US1966416A - Printing machine - Google Patents

Description

' W. L. PARMELE ET AL 'July 1o, 1934.

PRINTING `lIA('JI'IINEA vFiled May 21, 1932 10- sheets-sheet;

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@www mi@ July'10,'1934. U w.l: PARMELE ETAL i 1,966,416

PRINTING MACHINE f gy* July 10, 1934. w. PAMELE ITAL 1,966,416

PRINTING MACHINE Filed May 21. 1932 1o Sheets-sheet :s

July 10 l934- w. l... PARMELE 'Er AL y 1,966,416

PRINTING mcrgnm A10 Sheets-Sheet 4 Filed lay 21, 1932 July 10, 1934. w. L. PARMELE En' L PRINTING MACHINE Filed nay V-21, 1952 10 Sheets-Sheet 5 fifa/g W22?,

@n/frs I @yx-@JJ July 10, 1934- -w. l.. PARMELEv Erm. 1,966,416

6 PRINTING MACHINE n O Filed May 21'. 19s2 1o sheets-sheet e 10 Sheets-Sheet 7 July 10, 1934. w. L. PARMELE Er AL PRINTING MACHINE Fild May 21. 1932 July 10, 1934. w. L. PARMELE Er AL PRINTING MACHINE Filed May 421, 10 sheets-sheets NRI' @gli 205 July 10, 1934. w, L. PARMELE Er AL l 1,966,416

` PRINTING MACHINE l Filed may 21,-1932 io sheets-.sheet 1Ao Patented July 10. 1934 A PRINTING MACHINE Welling L. Parmele 'and Howard W. Parmele, Chicago, Ill., assignors to Naz-Dar Company, Chicago, Ill., a corporation of Illinois Application my 21, 1932, serai Nn. 612,722 25 calms. (o1. 10i-123) This invention relates to an improved machine for printing or stenciling designs on cardboard, orother sheet material, by the use of inks or paints whichare applied to the sheet through a silk stencil, or other suitable screen, the paint being applied by the use of a squeegee which is moved over the stencil to rub the paint through 'the penetrable areas of the stencil onto the underlying sheet.

In machines of this class there is usually provided a bed plate, upon which the sheet rests during the interval of printing, and in combination therewith a printing or stencil-supportingframe which is arranged to be moved vto and from printing position on the bed plate. The

squeegee is supported in .the printing frame, being arranged `for movement therein over the stencil. Ordinarily means is also provided for supplying fresh sheets to the bed plate, and for removing the printed sheets therefrom.

One of the important objects of the present invention is to provide' in a machine of this class improved means for operating the squeegee in a manner which will prevent accumulation of paint on th stencil in front of the squeegee at the end of the active stroke of the latter.

Another object of the invention is to provide an improved sheet conveyor means, and control mechanism therefor, which will operate to position a fresh sheet on the bed platein accurate registration with the stencil'. Another object of the-invention is to provide means for adjusting the position of the printing frame relative to 'the bed plate, whereby to ac'- 5 commodate the machine to the printing of sheets of various thicknesses. .Another object of the invention is to provide means for mounting the printingfram'e on the bed plate base in a manner to permit limited vertical movement of said frame relative to the bed plate and also to permit tilting of the frame about one side to semi-vertical position. y

Another object of the invention is to provide vmeans for automatically supplying paint in regulated amount to the face of the stencil.

`. A still further object 'of the inventionis to provide manually-controlled means for rendering the squeegee drive mechanism inoperative in the event of an emergency such as a failure of the sheet -feed means. i

. 5 5 Otherobjects and advantages of;` the invention will be apparent from the following' detailed description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

Fig. 1 is a side elevational view of the machine showing the generalrclationship between they bed plate, the printing frame, the feed table, and the discharge platform;

Fig. 2 is a top plan view showing the printing @5 frame and adjacent portions of the'feed table and the discharge platform.; L',

l Fig. 3 is an end elevational View of the machine as viewed from the right in Fig. 1; v

Fig. 4 is a fragmentary elevational view of a 70 portion of the back of the ymachine'showing parts of the squeegee drive mechanism;

Fig. 5 is a transverse section through the machine taken on line 5-5'of Fig. 4;

Fig. 6 is a detail section showing a portion of 75 the gear train for driving the sheet conveyor,

.the view being taken on line 6 6 of Fig. 1;

Fig?? is a fragmentary elevational view showing a portion of the gear mechanism for driving 8 the sheet conveyor; 0

Fig. 8 is a horizontal section taken on line 8-8 of Fis. '7;

Fig. 9 is a 'longitudinal section through the bed plate` and printing frame, the view being taken online 9-9 of Fig. 2; v

Fig. 9a is a partial side elevational view of the automatic paint feed means;

stroke; Y

Fig. 13 is a top plan view of the mechanism 100 l shown in Fig. 12;

Fig. 14 is asection taken on line 14--14 of Fig.

Fig. 15 is a top plan view of an edge portion of the printing frame and the bed plate, 'the view 105 showing-the safety mechanism for preventing movement .of .the printing' frame onto the bed plate; i.

Fig. 18 is a fragmentary section through a por- `tion of the discharge platformxshowing the means for releasing the gripper bars from the sheet;

Fig. 17 is a section through the gripper bar release mechanism taken on line 17-17 of Fig. 16;

and

Fig. 18 is a detail plan view showing the connection between the end of one of the gripper bars and the associated conveyor chain.

Referring to the general views of the machine shown in Figs. 1 to 3, and Fig. 5, the numerals 21 and 22 indicate front and back side frame members supported on vertical posts 23 and tied together by cross-bars 24 and 25. A bed plate 26 is supported in horizontal position on members 21 and 22 by a frame piece 27, the latter consist-v ing of spaced side members 28 and 29 which are supported, respectively, upon frame members 21 and 22. The side members 28 and 29 are tied together by heavy cross pieces 31, which are formed as an integral part of bed 26, theends of said members 31 being connected to side members 28 and 29 by key strips 32. A printing frame is disposed over bed plate 26 and is adapted to be raised and lowered relative to the latter by mechanism later to be described. This frame is rectangular in shape and consists of side members 33 and 34,

and end members 35 and 36, these members being preferably formed integrally withv one another to provide a rigid frameunit. The printing frame is adjustably supported on the base frame at itsl four corners bygroller devices indicated generally by the numeral 20, the construction of which will be later described. A stencil 30 mounted in the printing frame is arranged for movement with the latter to and from printing position on the bed plate in a manner which will hereinafter more fully appear.

