US2758540A - Apparatus for printing, sheets, films or lengths of material, notably textile material, by means of screen printing - Google Patents

Description

Aug. 14, 1956 R. R. LAUPMAN 2,758,540

APPARATUS FOR PRNTING, SHEETS. FILMS OR LENGTHS OF MATERIAL, NOTABLY TEXTILE MATERIAL, BY MEANS OF' SCREEN PRINTING Filed May 1, 1952 s sheetsfshee. 1

2,758,540 LIGTHS llg- 14, 19::6 R. R. LAUPMAN APPARATUS FOR PRINTING, SHEETS. FILMS OR F MATERIAL, NOTABLY TEXTILE MATERIAL MEANS OF' SCREEN PRINTING 3 Sheets-Sheet 2 Filed May l. 1952 INVENTOR Rer? Lau/oma);

ug- 14, 1956 R. R. LAUPMAN 2,758,540

APPARATUS FOR PRINTING, SHEETS, FILMS OR LENGTHS OF' MATERIAL, NOTABLY TEXTILE MATERIAL, BY MEANS OF` SCREEN PRINTING Filed May l, 1952 3 Sheets-Sheet 3 FEA-925 INVENTOR. ROBERT R. LAUPMAN BY WM,MM PMA ATTORNEYS United States Patent APPARATUS FOR PRINTING, SHEETS, R i

L'ENGTHS 0F lVIAERINL., NOTABIlY 'TEXTILE MATERIL, BY A'0F TSCREEN RINTJNG Robert Ronald Laupman, Wychen, Netherlands Application May -1, 1952, fSexial No."2f8i5,`512 Claims priority, 'application Netherlands May 2v, 1-951 3 Claims. (Cl. lill-'126) YThese steps areintermitftent. -In many "ways it lhas been tried -to meehanize these steps: electrically, with 'the vhelp of contact rollers and relays, vmechanically with the'help `or" various cams, ratchet mechanisms, etc. However, towing 'to their being highly complicated lthe machines which mechanize the steps in question AAgive -rise 'to the `danger that one o'f their parts will stall, soth'atmisprints will -result which can vdestroy an lentire ilength of cloth.

Now it is an object of the present invention to carry .out the said steps by means o'f a 'very simple apparatus,

`said steps 'being split -up into -two groups:

l. rPhe steps ysynchronous with fthe passing on of the cloth;

2. The movement of the squeegee.

The apparatus according to'the :invention is based on a very simple pinciple, which, however, by its very simplicity, opens up very vattractive perspectives from the vpoints of view of construction and foperation.

The new vapparatus is ycharacterized `Ain 'thatzin the lifted coupling v.periodically displaces E'the conveyor 5-belt for the Imaterial it'o be printed. f

rif llarge lengths are to =be printed, so l'that Athe size of Ith'efscreen 'orfscreens -is insu'i'cienn it fis possible, if more than one fsqueegee is lused, Lto make the squeegees adjustable in vertical direction relatively to the squeegee carrier -by means of 'a facqu'ard mechanism.

This iis also 'very-suitable for obtaining a greater `vari ation in lthe pattern.

The invention is further elucidated hereinafter with reference to .the accompanying drawing.

In this drawing:

Fig. l is a diagrammatic Iside view'of 'the screen printing machine;

Fig. la is a side viewfof the ends Y'ofthe carrier belt .for 'the material to be printed;

Fig. 2 on va larger scale `shows 'a-cross section taken -on the 'line III-II gin Fig. 7l;

'Fi'g. 3 .isra 'fragmentary'viewzof the cam disc for lifting and lowering the lscreen support and the 'squeegee-carrier;

lFi'g. Zldiagrammatically `shows the movement of a squee- 'gee `rbetween two subsequent worlcing end positions;

Pig. '5 is ,a planview of a inumber -of screen frames, each 'provided with va printing screen;

yFig. .6 on 'alarger scale s'howsf'a-'cros's section taken on vthe line XII-@VI in fFig. il. Y

`JR'eferring to fthe drawings, the screen printing machine comprises a main frame il,which carries at v'its ends rollers 3 land 2f7for-supportingan endless belt y2'6which is driven intermittently fand ia'dju'stably tolmovethe 'fabric '28 Yto .be

printed successively 'to the printing positions.

position the squeegee performs an/even number of `inoper ative strokes, starting ljustbe'fore the squeezed oli print ing paste 4and ending just behind said v-printing paste, to subsequently perform a numberof operative stro'keswhich number is smaller than the numberof'inopera'tive strokes.

