US2688917A - Silk screen printing press - Google Patents

Description

Sept. 14, 1954 G. w. REINKE SILK SCREEN PRINTING PRESS 5 Sheets-Sheet 1 Filed Nov. 5, 1950 INVENTOR. E W REINKE g EORG L I'LL! @O-OJE/YM ATT'YS Sept. 14, 1954 G. w. REINKE Y SILK SCREEN PRINTING PRESS 5 Sheets-Sheet 2 Filed Nov. 3, 1950 FIG.2

INVENTOR: GEORGE W. REINKE BY WNZoo-b ATT'YS P 1954 G. w. REINKE 2,688,917

SILK SCREEN PRINTING PRESS Filed Nov. 3, 1950 5 Sheets-Sheet 3 INVENTOR: GEORGE W REINKE MYM ATT'YS Sept. 14, 1954 G. w. REINKE 88,917

SILK SCREEN PRINTING PRESS Filed Nov. 3, 1950 5 Sheets-Sheet 4 INVENTOR: GEORGE W REINKE ATT'YS SILK SCREEN PRINTING PRESS Filed Nov. 3, 1950 5 Sheets-Sheet 5 ATT'YS Patented Sept. 14, 1954 SILK SCREEN PRINTING PRESS George W. Reinke, Park Ridge, 111., assignor to Roto-Screen Company, Chicago,

ration of Illinois 111., a corpo- Application November 3, 1950, Serial No. 193,904

9 Claims. 1

This invention relates in general to printin presses and, more particularly, to a new and improved silk screen printing press.

The method of printing, utilizing the silk screen process, is relatively old, having been performed by hand for many years. More recently, machines have been developed for carrying out the process, but for the most part they have been large, bulky devices expensive to manufacture and operate. Most silk screen printing machines have heretofore utilized the principle of a rotating drum or cylinder around which the stock to be printed upon is rolled during printing, while a silk screen is reciprocated in contact with the stock.

The hand method of utilizing the silk screen printing process avoided the use of expensive rollers and registering devices, but necessitated some means by which the screen could be withdrawn from the paper as the printing was being performed.

The principal object of the present invention is to provide a machine utilizing the silk screen method of printing wherein all of the advantages of both the hand method and machine method are combined into a simple and efiicient mechanism.

Another object of the invention is to provide a silk screen printing press which, by means of simple adjustments, may be utilized for printing on flexible material such as paper or cardboard, as well as on rigid material such as glass and sheet metal.

A further object of the invention is to embody in a single machine a novel arrangement of mechanism, whereby the various operations necessary for performing silk screen printing are all carried out'in a predetermined sequence and timed relationship.

Still another object of the invention is the provision of a so-called flange or hold-down bar which is caused to move in a predetermined path during operation of the machine for gripping the edge of flexible material, such as paper, during the printing operation, but which may be adjusted to become ineffective for gripping purposes when rigid stock is used.

A still further object of the invention is to provide a novel arrangement for the squeegee member which operates to force ink through the open interstices of the silk screen during the printing operation.

Another object of the invention is to provide a flexible frame for the silk screen, together with novel means operable to fiex the screen progressively away from the stock being printed upon during the printing operation so that, at the completion thereof, the screen will be completely free of the stock and may be removed to allow the next succeeding sheet to be inserted in its place.

A further object of the invention is to provide a novel arrangement in a silk screen printing press, whereby the stock printed upon will be allowed to leave the machine by gravity, thereby permitting the next succeeding sheet to be fed into the machine.

A further and more specific object of the-invention is to provide a novel arrangement for the inking fountain on the frame of the silk screen, together with a wipe-off bar at the opposite end of the screen, whereby the squeegee may cooperate with these two members to apply the right amount of ink through the screen and yet prevent any excess of ink from dropping back onto the screen after the printing operation has been completed.

Other objects and advantages of the invention will become apparent upon reading, the following description taken in conjunction with the accompanying drawings in which:

Fig. 1 is a rear elevational view of a machine embodying the present invention;

Fig. 2 is a vertical sectional view through the machine taken along line 2-2 of Fig. 1;

Fig. 3 is a fragmentary perspective view taken substantially along the plane of line 33 in Fig.

1 and illustrating the relative positions of all of the cams on the main cam shaft at the time a sheet is being placed in the machine prior to printing thereon;

Fig. 4 is a fragmentary vertical sectional view along. the line 4-4 of Fig. 3 illustrating the relative positions of the squeegee, screen, and two of the cams;

Fig. 5 is a fragmentary vertical sectional view along line 5-5 of Fig. 3 illustrating in elevation the position of the cam for operating the side guide;

Fig. 6 is a fragmentary vertical sectional view along line 6-6 of Fig. 3 showing in elevation the cam for operating the flange bar;

Fig. '7 is a fragmentary perspective view similar to Fig. 3, but showing the relative positions of the various cams at the beginning of the printing operation;

