US2369290A

US2369290A - Means for screen printing on cloth

Info

Publication number: US2369290A
Application number: US443411A
Authority: US
Inventors: Robert F Foard
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-05-18
Filing date: 1942-05-18
Publication date: 1945-02-13
Anticipated expiration: 1962-02-13

Description

Feb. 13, 1945. FQARD MEANS FOR SGREENPRINTING ON CLOTH Filed May 18, 1942 4 Sheets-Sheet l INVENTOR @aier ffib/JED BY ATiORNE 13, 1945. FOARD 2,369,290

MEANS FOR SCREEN PRINTING ON CLOTH Filed May 18, 1942 4 Sheets-Sheet 2 INVENTOR faaserf/- fia ATTORNEY 4 Sheets-Sheet INVENTOR.

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Feb. 13, 1945. R. F. FQARD MEANS FOR SCREEN PRINTING ON CLOTH Filed Ma '18, 1942 190.6597 7'. Fnea Feb. 13, 1945. R. F. FOARD MEANS FOR SCREEN PRINTING ON CLOTH 4 Sheets-Sheet 4 Filed May 18, 1942 WNQ INVENTOR. 1905597 ff f'o'meo BY Patented Feb. 13, 1945 Means Foa scam rnm'rmc N a Robert F. Foard, La Angeles, Calif.

Application May 18, 1942, Serial No. 443,411 I REISSUED JAN 2 a mu a Glaims. 01. 101-115) My invention relates to means for screen printing on cloth, and among the objects of my invention are:

. First, to provide a screen printing means which is particularly adapted for use in conJunction with my screen printing apparatus embodied in Patent Number 2,206,176, issued July 2, 1940;

Second, to provide a screen printing means which adapts thescreen printing apparatus of the above named patent to the screen printing of yardage; that is, an entire bolt or web of cloth may be screen printed.

Third, to provide a screen printing means which incorporates a novel arrangement for insuring proper registry between succeeding design units; that is, a continuous design may be printed in sections or units and the confrontingedges of the sections'matched or registered so that there is no'noticeable break design.

Fourth, to provide a screen printing means whereby designs formerly capable of being printed only by expensive rotary printing machines may be printed by a comparatively inexpensive screen printing equipment; thereby making feasible the printing of a comparatively few yards or discontinuity in the of a particular design, whereas the conventional rotary printing machines must print literally thousands of yards to justify economically the expense of rotary printing plates, and preparing or setting up the rotary printing machinery.

Fifth, to provide a screen printing means which not only accomplishes satisfactory registry between design printing a continuous design butalso provides inherently very close registry between a series of printing screens applied to the 'same area for the purpose of multiple color printing.

With the above and other objects in view, reference is made to the, accompanying drawings, in which:

Figure 1 is a fragmentary perspective view of my screen printing means shown in conjunction with the screen printing apparatus of my former patent mentioned hereinbefore;

Figure 2 is a fragmentary sectional view through 2-2 'of Fig. 1 showing particularly the registry switch;

Figure 3 is a diagrammatical view showing the manner in which the cloth is moved through the printing means and into the dryer or steamer;

Figure 4 is a sectional view through 4-4 of Fig. 3 showing the relationship of the cloth and the photo-electric control means;

Figure 5 is a fragmentary sectional view units for the purposes of .dyestufl. The dyestuff is worked on the pins 5.

through 8-5 of Fig. 3 illustrating the speed concontrol circuit for the cloth feeding mechanism;

Figure 8 is a plan view of a modified form of my apparatus;

Figure 9 is a partial elevational, partial sectional view through 9--9 of Fig. 8;

Figure 10 is a transverse sectional view through Ill-l0 of Fig. 8; and

Figure 11 is an enlarged fragmentary transverse sectional view through ll-ll of Fig. 8.

The screen'printing apparatus for the embodiment of my invention disclosed'in Fig. 1 is particularly adapted, and which is disclosed more fully in the aforementioned patent, comprises a housing I, in which ismounted an elevator cage 2. The elevator cage carried a plurality of printing frames 3 which are adapted to be withdrawn from the cage and be placed over the cloth to be printed which rests on a table 4. Each printing frame includes a screen formed of silk or finemeshed cloth on which has been formed suitable design portions ofwhich are impermeable and other portions of which are permeable to ink or through the permeable portions of the screen by a "squeegee and onto the cloth below.

