MECHANISM Otis F. Wood, New Brighton, N. Y.

Application March 3, 1931, Serial No. 519,710 9 Claims. (01. 101-122) pressed against the fabric the latter picks up the ink out of the depressions. Usually, the printing cylinder is of copper and it must be ground and finished to a very smooth and true surface with no flaws or scratches to catch the ink and produce false lines and areas in the printed design. The cost of these cylinders and of preparing them for printing is high, particularly in cases where a large design is to be printed, because the circumference of the cylinder must be equal to the length of the design.

It is an object of my invention to dispense with the. etched copper cylinders and replace them with printing elements of extremely low cost. Instead of an etched cylinder, I use an endless flexible band with openings therein forming the design. The band is then pressed against the web that is to be printed and a roller forces ink, dye or other printing fluid through the openings inthe band and upon the web.

My invention is thus a development of and improvement on what is known in the art as "screen printing. Heretofore this type of printing has had to be done by hand. The printing element consists of a strip of silk bolting cloth which is prepared for printing by masking out the parts that are not to be printed with shellac, lacquer or the like. The strip is then laid on and clamped to the fabric that is to be printed and liquid coloring matter is deposited on the strip. After which the operator uses'a squeegee to force the coloring matter through the unmasked parts of the strip to print the fabric. This process must be repeated for consecutive sections of the fabric, care being taken to match up the' designs at the junctions of such sections. My invention calls for the use of endless bands in place of the short strips so that the pattern is repeated throughout the length of the web that is being printed, without showing any joints and without requiring any skilled matching at the junctions of the repeats.

My invention also includes automatic means for feeding the printing band with the web, and for forcing ink or other printing fluid through the band.

While my invention contemplates the use of endless bands of bolting cloth or other textile 5 fabric for the printing element, I prefer in many instances to use a metallic printing band so as to prevent stretching. This is of prime impor tance in multi-color printing where each impression must register perfectly with the rest of the 10 than a line bearing, of the printing band against 20 the impression cylinder, so as to confine the printing fluid to the design and prevent spread of the fluid under the band at the margins of the design, as would occur if the band were tangent to the web.

However, my invention has for a further object to provide a mounting for the band and its inking system such that the band may be adjusted toward or from the impression cylinder to vary the depth or heaviness of the impression made 30 on the web. Thus the band may be withdrawn to" such an extent as to provide substantially a line contact with the web. In such case, undue spread of the printing fluid may be prevented by using a fluid of increased viscosity. 35

Other objects and advantages of the invention will appear in the following description of 'a preferred embodiment and thereafter the novelty and scope of the invention will be pointed out in the claims.

In the accompanying drawings;

Figure 1 is a fragmental view mainly in section of a two-color printing machine embodying my invention, the section being taken substantially on the line of Fig. 3; 1

Fig. 2 is a side elevation of a portion of the printing machine and looking in the same direction as in Fig. 1;

Fig. 3 is a view in transverse section taken on the line 3-4 of Fig. 1;

Fig. 4 is a detail view showing a section taken on the line 44 of Fig. 3;

Fig. 5 is a fragmental view in perspective of a printing belt; 3

r a transverse shaft I. Mounted upon and secured to this shaft is an impression cylinder |2. The shaft II is provided with a pulley l3, at one end which is driven by a belt (not shown) from apulley 4 over head. An endless blanket I5 of rubber or other suitable material passes about the impression cylinder i2 and is guided to and from said cylinder by rolls I6 and H. A blotter strip i8 passes around the impression cylinder l2 over the blanket 5, being guided over rolls l3 and a fixed guide 20. The web 2|, which is to be printed, -passes about the impression cylinder |2 over the strip |3,.being led into the machine over a roller 22 and fixed guide 23.

Each frame member i is provided at the right hand side, as viewed in Fig. 1, with a slideway 25 in which slides a carriage 23. The carriages provide bearings for a printing cylinder 21 which is adapted to bear against the web 2|. This cylinder is etched or engraved with the design that is to be printed on the web and is inked in the usual well known manner. However, the inking mechanism is not shownin the drawings. The mechanism so far described follows the standard practice in machines of this character.