Referring to Figs. 3-5, the printing frame is arranged for limited vertical movement relative to the bed plate to allow sheets to be fed onto and removed from the bed, ancis also arranged to be pivoted about one of its sides into semi-vertical position in order lto facilitate removal of the stencil and to give free access to the bed plate. To this end there is provided a pivotal and sliding connection between the printing frame and the y base which connection comprises a bracket 37 which is bolted to frame member 21, and a second bracket 38 carried by member 33 of the printing frame. Brackets 37 and 38 are interconnected by means of arod 39 which is journaled at its opposite ends in bracket 37 and the central portion of which engages a U-shaped bearing piece 41 which forms a part of bracket 38. 'I'he printing frame is tilted to and from vertical position by means of a cable 42 which is secured at one end to a cross piece 43 carried by the printing frame, the other end of said cable being wound on a drum 44 which is journaled in the upper freel end of an arm 45 which is secured through bracket 37 to the base. The shaft of drum 44 is provided with a worm wheel 46 which meshes with a worm 47, the latterbeing turned by a handwheel 48. By turning wheel 48 in the proper direction, cable 42 is wound up on drum 44; thereby tilting the printing frame upwardly to the-dotted line positionlshown in Fig. 3. Reverse movement of wheel 48 effects lowering of the printing frame back into normal printing position on the bed plate. y

As shown in Figs. 1 and 2, a feed table 49 is supported adjacent one end of the bed plate by a pair of frame pieces 51 which are secured to and form continuations of side frame members 21 and 22. A baseplate 52, extending transversely of the machine between frame pieces 51, affords a rigid support for table 49. A discharge platform 53 provided on its side edges with guide rails 54 is mounted adjacent the other end of the bed plate in position to receive the printed sheets as they are removed from the latter. Platform 53 is supported upon a. pair of side frame pieces 55, the latter being tied to the main portion of the frame by brace arms 56. The outer ends of frame pieces 55 are supported by legs 57 which depend from side frame brackets 58. Referring to Figs. 1 and 10, conveyor means is provided for feeding sheets from table 49 onto bedl plate 26 and for removing the printed sheets from said plate onto discharge platform 53. In the embodiment shown this conveyor mechanism comprises a pair of endless chains 59which are mounted on the opposite sides of the machine and which are provided at regularly spaced intervals with a series of gripper bars 61 (Fig. 10) which extend across the chains and which are secured at their ends to the links of the chains. These chains 59 pass upwardly between feed table 49 and the adjacent edge of the bed plate around a pair of sprockets 62 which are secured to a shaft 1m 63, said shaft being journaled at its opposite ends in bracketsv 51. From sprockets 62 the conveyor chains extend along the opposite sides of bed plate 26, the chains during this portion of their run being supported in guide channels 64 (Fig. 5) 105 which are formed in the upper edges of base frame members 28 and 29. The horizontal stretch of the chains continues from the bed plate over the top of discharge platform 53, from which point the chains p ass downwardly around sprockets 65 110 which are carried on a shaft extending between frame brackets 58. From this point the chains pass under a pair of take-up sprockets 66 which are carried on stub shafts 67, thence over a pair of idler sprockets 68 whichare mounted for free 115 rotation on a shaft 69, thence under a pair of drive sprockets 7l which are xedly secured on a shaft 72, and finally back to sprockets 62. Shafts 67, which carry take-up sprockets 66, are journaled in arms 73, the latter being suspended from the frame on a shaft 74. Arms`73 are provided with clamps 75 which permit of their adjustment on shaft 74, thereby permitting a setting of sprockets 66 to take up for slack in the chains.

The construction of the gripper bars is best shown in Figs. 10, 16, and 18. These bars are all of similar construction and hence will be described in the singular. Each bar comprises: a. blade 76 which extends between the conveyor chains; end plates 77 fixedly secured to the op- 130 posite ends of blade 76 and provided on their lower edges with rollers 78; blocks 79 for connecting the ends of blade 76 to the links of the carrier chains; a clamping jaw, indicated generally by the numeral 8l, and consisting of a series of bars or hold-down` fingers 83 which are rigidly secured to a rock shaft 82 (Fig. 2); and arms 84 rigidly secured to the ends of shaft 82. l

End plates 77 are cut away to provide a recessed portion 85 (Fig. 17) in which are mounted 140 latch levers 86, said levers being carried on pins 87 which are journaled in the wall portions of the end plates. Levers 86 are of bell-crank shape, the short arms 88 thereof being provided with Y. lateral projections 89 which are urged toward 145 arms 84 by coil springs 91, the latterbeing contained in a recess formed in end plates 77. In Figs. 16 and 17 clamp jaw 81 is shown in the unclamped position, in which position arms 84 are out of engagement with latch-levers 86. When said arms 84 are thrown upwardly, by means presently t0 be described, levers86 are 'pivoted in a clockwise direction, viewing Fig. 17, thereby throwing projections 89 underneath arms 84 to hold the latter, together with jaw 81, in clamped ficient to position a fresh sheet below the printing frame will now be described. Referring to Figs.

.1, and 6-8, this drive mechanism comprises: a

motor y93 which is mounted. on a cross-bar 94 carried bythe frame; a sprocket 95 mounted for free rotation on a stub shaft 96 and adapted to be driven from the armature of motor 93 through a chain 97 which takes over a sprocket 98 secured to said armature shaft; a spur wheel 99. secured to the hub of sprocket 95 and positioned in permanent driving engagement with a second spur wheel 101 which is iixedly secured to a stub shaft 102, the latter being provided at its outer end with a hand wheel 103; a spur wheel 104 flxedly secured to a cross shaft 105 and positioned in driving engagement with a spur gear 100 carried on shaft 102; a disc 106 fixedly secured to the front end of shaft 1'05; a crank 107 eccentrically connected through a pin 108 to disc 106; a drive segment 109 rotatably supported on a stub shaft 111 and pivotally connected through a. pin 112 to crank 107; a drive disc 113 fixedly secured to shaft 111 and providedv on its periphery with three equally spaced shouldered notches 114 adapted to be engaged by a pawl 115 carried by drive segment 109; and means providing a drive connection between shaft 111 and sprocket drive shaft 72, said lastmentioned means including a gear train con- 119 carried .by the hub of wheel 116 and adapted to be driven from shaft 111 through a spur wheel 121 carried by said shaft 111.

Motor 93 is arranged to operate in such direction that it drives crank disc 106.in a counterclockwise direction, viewing Figs. 1 and 7. Continuous rotation of disc 106 causes` crank 107 to produce oscillatory movement of drivesegment 109. In the position-of the parts shown in Fig. 7, the crank has completed its stroke and drive disc 113 has completed its rotation through 120 under the action of segment 109 and pawl 115. Upon movement of crank 107 to the left, viewing Fig. 7, drive segment 109 will be turned in a clockwise direction on shaft 111 until pawl 115 engages in lthe succeeding one of the'notches 114, this engagement being effected by a lU-shaped leaf spring 121 which is carried by pin 112 and whichv bears against said pawl. Upon the return stroke of crank 107, drive segment 109 will turn disc '113 in a'counter-clockwise direction through 120,

lsheet from the bed plate and to replace it by a fresh sheet.

A stop `device is provided for insuring that the conveyor chains will stop 'at exactly the point which will bring the fresh-sheet into printing position. This mechanism, which is'shown in are normally held in iixed position between rails.