Fig. 8 is a fragmentary vertical sectional view along line 8-8 of Fig. 7 and similar to Fig. 4

showing the positionsof the squeegee, the screen, the cams for operating the front guide fingers and for elevating the screen at the beginning of the printing operation;

Fig. 9 is a fragmentary vertical sectional view lar to Figs. 3 and 7, but showing the cams on the same shaft in their respective positions near.-

the completion of the printing operation;

Fig. 12 is a fragmentary vertical sectional-viewtaken along line |2-I2 of FiglLand. similar to Figs. 4 and 8, but showing certain of, the screen and front guide finger cams in their position near the completion of the printing operation;

Fig. 13 is a fragmentary vertical sectional View 1 taken along line I3-l3 of Fig. 11 and similar to Figs. and 9 illustrating the position of the side guide. cam= near. the completion. of. the. printing operation;

Fig..1. 4=is a-fragmentary vertical sectional. view takenalong line. I l-[4 of Fig. 11 andsimilar to. Figs. 6. and 10, but showi'ngthe, flange. bar cam in .itsposition near the completion.ofitheprinting. operation;

Fig. isafragmentar-y perspective view simicams immediately after completion of. the printing. operation;

Fig.16 isa fragmentaryvertical. sectional view taken along line- I'6.-l6. of Fig. 1 5, and showing thevarious parts of. Fig. 12. i'nclud'ingthe screen and, front. guide finger, cams. intheir positions immediately. after the completion of, the printing operation;

Fig. 117 is afragmentary vertical sectional View taken along line lT-ll of. Fig. 15' and similar to Fig. 13, but showing the side guide cam. in its position immediately. after completion of the printing. operation;

Fig. 1-8 is a fragmentary vertically sectional'view taken along line. |8'.|8 of Fig. 1'5 and similar to Fig... 14,. butshowing the'fifange bar cam. inits position immediately. after. completion. of the printing. operation;

Fig. 19 isanenlarged-fragmentary vertical sectionaLview illustrating the. position of. the end gauge. fingers. and theflange or. hold-down. bar at the time when the; stock is. fed into. the machine;

various parts in their position at thebeginning of the: printing operation;

Fig. 2 1 .issimi1artoFig. 201. and illustrates. the.

partsintheir positions. near theend of the. printing operation;

Fig..22..is. a. view similar toFigs. 19,. 2.0 and-21,

but-showing. thepositions ofthe. parts after the.

printing operationhas. been completed. wherein the printed stock is allowed to be d'eliveredf'rom the. machine Fig- 23 is an. enlarged fragmentary sectional view through the end. gauge. fingers and flange or. hold-down bar illustrating. the parts in their positions when adjusted-for rigid stock such as Fig..2 0 is aview. similar. to Fig. 19 showingthe,

. lar. to. Fig. 11, but. showing, the positions-of the Referring now more particularly to the drawings and especially to Figs. 1 and 2, the machine comprises a suitable frame structure adapted to support the various moving parts thereof, which frame structure includes vertical side members I and 2 at the rear of the machine and similar vertical side members 3 at the' front of. the machine. A suitable form of base 4 may. be rigidly secured between the rear side members I and 2, and one or more additional side members 5 may be provided intermediate the front and back of the machine.

A reinforcing. anglev member 6 is preferably horizontally disposed at each side of the frameworkeand may extend from the front to the rear of the machine. Other reinforcing angle members may be provided such as the member 'i extending. across the rear of the machine and the members 8 horizontally disposed at each side of theframe- Other. horizontal reinforcing angle members 9 may alsobe provided. as illustrated, all of which maybe suitably. securedtogether. to. form a rigid framework- Within the framework of. the machine. there. may bev a supporting. memberv 19 in the formof.

a T extending horizontally betweenthe sidesof.

the frame for supporting a. bearingmounting I];

intermediate the ends. thereof- Abearing. I2 is.

mounted on the supporting member, li'in which a horizontally disposed. shaft. l.3'.is.journaled for rotation. The endsof shaft l3 may be rotatably. mounted in suitable bearingsat each side .ofthe framework. 7

Shaft I3 is the main cam shaft and has mounted; thereon four cams adjacent each end thereof. These. cams are so shapedandipositioned' onthe shaft relative to eachother. as to-eachoperate a different part, of thepress in synchronizedtimed relation during. the. operation thereof. These four cams, which have identical corresponding, cams. at thev opposite end of. shaft l.3,j are indicated by the numerals, l4, l5, ISand l1 andmay be, seen in rear elevation in Fig. 1 and inperspective in Figs. 3',- 7, 11 and 15..

A second camshaft. I 8; is located. above. and rear.- wardly of shaft l3 and is mounted for rotationirr suitable bearings at eachside. of. the machine.

Cam shaft [8- is provided withtwo identical cams.