The frame members iii are provided with arms 30 and 3| respectively, which project toward the left, as viewed in Figs. 1 and 2. The arm 30 is provided with ways 32 for a slide block 33. Hinged upon the slide block at 34 is a carriage 35 in which is supported my improved printing band. This carriage comprisesa U-shaped frame 36 which at its free end is formed with alug 31 adapted, when the parts are in printing position, to engage a hook 38 formed on the arm 3|.

The frame 36 provides bearings for two shafts 40 and at its forward end and a shaft 42 at the rear end. Mounted on and fixed to these shafts are rolls 43, 44 and 45 respectively. Sleeved upon these rolls is an endless printing band 41. The shaft 42 is adjustable in slots 36a formed in the frame 36, so as to vary the tension of the band 41. Each end of the shaft engages a screw eye 39 which has sliding engagement with a lug 36b formed on the frame 36. Nuts 33a on the screw eyes and bearing against opposite sides of the lugs serve to hold the shaft 42, at any desired adjustment. The latter is formed with openings therein through which the design is printed upon the web 2|. Also carried by the frame 35 is a pan 43 for printing fluid. The fluid used depends upon the nature of the material to be printed. In the case of fabrics, it is more in the naturebf a dye, whereas if paper is being printed it may be more like printers ink although not so heavy and viscous. For convenience, the fluid will hereinafter be termed ink although the term will be understood to apply to any. printing fluid. In the pan 48 is mounted a fountain roll 43. An inking roll 50 picks up ink from the fountain roll 49 and presses it through the openings in the printingband and uponthe web 2|. A doctor blade serves to limit the thickness of the fluid film picked up by the roll 50. The

ink pan 48 is removably mounted in the frame 38 and may be withdrawn therefrom when desired. I

Since the carriage 35 is hinged to the slide block 33 it may be moved toward and from the impression cylinder or platen I 2. The purpose of this is to permit of replacing the printing band with another band. When this is to be done the carriage is withdrawn to the position shown in Fig. 2; the ink pan is detached from the frame 36 and removed; the screw eyes 39 are adjusted to slacken the tension in the printing band; the carriage is swung up on its hinge 34 to clear the arm 3|; and the band 41 is slipped off the rolls 43, 44 and 45, in axial direction. Another band may now be sleeved upon said rolls and after which carriage is dropped to normal horizontal position with the lug 31 resting on the arm 3|, and the nuts 39a are adjusted to give the band the desired tension. If a different color of ink is to be used the inking rolls are also replaced and a. fresh ink pan is secured to the carriage. The carriage then is moved forward to printing position with the band 41 bearing against the web 2|. The ease with which the printing bands may be replaced is an important feature of my invention.

Slidable in the ways 32 with the slide block 33 is another block 53. The latter provides a bearing for an adjusting screw 54 which is threaded into a lug 55 carried by the slide block 33.. A threaded shank 56 depends from the block 53, passing through a slot 51 formed in the arm 30. Screwed upon this shank and bearing against the underface of the arm 30 is a clamping nut 53. When the carriage 35 is moved toward or from the impression cylinder l2, the block 53 will slide therewith because of its conmotion by screw 54 to the block 33. When the carriage has been moved forward to approximately the desired position, the nut 58 is turned to clamp the block 53 in fixed position on the arm 30 and thereafter the screw 54 is turned to adjust the pressure of the band" against the web 2|. The object of varying the pressure is explained hereinafter. v

Secured upon the shaft ii is a gear wheel 60 the carriage 35 is moved to printing position, so

that there is also a positive drive of the inking roll 50.

Fig. 2 shows the carriage 35 withdrawn from the impression cylinder l2 and it will be noted that the lug 36 has been withdrawn from under the hook 31 so that the carriage may be swung up on its hinges. However, when the carriage is moved forward to its printing position, the lug 3'! is caught under the hook 38 so that there is no danger of lifting or displacement of the carriage during the printing operation.

The printing band 41 may be made in a number of different ways. Fig. 5. This consists of an ordinary wiremesh fabric 65 formed into an endless band by soldering, welding or otherwise securing the ends together. On this band the design is formed by masking or blanking out the background with a suitable filler 66, such, for. instance, as celluloid dissolved in acetone. However, any other liquid or plastic filler material can be employed for the purpose which will harden when in place, and which when hardened will be sufficiently fiexible to pass around the rolls 44 and bear against the web or fabric 2| without breaking or cracking One form is shown in I may also use a metal filler such as lead, zinc, etc. The filler whether of metal or other material may be etched out to form the design.