Figs. 7 and 8, comprises a latch arm 122 pivoted at 123 to the frame and provided at its free end with a roller 124 which is adapted to be received in V-shaped notches 125 formed in the rim of disc 113. Roller 124 is yieldingly pressed against the rim of disc 113 by a coil spring 126 which is disposed about the shank of bolt 127, said bolt being carried by lever 122 and having sliding engagement with a lug ,128 on the frame which' serves as a stop for one end of 'spring 126, the other end of said spring bearing against arm 122. The v-shaped notches 125 are spaced on disc 113 at intervals of to correspond exactly to the spacing of drive notches 114, and arm 122 is so positioned that roller 124 will be seated against one of the notches at exactly the point at which segment 109 completes advance movement .of drive disc 113. The conveyor chains are thus brought to a positive stop at exactly the right time 4to insure the positioning of the sheet in' proper position on the bed plate. Additional means'for further insuring accurate registration of the sheet with respect to the printing frame and stencil will be presently described.

rails and their associated cam blocks as indicated 110 A at 133 (Fig. 5). The lower edge of each of the blocks 131 and 132 is toothed as indicated at 134, and the upper edge of each of said blocks is p rovided with anupwardly sloping cam surface 135 which-terminates at its upper end in a comparatively short ilat surface portion 136, the lower end of inclined surface 135 terminating in a com# paratively long fiat surface portionI 137. The printing frame is provided at each corner with a roller 138 which is journaled in the lower end of a block 139, said block being supported for vertical sliding movement between a pair of guide rails 141 and 142 which are secured to the side members of the printing frame. Blocks 139 125 141 and 142 by levers 143 which are pivoted at 144. to the side of the printing frame. The ends 145 of each pair of levers 143 at'the opposite ends of the frame are held down by a cross-bar 1'46 (Fig. 3) which is supported from the end wall 130 of the frame by a guide rail 147, the latter being secured to the frame and having tongue and groove connection with a strip' 148 which is carried 'by bar 146. 'I'he opposite ends of bar 146 are provided with downwardlyl extending cam 135 projections 149 (Fig. 3) having cam surfaces 151 for engaging against the 'ends of levers 143. 'I'he movement of bar 146 is effected by means` of aworm 152 carried by a shaft 153 which is Journaled in a bracket 154 carried by the end Vvvall of 140 'the printing frame.

Worm 152 meshes with a toothed rack 155 which is formed on bar 146. Av hand wheel 156 secured to the outer end of shaft 153 provides means for turning the latter together with worm' 152 to effect either forward or 145 backward movement of bar 146. Movement of bar 146 toward the right, viewing Fig. 3, will depress levers 143, which in turn push blocks 139 and rollers 138 downwardly relative to the printing frame, thereby raising the latter relative to cam blocks 131 and 132. The lower limiting position of the printing frame relative to the bed plate is thus readily adjusted to accommodate the machine to the printing of stock of various thicknesses. C oil springs 157 (Fig. 4) extending between blocks '139 and a fixed point on rails 142, serve to hold said blocks in yielding engagement with levers 143.

Referring to Figs. 1, 4, and 5, cam bars 131 are reciprocated in their associated guide supports 128 by a pair of toothed segment gears 158 which are xedly secured to shaft 69. The teeth of segment gears 158 mesh with the teeth 134 extending along the under sides of bars 131. Similarly cam bars 132 are reciprocated in their associated guides 129 by a pair of toothed segment gears 159 which are rigidly secured to a shaft 160 which extends transversely of the frame. The teeth on segment gears 159 mesh with the teeth 134 on the under surfaces of the blocks 132. It will be apparent that turning of segment gears 158 in a counter-clockwise direction, viewing Fig. 1, will slide cam bars 131 to the left to cause rollers 138'to ride Aup the inclined surfaces 135 on said bars, thereby raising the end of the printing frame. Aclockwise movement of segment gears 158 will move bars 131 to the right, viewing Fig. 1, to lower the end of the printing frame. The operation of segment gears 159 at the other end of the frame is similar. Turning 'of said gears in a clockwise direction, viewing Fig. 1, draws blocks 132 to the right to raise the frame, and movement of said gears in a counter-clockwise direction moves blocks 132 to the left to lower the frame.

Shafts 69 and 160 which carry segment gears 158 and 159, respectively, are driven in timed relation to the feed means from shaft which, it will be recalled, is also used to drive the conveyor chains. Referring particularly to Figs. 1 and 5, shaft 105 carries a spur gear 161 which meshes with a spur wheel 162 carried by a stud shaft 163, said gear wheel 162 in turn meshing with a spur gear 164 which is carried by the hub of a crank disc 165, said gear 164 and disc 165 being journaled for free rotation on a stub shaft 166. Crank disc 165 connnects with shaft 150 through a link 167 which connects at one end with an eccentric pin 168 carried by disc 165,

the other end of said link 167 having pivotal connection with an arm 169, the latter being rigidly secured to shaft 160. Disc 165 is driven in a clockwise direction, viewing Fig. 1, and for each complete revolution produces one complete oscillatory movement of segment gears 159. Segment gears 158 are similarly driven from shaft 105 through a train of gears 171, 172, and 173 (Fig. 5), the latter being secured to the hub of a second crank disc 174. Shaft 69 connects with crank disc 174 through a crank 175, the -latter connecting at one end with an eccentric stud 176 carried by disc 174, the other end of said link connecting with an `arm 177 which is carried by shaft 69. Disc 174 is also turned in a clockwise direction, viewing Fig. 1, each revolution of the disc producing one complete oscillatory movement of segment gears 158.

The at surface portion 137 of cam blocks 131 and 1-32 is provided to prevent raising of the printing frame over an interval sufficient to allow for the movement of the squeegee over the stencil. Although these cam blocks are moving continuously, they do not raise the frame until the inclined surfaces 135 strike the rollers 138, and the drive means for effecting movement of .the vertical movement of the latter.

these blocks is so timed relative to the means for operating the squeegee, hereinafter described, as to insure that the printing frame will be in the lowered position during the interval of movement of the squeegee over the stencil. Also the drive means for operating cam blocks 131 and 132 is accurately timed relative to the conveyor drive means. These two systems of driving gears, both of whichhave a common source of power through shaft 105, are so arranged that the inclined surface portions of cam blocks 131 and 132 move into engagement with rollers 138 simultaneously with the driving stroke of crank 107 and segment 109 which operate the conveyor` chains. Therefore, the printing frame is raised during the interval in which movement is imparted to the conveyor chains and is lowered during the return stroke of crank 107 and segment 109 during which interval the conveyor chains remain stationary.

