US3155034A

US3155034A - Silk screen printing press

Info

Publication number: US3155034A
Application number: US149332A
Authority: US
Inventors: George W Reinke
Original assignee: Rineglas Inc
Current assignee: Rineglas Inc
Priority date: 1961-11-01
Filing date: 1961-11-01
Publication date: 1964-11-03
Anticipated expiration: 1981-11-03

Description

G. W. REINKE SILK SCREEN PRINTING PRESS 8 Sheets-Sheet 1 Iln 36 INVENTOR. GEORGE W. REINKE BY www ATTORNEYS Nov. 3, 1964 Filed Nov. l, 1961 Nov. 3, 1964 G. w. REINKE SILK SCREEN PRINTING PRESS 8 Sheets-Sheel 2 Filed Nov. l, 1961 INVENTOR.

GEORGE VV. RElNKE AT TORNEYS Nov. 3, 1964 G. w. REINKE SILK SCREEN PRINTING PRESS Filed Nov. l, 1961 INVENTOR. GEO RGE VV. REINKE AT TORNEYS Nov. 3, 1964 G. w.RE'|NKE SILK SCREEN PRINTING PRESS 8 Sheets-Sheet 4 Filed Nov. l, 1961 I NVENTOR.

ATTORNEYS Nov. 3, 1964 G. w. REINKE 3,155,034

SILK SCREEN PRINTING PRESS Filed Nov. l, 1961 8 Sheets-Sheet 5 INVENTOR. GEORGE W. REINKE ATTORNEYS Nov. 3, 1964 G. w. REINKE SILK scREEN PRINTING PRESS 8 Sheets-Sheet 6 Filed NOV. l, 1961 W G F INVENTOR,

GEORGE VV4 REiNKE ATTOF? NEYS Nov. 3, 1964 Filed Nov. l, 1961 G. w. REINKE 3,155,034

SILK SCREEN PRINTING PRESS 8 Sheets-Sheet 7 INVENTOR.

GEORGE w REW KE ATTORNEYS United States Patent Oiice 3,155,034 SLK SCREEN PRINTHQG PRESS George W. Reinke, Barrington, Ill., assignor t Rinegias, Inc., a 'corporation of Illinois Filed Nov. 1, 1961, Ser. No. 149,332 S Claims. (Cl. i- 120) This invention relates in general to a silk screen printing press, and more particularly to a silk screen printing ress capable of printing on either iiexible or rigid types of materials with great speeds. Still more particularly, the press of the present invention includes a drum over which the silk screen is driven in continuous motion in one direction.

Heretofore, attempts have been made to develop a silk screen printing press where the screen was to be arranged in cylindrical form, but diiiiculties encountered prevented the successful development o-f any such press. One of the main problems resided in the handling of the screen, wherein a sagging, bagging, bulging, or the like problem always existed.

I-t is therefore an object of this invention to provide a silk screen printing press, wherein the silk screen is arranged in cylindrical form, and wherein the above identitied difficulties have been overcome.

Another object of this invention is to provide a silk screen printing press wherein the silk screen is arranged in cylindrical form and continuously driven to thereby provide greater attainable printing speeds.

A sti-ll further object of this invention is to provide a silk screen printing press wherein the silk screen is arranged in cylindrical form and supported over a drum which eliminates any sagging or the like condition in the screen during operation of the press.

The press of the invention includes a stationary drum having a plurality of longitudinally extending and circumferentially spaced silk screen supporting elements over which the silk screen may be continuously driven in one direction by driving means arranged at opposite ends of the drum. A frame is provided for supporting the silk screen and :is mounted o-n the driving means for rotation therewith relative to the drum. In a preferred embodiment, the screen supporting elements on the drum comprise freely rotatable rollers, although it should be appreciated that the roller-s may be driven if so desired. In another embodiment, the screen supporting elements comprise corrugated sheeting arranged in cylindrical form, wherein the corrugations define longitudinally extend-ing and circumferentially spaced screen supporting elements.

A squeegee is provided within the drum to engage against the inner surface of the silk screen and to drive ink therethrough in the appropriate places, which ink may be fed to the screen by means of an elongated troughshaped reservoir arranged within the drum. A lower roller is driven at the same speed as the silk screen and for supporting material to be printed in engagement with the silk screen, and any suitable means may be employed to feed the material to be printed to the silk screen.

it should be appreciated that the present invention is being described in connection with the usage of a silk screen, but that metal stencil material or other suitable material may be util-ized in place of the s-ilk screen. Moreover, a metal wire screen may be mounted on the drum, where the screen is formed into a cylindrical shape,

ansias Patented Nov. 3, 1964 either by weaving, welding or some other satisfactory method. Accordingly, the term silk screen or silk screen printing are terms used in this application that include the use of screens formed of other suitable materials, such as metal, nylon and the like.

Another feature in lthe invention is to have a silk screen .supporting frame capable of stretching the silk screen about the drum. The frame is initially in the flat when fthe silk screen is .attached thereto, but so constructed as to permit the screen to be cylindrically formed about the drum. A silk screen driving arrangement is provided at each end of the drum to which the silk screen frame is attached. The `frame .includes a pair of spaced wooden members that are cut partially through at spaced intervals to render them flexible so that they may be formed in a cylindrical fashion for likewise forming the silk screen. Spring steel plates are bolted to the Wooden side members to give them the neces-sary strength, and at opposite ends wooden end members are provided for attachment to the side members and to define a rectangular frame to which the silk screen may be attached.

