US2710577A - Screen printing machine - Google Patents

Description

June 14, 1955 K, PRET-r 2,710,577

SCREEN PRINTING MACHINE Filed July 24, 1951 ATTOR/v SCREEN PniN'riNo MACHINE Konrad Preti, Dornbirn, Austria, assigner to the firm Kerag, Kesselschmiede, Apparateund Maschinenbau, Richterswil, Switzerland, a corporation of Switzerland Application July 24, 1951, Serial No. 238,244

Claims priority, application Austria July 25, 195D i2 claims. (ci. 10i-124) This invention relates to a screen printing machine for printing repeat patterns on webs of iiexible textile material.

Known screen printing machines comprise at least one printing stencil which is movable vertically toward and from the web of the fabric to be printed, which is intermittently passed over a flat backing. A reciprocating doctor distributes the color on the stencil and transfers it to the fabric when the same contacts the stencil. To avoid distortion of the fabric it was necessary to paste it on an endless belt of rubber or the like, which is intermittently pulled through the machine. This arrangement involves certain irregularities in the application of the adhesive and inevitable inaccuracies in the pattern repeat, with resulting defects in the printed product.

Moreover, a screen printing machine for repeat printing on webs of iiexible textile material has been suggested, in which a at printing stencil, which is movable without altering its location, is rolled over a stationary, cylindrically curved backing, which holds the fabric to be printed only by friction contact. Preferably the fabric is stretched over a cylinder which is held fast during the printing step and can be rotated in steps corresponding to a repeat length, and above said cylinder a nonshiftable, at printing frame is provided, which contacts the cylinder along a generatrix and which is positively coupled with the doctor to perform a rocking printing motion which causes it to roll on the cylinder periphery. This eliminates pasting of the fabric.

The large cylinder necessary in that arrangement, however, prevents the use of that machine in many cases.

The invention provides a screen printing machine of the type which has been described rst hereinbefore, and differing from the machine described in the second place by the fact that a rotatably mounted cylinder is provided, which together with guide rollers arranged in front of and behind it holds and guides the web of the fabric to be printed, which is constantly maintained under tension, directlyon its periphery only by friction contact, and is positively though detachably coupled with a at printing stencil, the cylinder, which forms the backing and oscillates about its axis of rotation, and the printing stencil, which reciprocates in a plane tangential to the cylinder, being in rolling Contact with each other during the printing stepvand cooperating with a stationary doctor effective at Vthe respective line of contact of the cylinder with the stencil.

, Since in this machine the printing template no longer exercises a rocking motion, the cylinder supporting the material to be printed may be of much smaller size. Therefore, the material lies more firmly on the cylinder andthe space requirement as well as the expense of constructional material for the machine are reduced to a minimum. The several colors of multicolored patterns are printed in succession and after one repeat has been completed the material is advanced for the next one like inv most'of the known machines. The novel machine, however, is the first one to perform this exchange of stenice cils and the printing in a single operation, the printing cycle beginning as the printing frame is introduced and being completed as the frame is removed. Thus the machine prints multicolored patterns almost twice as fast as the known machines. During the removal of the printing stencil after a repeat has been printed the material on the cylinder is turned towards the side of the cylinder while still wet. In this position the material printed may be subjected to intermediate drying by blowing or radiation after the printing from each stencil, to avoid a running of colors even when they are printed one on the other.

An embodiment of the invention is shown in the drawings in the diagrammatical Fig. 1 in a side elevation, and in Fig. 2 in a sectional view taken along the line A-B of Fig. l.

A horizontal shaft 1 has rotatably mounted on it a cylinder 2 serving for supporting and guiding the web of material to be printed. The latter is pulled from a supply roll 3 and passes around the guide rollers 4 and 5 having between them a loose roller 6 exercising tension on the material under the action of the spring 7. The web of tlexible textile material further passes in the clockwise sense around a part of the periphery of the cylinder 2. The angle of contact between the web and the cylinder must be suicient for the material to be held on said periphery by friction contact alone under the action of guide means, to be described hereinafter. actual amount of the angle of contact depends, of course, on the surface characteristics of the cylinder periphery and the web, and on the tension exercised on the web. Then the web passes around a roller 8, which is carried in two straps 8a radially protruding beyond the periphery of the cylinder 2 and rigidly connected each to the outer end face of one of two disks 9 and 1t) equal in diameter' with the cylinder 2. These disks 9 and 10, which will'be further discussed later in this specification, are freely rotatably arranged on the cylinder shaft 1 at both ends of the cylinder 2 and can be coupled rigidly though detachably with the cylinder 2. Hence, when the coupling is established, the roller 8 will follow a rotation of the cylinder 2. From this roller 8 the web of the printed textile material passes around two guide rollers 11 and 15 and is wound up on the winding roller 16. To preclude smearing of the wet print on the web, the rollers 8, 11, 1S are arranged to guide the web while contacting it only on the side Which having been in contact with the periphery of cylinder 2 has not been printed. A rod assembly 12, 13, which comprises a toggle joint, rods 12 articulated to the disks 9, 10 through the intermediary of the bearing pins of roller 8, and rods 13 which are pivotally suspended at the machine frame has arranged the roller 11 in its hinge points and the roller 15 in its points of suspension.