The clamping means on the gripper bars 61 is also operated in timed relation to the movements of the printing frame and the conveyor chains. The mechanism for operating the gripper clamping means is shown in Figs. 10, 16, and 17. This mechanism is duplicated for the opposite sides of the machine and hence will be described in the singular. In the position of the parts shown in these gures, clamping jaw 81 is in the un- .clamped position, the arm 84 being out of engagement with latch lever 86. As the gripper bar moves'argund sprocket 62 and reaches the feed end of the bed plate, the forward end of arm 84 rides over the top edge of a block 177 which is mounted for vertical sliding movement on4 a bracket 178 which is secured to the innerface of the frame, a sliding T-connection 179 being provided between bracket 178 and block 177 Ato guide Block 177 is thrown upwardly to move arm 84 to clamping position by an arm 181 which is secured on shaft 160. The end of arm`\,181 is provided with a spring-held pawl 182. When shaft 160 is turned in a clockwise direction, viewing Fig. 10, pawl 182 is thrown against the lower edge of block'17'7, thereby throwing the latter to the dotted line 1 position shown in Fig. 10, during the course of which movement arm 84 is moved sufficiently to bring jaw 81 into clamping engagement with the leading edge of a sheet 183. Arm 84 and jaw 81 are held in this clamped position, represented by 1 the dotted lines in Fig. 10, by latch lever 86 (Fig. 17), the tip 89 of which engages under arm 84. Shaft 160, it will be recalled, is given a movement of oscillation by crank disc 165 so that on the return stroke of arm 181, pawl 182 will pivot on 130 arm 181 and move past the lower end of block 177. Arm 181 is so positioned on shaft 160 that it will effect actuation of block 177 while the printing frame is in lowered position and while the conveyor chains are stationary..

Referring particularly to Figs. 16 and 17, the.

shaped bracket 185, the lower edge of which is shaped to provide an upwardly inclined cam surface 186 which is positioned to engage an arm of latch lever 86 as the latter moves past block 184. As the arm of lever 86vrides up on cam surface 186, said lever is pivoted in a counter-clockwise 1 raised position and engages lug 79 on the gripper,

direction, viewing Fig. 17, thereby releasing arm 84 from the tip portion 89 of the lever which drops downwardly and` moves jaw 81 to released position; Arms 84 at the opposite Aends of shaft 82 being thus released, clamping jaw 81 is `sprung upwardly from the sheet by coil springs (not shown) which are positioned in sockets formed in bladeV 76 and which bear upwardly on metal strips 190 (Fig. v2) carried by shaft 82. A pair of guide fingers 191 (Fig. 16) are positioned on the discharge platform at the opposite sides thereof, and serve to keep the sheet aligned on the platform as-it moves to discharging position. These fingers are pivotally secured at one end to the platform, and the other ends thereof are pressed upwardly by coil springs 192 which areA contained in openings or wells formed in the platform.

In order to facilitate feeding of the sheets from the feed table .into the gripper bars, there is provided between the feed end of the bed plate and the feed table a feed panel 193 (Fig. 2) which is secured to a supporting shaft 180 the latter being journaled at its opposite ends in frame brackets 196. Table 193 is normally positioned horizontally, asshown in Figs. 2 and 9, in which position it'forms a continuation of feed table 49.

A shaft 195, supported=on shaft 180 by a pair of arms 194,.is provided with a series of resilient fingers 197whieh yieldngly engage the leading edge of the sheet to guideit into the gripper bars'. Shaft 180, together with platform 193, is turned on its axis at regular intervals in order to clear the gripper bars as they move into receiving position. For thispurpose an arm 198 is secured to shaft 180 in position to be engaged by the end of one of thecam blocks 132 when the latter moves outwardly preliminary to the raising of the printing frame. As the block 132 recedes it allows the shaft 180 and panel 193 to return to the normal position shown in Fig. 2. I

Mechanism in addition to the locating arm 122 (Fig. 1) is provided for accurately positioning the gripper bars onthe feed bed. It is of great importance that there be provided means for obtaining accurate registration of the sheet with the stencil since for multi-color work it is necessary to have the various colors printed in accurate registration with one another. This locating means includes devices for positioning the gripper bar as it comes to rest at the feed end of the platform and also includes devices for positioning the immediately preceding bar adjacent the disand 11. This mechanism is' duplicated for each side of the machine and therefore will be described in the singular. It comprises: a locating,

block 205 which is mounted for verticalmovement in a guide channel formed in bracket 178; an actuating varm 206 secured to shaft '160 and provided at its outer end with a cam piece 207 which is pivotally connected at 208 to arm 206; and a latch 209 for holding block 205 in lowered position.

The upper end of block 205 is cradle-shaped, a portion thereof being cut away as indicated at 211 to receive the end lug 79 (Fig. 18) which connects the gripper bar to the conveyor chain. The rear edge of block 205 projects upwardly a considerable distance ,above the cut-awayV portion 211 to 'provide a stop 212 for engaging the edge of lug 79. In the position of the parts shown by the'solid lines in Fig. 10, block 2051s in the held in such position during bar to accurately position the latter relative to the feed table. Block 205 is pulled downwardly to the dotted line position shown in Fig. 10 to allowl advance movement of the conveyor chains, this movement being effected by the swinging of cam piece 207 to the dotted line position in said figure. In swinging to this position, a flange portion 213 'carried by cam piece 207 engages over a stud 214 secured to the lower end of block 205 to pull the latter downwardly. `In the backward swing of arm 206, cam piece 207 brushes past roller 214, it being yieldingly connected with arm 206 by a leaf spring 210. This operation iseffected in proper timed relation with the movement of the printing frame since arm 206 is operated from shaft 160 which also operates the means for raising and lowering one end of the printing frame. As. block 205 moves downwardly it is engaged by an arm 215 of latch 209, the latter being normally urged by a spring (not shown) toward the dotted line position shown in Fig. 11, in which position it seats on the top of a shoulder 216 on block 205 to hold the latter in position which will allow -the gripper bar to clear the upper end of said block 205. A coil spring 217 extending between block 205 and the as soon as the gripper bar becomes posi ioned over the latter, this being effected by a cam plate 218 which is secured to a link on the conveyor chain adjacent the gripper bar.v As this'cam plate approaches the position shown in Fig. 10, it strikes an upwardly projecting arm 219 carried by one ,arm of lever 209, and as it moves past the projection 219 it pivots lever 209 to the solid line position shown in Fig. 11, thereby releasing block 205 which is immediately pulled upwardly to engage lug 79 on the gripper bar. The incoming gripper bar is thus accurately positioned on the bed and the printing operation.

The second of the above-mentioned locating devices, namely, the one which holds the bar accurately in position at the discharge end of the bed plate, is shown in Fig. 9. This mechanism is duplicated for each side of the frame and will be described in the singular. It comprises: a locating bar 221 which is arranged for vertical movement in a mounting block 222, a cam disc 223 flxedly secured to shaft 69; and a lever 224, -one end of which is pivotally connected at 225 to block 221, the opposite end of said lever being provided with a roller 226 which engages a cam groove 227 formed in the face of disc 223.