Each printing frame prints a single color and several frames are used for multiple color printing. Each of the frames is provided with suitable means which register with registering pins 5 provided in the table 4. Each frame includes means whereby it may be adjusted in order that the frames register with each other when alined In my previous patent, clamp frames were provided in the table 4 to hold the material to be printed, which material was cut to size and was therefore suitable only for comparatively small units of cloth as distinguished from yardage. In the present application, the adhesive characteristics of the dyestufli is employed to hold the cloth on a backing sheet and is advanced across the table by the backing sheet in stages so that an entire bolt of cloth may be printed with a continuous design and later cut as desired.

. Below the table 4 is a frame I I on which are mounted two drums, an idler drum I! at the lead- 7 ing side of thetable and a driving drum It at the trailing side of the table. An endless backing sheet I passes around the drums, the operating or upper side extending across the top of the table 4 and the return or lower side passing below the table.

The loop formed by the backing sheet has a I length which is a multiple of the width of the defunctions of the backing sheet will be described in more detail hereinafter.

' It is desirable that the backing sheet travel around the drums without lateral or edgewise shifting. This is accomplished by maintaining the surfaces of the drums in parallel planes. Practically it is difilcult to maintain exact parallelism; therefore, in order to control edgewise shifting of the backing sheet, one end of the drive drum I3 i provided with means for shifting its axis slightly. Movement of only a few thousandths of an inch is sufficient. One of the end bearings l6 of the driving roller includes an eccentric'plate l1 fitted with an eccentric l8 from which extends an arm Hi. The arm I9 is actuated by the armature -28 of a solenoid 2|. The solenoid may have two coils so that when one is energized the bearing 16 is moved one direction a fewthousandths of an inch, and when the other is energized the bearing is moved a like amount in the opposite direction. The solenoid 2| is controlled by two switches 22 mounted below the upper side of the backing sheet l4 from which extends arms 23 which engage the edges of the backing sheet at the edge of the work table 4 adjacent the driving roller. The switches 22 may be the type known commercially as Microswitches."

Such switches are capable of adjustment so that movement of as little as a thousandth ofan inch causes them to open or close and little pressure is required, well within the permissible pressure against the edge of the backing sheet.

The driving drum I3 is provided at one end with a ulley 3| and connected by belt 32 and drive pulley 33 with an electric motor 34. Interposed between the drive pulley 33 and motor is a speed control mechanism shown in Figs. and 6. The drive pulley 33 journals on the shaft 35 of the motor\34. Secured to opposite sides of or formed integrally with the drive pulley are

ratchet wheels

36 and 3 Adjacent ratchet wheel 36 and secured to the shaft 35 is a forward drive gear 38. Similarly, adjacent the ratchet wheel 31 but journaled on the shaft 35 is a reverse drive gear 39. The

drive gears

38 and 39 carry pawls 40 which engage their respective ratchet wheels. .The for-.

ward drive gear is connected through a speed re.-

, duction unit 4| with the reverse drive gear.

The ratchet wheels and their respective pawls are so arranged that when the motor shaft 35 is rotating in one direction, the forward drive gear 38 is connected through its pawl 40 to the corresponding ratchet wheel 36 so that the drive pulley 33 rotates at the same speed and in the same direction as the shaft 35, and ratchet wheel 31 and its pawl slip. When however, the shaft 35 is rotated in the opposite direction the pulley wheel does not change its direction of rotation, but instead moves at a slower speed. Thus, by reversing the direction of rotation of the motor, the speed of forward travel .of the backing sheet. may be changed from fast to slow.

The motor is controlled by a relay system, to be described hereinafter, which is initiatedby contact roller 51 mounted so as to ride along a margin of the backing sheet l4. The backing sheet has provided therein along the path of the roller a series of accurately placed slots 52. These permit engagement by the roller of a contact plate 53 mounted on the work table below the roller. Therelay system is so arranged that when the contact roller makes contact with the plate 53, the

forward speed of the backing sheet drops from fast to slow, and when the backin sheet again breaks contact as the slot passes beyond the roller the backing sheet stops. The relay system is shown diagrammatically in Fig. 7. The motor 34 is started by a motor starting relay 54 which is provided with motor supply contacts 55 and holding contacts 56. The supply contacts 55 are in series with the source of electrical energy so that when closed complete the circuit to the motor. The holding contacts are in series with the armature 51 of the relay. A starting switch 58, adapted to be momentarily closed by the operator, is placed in parallel with the holding contacts 56 and in series with the armature 51 so that when the starting switch 58 is closed momentarily, the motor starting relay 54 is actuated to start the motor and remains energized after the starting switch 58 is released.