19, one adjacent each end thereof. Cams [.9 .oper.-. ate toraise and lower. the bedframe on which the stock is positioned for printing and are. actIn-J. ated in timed relation with the cams onshaft. 1.3... Asprocket. wheel 20, is secured on. shaft l.3.at. one end thereof, and a similar sprocket. wheel1 2.l is. mounted on one end ofshaft I8 Suitable con.- necting means between these sprockets andfla power source causes. the, two. shafts. to rotate simultaneously at the same rate of'speed.

The driving mechanism Thepower for driving the cam shafts'and causing operation of the machine isprovided by a suitable source such as an electric motor 22 provided with a pulley 23 on the shaft 24. (Fig. 1).. A belt 25 is trained over the motor pulley 23' and. over a pulley 26 mounted on shaft 2] of a speed reducer 28. A shaft 29 extends from the. speed reducer 28 and has a sprocket wheel 30 mounted on one end thereof. A chain 3| is trained around; sprocket wheel 30 aswell as sprocket wheel 20 on shaft [3 and sprocket wheel 2] on shaft 18. Any slack in the chain is taken up by an idler sprocket wheel 32 suitably mounted for adjustment at one, side of the frame.

Another sprocket wheel 33 is mounted on the opposite end of shaft 29. A chain 34 is trained around sprocket wheel 33 and another sprocket wheel 35 mounted on shaft 36 which shaft extends .belt 38 trained therearound and around a corresponding pulley 39 on shaft 40. This shaft 40 is suitably mounted for rotation in bearing members 4| located on the outer ends of upwardly and outwardly extending supporting arms 42 at each side of the machine. Rotation of shaft 29 from the speed reducer will thus drive the pulleys 31 and the various belts 38 for the purpose of removing the printed stock from the press after the printing operation, as will be pointed out more specifically hereinafter. The printed stock is allowed to leave the bed frame by gravity after the printing operation has been completed, whereupon it is delivered to the moving belts 38 where any operator may remove the printed stock from the machine.

The bed plate A bed frame is provided to which the stock is fed and which supports the stock during the printing operation. This bed frame generally indicated at 43 in the various figures of the drawings, consists of spaced side arms 4445. These side arms are preferably secured together by one or more cross members 46 to maintain the bed frame rigid. Aplurality of supporting plates 41-48-49 may be fixed to the cross member 46 in spaced apart relation so that a bed 50 may be rigidly secured thereto.

The side arms 44 and 45, together with the bed plate 50, comprising the bed frame 43, are mounted for rocking movement on shaft l3. As will presently appear, the screen is mounted above the bed plate 50 and suitable means are provided to rock the bed frame from the open position of Fig. 4, at which time the stock may be fed thereto, to the closed position of Fig. 8 against the underside of the screen. This rocking movement of the bed frame is accomplished by rotation of cams 9 mounted on each end of shaft l8. Each of the side arms 44-45 has a cam follower 50a mounted thereon in rolling contact with the edge of cam l9. Thus, it will be evident that as cam |9 rotates in a counterclockwise direction from its position of Fig. 4 to its position of Fig. 8, the side arms 44 and 45 will be rotated in a counterclockwise direction about the shaft l3 as a center.

The front gauge One of the novel features of the present invention includes a front gauge or guide means for the stock so that each sheet will be fed into the machine to the same position for every printing operation. In the present machine the front gauge fingers are caused to be elevated a short distance above the bed plate at the time the stock is fed into the machine. These fingers are then lowered a short distance during the printing operation, and are then lowered still farther after the printing is completed, so that the printed stock may fall by gravity over the front gauge to be carried away by the belts 38.

A shaft 5| extends between the lower ends of the side arms 44 and 45 andhas mounted thereon in spaced relationship a plurality of arms 52. These arms are secured together intermediate their ends by means ofa cross bar 53. While Fig. 1 shows that there are four such arms 52, it will be evident that any suitable number desired may be utilized.

These arms 52 extend rearwardly and upwardly from shaft 5| and each is provided at its upper end with a gauge or guide finger 54 mounted thereon by any suitable means such as screws 55.

These gauge fingers are illustrated in section in Figs. 19 to 22, and 25, and are shown in relation to the bedplate in Figs. 3, 7, 11 and 15. All of the arms 52 together with their respective gauge fingers 54 are raised and lowered at properly timed and synchronized intervals by means of the cams 4 adjacent each end of shaft I3. The outermost of the bars 52 each has a cam follower 56 which is maintained in contact with the edge of its associated cam l4 by gravity. The

cams M are so shaped that during the rotation,

thereof the arms 52 will be elevated above the bed plate 50 at the time the stock is fed into the machine. The forward edge of the stock will then come against the gauge fingers 54 which regulate the position of the stock with respect to the screen. Each cam |9 rotates to elevate the bed plate 50 against the underside of the screen after the stock is in proper register. The arms 52 will then drop downwardly a short distance as will presently be described.