, The upper end of block 221 iscut away in the same manner as block 205 which is located at the feed end of the bed plate, thepurpose of this being to provide a cradle in the upper end thereof for receivinglug 79 on the. end of the gripper bar. In the position of the parts shown in Fig. 9,

lug 79 is seated in the upper end of block 221 and y the gripper bar, with the sheet secured therein. is thus heldin accurate registration with the printing frame and the stencil. Block 221 is raised and lowered in timed `sequence with the raising and lowering of the printing frame'by the movements of cam segment 223 which, itwill be noted, is carried on shaft 69 which, as previously explained, operates themeans for raising and lowering one end of the printing frame. As cam segment 223v pivots in a counter-clockwise direction, viewing Fig. 9, roller 226 strikes a raised portion 228 in groove 227 which pivots lever 224 in direction to lower locating block 221. This operation, which occurs just before the printing frame is lifted, frees the gripper bar from block 221, thereby avoiding interference with the next movement of the conveyor chains.

The construction and operation of the paint supplying means will now be described, reference being rst had to Fig. 12. Stencil 30 is secured to a rectangular wooden frame 229, which is in turn secured by screws 231 to a rectangular metal frame 232. Frame 232 fits into the bottom of the printing frame, the latter being provided with an inwardly extending flange 233 which engages the upper face of frame 232. The stencil frame is removably secured in the printing frame by spring-pressed plungers 234 which proj ect through the sides of the frame into notches 235 formed in frame 232. By pulling outwardly on'plungers 234 the stencil frame may readily be released from the printing frame.

Referring to Figs. 2, 9 and 9a, paint is supplied to stencil 30 from a hopper 236 which is removably secured in one end of the printing frame by means of lugs 237 which project from the end walls of the hopper and which are received in U-shaped sockets 238 formed in brackets 239 which are carriedby the side members of the printing frame. The hopper is shaped to provide a storage reservoir 241, the lower end of which is closed by a gate bar 242 which is carried on a shaft 350, the latter being journaled at its opposite ends in brackets 349 which are secured to the walls of the hopper frame. Bar 242, in the closed position shown in Fig. 9a, bears against a stop 351 which is secured to the fountain wall. When bar 242 is turned to open position, paint ows from the reservoir 241 along a curved guide wall 244 and from thence onto the stencil.

Referring particularly to Fig. 9a, means is provided for automatically controlling the opening and closing of gate bar 242 in accordance with the movements of the printing frame. 'Io this end shaft 350 is provided with a pair Vof spaced brackets 352, the upper ends of which are apertured at 353 to receive bolts 354, the latter being secured in blocks 355 which are carried by the side wall of the hopper 236. Coil springs 356, interposed between brackets 352 and the heads of bolts'354, urge shaft `350 in a cou'nterclockwise direction, viewing Fig. 9a, thus tending to move bar 242 -to open position. Fastened to the opposite ends of shafts 350 are a pair of brackets 357, the free ends of which are provided with adjusting screws 358 which are positioned in alignment with bars 359, the latter being secured to the side rails of discharge platform 53. It will be apparent that when the printing frame and hopper 236 are in raised position. springs 356 will move gate bar 242 to open position, thereby allowing paint to flow down onto the stencil. Upon lowering of the printing frame and hopper screws 358 will strike against bars 359, thereby causing brackets 357 to turn shaft 350 and gate bar 242 in a clockwise direction, viewing Fig. 9a,

to effect closing of the hopper. The ow of paint onto the stencil is thus automatically regulated by the movements of the printing frame.

Paint which is supplied to the stencil in the manner just described is pressed through the stencil onto the sheets by a squeegee which is arranged to wipe the paint over the stencil to force it through the penetrable areas forming the Adesign to be printed. In accordance with one of the novel features of our invention, the squeegee is arranged to wipe the paint over the Stencil during its advance stroke and then to return paint which has accumulated on the stencil at the end of the advance stroke back to the rear edge of the stencil, from which point it may be wiped over the stencil on the succeeding advance stroke.

Referring to Figs. 12, 13, and 14, the squeegee comprises a trough-shaped back member 245 which is formed from a pair of oppositely inclined side pieces 246 and 247 which ordinarily are formed as a single piece. The lower edge of arm 246 is channeled to receive a rubber wiping element 248, and the lower edge of arm 247 is preferably protected by a strip of rubber 249. The squeegee is supported in the printing frame by means of stub shafts 251 which extend through rollers 252, the latter in turn resting on flanges 233 which extend along the sides of the frame and serve as guide tracks for said rollers. The ends of shafts 25lcarry arms 253 which are provided at their free ends with rollers 254 which engage guide rails 255 projecting inwardly from the sides of the frame. The squeegee is moved back and forth over the stencil by endless conveyor chains 256 which take at one end over idler sprockets 257 and` at the other end over drive sprockets 258. The upper run of the chains also takes over a pair of idler sprockets 259. The opposite pairs of sprockets 257 and 259 are carried on stub shafts which project inwardly from the sides of the frame. Drive sprockets 258 are secured on the opposite ends of a drive shaft 261 which is turned in a counter-clockwise direction, viewing Fig. 9, until the squeegee has completed its advance stroke, after which Vshaft 261 is reversed to return the squeegee to the rear edge of the stencil. The drive means for shaft 261 will be presently described. The squeegee is connected to chains 256 through stub shafts 251 which extend through bearing links 262 connected into the links of said chains.

' In Fig. 9 the squeegee is shown in the position which it assumes during its advance stroke. In this position, wiper element 248 is in pressure contact with stencil 30 and rollers 254 carried onthe ends of arms 253 are positioned below guide rails 255 so as to hold the wiping element against the stencil. As the squeegee moves to the right it brushes the 'paint over the stencil, and asl it reaches the end of its stroke there is accumulated in front of it a batch of excess paint 263' (Fig. 12). As the squeegee reaches the end of its advance stroke, rollers 254 move to the position shown in Fig. 14 where they strike against the under faces of pivoted cam blocks 264 which normally pivot under their own weight to the dotted line position shown in said figure. As the squeegee completes the end of its stroke, rollers 254 move past blocks 264, whereupon the latter pivot downwardly to the dotted line position shown in Fig. 14. ,Upon the return stroke of the squeegee, rollers 254 ride up on blocks 264 to assume the position shown by the dotted lines in Fig. 14. The upward swing which is thus imparted to arms 253 at the beginning of the reverse stroke pivots or rocks the squeegee from the position shown by solid lines in Fig. 12 to the position shown by the doted lines in said gure, in which latter position wiping element 248 is held out of contact with the stencil. The squeegee is held in this raised position throughout its return stroke and is again returnedto active wiping position when it reaches the end of the return stroke, at which point rollers 254 drop from the rearends of guide rails 255, thereby dropping wiping element 248 back into engagement with the stencil.