Any type of reversible motor may be employed. Reversal is effected with most types by reversing the electrical connections of the motor field coils. Accordingly a reversing relay 59 is provided which includes double pole, double throw reversing contacts 41. The armature 60 of the reversing relay 59 is energized by engagement of the contact roller 5| with contact plate 53 and remains energized only so long as the contact is maintained.

In order that the motor will not return to high speed but will stop when contactis broken by the backing sheet after such contact, a resetting relay 6| is provided. The armature 62 of this relay is energized by closure of control contacts 33 incorporated in the reversing relay 59. These contacts are closed when the reversing relay is actuated. The reversing relay is provided with supplemental holding contact 54 connected in series with the holding contacts 55 of the starting relay 54. Similarly the resetting relay 6| is provided with supplemental holding contacts also in series with the holding contacts 56, but'in parallel with the contacts 64; thus if either of the

supplemental holding contacts

64 or 65 are closed along with the holding contacts 56, the circuit through the armature of the starter relay is held closed. The resetting relay Bl arranged so that its supplemental holding contacts 65 are normally closed, whereas the supplemental holding contacts 64 are normally open. Thus, when the reversing relayis operated,

contacts 64 close, while contacts 65 open. A time delay means 66 is incorporated in the resetting relay 5| so that contacts 65 lag in closing and for a moment following release of the reversing switch both

contacts

64 and 65 are open, thereby de-energizing the starter switch and shutting off the motor.

Operation. of my screen printing apparatus is as follows:

The backing sheet l4 may be formed of paper. It is extended around the rollers l2 and I3 and its ends cemented together. The length of the backing sheet is carefully determined so that its circumference is an exact multiple of the length of design to be printed on the cloth; that is, the

adhesive paper may until the succeeding slot 52 width of the sheet, other material may design may be three feet long and the backing sheet be twelve feet in length. Slots 52 are punched along one margin of the backing sheet. These slots, particularly the trailing edge or the edge which breaks the contact between the roller and plate 52, are accurately located for these edges determine at what points the movement of the backing sheet stops. The, backing sheet should stop each time so that it is in predetermined relationship to the work table and printing frames and moves each time a distance equal to the length of the design unit. .Inasmuch as the backing sheet is formed of paper, an ordinary paper punch may be used to form the slots 52. Should they be improperly placed, small bits of be applied over the trailing edges of the slots to effect the desired adjustment.

.After checking the operation of the backing sheet and the switch arms 23 to determine if any tendency to shift laterally is adeq ately controlled, a print is made on the backi g sheet by use of one of the printing frames 3. This may be made at only one position or repeated around the'length of the backing sheet.

Cloth C from a bolt or roll Cl is fed through guide rollers 9 l onto the backing sheet.

cloth in passing therefrom is substantially flush with the surface of the backing sheet. The extremity of the cloth is placed over the backing sheet and onto the to make the'printcontains sufficient adhesive material to stick the cloth to the backing sheet.

The print made by the first printing frame is repeated on top of the cloth and'the remaining printing frames used-to make a complete multiple color printon the cloth. When all colorsof the design are printed, switch 58 is closed. The backing sheet moves forward at its fast speed permits contacts 5| and 53 to close; thereupon, the backing sheet creeps forward at slow speed until contact again breaks causing the motor to stop. The adhesivenessbetween the backing sheet and cloth is sufficient to pull the cloth forward to the following position without other means of connection therebetween. The peated," the on until the Normally cloth to maintain sufficient bond for moving the cloth along heavy cloth, it is "sometimes desirable to supplement the dyestuff with an adhesive by applying the adhesive directly to the backing sheet, preferably opposite the margins of the cloth if the design is less than the width of the cloth leaving such margins unprinted.