I The flange bar Inasmuch as the machine of the present invention has universal application and is designed to accommodate any kind of stock, including thin paper, flexible cardboard and heavier rigid material, such as glass and sheet metal, mechanism is provided which is useful in connection with certain material, but unnecessary when other material is used. For example, one common way of preventing movement of thin paper on a bed plate is by means of a vacuum. Thus, a vacuum may be created to hold the paper in place during theprinting operation and then released after the printing has been completed. Such a vacuum bed may be used in connection with the present machine although the details thereof have not been shown since it is a well-known expedient.

When other stock, such as card-board, is used,

-" then it may be desirable to provide some gripping or clamping means to grip the edge of the stock and hold it in place during printing. When other material, such as glass or sheet metal, is printed upon, it is unnecessary to provide any additional holding means therefor, it being sufficient to allow the sheet to rest at its forward edge against the gauge fingers during printing, although additional means, such as a vacuum bed, could be used if desired.

In the present case a flange bar or hold-down bar 51 is mounted transversely of the arms 52 adjacent the upper ends thereof and may be broughtinto position for the purpose of clamping stock to the bed plate during printing. This flange bar 51 is provided with a plurality of elongated openings 58 each in alignment with one of the bars 52. The lower inner part of each slot 58 is made smaller as at 59 thereby providing a shoulder and lower faces of the flange bar 51 (Figs. 19 to 22). The upper part of each slot 58 is of a size to receive the heads 6| of a pairof bolts 62, the undersides of the heads 6| being adapted to bear against the shoulder 60. The bolts 62 7( extend downwardly through the associated bar 52 and thus secure the 52. I

The flange bar 51 will thereupon be raised and lowered with the bars 52. The slots 58 in the flange bar cooperate with the bolts 62 to permit flange bar 51 to the bars or ledge 60 between the upper also a sliding: movement-60f flange bar. 51; in. a direction toward; and. away from the bed plate 9*. Fi l-us, Fig. 19. illustrates the flange bar 51 m an intermediate position.

Figs. 20 and 21 show the flange 'bar 511 in its extreme position toward the bedplate 5G", while Fig. 22: illustrates the flange bar its: extreme position away from the bed plate 5.0. This forward and backward movement of" the flange bar 511 is accomplished by means of thecams I15: mounted at. each end of shaft IE3. E ach'end of the flange bar 51' has secured to the underside thereof abar 63: flXed by meansrof bolts: 64 An arm 655 extends angularly downwardly from each bar 63: and has a cam follower 66 rotatably mounted thereon- Each cam tollower 6 6 is adapted to contact the edge of a cam I15 at oppositesides. of the machine,

1 which thereupon 'move the flange bar .51 with of a. sheet of. stock which has been fed into the machine. aga nst the guide fingers 54. In the various. figures thenumeral 68 represents a sheet of stock fed into the machine until the forward edge. thereof contactsvthe guide fingers 54. The

position of the various parts will be like that shown in Figs. 3, a, and 19,. When the flange bar is used, the cam l5 will cause the flange bar to move toward the bed plate 50 to the position shown in Figs. and 20, while at the same time cam. it has permitted the bars 52 carrying the flange. bar 5! to drop downwardly to a position where the forward edge of the flange bar contacts and holds the edge of the stock in the machine. As the machine continues with its cycle, and during the printing, the bars 52 and flange bar 51 will remain in the position shown in Figs. 20 and 21'. When the printing has been completed, suitable means, such as the spring.

69, will draw the flange bar 5'1 away from the bed plate when it is permitted to do so by cam i5, whereupon cam M will allow the bars 52 and. flange. bar 5'? to drop downwardly below the forward edge of bed plate 50 to the position shown in Figs. 15, 16 and 22. then be free to slide downwardly by gravity to the helts 3 8.

The foregoing describes briefly the operation. o f th e front guide fingers and the flange bar when.

stock" of particular material, such as paper or cardboard; is used and which must be held against the bed plate at its forward edge. As stated. hereinabove, it is not necessary to use the flangebar when certain other materials, such as. thin paper, glass or metal, is the stock printed upon. In all cases the stock is fed into the machine until the forward edge thereof comes against the gauge fingers. With certain materials no additional holding means is. necessary to hold them against inadvertent shifting movement during printing or after registering. In other cases a vacuum bed may be provided. In any event, the machine embodying the present invention is capable of being used with any of these materials.

Considering Fig. 23, the adjustment is there. shown, whereby the flange bar. may be moved.

The stock will.

8; to: a. position; where: it will notibe. caused: to move. toward and away from the: bed plate or at least will notbe caused to so move a sufficient; distance tov be effective. as a clamping means.

When this adjustment is to be. made; the bolts 84 may be loosened: and the bar 63 and arm 65 carrying. the cam follower 86. at each side of the machine: may be moved ashort distance the direction of the bed plate so that the cam follower 615 will be moved either entirely out of thepath of cam 15 or substantially so, therebypreventing: any substantial movement of' the flange bar to-- ward and away from the bed plate. When the flange bar ST is thus adjusted, it will still move up: and down. with the arms 52 by means of the cams. H, but will not" have sufiicien forward move-- ment' to overlap the work. I

' If desired, any suitable means such as a pin (not shown)" may-be positioned at'a suitable place on the machine frame to maintainthe arms and gauge fingers se a sufficient distance above the bed plate 50 to retain the stock thereon dur-- ing the printing operation. At the completion of the printing these parts may then be allowed to; drop downwardly, as previously described, to permit the stock to fall by gravity to the bolts 38..