In order to prevent accumulation of paint in the forward end of the stencil frame, means is provided for picking up the paint at the forward end of the stencil and returning it lto a point from which it may be wiped over the stencil upon the next advance stroke of the squeegee. VThis means is shown in Figs. 9 and 12 and comprises: a swingingscoop formed from a piece of curved sheet metal 265, and a pair of end plates-266. End plates 266 are secured to back member 245 by means of stub shafts 267 which project through brackets 268, the latter being secured to the ends of back member 245, and said stub shafts 267 being secured at their inner ends to end plates 266. The outer ends of stub shafts 267 are provided with arms 269 which are provided .at their ends with rollers 271. Guide rails 272 are supported from the sides of the printing frame byv brackets v273 (Fig. 5) and engage rollers 271 to l control the position of the scoop supporting arms 269. When the squeegee is in active wiping position, as shown in Fig; 9, rollers 271. engage the under face of guide rails 272 to hold the scoop against the front side 247 of the squeegee. In this position paint which is contained in the scoop may flow therefrom onto the stencil im-v mediately in front of wiping element 248. In other words, in this position the squeegee is arranged to deliver paint contained therein onto the stencil. As the squeegee approaches the end of its stroke theseoop. is swung from the position shown in Fig. 9 to the position shown by the solid lines in Fig. 12, this pivotal movement being eiected by upwardly inclined guide blocks 270 which engage rollers 271 and cause arms 269 to` swing in a clockwise direction, viewing Fig. 12. The scoop is thus swung against the back side 246 of the squeegee and as the latter completes its advance stroke the scoop picks up paint as indicated in Fig. 12. Upon the return stroke the squeegee is pivoted from the position shown by solid lines in Fig. 12 to theposition shown by the dotted lines to bring the front side 247 against the scoop. The paint is thusheld in the scoop between the curved metal piece 265- and the front side wall 247 of the squeegee. 'I'he arms 269 are quite heavy as compared to the Weight of the scoop and serve to hold the latter while in the carrying position against the front side 247, this being clearly illustrated by the dotted line position in Fig. 12. 'Ihe -scoop remains in the carrying position throughout the return stroke. y At the end of the return stroke A the squeegee. is pivoted back to the position shown in Fig. 9, as previously explained, and arms 269 cause the scoop to swing with the squeegee. This swinging movement brings rollers 271 below guide rails'27-2so that during the advancev stroke the scoop is positively held inthe delivering position. The squeegee, together with its timed relation to movements of theA printing frame and the sheet feed means, the arrangement being such that the squeegee is advanced over the stencil whilethe printing frame is in lowered position on the be'd plate and returnedv ing frame is removed from the bed plate.

back to the printing' position at the rear edge of the stencil during the interval in which the print- This drive mechanism is shown in Figs. 3 and 4. A crank disc 274 carried on the end of shaft is arranged to have driving connection with said shaft 105 through a latch lever 275 which is pivoted at 276 to the inner face of disc 274. One arm 277 offsaid lever 275 engages a drive shoulder 278 formed in a collar carried by shaft 105. A bolt 279 carried by arm 277 has sliding engagement with a guide lug 281 carried by disc 274. A coil spring 282, which is confined between lug 281 and lever 277, holds the latter in l driving engagement with shaft 105.

A segment gear 283 is secured to one arm of a bell-crank 284 which is pivoted at 285 to the frame, the other arm of said crank being slotted, as indicated at 286, to engage an eccentric pin 287 carried by disc 274. Rotation of disc 274 will thus vproduce oscillatory movement of bellcrank 284 and segment gear 283.

Segment gear 283 meshes with a pinion 288' carried on 'a stub shaft 289. A spurgear 291, which' is rigid on shaft 289, drives a stub shaft 292 through a spur gear 293. Shaft 292 drives the squeegee chain drive shaft 261 through a beveLgear 294 which meshes with a bevel pinion l'295; 'the iatter driving a second bevel pinion 29s through a shaft connection. '297. Pinion 2.96 105 has driving engagement with; abe'yel pinion 298 carried on the end of shaft 261. Since the oscillatory movements .of segment gear 283 are obtained from shaft 105, which also is connected inthe gear drive Asystems for the printing frame actuating mechanism and the :conveyor means for the gripper bars, it follows that the squeegee conveyor chains,- which are driven from-shaft 261, will be operated lin timed relation to the movements of the griper bars and the printing frame.V The gear drive between shaft 261 and the oscillating gear 283 is arranged so that the squeegee will be advanced over the stencil while the printing frame is in lowered position and will be carried back to the rear edge of the stencil while the printing frame is in raised position, during which period the gripper bars are moved to bring a fresh sheet into printing position.

Since the printing frame is raised and lowered on the bed plate, it is necessary to provide a universal joint connection between bevel pinions 295 and 296 which are disposed on the opposite ends of connecting member 297. To this end said member 297 is formed of two separate shaft portions 299 and 301, each of which is provided with a universal joint connector 302. The provision of these two universal joint connections allows connecting arm 297 to bend when the printing frame is tilted about shaft 39. The portion 301 of member 297 has a plug portion 303 1-35 which iits into a corresponding socket formed in the portion 299. A longitudinal key connection between this plug and its associated socket allows longitudinal movement between these parts to maintain the drivingv connection during themovements of the printing frame to and from 297 thus maintains thedriving connection to the squeegee chain drive shaft 261 for all positions of the printing frame.v 'Ihe portion 301 of con- 145 nector member 297 is secured to shaft 292 through a bracket304 and the portion 299 of said connector is secured to the printing frame through a bearing bracket 305 and a 'connector arm 306 (Fig. 2). 150

A vsafety device is provided for preventing operation of the machine should an emergency arise, such as failurevof the sheet feed means, or the like. To take care of such emergencies, I provide a manually controlled device for checking the downward movement of the printing frame for stopping operation of the squeegee. Referring to Figs. 4, 9, and 15, a throw-out cam 307 is mounted in a guide bracket 308 which is secured to the frame adjacent crank disc 274. When cam 307 is raised from` the solid line position shown in' Fig. 4, it will engage a roller 309 carried on one arm of latch lever 275 to throw the latter out of driving engagement with shaft 105. The drive to the squeegee chain drive shaft 261 is thus interrupted to stop movement of the squeegee as soon as disc 274 brings roller 309 into engagement with cam 307. Cam 307 is operated from the front of the machine through a hand lever 311 (Fig. 1) which is secured to a cross shaft 312, the latter being connected through an arm 313 and a link 314 to one arm of a bellcrank 315 which is pivoted to the bracket which supports cam 307. The other arm of bellcrank 315 connects through a link B16-with cam 307;