A carrying frame 19 is movably guided above the cylinder 2 in lateral horizontal slideways 17, 18 of the machine frame. In this carrying frame the frame 20 of the printing stencil, which during the printing step is constantly in linear contact with the cylinder is unmovably xed by suitable means known in the art. This stencil is thus movable together with the carrying frame 19 in a horizontal plane which is tangential to the periphery of the cylinder 2. As shown in Fig. l the top face of one of the end members of the carrying frame 19 is arranged in a common plane with the bottom face of the other end member of frame 19. Adjacent to the peripheries of said disks 9 and 10 each of the end members of the carrying frame 19 has rigidly fixed to it within said common plane one end of two steel strips 21 and 22 (indicated by dash-and-dot lines in Fig. l). The other ends of the steel strips 21 and 22, which extend alongside each The other and in mutually opposite senses around each of the disks 9 and 10 so as to cross each other, are aixed at 23 and 24, respectively, to the periphery of the respective disk 9 or 10. By these steel strips 21 and 22 the carrying frame 19 and with it the printing stencil frame 20 fixed therein are positively connected to said disks 9 and E6 and to the cylinder 2 when the latter is coupled to the disks.

To provide a positive, selectively detachable coupling between the disks 9, 10 and the cylinder 2, the end faces of the cylinder have bores 2a and 2b arranged with a regular angular spacing. On the periphery of cylinder the arcs corresponding to said angular spacing equal a repeat length of the pattern to be printed. Each of the disks 9 and 10 has a bore 9a and 10a, respectively, both of which lie on a common straight line parallel to the axis of the disks. When these bores 9a, lila are in register with two bores 2a and 2b lying in the saine radial plane, a coupling pin 2c or 2d, respectively, may oe stuck into each of bores 9a, 10a. Extending through the registering bores 9a, 2a, and 10a', 2b, respectively, the pins 2c, 2d rigidly couple the cylinder 2 to the disks 9 and 10. This coupling can be disengaged easily by pulling the pins 2c and 2d. When the coupling is established and the carrying frame 19 is reciprocated in the direction of the arrow in the guideways 17 and 18, the positive connection of the carrying frame through steel strips 271, 22 to the disks 9, 10 will cause the cylinder 2 to perform a rotary oscillation. As a result the stencil 20 and the cylinder 2 roll one across the other entirely without slip. It is thus seen that the carrying frame 19, in which the stencil frame 20 is unmovably fixed, the steel strips 21 and 22 fixed to the carrying frame 19, and the disks 9, 10 are representative of transmitting means positively connected to said stencil whereas the coupling pins 2c and 2d are representative of disengageable coupling members positively coupling the cylinder to said transmitting means to transmit the reciprocating motion of said stencil through the intermediary of said transmitting means to said cylinder. main frame of the machine above the line of contact of the cylinder 2 with the printing frame 20. This line of contact lies always at the apex of the cylinder.` The doctor, in the manner known, will distribute the color applied to the stencil' surface and will transfer the color to the material positioned below said printing frame according to the pattern as the printing frame is being moved. As a result of the aforedescribed, entirely slipless rolling motion enforcedl by the steel strips, all points of the pattern printed on the textile web during the forward stroke of the stencil towards the doctor 2S will be in perfect register with the corresponding points of the stencil during the return stroke thereof to an initial` position. Thus misprints are prevented in spite of the continuous contact of the doctor 25. Owing to the pivoted arrangement of the rollers 8 and 11, uniformly spacedfrom eachother bythe rod assembly 12, 13, the wet printed textile web is pulled approximately tangentially from the cylinder 2 so that it cannot curl and cause smearing of the colors printed. The unprinted material entering the machine is held under uniform tension by the tension roller 6 which when the supply roll 3 is at a standstill and the cylinder 2 is rotated in the counterclockwise sense will pull up under the action of the spring 7 the slack fabric web in the form ofa prolongedloop which becomes shorter and finally disappears when the cylinder 2 rotates in the opposite sense.