Where a preformed metal wire cylinder is employed, the

ends may be supported on. solid metal rings, the wire being attached to the inner surfaces of these rings.

Therefore, it is .another object of this invention to provide a silk screen frame for mounting a silk screen on a drum in cylindrical form.

A further object of this invention is in the provision of a `flexible silk screen frame adapted to have a silk screen attached thereto and which is so constructedy that it may be ben-t into a cylindrical form for mounting a silk screen and driving a silk screen on a stationary drum.

During the printing operation, and when a sheet of material to be printed is not fed between the silk screen and the lower roller, the ink to be normally received by a sheet of material to be printed will then be impressed on the lower roller. I-f this ink is allowed to remain on the lower roller, a messy operation of subsequent printing and the ruination of several sheets of material take-s place until the ink is completely removed fromthe lower roller. In order to avoid this situation, another feature of the invention resides in the provision of a scraper capable of clean-ing the lower roller when it is impressed with ink because of the failure of a sheet o-f material to be fed -to the silk screen. Normally, the scraper .is not in engagement with the lower roller, but may be actuated into engagement by means of any suitable device. A mechanical or electrical detection device is employed adjacent one side of the .silk screen .and lower roller to detect the absence of a sheet of material and to actuate the scraper into engagement with the lower roller.

It is a further object of this invention to provide a mechanism for removing ink from the lower roller of a silk screen printing press which has been impressed thereon because of the failure of a sheet of material to be printed.

It should be further appreciated that with the advent of newly developed inks which man be printed wet color over wet color, that the present invention may be readily utilized in tandem or multiple for carrying on a multiple color printing operation. Where sheets of material are to be used to be printed on, the arrangement of a plurality of presses as in the present invention in alignment with each other may be employed wherein a single sheet feeding means extends through a line of presses. Where printing is to be accomplished on a web of material, multiple color printing may also be accomplished, but in this case the silk screen supporting drum would be movable along the vertical to accommodate the silk screen frame end members when they pass the lower roller. Either rigid or flexible types of materials to be printed on may be employed, wherein no sheet handling changes are needed.

Accordingly, it is still a further object of this invention to provide a silk screen printing press that is adaptable to be used in tandem or multiple for expediting multiple color printing operations with great speeds.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts, in which:

FIG. 1 is a perspective View of the silk screen printing press of the present invention, and looking at the sheet feeding end of the silk screen drum;

FIG. 2 is an enlarged fragmentary side elevational view of the printing press of FIG. 1, and illustrating the parts of the sheet feeding mechanism in another position than that shown in FIG. 1;

FIG. 3 is a transverse sectional view of the printing press and taken substantially along line 3 3 of FIG. 1;

FIG. 4 is a fragmentary enlarged perspective view of a detailed portion of the feeding mechanism and taken substantially along line 4 4 of FIG. 1;

FIG. 5 is a View similar to FIG. 4 but showing the parts in another position;

FIG. 6 is a fragmentary enlarged perspective view of a detailed portion of the sheet feeding means;

FIG. 7 is an enlarged fragmentary view of a portion of the silk screen supporting drum and associated parts at one end thereof;

FIG. 8 is a transverse sectional view taken substantially along line 8 8 of FIG. 7;

FIG. 9 is an enlarged transverse sectional view, partly fragmentary and taken through the stationary drum and lower roller, and illustrating the cooperation of the sheet feeding means, lower roller and silk screen frame elements;

' FIG. 10 is a bottom .plan view of the trough-shaped ink reservoir and taken substantially along iine 10 10 of FIG. 9;

FIG. 11 is an enlarged detail sectional view of a roller mounting taken substantially along line Il ll of FIG. 9;

FIGA 12 is a perspective view of the silk screen supporting frame according to the invention and shown in cylindrical form as it would appear on the supporting drum;

FIG. 13 is an enlarged top perspective view of the silk screen supporting frame with a silk screen in position laid out along the horizontal and shown before being mounted on the drum;

FIG. 14 is a perspective view of the bottom of the silk screen supporting frame shown in FIG. 13;

FIG. 15 is an exploded view of the silk screen sup porting frame and silk screen of FIGS. 12-14 showing the parts relative to each other;

FIG. 16 is an enlarged detail view of a portion of one` of the side members of the frame;

FIG. 17 is an enlarged fragmentary sectional View taken substantially along line 17 17 of FIG. 14;

FIG. 18 is a perspective View of a power train for the press of the present invention;

FIG. 19 is a perspective view of a modified drum;

FIG. 20 is a fragmentary enlarged and broken View of one end of the drum in FIG. 18;

FIG. 21 is a perspective view of a plurality of presses according to the present invention arranged in line rand for printing on sheets of paper;

FIG. 22 is a perspective view of a plurality of printing presses according to the present invention arranged in line and for printing a web of paper; and

FIG. 23 is a top plan View of the squeegee arrangement showing the main squeegee and the auxiliary squeegees.

Referring now to the drawings, and particularly to FIGS. l, 3, 7, 9 and 18, the silk screen printing press of the present invention includes generally a silk screen drum 22 about which the silk screen is driven, a silk screen frame 23 for mounting the silk screen on the drum, a driving ring 24 at each end of the drum to whichthe silk screen frame is connected and for driving the silk screen about the drum, a lower printing roller 25 arranged to support the material to be printed in engagement with the silk screen, and means for detecting the absence of the material to be printed and for removing ink from the lower roller which includes a detector 26 and a scraper 27.