As shown in Fig. 5, the open or unfilled part of the wire meshconstitutes the design 81 which is to be printed by forcing ink therethrough. The wires of the fabric run across the design serving to preserve the open spaces against distortion and also to give strength to the printing band. As shown in the drawings, the designincludes an annular opening 68 surrounding an island 69. The latter is supported and maintained in position by the wires of the fabric. It will be noted that the surface of the band 41 is smooth and the margins of the design are clear out. When the ink is pressed through the open design by the roll 50, it might at first be thought that the net work of wires in the fabric would show in the printed design. However, the wire fabric touches the web only at the knuckle points where the wires intersect. y In other words, there are no line contacts but merely point contacts and the ink used is 'sufliciently fluid to spread under these knuckles or intersecting points of the wire mesh.

The size of mesh, viscosity of the ink and pressure applied by the inking roll, are all important factors in determining the character of the printing. However, the sharpness of outline is not affected by the coarseness of the mesh, because the margin of the design is not checkered, as; it would be were it obliged to follow the pattern of the wire mesh, but may cut'across the mesh in any direction desired.

As clearly shown in Fig. 1, the band I! has a broad bearing surface against the web 2|. Instead of being merely pressed against the web by the inking roll 50, it is held thereagainst by the rolls 43 and H and the web between said rolls is concaved so as to conform to the curvature given to web 2| by the cylinder 12. If the band 41 ran tangent to the web 2| instead of having a broad surface contact therewith, or if it were given a convex form about the inking roll 50 so that there was merely a. line contact between the band 41 and the web 2| there would be a chance for the ink to ooze out of the openings in the band 41 at each side of the line of contact with the web 2 I, thus distorting and blurring the design. However, when'a light impression is desired the pressure of the printing band is reduced by adjusting the screw 54. As the pressure is reduced the area of engagement of the band with the web approaches a line contact and ink of greater viscosity must be employed to prevent it from oozing out beyond the boundaries of the design. As the pressure of the band is reduced the slack is taken up by adjusting the roll 45. If the carriage is to be adjusted away from the impression cylinder the printing roll must be capable of corresponding adjustment toward the cylinder. provided in the bearings of the shaft 62, set screw 62a serving to retain the shaft at the desired.

adjustment. The pan 48 and roll 49 are also correspondingly adjustable.

Instead of using a wire mesh for the band 41,

I may employ a netting of other material, or.

Such adjustment is v tersecting ribs 1| 0:: one face thereof, the other face being left smooth. The intersecting ribs produce a grid-like formation, such as shown *in Fig. 6, with rectangular pockets or depressions I2. The design may then be photographedlor otherwise formed on the flat face of the metal sheet, after which the design is etched out until it eats through the bottom walls of the pockets 12, leaving open spaces sharply defined on the smooth face of the sheet by marginal walls 11 but bridged over on the other face by an open grill of intersecting ribs or bars H. The sheet is then formed into an endless band by soldering, brazing or welding'or locking the ends together. The band is used in the press with the smooth side bearing against the web 2|, so that the ink will pass under the net work of bars H, and the latter will not contact with the web. It will be understood thatin Fig. 7 the thickness of the band is exaggerated, for the purpose of clarity. I

As so far described, I have referred to" the printing band as a screen through which ink is forced to print the web. However. it is within the purview of my invention to use the imperforate areas of the band as printing surfaces. To this end, I provide on the carriage 35 a pair of brackets 15 which carry an inking roll 16 adapt-- ed to bear on the band where it passes about the roll 45. The roll 16 is supplied with ink by a fountain roll 11 running in an ink reservoir 18. Thus, the web may be printed in one color with ink applied to the surface of the band and with ink of another color forced through the openings in the band.

While in Fig. 1, I have shown only one printing band unit, obviously a number of printing band units could be applied to the same machine to produce multi-color printing. The printing band may be used in connection with one or more etched copper cylinders, as shown in the drawings, or the latter may be replaced with a printing band unit, if so desired.