The side guide In. printing operations the stock must be reg.- istered not only at its forward. edge, but. also along one side thereof to insure that the stock lies; squarely on. the bed plate with respect tutti-1e.- screen. In the present instance, the side guide: or. gauge pin mechanism and the-operation thereof. are clearly illustrated in perspective. in Fig-st 3, '7, 11 and 15. Their corresponding sectional. views. are particularly shown in Figs. 5, 9,. l3 and Referring particularly to. these figures, it will; be noted that the. bed plate 55 is provided adjacent the forward edge thereof, and. preferably" at. each side, with several openings such. as those; shown. at H! and H. A transversely extending; bar. 12 is located below the bed plate 5.0 and i-mmediately beneath the various. openings. 10. and; LI. A forwardly extending arm 1-3 ismounted om each end. of .the bar 12 and has pivotal: movement. on the. side frame members 4.4, and 45.- as? at 14. Thus, the transversebar 12 maybe raised;v andlowered in. accordance with a rocking motiom imparted to the armsv 13. 1

A pin or cam follower I5 is positioned adjacent the forward end of each arm 13 and is adapted to contact the edge of the. adjacent cam- I-B. on the lower side thereof. The arrangementofi arms 13, bar, 12, and pivots 14 is such that: the. weight behind pivot pins M will have a tendency: to: rotate arms 13 ina clockwise direction and urge the pins 15 upwardly against the edge: of cams. l6. These cams [6 are so shaped as to cause the arms 13 to rock causing the transverse bar 12 to be raised and lowered at predetermined timed intervals during the cycling of the press? The transverse bar 12 is provided with a-plurality of upwardly extending pins 16 each positioned immediately below one of the openings 101 and TI. A side guide member or gauge finger 11 is adapted to be placedover any one of the pinslli and is of such length that it will extend. through the adjacent opening 10' or H and above the upper surface of bed plate. 50' when thebar 1:2?is in elevated position as shown, for example. in. Figs. 3, 4 and 5. I

When stock is inserted in the .press,.--the fore Ward edge thereof may come against the front guide fingers 54, and one side thereof is caused to contact the side guide 11. When the stock is thus in register and the bed plate is elevated to come against the underside of the screen, the cams I6 will have rotated to their positions shown in Figs. '1 and 9 thereby allowing the bar 12 to move downwardly a sufficient distance to bring the side guide 11 below the upper surface of bed plate 50. Thus, the side guide does not create any interference with the screen or screen frame as the squeegee is moved thereover. After the printing operation has been completed, the cams I6 will have rotated to the position of Figs. 15 and 17 to elevate the side guides 11 a sufficient distance again to be in registering position for the next sheet of material.

The screen and screen frame At each side of the machine additional strengthening members in the form of elongated plates or bars 18 are rigidly secured between the intermediate uprights and the rear uprights I and 2. A cross member 19 extends between these plates 18 at the upper rear end thereof as may be seen clearly in Figs. 1, 2, 4, 8, 12 and 16. An additional cross member 80 is welded or otherwise fixed to member 19 and has mounted thereon a plurality of spaced L-shaped clamping members 8I. As is customary, the silk screen is secured in a frame, but the frame in this instance, generally indicated by the numeral 82, has certain novel features of construction which will now be described. The screen frame 82 has a cross member 83 at its upper end preferably consisting of a wooden member 84 and a thin metal plate 85 mounted on one side thereof. The side members of the frame also consist of a bottom wooden member 86 and a top metal member 81 fixed thereto. This construction, including the combination of a thin metal stri and a wood strip, provides for strength in the frame as well as permitting a certain amount of resiliency so that it may be easily bent or flexed during the printing operation to lift the screen away from the stock progressively as the ink is being applied thereto.

The bottom of the frame has a cross member 88, and a trough 89 is located between the framesides at the bottom thereof and is adapted to hold a quantity of ink.

The entire screen frame is held against lateral movement by clamping in the machine framework. The upper end 83 of the screen frame consisting of the cross members 84 and 85 is placed against one side of the L-shaped members 8| and are then held in that position against movement by a clamping or wipe-off bar 90. A

plurality of bolts 9| corresponding in number to the L-shaped members 8I each extends through a lug 92 extending forwardly from the cross member19. The bottom ends of bolts 9I thereupon contact the upper face of clamping bar 90, thereby clamping the upper end of the screen frame 82 rigidly in place.