The material to be printed may be paper or any other suitable type of material, but for purposes of simplicity it will be hereinafter referred to as paper in describing the present invention. Further, the printing press of the present invention may be employed as capable of printing on sheets of paper or a web of paper depending upon the desires of the user, but the invention is herein shown as associated with printing sheets of paper. In this regard, a sheet feeding means, generally indicated by the numeral 28, FIG. 1, is provided to successively feed sheets of material between the drum and lower printing roller. Any other type of sheet feeding means may be used if so desired.

The press includes the usual type of framework, such as opposed side plates 29 and 30 arranged with respect to

opposed end plates

31 and 32 to define a rectangular framework, and which is supported above the oor by means of corner legs 33. Extending upwardly from the opposed side plates 29 and 30 are

drum mounting members

34 and 35 interconnected at their upper ends by a cross member 36.

The drum 22 includes a pair of transversely extending spaced supporting

rings

37 and 38 mounted on four longitudinally extending and circumferentially spaced support rods 39, as shown more fully in FIGS. 3 and 18. These support rods extend completely across the machine and are secured at their opposite ends to the

drum supporting members

34 and 35. The support rings 37 and 38 receive therebetween a plurality of closely circumferentially spaced and longitudinally extending silk screen supporting rollers 40. These rollers may be constructed in any suitable manner such as being hollow as shown in FIG. 11, and having a bearing 41 mounted at each end receiving a stub shaft 42 which may be threaded at its outer end and received in an opening in the corresponding support ring and fastened thereto by a nut 43. The rollers 40 as shown are freely mounted to rotate by action of the silk screen engaging therewith and moving about the drum, although it may be appreciated that the rollers may be power driven so that their peripheral speed equals that of the silk screen, if such an arrangement is thought to be necessary. As seen in FIG. 9, a silk screen 44 is carried by the frame 23 and arranged about the drum so that it is tensioned over the rollers 40, whereby any sag or bulge is completely eliminated.

AIT alternative embodiment for providing circumferen- 4tially spaced and longitudinally extending silk screen eliminated and that essentially the corrugated plates would be substituted therefor.

In order to mount the silk screen 44 about the drum 22 and to drive the screen thereabout, the specially constructed silk screen frame 23 is provided which is capable of being laid out or arranged in the flat as shown in FIGS. 13 and 14 when mounting the silk screen thereon and being flexible to be bent around the drum as seen in FIG. 12. Further, the frame is wrapped around and connected to the driving rings 24 which serve to drive the silk screen about the drum. Referring particularly to FIGS. 1217, the silk screen frame includes opposed Wooden side bars 48 and end bars 49. The side bars 48 are flexibly constructed so that they can be bent around the driving rings 24, and in this regard these wooden members are preferably of plywood and include a plurality of sections 48a each having a plurality of transversely extending slots 50 along the side that faces inwardly toward the driving rings as seen in FIG. 12. The slots 50 are cut with a depth necessary to give the required flexibility of the frame when training it around the drum, but not to such a depth as would cause fracturing of the wooden bars. In order to reinforce the wooden bars 48 and to connect the sections 48a together, a metal plate 51 of the same length as the bars is arranged along the side opposite the slotted sides of the bars. To further reinforce the wooden bars, a plurality of shorter metal plates 52 of any desired number are provided along the metal plate 51 and are together therewith secured to the wooden bars. These

plates

51 and 52 and the wooden bars may be secured together in any suitable fashion such as by rivets, where the holes through which the rivets extend are sized to allow some slidable movement between the plates when the plates are bent into a circular form as when the frame is mounted on the driving rings.

The silk screen is suitably fastened to the

wooden bars

48 and 49 by staples, tacks or other such fastening means, and as can be seen more clearly in FIG. 17, opposite edges of the silk screen 44 may be fastened to the plain side of the wooden-bars 48 or the side remote from the slots 50, and to the top side 49a of the wooden bars 49. It may be noted in FIG. 17 that the width of the metal plates is less than the width of the wooden bar 48 to provide an attaching edge for the silk screen. Bolts may be provided for securing the corresponding ends of the side and end bars together, which are respectively provided with slotted

bolt receiving holes

54 and 55 in order to permit adjustable connecting relationship between the side and end bars. Likewise, the rnetal plates 51 are provided with slotted openings 56 which mate with the slotted openings 54 in the end bars 48.

In mounting the silk screen frame 23 on the driving rings 24 so that the silk screen is trained about the drum 22, the end bars 49 are brought toward each other to abut against a mounting bar 57 which extends across the machine and is connected at opposite ends to the opposed driving rings 24. As seen particularly in FIG. 9, gaskets or seals 58 may be provided between the end bars 49 and the mounting bar 57 to prevent the leakage or seepage of ink between the end bars 49 and mounting bar 57. Bolts 59 are employed to extend through the frame and bars 49 and be received ink tapped bores in the mounting bar 57. In this instance, it is preferable that the mounting bar be of steel. The mounting bar 57, as above noted, is fastened to the driving rings 24 and as shown in FIG. 9 may be so fastened by bolts 60. Alternatively, the mounting bar may be omitted and the frame and bars 49 would then be connected to each other and in turn to the driving rings 24.