By the exercise of a little care very close registry may be obtained between the adjacent edges printing operation isthen rebacking sheet againmoved and so entire bolt of cloth is printed.

I of succeeding prints so that a continuous design may be printed on the cloth, comparable in appearance and accuracy of'registration to that obtained bylfar more expensive rotary printing machines.

While paper has been used as the backing be used. By reason of the fact that the cloth remains attached to and is held by the backing sheet during the entire multiple color printing operation very close registry is obtained. The cloth is prevented by the adhesiveness of the dyestuff from shifting on the backing sheet and the backing sheet is sufiiciently stiff and stretch free to maintain its position.

. The 7 guide rollers are preferably arranged so that the print. The dyestuff employed suiIicient dyestufi' seeps through the It is necessary that each time a particular section of the design on the backing sheet returns to position it registers perfectly with the printing frames. Although the backing sheet is used repeatedly there error is introduced by any slippage between the drums and the for each section of the backing sheet is determined by a corresponding slot 52; Furthermore, even though there may be an appreciable change in thelength of the backing sheet due to shrinkage or expansion, the only error that is thus introduced is the amount of shrinkage or expansion that has taken place between each slot and its corresponding section of the backing sheet, an obviously insignificant amount.

In practice, it has been found that a backing sheet of ordinary wrapping paper will permit printing of a standard bolt of cloth before the cumulative seepage of dyestuif through the cloth becomes objectionable. This, of course, may be controlled by regulating the viscosity of the dyestufi;- however, it is the matter of only a few minutes to replace the backing sheet so' that, in practice, the backing sheeti's replaced as each bolt is completed. If other materials such as sheet plastic is used, the backing sheet need not be replaced but merely cleaned from time to time. A still more permanent backing sheet may be made of sheet metal, in which event the operation of. the roller switch 5| isreversed; that is, it is arranged'to normally make contact and with the backing sheet. In printing to a drum forms with the cloth C a second roll I8. The I the circuit is open when the slot is engaged or a small piece of insulating material is applied in place of the slot.

The bond between the cloth and the backing sheet need not be great, but is weak enough to permit the cloth to be peeled therefrom For example, as shown in Fig. 3, the cloth passes from the printing apparatus or steamer II depending upon the subsequent treatment required for the dyestuii'. In either case. a housing I2 is provided. Guide rollers I3 and I4 are arranged at each end. A markoif sheet I5 initially formed in a roll I6 feeds over roller I3 through the housing If over roller I! I1 driven by a motor, not shown, and

cloth, after printing, passes onto the mark-off sheet and 'with mark-off through the housing II and is rolled therewith around the drive shaft 11.

Tocoordinate control of the printing apparatus and the dryer or steamer, a photo-electric unit may be employed. This consists of .a source of light 8| directed to a photo-electric cell 82 and positioned between the printing apparatus and the roller 15. The photo-electric unit is so arranged, as shown in Fig. 4, that when the cloth follows around the backing sheet as indicated by solid lines in Figs. 3 and 4 a relay is actuated to cause movement of the steamer or dryer is stopped.

My novel method, herein involved. of printing on cloth consists essentially in less backingsheet to pass in front of the screen printing apparatus; utilizing the adhesiveness of the dyestufi used in screen printing to hold the cloth to the backing sheet thereby to facilitate registry to permit multiple color printing; and

utilizing the adhesiveness of the dyestuff to draw is no cumulative error and no backing sheet because registration into either a dryer the marking-off sheet and. cloth through the dryer or steamer. When the utilizing an enddescribed structure,

the cloth from the source of supply onto the backing sheet. 7

Attention is now directed to the construction shown in Figs. 9 through 11, which incorporates an arrangementof the screen printing frames in which the frames are arranged in lateral series and, may be applied simultaneously to the cloth.

A bed frame IOI supports a pair of cross members I02 which in turn support a table I03. At

the extremities of-the table are rollers I04 and I05 around which pass a backing sheet I06. In place of the endless backing sheet I4 of the first the backing sheet is in the form of a web coextensive with the cloth to be printed. The sheet is supplied from a roll I01 mounted under the entering or beginning end of the table on suitable bracket bearings I08, and winds up after passing over the table on a roll I09 mounted on bracket bearings ll under the training or finishing end of thetable. The bearing brackets are arranged sothat the rolls may be readily inserted or removed.