A suitable embodiment comprises two rotating driving shafts or spindles, "one of which `periodically idisplaces the material to be printed, while the other shaft or spindle imparts a reciprocatory movement to a squeegee-carrier, adapted to be V'lifted by meansof azcam or cam disc, which is rotated vby said first-named spindle, the screen being lifted by the same or by anothercamf'o'r cam discrotated by said spindle, the ratio between the numbers v'of revolu- .tions of said spindles or shafts Abeing 2: {llaa-431), -inlwhi'ch formula x and y 'represent integers which 'at"lea'stequa'l vvl.

If only one cam disc is used, :it is 'to be :recommended that vthe part cooperating with this cam disc and lifting the squeegee carrier likewise cooperates with some play with the screen part to be lifted.

In order -to enable the material to be printed lto vbe passed on periodically it is of advantage if the `lrs't shaft rotates an arm the length of which l'is preferably adjust'- able, which arm drives a one-way coupling in opposition 'to a spring -by means of a chain or ato'othed rack, which The fabric 28 is fed from asupp'lyreel 29 and is secured to the be'lt lby means o'f fan'a'dhesive. n After-the `fabric 28,ha's been -print'edfit leaves the feXit end of the .machine and is fstrip'ped 'from lthe 'ebelt '26 by a stripping knife 30. Y

The :main frame -1 gis further provided with a -motor f2 for driving the shafts 4 and 1l), which 'shafts are rotatab'ly t-supported by the main Iframe 1 vand which are each provided with a gear. The Igears a'r'e Iinterconnected with `ea'c'h 'other 'and with the lmotor "by .a driving chain l3.

.Am Iarm 5 ixed to one fend 'df 'the shaft l lhas lan adjustable sleeve 6 thereon Ito which l"a Icable 7 is secured, whichfcableiis fpassedoverfapulley-of a one-way coupling ion'the :roller 8. The lofther 'end of 'cable 7 lis secured -to a drawspring 9 which is llixed ltorthe main frame '1.

During the rotation of theshaft 2i, `driven by the motor f2, the roller S together 'with fthe 'endless belt 25 and ythe :fabric 28 is intermittently dxven to advance vthe vvfabric ZS vfrom fone position tto fthe next. The distance the belt moves on each stroke may be adjusted fby adjusting the position of-sleeve 6.

iA V,framework composed of longitudinal -rods 16 and :17 pivoted'to each other at their adjacent ends at 1S and cross bars 22'and S24, Vis-sosusp'ended fromthe ylongitudinal walls of .the 'main frame 1 lthat the Itwo `halves of said framework are adapted :to .oscillate labout the shafts .20 :and '21 respectively.

The framework lcarries rollers 25 :at its two longitudinal sides, on which rollers a squeegee -carrier A.14 bears. A number :of 'squeegees 34 are secured :to vthe ycarrier by means -of cross bars 33 and clamps 32. The squeegee carrier is adapted to travel over the rollers 25. The

squeegee carrier 14 .isprovided with an .arm .31 to which the one end of va connecting rod 13 is coupled. The other end is coupled by an adjustable sleeve l2 to an arm 11 secured to the Vshaft 10.

'During the rotation of the shaft 10 which isdriven by the motor 2, `the 'squeegee carrier '14 is lreciprocated over the rollers v25 by the `connecting rod v13.

l "Within the space defined by thesqueegee carrier 14 a support for a number of screens is located. This screen support consists of a framestructure composed of longitudinal and transverse rodsc41 and 4t) and of auxiliary rods 43. The hooks 39 of supporting rods 38 are secured thereto by means of bolts 42. Said supporting rods 38 serve for securing thereto the screens, which screens consist of a metal frame 37 surrounded by a wooden framework 36 against the lower side of which a patterned piece of gauze 35 is secured.