Each of the driving rings 24 includes a cylindrical mounting plate 61 around which the frame 23 is arranged and mounted thereon, a ring sprocket 62 attached to the outer end of each cylindrical mounting plate and arranged to have teeth 63 extending radially outward of the outer surface of the cylindrical mounting plate 61 and a flange portion 64 extending radially inwardly of the inner surface of the mounting plate 61. The driving rings 24 are rotatably mounted on the support rods 39 by means of grooved rollers 65 which are bearinglyrmounted on the rods and which receive the flange portion 64 of the ring sprocket 62.

The driving rings 24 are driven by means of a pair of spaced chains 66 arranged at opposite sides of the press. One of the chains is arranged to drive one of the driving rings and the other is arranged to drive the other driving ring. Each chain 66 includes

runs

67 and 68, and the run 67 is in meshing engagement with the ring sprockets 62 of the drive rings 24. Longitudinally extending chain guides 69, as seen in FIG. 7, are provided to supportthe chain along the horizontal. The chains 66 are trained about longitudinally spaced idler sprockets 70 and 71` which are, in turn, mounted on

shafts

72 and 73, respec' tively. Power is transmitted to the chains 66 by means of a pair of sprockets 74 carried on a transversely extending shaft 75 upon which is also mounted the lower printing roller 25. At one side of the press, a gear 76 is provided and mounted on the shaft 75 and which is in engagement with a gear wheel 77 on the output shaft 78 of a clutch 79, FIG. 18. The clutch is provided with an input shaft 80 having a pulley 81 thereon which is drivingly connected to a pulley 82 carried on an electric motor shaft 83 by means of a belt 84. The shaft 83 constitutes the drive shaft of an electric motor 85. The sprockets 74 are in engagemnet with the run 68 of each of the chains 66, as seen most clearly in FIG. 7. Moreover, the size of the sprockets 74 and the ring sprockets 62 is the same so that the speed ofthe drum is equal to the speed of the lower printing roller 25. As seen in FIG. 3, the diameter of the lower roller 25 is substantially identical to the diameter of the silk screen 44 mounted on the stationary drum 22 so that the linear speeds of the roller and silk screen are the same.

The lower roller 25 is provided with a longitudinal cutout or groove along its periphery and identied by the numeral 86 for accommodating the passage of the end bars 49 of the frame and the mounting bar 57, together with sheet feeding grippers 87, as seen most clearly in FIG. 9. Otherwise, the cylindrical roller 25 serves to support the paper as it is being printed while in engagement with the silk screen 44, `as may be seen somewhat in FIG. 3. After the sheets of paper leave the silk screen and printing roller, they are supported until discharged from the press by means of an endless driven conveyer 88. This conveyer includes a plurality of transversely extending and spaced slats 89 connected at opposite ends to endless chains 90 at each -side of the press. The chains 90 are trained about spaced sprockets 91 and 92 at each side of the press which are, in turn, mounted on shafts 93 and 94, respectively. At the outer end of the shaft 94 at one side of the press, a driven sprocket 95 is mounted and in meshing engagement with a driving chain 96 which is also trained around a drive sprocket 97 mounted on the shaft 75. Thus, the endless paper supporting conveyer 88 is driven from the shaft 75 and in timed relationship to the driving of the silk screen and the lower roller.

Within the drum 22, an elongated angle-shaped mounting bar 98 is arranged eccentrically thereof and secured at opposite ends through appropriate mounting means (not shown) to the opposite sides of the press. The bar 98 serves to support an elongated rubber squeegee 99 arranged to be in engagement with the silk screen 44 as seen in FIGS. 3, 7 and 9, and an elongated ink trough 100. Ink is delivered to the ink trough 100 from an ink fountain 101, FIG. 3, that is mounted on top of the frame cross member 36 by means of conduits 102. The conduits 102 extend from opposite ends of the ink fountain 101 along the upper side of the cross member 36 and down along the sides of the drum supporting members 34 and through an opening 34a formed in the supporting membersand on into the hollow of the drum 22. Thus, a supply of ink is maintained in the trough 100 from the fountain 101.

As seen most clearly in FIG. 23, auxiliary squeegees 99a and 99h are arranged on the leading side of the main squeegee 99. These auxiliary squeegees` are relatively short and extend slightly outward of the end of the main squeegee, and are inclined thereto for the purpose of drawing the ink that flows beyond the outer ends of the main squeegee back into the stroking area of the main squeegee toward the center of the screen before the next print is made, thereby preventing ink from running outwardly toward the edges of the screen and getting out of control.

An elongated aperture or nozzle 103 is provided along the bottom of the trough 100, FIGS. 3, 9 and l0, for feeding ink onto the silk screen ahead of the squeegee 99. The squeegee 99 serves to drive the ink through the silk screen so that it may be imprinted on the paper as' it is fedv between the silk screen land lower printing roller. In order to accommodate the squeegee continuously across the entire width of the silk screen, a portion of the support rings 37 and 38 is removed, FIGS. 3, 9 and 17, to dene openings 104. Y

The oW of ink through the nozzle or opening 103 in the trough 100 is controlled by a plurality of butterliy or Hutter valves 105' arranged in the nozzle 103, as seen in FIG. 9. The butterfly valves 105 are separated as is the trough by dividers or bottles 106, FIG. l0, so that the amount of ink permitted to pass through the nozzle may be concentrated along either end thereof or the center, or equally entirely along the width of the silk screen. Actually, individual controls for the butteriy valves 105 are provided such as the control knobs 107, FIG. l0, for the two outer butterfly valves. Y

The sheets of paper to be printed are stacked upon a table 110 arranged at the inlet side of the drum. A feeding mechanism is provided to successively feed sheets of paper to the drum and carry them between the drum and lower roller 25, and it should be appreciated that any type of sheet feeding means may be'employed. However, the particular sheet feeding means herein disclosed and which will be hereinafter described is somewhat unique.