The cams I1 at each end of shaft I3 are the operating cams for elevating the lower end of the screen during the printing operation. In order to accomplish this, there is provided a bar 93 (Figs. 3, 7, 11, 12, 15, 16 and 22) at each side of the machine pivotally mounted on the shaft 5|. The upper or rear end of each bar, 93 has a pin 94 extending inwardly therefrom. The pin 94 at each side of the machine is of suflficient length to accommodate a cam follower 95 and a roller 96. The cam follower 95 engages the edge of its associated cam I1, whereby rotation of the cam will raise and lower arm 93. Roller 96 is adapted to contact the underside of the side members of the screen frame so that as the bar 93 is raised and lowered the lower end of the screen frame will likewise be moved upwardly and downwardly.

The cams I1 are so positioned on shaft I3 with respect to the other cams heretofore described that rotation thereof during the machine cycle will cause the bottom portion of the screen to begin an upward movement immediately behind the squeegee as the printing operation is being carried out. As soon as the printing operation has been completed and the printed stock has left the bed frame, the cams I1 will permit the screen to assume its normal fiat position as the bed plate is being lowered to receive the next succeeding sheet of material.

The squeegee assembly A stub shaft 91 (Fig. 2) is mounted at one side of the machine and has two sprocket wheels mounted for rotation thereon. One such sprocket wheel may be seen in Fig. 2 and is indicated at 98. Another sprocket wheel 99 is mounted for rotation on a stub shaft I00 at each side of the machine at the upper part of the plates 18. Referring for a moment to Fig. 2, it will be noted that a chain IOI is trained around sprocket wheels on shaft 36 and shaft 91. Chain I 02 at each side of the machine is trained around the sprocket wheels 98 and 99. Whenmotor 22 drives shaft 29 from speed reducer 28 to rotate shaft 36, as heretofore explained, chain IOI will drive chain I02 by means of the respective sprocket wheels around which these chains are trained.

The squeegee assembly is generally indicated by the numeral I03 in Figs. 4, 8, 12 and 16, and the details of this assembly may be understood more clearly by viewing Figs. 25 and 26. This squeegee assembly I03 is mounted for movement with chain I02 and is maintained in proper position during the printing operation by the aid of a bar I04 at each side of the machine extending between the respective sprocket wheels 98 and 99. v

The squeegee assembly is composed of an upper plate I05 which has a pair of spaced bars I06 and I01 rigidly attached thereto and extending downwardly therefrom. A spacer or backing bar I08 is located between the bars I06 and I01 and is adapted to back u the edge of the squeegee blade I09. This blade I09'is formed of a flexible material such as rubber, or the like, and is clamped between the bars I06 and I01 by means such as screws. The outer edge of blade I 09 will extend a sufiicient distance beyond bars I06 and I01 so as to flex slightly and yet be sufliciently firm when in contact with the silk screen to force the ink through the screen onto the stock.

This squeegee assembly I03 extends between the chains I02 at each side of the machine and is provided with a novel mounting means whereby the assembly may be carried with the chains as they are driven during the cycle of the machine.

A hub member I I I at each side of the machine is adapted to have the ends of plate I05 secured thereto by means such as bolts II2. Each hub III also has mounted thereon a pair of spaced rollers II 3 and H4 between which is located a substantially triangular plate member I I5. A connecting bar I I6 is fastened at its ends to the plates 11 H :to increase the rigidity 'of the entire assembly and to cause the assembly to be maintained in :proper alignment at all times.

The narrow end of each plate H5 is provided with a pin ll'i on which a roller I I8 is rotatably mounted. The outer end of each hub member -I l l is secured rigidly to the associated chain 102 by fixing one of the links of the chain to the end of the hub to prevent any relative rotation thereof. This mounting may be accomplished in any suitable manner but in actual practice it has been found expedient to remove adjacent pins from one of the chain links and substitute therefor longer pins having a press fit into suitable openings on opopsite sides of the center of the hub.

The outer roller H4 at each side of the machine and the smaller rollers I I8 cooperate to maintain the squeegee blade I09 against the screen during the printing operation by contacting the lower edge of bar NM. The inner roller 1 13 is caused to bear downwardly and roll against the side members of the screen frame, thereby preventing cam I?! from elevating the screen away from the stock at any :point except rearwardly of the squeegee during printing, andlinsures .that the screen will be maintained against the stock at all points forwardly thereof.

.A quantity of ink H9 is initially placed in the trough 89 so thatthesqueegee blade may pick up some of this :ink and spread .it over the screen during printing. At the end of the printing operation there will still bela quantity of ink which theblade will carrywithittothetop of the screen and which will be left at that .point as .the blade leaves the screen. Such quantity of ink at the top of the screen is indicated by the numeral [218. In order to prevent any excess ink from running back onto the blade .and dropping back onto the screen, the lowermost edge of wipe-off bar 90 .is so positioned .as to-act :as a wipe-off :member against which the forward edge of the squeegee blade may come as it is caused to move upwardly away from the screen, as illustrated more clearly in Fig. 1-6.