The longitudinal rods 41 of the screen support are provided with vertically adjustable pins 15 and 23 which end at some distance above the cross bars 22 and 24 of the framework 16 and 17. The transverse rod 22 in the framework carries a roller 19, which bearson the circumference of a cam disc 46 secured to the shaft 4.

During the rotation of the shaft 4 and the cam disc 46, the roller 19 resting on the cam disc will lift the outer ends of the rods 16 and 17 upwardly and downwardly so that the squeegee carrier 14, supported on the rollers 25, together with the squeegees 34 is likewise moved upwardly and downwardly. During the upward movement of the outer endstof the rods 16 and 17 the ends thereof will contact the lower ends of the pins 23 and 15 and the screen support will be moved upwardly. During the` downward movement of the outer ends of the rods 16 and 17 the screen support will follow this` downward movement until the auxiliary rods 43 of the screen support come to a standstill by their running against the main frame 1. The lower ends of the pins4 23 and 15 will no longer contact the levers 16 and 17 during `the subsequent lowering of the squeegee carrier 14.

During the upward and downward movement of the squeegee carrier and the screen support and during the intervals between said upward and said downward movement the squeegee carrier 14 performs an uninterrupted reciprocatory movement over the rollers 25.

For timing said upward and downward and reciprocatory movements the chain gears secured to the shafts 4 and 1t) are so constructed in the embodiment shown that the shaft 4 will perform two revolutions in the time during which the shaft 10 performs three revolutions, and the cani disc 46 secured to the shaft 4 has a circumferential shape as shown in Fig. 3.

As long as the roller 19 bears on the portion of the largest radius of the cam disc 46, the screen support and the squeegee carrier 14 will be lifted in the highest position so that they are free from the carrier belt 26 carrying the fabric 2S. The belt 26 with the fabric 28 will be advanced by the rotating arm 5 and the cable 7 to a next printing position. All of this happens during a rotation of the cam disc 46 over the angle Ta.

After (in case of the cam disc 46 having the direction of rotation shown in Fig. 3) the radius I has passed the roller 19, the screen support and the squeegee carrier will start moving downwardly.

when the point of intersection of the circumference of the cam disc and the circle g passes the roller 19 the screen support has reached its lowest position and the screens (47, 48, 49, Fig. 5) will lie on the fabric 28.

When the point of intersection of the cam disc circumference and the radius k pass the roller 19 the squeegees 34 (which have meanwhile arrived again in their extreme left hand or, as shown in Fig. 4, right hand position) also will have reached their lowest position and have come to rest between the printing `colour 45 present on the closed edge 50 of each screen and the associated screen frame 37.

`When the cam disc 46 continues rotating, the printing colour 45 is pushed off said closed screen edge 50 by each squeegee (then moving to the left according to Fig. 4) during the time when the cam disc covers the angle between the cam discovers the angle between the radii l and m the squeegees will push the printing colour 45 onto the opposite closed screen edge 50, and immediately tit) the radii k and l; during the time when yhave reached their highest position,

is lifted off the associated according thereafter each squeegee `34 screen (the opposite stroke a of the squeegees to Fig. 4).

During the time when the cam disc 46 covers the angle between the radii n and o the squeegee carrier 14 together with the squeegees 34 is lifted higher and also the screen support is moved upwardly.

After the screen support and the squeegee carrier 14 the advancement of the belt 26 with the fabric 28 to the next position starts.

During this advancement of the belt 26, which continues until the radius I of the cam disc 46 passes the roller 19 again, the squeegees 34 in their lifted position perform the inoperative strokes b and c which have already started in the meantime (Fig. 4). During the subsequent complete revolution of the cam disc 46 the squeegees 34 continue moving without coming to a stand still, for performing an operative stroke a and two inoperative strokes b and c, this time, however, according to the mirror image of Fig. 4, while during the operative stroke the printing colour 45 is pushed in opposite direction across the screen having the new portion of the fabric to be printed located thereunder. This continues as long as the cam disc 46 rotates.

According to the embodiment the belt 26 is periodically advanced over a distance e (Fig. 5) so that each printed portion of fabric 28 is advanced first to an intermediate position and subsequently to the next printing position.

Because during the operation of the screen printing machine the squeegee carrier 14 with the squeegees 34 continues moving, high printing speeds can be reached, while the chance of misprinting is minimized.