The means provided for checking downward f movement of the printing frame in the event of an emergency is shown in Figs. 9 and 15. A pair of stop blocks 317 and 318 are secured to resilient arms 319 and 320, respectively, the latter in turn being bolted to a block 321 which is carried by the bed plate frame. A similar pair of stop blocks are mounted on the bed plate frame adjacent the opposite side of the printing frame, one block of the back pair being shown in elevation in Fig. 4. When the blocks are locatedin the solid line position shown in Fig. 15, the printing frame can not drop fully to printing position, since the blocks engage the sides sof the frame to prevent complete downward movement. Normally, however, these blocks are held in the dotted line position shown in Fig. 15, the holding means provided forthis purpose consisting of links 322 and 323 which are secured, respectively, to pins 324 and 325 which project downwardly through the bed plate frame. The free ends of links 322 and 323 are provided with upwardly extending pins 326 and 327, respectively, which engage resilient arms 319 and 320. The lower ends of pins 324 and 325 are provided, respectively, with laterally projecting arms 328 and 329 which are adapted to berespectively engaged by the upper ends of armsV 331 and 332 (Fig. 9). Arms 331 and 332 are secured, respectively, to cross shafts 333 and 334 and the latter are interconnected by a link 335 which is connected at its opposite 'ends to arms 336 and 337 carried by shafts 333 and 334, respectively. Shaft 334 is connected with the manually controlled shaft 312 through an arm 338, a link 339, and a second arm 341 which is secured to said shaft 312.

Assuming the blocks 317 and 318 are in the dotted line position shown in Fig. 15, movement of hand lever 311 to the right, viewing Fig. 1, will move arms 331 and 332 to the left, thereby allowing links 322 and 323 to pivot from the dotted line position shown in Fig. 15 to the solid line position shown in said gure. Both of the blocks 317 and 318 are thussimultaneously thrown under the edge of the printing frame. The blocks atV the back side of the frame are operated in similar manner. Moreover, this operation occurs simultaneously with the throw-out of the squeegee drive chain mechanism, since the latter operation is also effected by the throwing of hand lever 311 to the right, viewing Fig. 1.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, but the appended claims should be construed as broadly as permissible, in view of the prior art.

What we regard as new and desire to secure by Letters Patent is:

1. In a printing machine, the combination with a bed plate, a printing frame movably supported over the bed plate, and a stencil carried in said frame: of a squeegee mounted in the frame for reciprocation over the stencil; means including an endless carrier chain supported in said frame f and reversible drive means therefor for operating the squeegee; means for holding the squeegee in pressure contact with the stencil during the advance stroke; means for lifting the squeegee out of contact with the stencil after completion of the advance stroke; means for holding the squeegee in raised position during the return stroke; and means associated with the squeegee for picking up paint accumulating on the stencil in front of the squeegee at the end of the advance stroke and for returning said paint to a point on the stencil from which it may be wiped over the latter upon the succeeding advance stroke.

2. In a printing machine, the combination with a bed plate, a printing frame movably supported over the bed plate, and a stencil' carried in said frame: of a squeegee mounted in the frame for reciprocation over the stencil; means for holding the squeegee in pressure contact with the stencil during the advance stroke; means for lifting the squeegee out of contact with the stencil after completion Aof the advance stroke; means for holding thesqueegee in raised position during the return stroke; and means including a pivoted scoop associated with the squeegee and movable independently of the latter for picking up paint accurnnulating on the stencil in front of the squeegee at the end of the advance stroke and for returning said paint to a point on the stencil from which it may be wiped over the latter upon the succeeding advance stroke.

3. In a printing machine, the combination with a bed plate, a printing frame movably supported over the bed plate, and a stencil carried in said frame: of a squeegee mounted in the frame for reciprocation over the stencil; means for holding the squeegee in pressure contact with the stencil during the advance stroke; a scoop pivotally supported on the squeegee; means for holding the scoop in position to allow paint to flow Ytherefrom onto the stencil while the squeegee is in wiping position; means operative on approach to the end of the advance stroke to move the scoop from delivering position into position for eiecting pick-up of paint accumulating on'the stencil in front of the squeegee; means operative at the end.of the advance stroke to move the squeegee out of contact with the stencil and to swing the scoop to carrying position; means for holding the squeegee in raised position and the scoop in carrying position during the return stroke; and means operative at the end of the return stroke to return the squeegee to wiping position and the scoop to delivering position, whereby to return Vpaint contained in the scoop to a point on the stencil from which it may be wiped over the latter upon the next advance stroke.

4. In a printing machine, the combination with a bed plate, a. printing frame movably supported over the bed plate,and' a stencil carried in said frame: of a squeegee mounted in the frameffor reciprocation over the stencil; said squeegee including a trough-shaped carriage and a wiping element secured to the back side of said carriage; means for holding the squeegee in position to maintain the wiping element in pressure contact with the stencil during the advance stroke; a scoop pivotally supported on said carriage intermediate the sides thereof; means for holding the scoop in position to allow paint to ilow therefrom onto the stencil while the squeegee is in wiping position; means operative upon approach to the endof the advance stroke to move the scoop from said delivering position into position lfor effecting pick-up of paint accumulating in front of the wiping element; meansoperative at the end of the advance stroke to rock the squeegee about itssupport, thereby raising the wiping element from the stencil and moving the front side of the squeegee carriage into paint-retaining position against the side of said scoop; means for holding the squeegee in raised position during the return stroke; and means operative at the end of the return stroke to rock the squeegee back to wiping position and to return the scoop to delivering position, whereby to return paint contained in the scoop to a point on the stencil from which it may be wiped over the latter upon the next advance stroke.

v5. In a machine for printing sheet stock and the like: a base, including a bed plate; a printing frame movably supported on the base. over the bed plate; a stencil carried in said frame; means for moving the frame vertically relative to the base to carry the stencil to and from printing position on the bed plate; means including.

an endless conveyor operating in timed sequence with said last-mentioned means for feeding the sheetto be printed onto the bedplate and for removing the printed sheet therefrom; a squeegee mounted for 'reciprocation in the frame over the stencil; means for holding the squeegee in pressure contact with the stencil during the advance stroke; means for holding the squeegee out of contact with the stencil during the return stroke; and means operating in timed sequence with the movements of the frame for moving the squeegee through its advance stroke while the frame is in lowered position on the bed plate and for moving the squeegee through its return stroke while the frame is away from printing position.