Over the table are mounted screen printing units III, each unit comprises a hollow. rectangular outer frame 2 of angle iron section and an inner frame II3, the position of which is adjustable by quoins II4. Or, if desired the printing frame construction described in my previous patent may be used. Arms II extend rearwardly from each outer frame II2. Rearwardly of each frame is a plate 6 secured to the table I03. Each plate carries a pair of hinge pins II'I slidable in guide members 8' and adapted to be moved by a link and lever means I I9. The journal pins I H are adapted to move outwardly from each other to plvotally engage the extremities of the arms M5 and move inwardly to free the arms so that the printing units may be readily interchanged.

The journal pins hold the printing units in predetermined registry with the work table and are assisted by registry pins I03a set in the table which coact with sockets provided in brackets II2a extending from the outer frame II2 of each printing unit.

' Three printing units, designated generally A, B, and C, are illustrated, although two, four, or five may be provided. The printing units are positioned so that the width of the effective printing area I20 of each printing unit is just equal to the distance between the effective printing areas of adjacent printing units. 7

As in the first described structure the backing sheet is provided with registration slots 52 and the movement of the backing sheet is controlled by the apparatus shown in Figs. 5, 6, and 7 connected with the shaft of the roll I09. A roller switch I2I similar to the roller switch 5| is provided. The roller switch I2I is, however, provided with set screws I22 so that it may be accurately adjusted longitudinally with respect to the backing sheet. It is shown positioned over the rear marg n of the backing sheet between printing units B and C, but may be positioned elsewhere. g

Th registration slots 52 may be formed automatically in the backing sheet by a punch I23 positioned the proper distance from the roller switch I2I. The punch is shown positioned between the first pair of printing units A and B.

The printing frames are adapted to be tilted about the axes of the hinge pins. They may be raised manually or may be operated automatically or semi-automatically by a lifting mechanism polever I33 fulcrumed at its midportion and sitioned below the table along its rear portion. The lifting mechanism includes a lever I24 for each printing unit which is fulcrumed at its rear end by a bracket bearing I25 securedto the underside of the table near its rear edge and in substantial alinement with the, longitudinal axis of the corresponding printing unit. Each lever is bent upwardly at its forward or extended end and provided with a roller I26. The roller I26 is adapted to pass through an opening in and engage a plate I21 secured to the rear side of the outer frame I I2 of the corresponding printing unit.

The levers I24 areadapted to be raised by cams I28 mounted on a cam shaft I29 extending along the underside of the table I03. The shaft may be driven continuouslyby shown and the cams arranged so that the printing frames remain down long enough to permit the printing operation then raise to permit'movement of the backing sheet and cloth thereon. Or,

if desired, may go through-a single cycle of operation initiated each line by the operator. The frames are at all times free to be lifted manually by the operator.

The shaft I29 may also be utilized to operate the punch I23 as shown in Fig. 11. A lever I30 fulcrumed at its rear end by a bracket bearing I3I extends forwardly over the cam shaft and is connected at its forward end by a link I32 to the punch I23, which is shown as comprising a punch coactirlilg with a punch plate I34 under the backing s eet.

The backing sheet is adapted to be coated with an adhesive or semi-adhesivematerial I35 as it passes around the leading roller I04; The material is applied by a roller I36 which dips into a reservoir I31 containing the adhesive material.

The adhesive material should be just tacky enough to hold the cloth for the purpose of printing, but permit the cloth to peel therefrom as in the first described structure so that the cloth can .move into the steamer or dryer unit 1| as shown in Fig. 3. V

The various gums or adhesives which I have found suitable as an element in the printing dye such as tragacanth; gum arable, British gum" or dextrine. may be employed in the adhesive material I35. In addition certain elements of the printing dye age or evaporate and therefor require additions from time to time. These may be incorporated with the adhesive material I35 and absorbed by the cloth so as to be picked up by the dyestuff as it is applied to the cloth and thereby improve the printing operation. For example: in one family of dyestuff a material known commercially as Rongalite may be added to the adhesive to replace or replenish the Rongalite in the printing dye which may have deteriorated or evaporated. 7

Operation of the construction shown in Figs. 8, 9, 10, and 11 is as follows:

The printing units are adjusted with respect to each by means of the .quoins H4 so that the distance between their printing areas isjust equal to the width of their printing areas. The punch I23 is used to make an initial perforation 52.