When in the case of one-colored patterns one repeat has been printed the coupling between the disks 9, 10 and the cylinder 2 is disengaged, as has been described hereinbefore. Then the cylinder and the winding roll 16 are advanced in the clockwise sense by one repeat length, i. e., throughV such anextent that the bores 9a, 10a of the disks 9, 10 register with the next following bores 2a, 2bl

of the cylinder 2 in the sense of rotation. Thereafter the The doctor 2S is fixed to the coupling pins 2c and 2d are introduced again into the bores in register. This type of coupling ensures that in the successive printing cycles the repeat lengths to be printed in succession adjoin accurately, without spacing or overlap.

in the case of multicolored patterns stencils must be provided in a number which corresponds to the number' of colors to be applied in succession. These stencils are `successively used for printing, in the manner known, are accommodated in a stencil magazine 26, which is arranged at one end of the machine and can be lifted` and lowered in the sense of the arrows. As has been mentioned hereinbefore the textile material is printed with the respective color when the web of material on the cylinder is contacted by the stencil moved. That contact takes place in the same plane in which the stencil is moved continuously into and out of the machine. The heater 27 of known type and arranged at the side of the impression cylinder facing the magazine 26 subjects after the return of the stencil used at a time into the magazine the freshly printed material to intermediate drying after the printing from each stencil, either by blowing hot dry air or by radiating heat on the material.

The invention is not restricted to the embodiment shown and other constructions are possible within its scope as defined by the appended claims.

I claim:

l. A screen printing machine for printing repeat patterns on iiexible strip material, comprising a rotatably mounted cylinder, plane printing stencil, a track for said printing stencil, said printing stencil being movable ai said track in a plane which is tangential to the nhery of said cylinder, mechanism for coupling the cylinder to the printing stencil, said stencil being adapted to rollingly engage said cylinder along a line of Contact, a stationary doctor adapted to hold said stencil against said cylinder at said line of contact, a supply roller for the material to be printed, a winding roller for material printed, a Set of three guide rollers for guiding the material between said supply and winding rollers, said set of guide rollers comprising a movable, spring-loaded intermediate tension roller adapted to form a loop of material to be printed which is laid around the periphery of said cylinder and to maintain said material under uniform tension independently of an oscillatory motion of said cylinder caused by a reciprocating motion of said printing stencil when coupled to said cylinder, a rod assembly comprising a toggle joint and being pivotally suspended' at one end, a second set of guide rollers mounted on said rod assembly, one roller of said second set being mounted to the other end of said rod assembly and connected to said cylinder for transmitting said oscillatory motion of said cylinder to said rod assembly, said second set of guide rollers being adapted to guide the cloth between said cylinder and said winding roller.

2. A screen printing machine for printing repeat patterns on webs of ilexible textile material,V comprising, in combination, a rotatably mounted cylinder, a plane printing stencil, a trackV for said printing stencil, said printing stencil being movable along said track forwardly and backwardly in a plane which is tangential to the periphery ot said cylinder and being adapted to rollingly engage the cylinder along a line of contact, a stationary doctor adapted to hold said stencil against said cylinder at said line of contact, transmitting means positively connected to said stencil, disengageable coupling means positively coupling the cylinder to said transmitting means to transmit the reciprocating motion of said stencil through the intermediary of said transmitting means to said cylinder, and guide means for guiding said material to said cylinder to be printed thereon, said guide means comprising tension means operatively disconnected from said cylinder and stencil and adapted to constantly exercise tension on said material independently of the motion of the cylinder, to hold said material on said cylinderbyftic` tion contact.

3. A screen printing machine for printing repeat patterns on webs of exible textile material, comprising, in combination, a rotatably mounted cylinder, a plane printing stencil, a track for said printing stencil, said printing stencil being movable along said track forwardly and backwardly in a piane which is tangential to the periphery of said cylinder and being adapted to rollingly engage the cylinder along a line of Contact, a stationary doctor adapted to hold said stencil against said cylinder at said line of contact, transmitting means positively connected to said stencil, disengageable coupling means positively coupling the cylinder to said transmitting means to transmit the reciprocating motion of Said stencil through the intermediary of said transmitting means to said cylinder, tirst guide means for guiding said material to said cylinder to be printed thereon, said guide means comprising tension means operatively disconnected from said cylinder and stencil and adapted to constantly exercise tension on said material independently of the motion of the cylinder, and

second guide means arranged to guide said material from said cylinder, both said guide means being arranged relative to the cylinder and to each other to cause the textile material guided thereby to contact the periphery of the cylinder over an angle sufficient for the material to be held on said periphery by friction contact alone under the action of both said guide means.