6. In a printing machine: a bed plate; a printing frame movably supported over the bedplate; a stencil carried in said frame; means for raisingand lowering the printing frame relative to the bed plate; a squeegee mounted in the frame for reciprocation over the stencil; means for holding the squeegee in pressure contact with the stencil during the advance stroke; means for lifting the squeegee out of contact with the stencil after completion of the advance stroke; means for holding the squeegee in raised position during the v g moving the squeegee through the advance stroke while the frame is in printing position on the bed plate and for moving the squeegee through its return stroke while said frame is away from printing position; and means including a pivoted scoop associated with the squeegee and movable independently of the latter for picking up paint accumulating on the stencil in front of the squeegee at the end of the advance stroke and for returning said paint to a point on the stencil from which it may be wiped over the latter upon the succeeding advance stroke. f

'7. In a printing machine: a base, including a bed plate; a printing frame movably supported on the base over the bed plate; a stencil carried in said frame; means for moving the frame vertically relative to the baseto carry the stencil to and from printing position on the bed plate; a squeegee mounted for reciprocation in the frame over the stencil; means for holding the squeegee in pressure contact with the stencil during the advance stroke; means for holding the squeegee out of contact with the stencil during the return stroke; and drive means operating in timed sequence with the movements of the frame for moving the squeegee-through its advance stroke while the frame is in lowered position on the bed plate and for moving the squeegee through its return stroke while the frame is awayfrom printing position, said drive means including lan endless conveyor mounted in the printing frame and operatively connected with the squeegee, a motor mounted on the base,-

and means including .a reversing mechanism and .1 0

supported'over the bed plate; a stencil carried in the printing frame; means for raising and lowering the printing frame relative to the bed plate; means including an endless conveyor operating in timed sequence Jtvith said last-mentioned means for feeding the sheet to be 'printed onto the bed plate and for removing the printed sheet therefrom; a squeegee mounted in the frame for reciprocation over the stencil; means including an endless carrier chain supported in said frame and reversible drive means therefor for operating the squeegee; means for holding the squeegee in pressure contact with the stencil during the advance stroke; means for lifting the squeegee out of contact with the stencil after completion of the advance stroke; and means for holding the squeegee in raised position during the return stroke.

9. In a machine for. printing sheet stock and the like; abed plate; a printing frame movably sure contact with the stencil during the advance stroke;` means for lifting the squeegee out of contact with the stencil after completion of the advance stroke; means for. holding the squeegee in raised position during the return stroke; means operating in timed sequence with the movements of the printing frame for moving the squeegee through the advance stroke while the frame is in printing position on the bed plate 'and for moving the squeegee through its return stroke while said frame is away from printing position; and means including a pivoted scoop associated with the squeegee and movable independently of the latter for picking up paint accumulating on the stencil in front 'of the squeegee at the end of the advance stroke and for returning the same to a point on the stencil from 10. In a machine for printing sheet stock and the like: a bed plate; a printing frame arranged for movement vertically to and from printing position relative to the bed plate; a stencil cartied in said frame; a squeegee mounted in the frame for reciprocation over the stencil; means including an endless carrier chain supported in said frame and drive means therefor for advancing the squeegee over the stencil when the latter is in printing position, said drive means being operative to carry the squeegee through the return stroke while said frame is away from printing position; and means operating in timed sequence with the movements of the printing frame and the squeegee for feeding the sheets to be printed onto the bed plate and for removing the printed sheets therefrom. said means including an endless conveyor having a. series of sheet gripper bars positioned thereon at regularly spaced intervals, said bars being provided with clamping means for engaging and holding the leading edge of the sheet during movement of the latter over the bed plate.

l1. In a machine for printing sheet stock and the like: a bed plate; a feed table positioned in alignment with the bed plate .adjacent one end thereof; a'- discharge platform positioned in alignment with the bed plate adjacent the other end thereof; a printing frame movably supported over the bed plate; a stencil carried in said frame; means for moving said frame to and from printing position on the bed plate; a squeegee mounted in the frame for movement over the stencil; meanslincluding an endless carrier chain supported in said frame and drive means therefor for advancing the' squeegee over the stencil when the latterv is in printing position; and means operating in timed sequence with said frame-moving means for feeding the sheets to be printed from said table onto the bed plate and for removing the printed sheets therefrom onto the discharge platform, said means comprising an endless conveyor 'extending over said bed plate and the discharge platform, and a series of sheet gripper bars arranged on said conveyor at regularly spaced intervals, said bars being provided with clamping means for egag" ing and holding the leadingedge of the sheet during movement of the latter from the feed table raver the bed plate and onto the discharge platorm. 12. In a machine for printing sheet stock and the like: a bed plate; a feed table positioned in alignment with. said bed plate adjacent one end thereof; a discharge platform positioned in alignment with the bed plate adjacent the other end thereof; a printing frame; astencil carried in said frame; means for moving said frame to` and from printing position on the bed plate; a squeegee mountedV in the frame for movement over the stencil; means includingv an endless can'ier chain supported in said frame and drive i means therefor for advancing the squeegee over the stencil when the latter is in printing position; and means operating in timed sequence with said frame-moving means for feeding the sheets to Ahe printed from vsaid table ontol the bed plate and for removing the printed sheets therefrom onto the discharge platform, said means' comprising an endless conveyor extexidingoverv the bed plate and discharge platform, a seriesof x-gemetgpper bus positioned on the carrier at Y regularly spaced intervals, clamping means on said bars for engaging and holding the leading edge of the sheet, means for throwing said clamping means into clamping position on the sheet after the bar has become positioned on the feed end of the bed plate, and means for holding said clamping means in engagement with the sheet until the latter has moved over the bed plate and onto the discharge platform.

13. Ina machine for printing sheet stock and the like: a bed plate; a printing frame arranged for movement to -and from printing position relative to the bed plate; a. stencil carried in said frame; a squeegee mounted in the frame for reciprocation over the stencil; means -for holding the squeegee in pressure contact with the stencil during the advance stroke; means for lifting the squeegee out of contact with the stencil after completion of the advance stroke; means for holding the squeegee in raised position during the return stroke; means for moving the squeegee through the advance stroke while the printing frame is in printing position on the bed plate and for moving the squeegee through its return stroke while the frame is away from printing position and means operating in timed sequence with the movements of the printing frame and the squeegee for feeding the sheets to be printed onto the bed plate and for removing the printed sheets-therefrom.

14. In a machine for printingsheet stock and the like: a bed plate; a printing frame arranged for movement to and from printing position relative to the bed plate; astencilfcarried in said frame; a squeegee mounted in the frame for ieciprocation over the stencil; means for hold: ing the squeegee in pressure contact vwith the stencil during the advance stroke meansfor lifting the squeegee out .of contact with the stencil after completion of the advance stroke; means for holding the squeegee in raised position during.

the return stroke; mean for moving the squeegee through the advance s roke while the printing frame is in printing position on4 the bed plate and for moving the squeegee through the return stroke while the frame is away from printing position; means including a pivoted scoop associated with the squeegee and movable indepdend-v ently of the latter for picking up paint accumulating on the stencil in front of the squeegee at the end of the advance stroke and for returning the same to a point on the stencil from `which it may be wiped over the latter upon the for movement to and from printing position rel- -n "f ative to the bed plate: a stencil carried infsaid frame; sheet feed means including an endless conveyor extending over the bed plate and-having A a series of gripper bars mounted on the con-v position to advance the conveyor a distance suf-- plate and to feed a fresh sheet thereto; move ment-limiting means positioned on the bed plate in the line of travel of said conveyor; and means operating in proper timed relation with the sheet feed means for moving said limiting means into obstructingl engagement with the gripper bars as the latter complete their feed movement over the veyor at regularly spaced intervals; means operative while the frame is: away from printing' ilcient to lcarry the printed sheet from Athe

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