The backing sheet is moved the exact width of the the table suitable means not relation with the table; a series oi printing screen irames hingedto a side of said table, and adapted to overlie saidw'ork area, the spacing between said screens being equal to or a multiple of the width of their printing areas; whereby as said backing sheetis moved instages determined by said drive means and instrumentalitm sections 0! said backing sheet register consecutively with said printing screens; and means for securing over 10 said backing sheet, a. cloth to be printed.

ROBERT F. FOARD.

aseaaeo The cloth is then fed onto the backing sheet under the first printing unit, designated A. A print is made and a new perforation is formed in the backing sheet. Then the backing sheet is advanced the width of the printing area as controlled by the roller switch l2! and a second print made with unit A. This is repeated and unit 13 is used on the first print. Units A and B are then used until the first print or impression is in registry with unit C, then the process is continued, all of the units A, B, and C are applied between each advance of the cloth and backing sheet.

The driving mechanism shown in Figs. 5 and 6 is connected with the shaft of roll I09 and although the diameter of the roll changes, the spacing is unchanged as it is governed by the space between perforations 52. The cloth when printed is removed from the backing sheet and into thenext machine as shown in Fig. 3.

It should be noted that the endless backing sheet arrangement shown in Fig. 1 may be used in conjunction with the printing screen arrangement shown in Fig. 8; and conversely the continuous backing sheet arrangement shown in Fig.

8 may be used in conjunction with the printing n:-

said drive means :to cause said drive means to change from its fast speed to its slow speed and thereafter stop with said backing sheet in a predetermined relation with the table; a series of printing screens, means incorporated in said screens and said table for positioning said printing screens in predetermined relation-with said table and thereby in predetermined registry with said backing sheet; and means for securing cloth to be printed to said backing sheet whereby successive sections of said cloth is moved by the backing sheet into said predetermined registry with .said printing screens.

2. A screen printing means as set forth in claim 1 wherein said printing screens employ dyestufi containing an adhesive constituting, when applied to said backing sheet and cloth, means whereby the backing sheet and cloth are secured tov each other.

3. In a means for screen printing on cloth: a plurality of printing screens adapted to be operatively positioned over. a work area; an endless backing sheet adapted to be moved along said work area; a drive means for said backing sheet, I

of unidirectional drive means interposed between said motor and advancing means, one of said unidirectional drive means being operatively connected when the motor is driving forward and the other when the motor is driving in reverse, a speed reduction and reversing unit interposed between one of said drive means and said'motor, whereby upon rotation of said motor in one direction said advancing means moves at a fast speed, and upon rotation of said motor in the reverse direction said advancing means continues at a slowspeed; and control means for said motor incorporating said backing sheet and adapted to effect chang from said fast speed to said slow speed and thereafter stop said motor; said backing sheet adapted to receive and carry the cloth to be printed.

5. In a screen printing means for cloth, the combination with a work table and a series of screen printing frames adapted to be placed on said table in predetermined relationwith each other and with said table, of a cloth feedin means comprising; a backing sheet in. the form ing table; a plurality of rinting frames arranged in consecutive series along said table in predetermined spaced relation with each other; a backing sheet adapted to be fed over said printing table and under said printing frames and adapted to carry the cloth to be printed; means for adhering the cloth to the backing sheet; and drive means for moving said backing sheet and cloth in stages along said table.

7. A screen printing means, comprising: a work table defining a work area; a backing sheet; means for moving said backing sheet over said table including a drive means having a fast speed and a slow speed, and an instrumentality incorporating said backingsheet for controlling said drive means to cause said drive means to change from its fast speed to its slow speed and thereafter stop with said backingsheet in pre-determined relation with the table; a series of printing screen frames adapted to be stacked vertically above each other at one side of the work table and movable in sequence over said work area; means incorporated in said screens and said table for positioning said printing screens in 'pre-determined relation with said table and thereby in predetermined registry with said backing sheet; and

means for securing cloth to be printed to said backing sheet whereby'successive sections of said