The sheets of paper are manually fed to the sheet feeding means one at a time, wherein a sheet may be taken from the stack designated generally by the numeral 111, FIG. 3, and urged forward against a plurality of stops 112 (only one shown in FIG. 4) arranged along the forward edge of the table 110. The sheets are positioned beneath a plurality of retaining rollers 113 carried on a roller shaft 114 extending across the table. The opposite ends of the shaft 114 are supported at the ends of opposed arms 115 which are pivotally mounted to blocks 116 extending upwardly from the table 110. The other end of each arm 115 is connected toa rocking lever 117, FIGS. 1, 2 and 1S, by means of a connecting rod 118. A spring 119, FIG. 2, normally drives the rocking lever 117 in a clockwise direction as viewed in FIG. 2 about the pivot connection to the bracket 120 to raise the rollers 113 and roller shaft above the table and permit the placement of a sheet of paper against the stops 112. The rollers are moved to a paper engaging position to retain the paper in place and aid in the removal of the paper from the table by means of a pin 121 eccentrical-ly mounted on the sprocket 74, FIGS. 2 and 17, when it engages the corresponding end of the rocking lever 117 by rotation of thev sprocket 74.

It may be noted that the stops 112 have a portion ex-L tending over the top of the table to prevent the edge of the paper from moving upwardly and that the stops are mounted on a shaft 122 bearingly mounted at opposite ends to theopposed side plates 29 and 30. When the sheet feeding means comes into operation, the stops 112 are pivoted to a position completely out of the path of movement of the sheet of paper by means of a cam wheel 123 having a cut-down surface 124 and a high surface 12S.

This cam wheel is mountedroin the shaft 7S and is rotatable therewith as can be seen iii-FIGS. l, 2 and 18. The cam wheel 123 operates the stops 112 through a cam lever 126 pivotally mounted at 127 and having a cam roller 128 engageable with the surface of the cam wheel 123. Al rocking lever 129 is pivotally mounted to an upstanding, inverted, U-sh-aped bracket 135! secured to the side plate 29. The rocking lever 129 is pivotally connected at one end to an intermediate portion of the'cam lever 126 at 131, and pivotally connected adjacent the other end to the upper end of a connecting link 132. A stub shaft 133 rockably supports` the rocking lever129 to the bracket 130. The

other end of the link 132 is pivotally connected to a crankV arm 134, FIGS. 4 and 5, which is secured to the stop shaft 122. While the cam roller will be maintained in engagement with the cam wheel 123 by gravitational forces, a spring may be provided to positively urge the cam lever 126 downwardly and the cam roller 128 into engagement with 'the cam wheel 123. rlfhus, when the cam roller 128Y contacts the cut-down surface 124 of the cam wheel 123, the stop 112 will be rotated to a position away from the path of movement of the sheet of paper.

^ The sheets of paper are successively taken from the table 110 by means of a reciprocating gripper 13S which grips the leading edge ofthe paperV sheet and draws it about seven or eight inches from the platform until the sheet feeding grippers S7 are operated to grip the leading edge of the paper sheet and advance it forwardly betweenV The reciprocatingV` the drum 22 and the lower roller 25. gripper 135 acts to disengage the leading edge of the paper sheet at a time slightly after the sheet feeding gripper 87 has engaged therleading edge of the sheet.

The reciprocating gripper 135 includes an elongated bar 136 extending'transversely across the machine and the path of movement of the paper sheets, and which is supported at oppositeends on perpendicularly extending slides- 137 which slidably engage the upper edge of the cam levers` 126. It should be appreciated that a cam lever 126 is provided at both sides of the press. The slides 137 are drivingly connected to the cam wheels 123 by means of downwardly extending arms 138 that are pivotally connected to blocks 139 slidablealong connecting rods 140.' The blocks 139 are spring biased by means of a coil spring 141 against a stop 142 at one end of the connecting rod. The other end of the connecting rod is eccentrically connected to the cam wheel 123 on a pivot pin 143. Thus as seen particularly in FIGS. l, 2 and 18, when the reciprocating gripper 135' is driven forward toward the drum 22, the stop 142 will similarly engage the block 139, and when the gripper is driven away from the drum 22 and resilient connection by meanslof 4the spring 141 will operate and the gripper may be precisely positioned against a stop at theY table, 110.

Secured to the bottom side of the bar 136 is an angle mounting plate 144 which engages at the opposite sides of the machine stop rollers 145 Vthat are iixed tothe side plates 29 Vand 30. Thus, when the reciprocating gripper 135 reaches home position adjacent the table 110 vas shown in FGS. 2 and 4, the angleY mounting plate 144 will engagethe stop rollers 14Sand precisely positionthe gripper'` adjacent the table. Theresilient connection` between the arms 133 and the connecting rod 140 operates to allow over movement of the connecting rod and prevents breakage of `any parts while accurately positioning the recipro eating gripper 136.