Although according to the embodiment described each squeegee performs two inoperative strokes in its lifted position, which strokes start just before the squeegeed mass of printing colour and which end just behind said mass, whereupon each squeegee performs one operative stroke, it will be clear that a number of operative and a subsequent number of inoperative strokes of the squeegee or squeegees may be selected according to requirements, provided that the shape and the speed of revolution of the means for periodically driving the belt and for continuously driving the squeegee carrier, as well as the lifting and lowering of the squeegee carrier and the screen support be adapted thereto.

If the number of operative strokes is larger than l, the cam disc must be provided with a corresponding number of cams to lift only the squeegee carrier. The screens then remain in their places.

The only possibility of the operation getting out of .tune resides in the one way coupling. If however, the

lengths of repeat are normalized to multiples of a given unit of length, this coupling can be replaced by a ratchet so that mistakes are excluded.

The construction described admits of very high printing speeds with a minimum chance of misprinting, because the possibility of one of the operations being skipped is excluded.

I claim:

l. A screen printing machine for sheets and lengths of textile, paper and the like, comprising a main frame. two rollers and two shafts rotatably mounted on said frame, an endless belt supported for movement on said rollers and adapted to carry the material to be printed, one of said rollers having a one-way driving pulley thereon, adjustable means for intermittently moving said belt mounted on the first of said two shafts and comprising an arm having an adjustable sleeve thereon and a spring tension cable attached at one end to said sleeve and passing around said one-way pulley and having the other end attached to said frame, a screen support mounted above the endless belt, a squeegee carrier mounted above the screen support and provided with a number of squeegees fixed to the carrier, means for continuously reciproeating the squeegee carrier mounted on said second shaft and comprising an arm and a link pivotally connected to one end of said arm with the free end of said link pivotally connected to said squeegee carrier, means for periodically first lifting the squeegee carrier from the screen support and subsequently the spaced squeegee carrier and screen support from the endless belt and for first lowering the spaced squeegee carrier and screen support towards the endless belt and for subsequently lowering the squeegee carrier towards the screen support, said means for intermittently moving the endless belt being operable during the lifting of the squeegee carrier and the screen support7 and means on said frame for driving the second shaft at least one and one-half times as fast as said first shaft and for driving said lifting means.

2. A screen printing machine for sheets and lengths of textile, paper and the like, comprising a main frame, an endless belt supported for movement on the main frame and adapted to carry the material to be printed, adjustable means for intermittently moving said belt, a screen support mounted above the endless belt, a squeegee carrier mounted above the screen support and provided with a number of squeegees fixed to the carrier, means for continuously reciprocating the squeegee carrier, means for periodically'iirst lifting the squeegee carrier from the screen support and subsequently the spaced squeegee carner and screen support from the endless belt and for first lowering the spaced squeegee carrier and screen support towards the endless belt and for subsequently lowering the squeegee carrier towards the screen support comprisng a pair of levers pivoted at their centers to said frame in the longitudinal direction thereof and having their adjacent ends pivotally connected to each other, a pair of rollers mounted at the ends of said levers opposite said pivotal connection on which Ysaid squeegee carrier rolls, a follower wheel suspended from one end of said levers, pins adjustably mounted on said screen support over the ends of said levers opposite said pivotal connection and adjusted to contact the ends of said levers after said levers have been pivoted from the horizontal position, and cam means rotatably mounted on said frame contacting said follower wheel and adapted to urge said wheel upwardly to pivot said levers and thus lift said squeegee carrier and to continue to urge said wheel upwardly to bear against said pins and lift said screen support in timed relation to said means for moving said belt, said means for intermittently moving the endless belt being operable during the lifting of the squeegee carrier and the screen support, and means on said frame for driving said belt moving means, said reciprocating means and said lifting means.

3. A screen printing machine as claimed in claim 2 in which said cam means has a prolile to lift the squeegee carrier from the screen support at the end of at least one operative stroke of the squeegee carrier and to lower the squeegee carrier toward the screen support at the end of at least two following inoperative strokes of the squeegee carrier.

References Cited in the lile of this patent UNITED STATES PATENTS 2,612,835 Marek et al Oct. 7, 1952

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