4. A screen printing machine for printing repeatpatterns on webs of flexible textile material, comprising, in combination, a rotatably mounted cylinder, a plane printing stencil, a track for said printing stencil, said printing stencil being movable along said track forwardly and backwardly in a plane which is tangential to the periphery of said cylinder and being adapted to rollingly engage the cylinder along a line of contact, a stationary doctor adapted to hold said stencil against said cylinder at said line of contact, transmitting means positively connected to said stencil, disengageable coupling means positively coupling the cylinder to said transmitting means to transmit the reciprocating motion of said stencil through the intermediary of said transmitting means to said cylinder, first guide means for guiding said material to said cylinder to be printed thereon, said guide means comprising tension means operatively disconnected from said cylinder and stencil and adapted to constantly exercise tension on said material independently of the motion of the cylinder, and second guide means arranged to guide from said cylinder printed material contacting said second guide means only with the side that has contacted the cylinder, both said guide means being arranged relative to the cylinder and to each other to cause the textile material guided thereby to contact the periphery of the cylinder over an angle sufficient for the material to be held on said periphery by friction contact alone under the action of both said guide means.

5. A screen printing machine for printing repeat patterns on webs of flexible textile material, comprising, in combination, a rotatably mounted cylinder, a plane printing stencil, a track for said printing stencil, said printing stencil being movable along said track forwardly and backwardly in a plane which is tangential to the periphery of said cylinder, and being adapted to rollingly engage the cylinder along a line of contact, a stationary doctor adapted to hold said stencil against said cylinder at said line of contact, transmitting means positively connected to said stencil, disengageable coupling means positively coupling the cylinder to said transmitting means to transmit the reciprocating motion of said stencil through the intermediary of said transmitting means to said cylinder, iirst guide means for guiding said material to said cylinder to be printed thereon, said guide means comprising tension means operatively disconnected from said cylinder and stencil and adapted to constantly exercise tension on said material independently of the motion of the cylinder, and second guide means positively connected to said transmitting means to receive motion from said transmitting means, and arranged to guide said material from said cylinder, both said guide means being arranged relative to the cylinder and to each other to cause the textile material guided thereby to contact the periphery of the cylinder over an angle su'lcient for the material to be held on said periphery by friction contact alone under the action of both said guide means.

6. A screen printing machine for printing repeat patterns on webs of flexible textile material, comprising, in combination, a rotatably mounted cylinder, a plane printing stencil, two disks coaxial `with said cylinder and rotatably mounted relative thereto at mutually opposite end faces of the cylinder, disengageable coupling means positively coupling each of said disks to the cylinder, a carrying frame having rigidly affixed thereto and carrying said stencil, rails for laterally guiding said carrying frame, said frame being longitudinally movable along said rails, two tension-resistant exible strips fixed with one end to each of said disks and lying in mutually opposite senses one beside the other on the periphery of the respective disks so as to cross each other, the

other end of each strip being fixed to said frame, said frame being adapted to move said stencil along said rails forwardly and backwardly in a plane tangential to the periphery of said cylinder, said stencil being adapted to rollingly engage said cylinder along a line of Contact, a stationary doctor adapted to hold said stencil against said cylinder at said line of contact, and guide means for guiding said material to said cylinder to be printed thereon, said guide means comprising tension means operatively disconnected from said cylinder and stencil and adapted to exercise tension on said material independently of the motion of the cylinder to hold said material by friction contact on said cylinder.

7. A machine as set forth in claim 6, in which said carrying frame comprises end members to which said llexible strips are aflxed.