At the lower edge of `the angle mounting plate 144, a` plurality of fixed gripping ngers 1116 are provided to co' ticularly in FIGS. 4 and 5, the movable fingers 147 are mounted on a transversely extending shaft 149 which is journalled in a plurality of blocks 150 spaced along the angle mounting plate 144. A torque spring 151 is arranged about the shaft 147 and secured at one end to the shaft and at the other end to a biock 150 in such a manner as to continually urge the shaft 149 to drive the movable fingers 147 into engagement with the stationary lingers 146. Control of this shaft is accomplished by means of a cam lever 152 secured to one end of the shaft 149 and having a cam roller 153 thereon in engagement with the lower edge 154 of the rocking lever 129 which serves as a cam surface therefor. As the cam lever 129 is rocked by action of the cam roller 128 engaging the cut-down portion 124 of the cam wheel 123, the end of the rocking lever connected to the link 132 moves upwardly to simultaneously rotate the stops 112 out of the path of the paper sheet and to permit the cam roller 153 to move upwardly and rotate the movable finger shaft 149 so that the movable lingers 147 coact with the stationary lingers 146 and engage the leading edge of the paper sheet.

The recprocating gripper 135 then operates to draw the paper sheet from the table 110 to a predetermined point where the sheet feeding grippers 87 take over to carry the sheet of paper on through the press between the drum and the lower roller. Thus, the grippers S7 may be defined as carry through grippers and each gripper includes a transversely extending angle mounting plate 155 that is secured at opposite ends to the chain 66 and accordingly carried thereby. The carry through grippers 87 move together at the same speed as the reciprocating gripper 135 and are maintained in timed relation by a plurality of lugs 156 extending down from the angle mounting plate 144 of the reciprocating gripper 135 for engagement by the angle mounting plate 155 of the carry through gripper 87, FIG. 5. As noted in FIG. 5, the cam roller 153 is not even in engagement with the lower edge 154 of the rocking lever 129, and during this time the movable fingers 147 securely clamp the paper to the stationary fingers 146.

The carry through gripper S7 includes a plurality of movable lingers 157 mounted on a shaft 158 which is rotatably carried on the angle mounting plate 155. In gripping the leading edge of the paper, the movable gripping fingers 157 coact with the upper edge 159 of the angle mounting plate to grip the paper therebetween as more particularly seen in FIG. 9, wherein the leading edge of a sheet of paper 166 is held. The movable fingers 157 art staggered slightly from the lingers 146 and 147 of the reciprocating gripper 135 so as to not interfere with their operation, and also to allow the carry through gripper 87 to engage the leading edge of a sheet of paper prior to the ungripping action of the reciprocating gripper 135.

The gripping lingers 157 of the carry through gripper 87 are also normally biased into gripping position against the top edge 159 of the angle mounting plate 155 by means of a torque spring 161, FIG. 6. This torque spring is also secured at one end to the finger shaft 158 and at the other end to a stationary part of the shaft mounting means. Operation of this shaft against the biasing of the spring is accomplished by a cam lever 162 which is secured to the shaft 153 at one end and is provided with a cam roller 163 for engagement with a cam 164. The cam 164 is elongated and carried on the shaft 72 by a free titting relationship and is further held in place by being secured to a frame plate 165. Thus as the carry through gripper 87 is brought around the shaft '72, the cam rollers 163 engage the cam 164 to operate the shaft 153 and upon the movable gripping lingers 157 to condition the carry through gripper S7 for receiving and gripping the leading edge of a sheet of paper. As the reciprocating gripper 135 moves forward, the Acam roller 153 will engage the inclined surface 154a of the cam 154 to rotate the movable fingers 147 away from the stationary fingers 146 on the reciprocating gripper and release the reciprocating l() gripper from the leading edge of the paper. Before this release is effected, the carry through gripper 87 will have engaged the leading edge of the paper by the fact that the cam roller 163 will have advanced olf of the cam 164 to permit the movable fingers 157 to coact with the upper edge 159 of the carry through gripper angle mounting plate 155 and engage the leading edge of a sheet of paper.

It is then necessary to remove the reciprocating gripper from the path of the carry through gripper and sheet of paper, and this is accomplished by the cam Wheel 123 which drives the cam roller 128 upwardly by the high surfaces and thereby urges the cam lever 126 upwardly. Inasmuch as the slides 137 ride on the upper edges of the cam levers 126, the reciprocating gripper which is supported by the slides 137 also moves upwardly and out of the path of movement of the sheet of paper. And the reciprocating gripper will then return to the table 11i) and not be lowered until the sheet of paper has cleared the table; The cycle of feeding another sheet of paper from the table is then repeated.

As seen in FIG. 3, there are three grippers 87 secured to the chains 66 for carrying the sheets of paper between the drum and the lower roller. Thus, the reciprocation of the reciprocating gripper is in timed relation with the movement of each of the grippers 87. It should be appreciated that any number of grippers 87 may be provided and carried by the chains 66. Further, the chain carrying grippers 87 are arranged to pass between the drum 22 and the lower roller 25 by means of the elongated longitudinal gap 86 formed in the lower roller 25. And when a gripper reaches the discharge end of the press, at the shaft 73, cam means is provided to move the fingers 157 out of engagement with the paper to release the paper as the gripper moves around the shaft 73.

The endless chains 66 are guided below the lower roller 25 along guide tracks 166 and 167, FIG. 3, so as not to interfere with the operation of the drum and its associated components. As may be appreciated from FIG. 18, the drum 22, lower roller 25, chains 66, reciprocating gripper 135 and grippers 87 are driven continuously and in timed relationship with each other by the single motor 85.