While I have described a preferred embodiment of my invention, it will be understood that this is to be taken as illustrative and not limitative and that I reserve the right to make such changes in methods and in form, construction and arrangements of parts, as fall within the spirit and scope of the following claims.

.I claim:

l. A web printing press cylinder, a carriage movable toward and from the cylinder, a set of rolls supported by the car riage, an endless printing band carried bythe rolls, said band having openings therein forming a design, a pair of the rolls being adapted to bear against the cylinder whereby the run of the band between said rolls will be concaved when the carriage is advanced to printing position, means for guiding a web between the band and the cylinder, and means carried by the carriage for forcing ink through the openings in the band within the concaved area thereof to print the design comprising a printing web.

der, means carried bythe carriage for forcing ink through the openings in the band within the concaved area thereof to print the design on the web, and means for adjusting the pressure of the band against the web.

3. A web printing press comprising a printing cylinder, a carriage movable toward and from the cylinder, a set of rolls supported by the carriage, an endless printing band sleeved on the rolls, said band having openings therein forming a design, means for adjusting one ofthe rolls to vary the tension of'the band, ,a pair of the rolls being adapted to bear against the cylinder whereby the run of the band between said rolls will be concaved when the carriage isadvanced to printing position, means for guiding a web between theband and the cylinder, means carried by the carriage for forcing inkthrough the openings in the band within the concaved area thereof to print the design on the web, and means for adjusting the pressure of the band against the 4. A web printing press comprising a printing cylinder, a carriage movable toward and from the cylinder, a set of rolls supported by the carriage, an endless printing bandcarried by the rolls, said band having openings therein forming a design, a pair of the rolls being adapted to bear against the cylinder whereby the run of the band between said rolls will be concaved when the carriage is advanced to printing position,

means for guiding'a web between the band and the cylinder, means carried by the carriage for forcing ink through the openings in the band within the concaved area thereof to print the design on the web, and means for adjusting the carriage with respect to thecylinder.

5. A web printing press comprising'a frame,

an impression cylinder journall'ed therein, a member movable on the frame toward and from the cylinder, a carriage hinged to the member,

rolls supported by the carriage, an endless printing band sleeved on the rolls, the carriage being adapted to be swung. clear of the frame, to permit of removing the band, means for advancing the carriage toward the cylinder, means for leading-a web between the band and the cylinder, and means for inkingthe band to print the web.

6. A web printing press comprising a. printing cylinder, a carriage movable toward and from the cylinder, a set of rolls supported by, the carriage, an endless printing band carried by the rolls, said band having openings therein forming a design, a pair of the rolls being adapted to bear against the cylinder whereby the run of the band between said rollswill be concaved when the carriage is advanced to. printing position, means for guiding the web between the band andthe cylinder, means for inking the outer H face of the bandto print the web, and means for forcing ink through the openings in the band within the concaved area thereof to print the design on the web. 1

7. A webprinting press comprising a printing cylinder, acarriage movable toward andfrom the cylinder, a set of rolls supported by the carriage, an endless printing band carried by the rolls, said band having openings therein forming a "design, a pair of the rolls being adaptedto bear against the cylinder whereby the run of the band between said rolls will be concaved when the car-.- riage is advanced to printingposition, means forv guiding a web between the band and the cylinder, means supported by the carriage for inking the outer face of the band to print the web, and means supported by, the carriagefor forcing ink through the openings in the band within the concaved area thereof to print the design on the web. i

8. A web printingpress comprising a frame, an impression cylinder journaled therein, a carriage mounted on the frame, .rolls supported on the carriage, an endless printing band sleeved on the rolls, means for leading a webbetween the band and cylinder, means'for adjusting the carriage in a plane radial to the cylinder to a printing position with respect to the cylinder or in the opposite direction to a clearance position to permit of removing the band from the rolls, and means for inking the band to print the web.-

9. A webprinting press comprising a frame, an impression cylinder journaled therein, a car-s riage mounted on the frame, rolls supported on the carriage, an endless printing band sleeved,

on the rolls said band having openings therein forming a design, means for. leading a web between the band and cylinder, means for adjusting the carriage toward and fromprinting position with respect to the cylinder said carriage being movable to a clearance position to permit of re-

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