After the first printing operationhas occurred, the quantity of ink 12-0 at the top of the screen actually acts as the inking foun'tainr Thereason for this that after the ink has beendeposited there the squeegee assembly then travels downwardly along the upper reach of chains 113.2 to begin the next printing operation. The squeegee blade will have retained some of the 'ink thereon in a :s-u'fficient quantity for the next printing operation. When it reaches the top of the screen the :ink at that point will have started to flow downwardly, but the squeegee blade will pick up a quantity .of this ink .and .retain 'it during the movement downwardly and back to initial printing position. The wipe-off bar 90 merely wipes the @edge of the squeegee blade so that excess ink will not drop back onto the screen.

Operation roller 50a thereon is in contact with the lowest part .of cam 1l9. The arms 52 carrying the front guidefingers :54 will :be'in elevated position where the'cam rollers 56 are in contact with the highest part of cams l4. The arms 13 carrying bar '12 on i which the side guide H is mountedwillhave the campins '15 thereof in-contact with the highest :part of name '16 so that the guides H will be elevated above the surface of the bed plate 5!).

The parts are thus in position to receiveasheet of stock 68 on the bed plate '50 and to register :properly the stock at the forward edge thereof and along one side. -At this point the squeegee assembly I03 has almost reached the lower end of chain 102 prior to the beginning of the printing operation. I

As the machine begins its cycle, cams I9 rotate to elevate the bed :plate 50 with the stock 68 thereon up to a position into contact with the screen, as shown in Fig. -8. At this pointcam 14 will have rotated a 'sufii'cient distance so that the cam roller 56 will be in contact with the lowest point on the cam M to lower the bars 52, guide fingers 54 and flange bar 51 to clampingposition for clamping the forward edge of the stock, if the stock is of such nature that the flange bar is needed. Cam i6 will have rotated to .a position shown in Fig. 9 where pin 15 'is contact with the lowest point on the cam whereupon the .side guide ii will be lowered beneath the surface-of ,bed plate 50 and prevent "any interference with the screen. At this point the squeegee assembly 103 will have started its upward travel with the lower reach of chain I02 and is ready :to'begm the printing operation.

,As the printing continues cam 12"! being no tated to elevate arms as which have their rollers in contact with the underside :of the screen. The lower :end of the screen 'is thus elevated progressively as the squeegee :moves upwardly across the screen. The rollers ell-3 .at :each side of the machine, being in contact with the upper surface of the screen, will prevent the screen from being lifted from the :stockat all points forwardly thereof. Fig. 12 illustrates 'these various apaiits near the completion of the printing operation.

When the printing is completed .and the machine continues the cycle, the squeegee assembly I03 will continue it upward movement to pick up more ink to carry back to the initial printing position thereof. After this ink has been .pi'cketl up by the squeegee the front edge 'of the blade will be wiped off by the edge of bar 80.

When the printing operation has been completed, cams 14 will allow the flange bar t l-and guide fingers 54 to drop downwardly below the bed plate 50 whereupon the printed stock 68 will fall by gravity to the belts '38 :for conveyance away from the machine. 7 Cam 19 will have rotated to the position shown in Fig. 116 where :cam follower 50a begins to move toward the lowest point on the cam to returnthe bed plate 'E'Nl back to its original position. Cam l 6 acts on pin 15' to elevate the "side guide 11 bac'kto its position above the bed plate '50, and cam M ail-lows the screen to be returned to its initial position to begin the next printing operation. 1 From the foregoing description, it will be-cbserved that many novel features have been brought together andcornbined in a unitary machine which is capable of universal adaptation. That is to say, with the present -inver-ition it has become unnecessary to manufacture 'a different machine for each different material to "be printed upon. 7 All machines may be constructed in the same way and only minor adjustments are quired to permit printing on thin paper, heavy paper, cardboard or rigidma'terials, such as glass or sheet metal.

Changes may be made in the for-m, construe tion and arrangement of parts from those disclosed herein without in any way departing from 13 the spirit of the invention or sacrificing any of the attendant advantages thereof, provided, however, that such changes fall within the scop:

of the claims appended hereto.

The invention is hereby claimed as follows:

1. A silk screen printing press comprising a main frame, a bed adapted to receive a sheet of material to be printed upon, a screen positioned above said bed, means for imparting a relative movement between said bed and screen toward] and away from each other for printing, a squeegee for forcing ink through said screen, means for moving said squeegee from one end of said screen to the other end thereof and return, and cam means operable in timed relation with the movement of said squeegee for flexing said screen progressively away from said bed immediately behind said squeegee during printing.

2. A silk screen printing press comprising a main frame, a bed mounted for rocking movement on said frame and adapted to receive a sheet of material to be printed upon, a screen positioned above said bed, means for rocking said bed toward and away from said screen for printing, a squeegee for forcing ink through said screen, means for moving said squeegee from one end of said screen to the other end thereof and return, and cam means operable in timed relation with the movement of said squeegee for flexing said screen progressively away from said bed behind said squeegee during printing.