In the absence of a sheet being fed by the sheet feeding means to the printing drum 22, printing will take place on the lower roller 25. In order to prevent further messy operation and subsequent printing and the ruination of several sheets of paper, the ink is removed from the lower roller by an ink removal means. More specifically, the absence of a sheet of paper is detected by the detector 26 and the ink is removed from the lower roller by the scraper 27. The detector is arranged on the discharge side of the drum 22, although it may be appreciated that it could be arranged on the inlet side of the drum. The detector 26 shown is a photoelectric cell arrangement wherein a beam is directed across the path of movement of the grippers and the sheet of paper and associated with suitable electrical means to detect whether or not a sheet of paper is being advanced along by a gripper. It should be appreciated that a mechanical trip may also be provided as a detector or any other suitable means.

The scraper 27 includes a blade 168, FIG. 3, extending clear across the lower roller 25 and arranged to be selectively placed into engagement with the surface of the roller. This blade should preferably be flexible and may be of spring brass or other suitable material. The blade is mounted on a bar or arm 169 that is pivotally mounted to the frame at 170 in any suitable manner. An electrical solenoid 171 may be provided having its plunger attached to the bar 169 and for moving the bar and blade into and out of engagement with the other surface of the roller 25. Thus when a signal is received by the detector 26, the solenoid 171 may be operated to bring the blade into engagement with the outer surface of the roller 25, and to subsequently remove it from the surface of the roller. And the scraper will serve to scrape of the ink from the lower roller and thereby prevent printing on the underside of a piece of paper subsequently fed through the roller and drum. Mechanical means may be provided in place of the solenoid 171 as may be decided by the particular installation.

inasmuch as the scraper could not come into engagement with the groove or gap 6 in the lower roller, any suitable means may be provided to prevent such engagement. In the first place, the scraper should be located to engage the lower roller beyond the gap, and rollers may be provided for this purpose which would be supporting the scraper so that it would not engage the gap but move the scraper to a position to engage the outer surface of the roller by action of the gap edge against the rollers. Moreover, the trailing edge of the gap may be inclined to cam the scraper backwardly and onto the outer surface of the roller.

With the advent of newly developed inks, a first printing of wet ink may now be printed over with other wet ink without having the rst printing of wet ink dry. Actual- 1y, this is possible because of a slight surface set of the ink. Accordingly, the silk screen printing press of the present invention may be arranged in multiple where it is desired to provide a multiple printing operation, such as a multiple colo-r operation. As shown particularly in FIG. 21, a plurality of silk screen printing presses of the type disclosed herein are arranged together and designated by the

numerals

172, 173, 174 and 175, wherein a sheet of paper is taken from a table 176 and fed into the first printing press 172 and subsequently through the printing presses i173, 174 and R75. When a sheet of paper is discharged from the last press 175, it will have been subjected to the printing operations of each of the presses. In this instance, a relatively common frame may be provided for all of the presses, and it is noted that each press includes a drum 22 and a lower roller 25. Further, inasmuch as sheets of paper are eing printed, the chain carrying grippers may feed the sheets of paper through the entire line of presses. In this instance, the chains will be endless through all four presses whereby each gripper 87 will serve to carry a sheet of paper through each of the presses.

At high speeds, a short drying unit may be employed between presses, with a complete drying unit at the end of the line to effect complete drying of the ink.

Where it is desired to print a web of paper, an example of how several printing operations could be effected is shown in FIG. 22 wherein four presses l77, lS, E79 and 13th are arranged in a line all to print on a single web 181 which extends through all of the machines. As heretofore explained, the drum 22 in this type of machine would be movable upwardly to compensate for the movement of the grippers and the frame as they pass between the drum and the lower roller. Again the wet over wet inkx printing makes high speed operation possible, with and without intermediate drying cycles. However, other means of high speed drying of inks may also be employed for high speed web and sheet printing.

It will be understood that modilications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

The invention is hereby claimed as follows:

l. A silk screen printing press comprising, an elongated non-rotatable drum having a plurality of longitudinally extending and circumferentially spaced silk screen supporting freely rotatable rollers, a rotatably driven silk screen driving member at each end of said drum, a frame attachable to said driving members for mounting said silk screen about said drum and in tension engagement over said silk screen supporting rollers, whereby rotation of said driving members drives said silk screen about the drum, a lower printing roller for supporting paper to be printed in engagement with said silk screen, means for feeding paper between said drum and roller, and means for forcing ink through the silk screen and onto the paper.

2. A silk screen printing press comprising, an elongated non-rotatable drum having a plurality of longitudinally extending and circumferentially spaced freely rotatable rollers for supporting a silk screen driven thereover, a silk screen driving ring rotatably mounted at each end of said drum, a frame for mounting a silk screen and for stretching the silk screen over and in engagement with the rollers, said frame being attachable to said driving rings, a lower roller coacting with said drum for supporting paper to be printed in engagement with said silk screen, means for feeding paper between said drum and roller, means for forcing ink through the silk screen and onto the paper, and means for driving said driving rings and lower roller in unison, whereby the speed of the silk screen and the roller are the same.

3. The combination as defined in claim 2, means for detecting the absence of feeding paper during a printing operation, and means responsive and actuated by said detecting means for removing the ink from the lower roller.