8. A machine as set forth in claim 6, in which said tension-resistant exible strips are of steel.

9. A screen printing machine for printing repeat patterns on webs of flexible textile material, comprising, in combination, a rotatably mounted cylinder, a plane printing stencil, a track for said printing stencil, said printing stencil being movable along said track forwardly and backwardly in a plane which is tangential to the periphery of said cylinder, and being adapted to rollingly engage the cylinder along a line of contact, a stationary doctor adapted to hold said stencil against said cylinder at said line of contact, transmitting means positively connected to said stencil, disengageable coupling means positively coupling the cylinder to said transmitting means to transmit the reciprocating motion of said stencil through the intermediary of said transmitting means to said cylinder, a supply roll for material to be printed, a winding roll for material printed, and a set of three guide rollers for guiding material from said supply roll to said cylinder to be printed thereon, said guide rollers comprising a movable intermediate tension roller, and a spring connected to said tension roller and adapted to form a loop of material to be printed which is laid around said guide rollers including said tension roller and the periphery of said cylinder, said spring being operatively disconnected from said cylinder to maintain said material under uniform tension independently of the motion transmitted to said cylinder from said stencil through the intermediary of said transmitting and coupling means.

10. A screen printing machine for printing repeat patterns on webs of ilexiblc textile material, comprising, in combination, a rotatably mounted cylinder, a plane printing stencil, a track for said printing stencil, said printing stencil being movable along said track forwardly and backwardly in a plane which is tangential to the periphery of said cylinder, and being adapted to rollingly engage the cylinder along a line of contact, a stationary doctor adapted to hold said stencil against said cylinder at` said line of contact, transmitting means positively connected to said stencil, disengagcable coupling means positively coupling the cylinder to said transmitting means to transmit the reciprocating motion of said stencil through the intermediary of said transmitting means to said cylinder, a Winding roll for material printed, means for exercising tension on material laid around said cylinder to be printed thereon, and guide means for guiding printed material from said cylinder to said winding roll, said guide means comprising a rod assembly having a toggle joint and being pivotally suspended at one end, and a set of guide rollers mounted on said rod assembly, one roller of: said set, being mounted at the other end of said rod assembly and connected to said transmitting means for transmitting motion from said transmitting means to said rod assembly.

l 1. A screen printing machine for printing multicolored repeat patternsV on webs of exible textile material, comprising, in combination, a rotatably mounted cylinder, a track, a vertically movable printing stencil magazine arranged at one end of said track, a plurality of plane printing stencils receivable in said magazine, a carrying frame having one of said printing stencils positively connected thereto and movable along said track from said magazine over said cylinder and back to the magazine, transmitting means positively connected to said frame, disengageable coupling means positively coupling the cylinder to said transmitting means to transmit the reciprocatingV motion of said frame through the intermediary of said transmitting means to said cylinder, and guide means for guiding said material to said cylinder to be printed thereon, said guide means comprising tension means operatively disconnected from said cylinder and stencil and adapted to constantly exercise tension on said material independently' of the motion of the cylinder to hold said material in friction Contact on said cylinder, said frame being adapted to move said stencil forwardly and backwardly along said track in a plane tangential to the periphery of said cylinder, to etect in one operation and in the same plane the introduction and removal of a printing stencil and the printing of material laid around the periphery of the cylinder.

12. A screen printing machine for printing repeat pati? terns of definite length on webs of flexible textile material, comprising, in combination, a rotatably mounted cylinder the circumference of which is an integral multiple of' the repeat length, a plane printing stencil, transmitting means positively connected to said stencil, two disks coaxial with said cylinder and rotatably mounted relative thereto at mutually opposite end faces of the cylinder, coupling means, said cylinder being conformed to detachably receive and positively interlock with said coupling means selectively at any of several points spaced from cach other by a pitch angle proportional to a repeat length, said disks being conformed to receive and positively interlock with said coupling means, said coupling means when thus received byv said disks and by said cylinder being adapted to couple said disks to said cylinder means for guiding said material to said cylinder to be printed thereon, said guide means comprising tension means operatively disconnected from said cylinder and stencil and adapted to constantly exercise tension on said material independently of the motion of the cylinder to hold said material in friction contact on said cylinder, second guide means for guiding material from said cylinder, and a heater element arranged laterally of and partially encircling the periphery of said cylinder on the side thereof which lies between said line of contact and said second guide means in the direction of movement of said material ou said cylinder, for drying printed material 'loved adjacent to said heater element by a turning of said cylinder through said pitch angle after said coupling means have been detached therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 537,923 Hildyard Apr. 23, 1895 590,604 Wood Sept. 28, 1897 1,687,080 Beck Oct. 9, 1928 1,815,504 Gorner July 21, 1931 1,930,153 Smith et al Oct. 10, 1933 2,060,385 Shurley Nov. 10, 1936 2,206,176 Foard July 2, 1940 2,340,643 Campbell Feb. 1, 1944 tively in any of several angular positions, first guide-

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