3. A silk screen printing press comprising a main frame, an angularly disposed bed mounted for rocking movement on said frame and adapted to receive a sheet of material to be printed upon, a screen positioned above said bed, means for rocking said bed toward and away from said screen for printing, a squeegee for forcing ink through said screen, means for moving said squeegee from one end of said screen to the other end thereof and return, front end guide means and side guide means for properly registering the sheet for printing, means for elevating and maintaining said front guide means above said bed before and during the printing operation and for lowering the front guide means below said bed after completion of printing to allow the sheet to slide out of the press along said angularly disposed bed, means for elevating said side guide means above said bed prior to printing and for lowering and maintaining the side guide means below said bed during and after printing, and cam means operable in timed relation with the movement of said squeegee for flexing said screen progressively away from said bed behind said squeegee during printing.

4. In a silk screen printing press having universal application for printing on all types of materials, the combination of a bed for receiving a sheet of material, a screen positioned above said bed, means for moving said bed into contact with said screen for printing, a squeegee movable along said screen for forcing ink therethrough, and combined sheet registering and gripping means adjacent the forward end of said bed, including a plurality of arms mounted for rocking movement and terminating adjacent the forward end of said bed, a flange bar extending transversely of said arms and mounted thereon so as to be movable therewith and with respect thereto, means for elevating said arms above said bed and for lowering said arms a predetermined distance before the printing operation begins, means for moving and holding said flange bar toward said bed in overlapping relation with 14 the edge thereof to grip the sheet, during printing, and meansto withdraw said flange bar from said bed after completion of the printing, whereby said flange bar and arms will move below said bed to permit removal of the sheet therefrom.

5. In a silk screen printing press having universal application for printing on all types of materials, the combination of a bedfor receiving a sheet of material, a screen positioned above said bed, means for moving said bed into contact with said screen for printing, a squeegee movable along said screen for forcing ink therethrough, and combined sheet registering and gripping means including a plurality of arms mounted for rocking movement and terminating adjacent the forward end of said bed, a flange bar extending transversely of said arms and mounted thereon so'as to be movable therewith and with respect thereto, means for elevating said arms above said bed and lowering said arms a predetermined distance before the printing operation begins, means for moving and holding said flange bar toward said bed in overlapping relation with the edge thereof to grip the sheet during printing, means to withdraw said flange bar from said bed after completion of the printing, whereby said flange bar and arms will move below said bed to permit removal of the sheet therefrom, and means to render said flange bar'inoperative for gripping when sheet material of a different type is used.

6. A silk screen printing press comprising a main frame, an inclined bed mounted for rocking movement on said frame and adapted to receive a sheet of material to be printed upon, a screen positioned above said bed, cam means for rocking said bed into contact with said screen during printing, a squeegee movable over said screen and in contact therewith for forcing ink through said screen, and cam means operable against the underside of said screen adjacent one end thereof and in timed relation with said first cam means and with movement of said squeegee during printing for flexing said screen progressively away from said bed behind said squeegee.

7. A silk screen printing press comprising a main frame, an inclined bed mounted for rocking movement on said frame and adapted to receive a sheet of material to be printed upon, a screen positioned above said bed, cam means for rocking said bed into contact with said screen during printing, a squeegee movable over said screen and in contact therewith for forcing ink through said screen, guide means for registering the sheet prior to printing thereon, a second cam means for moving said guide means into and out of registering positions, and a third cam means operable in timed relation with movement of said squeegee during printing for flexing said screen progressively away from said bed behind said squeegee.

8. A silk screen printing press comprising a main frame, an inclined bed mounted for rocking movement on said frame and adapted to receive a sheet of material to be printed upon, a screen positioned above said bed, cam means for rocking said bed into contact with said screen during printing, a squeegee movable over said screen and in contact therewith for forcing ink through said screen, guide means including guide fingers for registering the sheet prior to printing I said clamp bar into gripping contact on said bed,

and for moving said guide means out of registerifig and damping position vbelow said bed after eom'pletion of the printing operation,- whereby the printed sheet will be permitted to slide from the bed due to the inclination thereof.

9; A silk screen printing press comprisin a main frame, an inclined bed mounted for rooking movement on said frame and adapted to reciv'e a sheet of material to be printed upon, a 'sereen positioned above said bed, earn means for melting said bed into contact Withsaid screen during printing, a squeegee movable over said soreen and in contact therewith for forcing ink throii'gh said screen,gi1ide means for registering the sheet prior to printing thereon, a second cam means for moving said guide means to registering position above said bed prior to printing and for moving said giiide means out of registering position below said bed after completion of the print; ing operation, whereby the printed sheet willbe ije'rmit'tedto slide from the bed due to the iriolinatio'n thereof, and a third earn means o erable in timed relation with movement of said squeegee during printing for flexing said screen progressively away from said bed behind said squeegee; said second and third cam means being mounted on a single cam shaft and arranged to operate in timed relation with each other and with said first cam iiieans.

References Cited in the fil'e or this patent UNITED STATES PAI'ENTS

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