4. In a silk screen printing press for continuously printing on a moving web of material, an elongated non-rotatable drum having a plurality of longitudinally extending and circumferentially spaced silk screen supporting freely rotatable rollers, means for mounting a silk screen on said drum and for tensioning same over and in engagement with said supporting rollers, means at each end of said drum connected to said screen mounting means for rotatably driving said screen on said drum, a back-up roller coacting with said drum to support paper to be printed in engagement with the silk screen, means within said drum for forcing ink through said screen at the area Where the back-up roller supports the paper in engagement with the screen, means for continuously feeding a paper web of material between said drum and back-up roller, and means for driving said screen driving means and back-up roller so that the screen and surface of the back-up roller have the same speed.

5. In a silk screen printing press, an elongated nonrotatable drum having a plurality of longitudinally eX- tending and circumferentially spaced freely rotatable rollers, means for mounting a silk screen on said drum and for tensioning same over and in engagement with said rollers, means at each end of said drum connected to said screen mounting means for rotatably driving said screen on said drum, a roller coasting with said drum to support paper to be printed in engagement with the silk screen, an elongated trough extending longitudinally through the drum for holding an ink supply and having an elongated slot-type nozzle for feeding ink to the inner surface of the screen and being spaced closely thereto, a squeegee arranged in engagement with the inner surface of the screen and to force ink therethrough which is fed to the screen from the nozzle at the area where the roller supports the paper in engagement with the screen, means for feeding paper to said screen, and means for driving said screen driving means and roller so that the screen and roller surface have the same speed.

. 6. The combination as dened in claim 5, and valve means in said nozzle for controlling the flow of ink therethrough.

7. In a silk screen printing press, an elongated nonrotatable drum having a plurality of longitudinally extending and circumferentially spaced freely rotatable rollers, means for mounting a silk screen on said drum and for tensioning same over and in engagement with said rollers, means at each end of said drum connected to said screen mounting means for rotatably driving said screen on said drum, a roller coacting with said drum to support paper to be printed in engagement with the silk screen, an elongated trough extending longitudinally through the `drum for holding an ink supply and having an elongated slot-type nozzle fo-r feeding ink to the inner surface of the screen and being spaced closely thereto, a

plurality of dividers in said trough defining a plurality of juxtaposed ink compartments, valve means in said nozzle for controlling the flow of ink therethrough, said valve means including one valve for each ink compartment, means for individually controlling each valve to concentrate the ink ow to any desired portion or all of the silk screen, a squeegee arranged in engagement with the inner surface of the screen and to force ink therethrough which is fed to the screen from the nozzle at the area Where the rollers supports the paper in engagement with the screen, means for feeding paper to said screen, and means for driving said screen driving means and roller so that the screen and roller surface have the same speed.

8. In a silk screen printing press, an elongated nonrotatable drum having a plurality of longitudinally extending and circumferentially spaced freely rotatable rollers, means for mounting a silk screen on said drum and for tensioning same over said roller, means at each end of said drum connected to said screen mounting means for rotatably driving said screen on said drum, a roller coacting with said drum to support paper to be printed in engagement with the silk screen, means Within the drum for supplying ink to the screen, a transversely extending squeegee arranged in engagement with the inner surface of the screen to force ink therethrough, and means for forcing any ink that ows beyond the ends of the squeegee 14 back towards the center of the screen, said means including an auxiliary squeegee at each end of said first squeegee at the leading side thereof overlapping each end thereof and inclined toward the center of the screen.

Recrences Cited in the le of this patent UNITED STATES PATENTS 782,341 Johnson Feb. 14, 1905 1,383,338 Pritchard July 5, 1921 1,442,338 Herr Jan. 16, 1923 1,895,309 Boomershine Jan. 24, 1933 2,071,824 Engert Feb. 23, 1937 2,134,041 Hamm Oct. 25, 1938 2,165,139 Hardin July 4, 1939 2,320,269 Darenberg et al. May 25, 1943 2,363,137 Metcalf Nov. 21, 1944 2,379,020 Maher June 26, 1945 2,542,073 Aberle Feb. 20, 1951 2,928,340 Stein et a1 Mar. 15, 1960 2,990,990 Wilkins et al. July 4, 1961 3,064,914 Meier Windhorst Nov. 2, 1962 FOREIGN PATENTS 166,183 Great Britain July 11, 1921 405,020 Germany Nov. 1, 1924

Claims

1. A SILK SCREEN PRINTING PRESS COMPRISING, AN ELONGATED NON-ROTATABLE DRUM HAVING A PLURALITY OF LONGITUDINALLY EXTENDING AND CIRCUMFERENTIALLY SPACED SILK SCREEN SUPPORTING FREELY ROTATABLE ROLLRS, A ROTATABLY DRIVEN SILK SCREEN DRIVING MEMBER AT EACH END OF SAID DRUM, A FRAME ATTACHABLE TO SAID DRIVING MEMBERS FOR MOUNTING SAID SILK SCREEN ABOUT SAID DRUM AND IN TENSION ENGAGEMENT OVER SAID SILK SCREEN SUPPORTING ROLLERS, WHEREBY ROTATION OF SAID DRIVING MEMBERS DRIVES SAID SILK SCREEN ABOUT THE DRUM, A LOWER PRINTING ROLLER FOR SUPPORTING PAPER TO BE PRINTED IN ENGAGEMENT WITH SAID SILK SCREEN, MEANS FOR FEEDING PAPER BETWEEN SAID DRUM AND ROLLER, AND MEANS FOR FORCING INK THROUGH THE SILK SCREEN AND ONTO THE PAPER.