US2189007A

US2189007A - Stencil printing machine

Info

Publication number: US2189007A
Application number: US205479A
Authority: US
Inventors: Kessel Josef
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-09-10
Filing date: 1938-05-02
Publication date: 1940-02-06
Anticipated expiration: 1957-02-06

Description

5 1940 .1. Kl-:ssEL

STENCIL .PRINTING MACHINE Filed lay 2, 1938 f5 Sheets-Shelf: 1

SHQ

3 Sheets-Sheet 2 Feb- 6, J KESSEL' STENCIL PRINTING MACHINE Filed May 2, 1938 Feb. s, 1940. J. AKESSEL 2,189,001

STNCIL PRINTING MACHINE Filed lay 2, 1938 3 Sheets-Sheet 3 445 400 mav Patented Feb. s. i940I f 2,189,007

UNITED STATE-s PATENT oFEicE 2,189,007 s'rENcn. PmNTmG MACHINE Josef Kessel, Krefeld, Germany Application May 2, 1938, Serial No. 205,479

In Germany September 10, 1936 13 Claims. (Cl. lol-123) Stencil printing machines are known with in- Fig. 1l is a top plan view of the front end of termittently travelling printing supports and with a stencil, y arrangement for automatically lifting and loW- Fig. 12 is a side elevation of Fig. l1, eringvthe stencils and for moving the doctors to Fig. 13 shows the lay out of the machine for and fro. electric drive. 5

The invention has for its object to carry out The stencil printing machine comprises subautomatically all operations lnecessary for the stantially a printing table covered with felt printing of webs and the like. This object is and adapted to be heated from below, around attained according to the invention in that the which table an endless band 2 of rubber, rublaterally unshiftable and unstretchable printbered fabric or the like circulates in the longitu- 10 ing support provided with a heating device, a dinal direction of the table and is moved in lonheated pasting and Washing device is driven by gitudinal direction towards a roll 3' by rolls 3 a suitable continuously running motor and conand 4 mounted on the short ends of the printtrolled by a gear and two clutches at two difing table i- The 1011 3 is keyed on the driving ferent speeds Whose change over from rapid shaft 5 of the machine to which the'rotary mo- 15 speed to creeping speed is` effected by a catch tions of a driving motor A are. transmittedl which clamps the support and during the forthrough the intermediary of a gearing arrangeward travel thereof successively disengages the ment B for full or semi-automatic operation. A clutch for rapid speed, engages and disengages pasting arrangement I is arranged adjacent the the clutch for creeping speed and actuates a roll 4 for automatically applying paste and above 20 fine adjusting device' whichindicates lthe regthe printing table stencils 6 are arranged which ister position and releases the catch for the rein conjunction with a doctor mechanism II serve turn movement and engages in the drive of the for printing the Web 1 of Smooth 01 Tough fiiili machine an auxiliary motor which imparts a or paper or other material running off a ro1l.

half revolution to a toothed wheel'and a switch Below the printing table i there is a washing ar- 25 disc connected -therewith and thus lowers the rangement III through Whieh the lower Side of stencils on to the web, and switches on another the band 2 passes to be automatically freed from auxiliary motor which actuates a doctor mechanpaste, printing ink or'the like adhering to its ism and again switches on the motor for raising surface. The printing table I, is composed of the stencils, which last mentioned motor eiects several plates adapted to be tted together, sup- 30 the engagement of the rapid speed clutch and Ported by girders 8 and closed at the sides, and the Aclamping of thel catch on the printing supis closed from below like a box byl the lower side port, 4 of the band. A heating arrangement 9 in this An embodiment of the invention is illustrated table is constructed as an automatic hot air,

by way of example in the accompanying drawsteam or electric heating arrangement,A or the 35 ings, in which: i like, or may be connected to a central heating Fig. l is an elevation of the machine viewed System and S0 installed, .that the heating mefrom the gearing side. dium passes not only through the printing table Fig. 2 shows the pasting arrangement of the but also through a pressure cylinder I0 for pressmachine in top plan view, ing the web I to be printed against the pasted 40 Fig. 3 is a top plan view of the gear with nne printing support 2, the Washing arrangement III adjustment device, y and the drying device IV for the. printed web. Fig. 4 is a' vertical central section through The heat radiated by the printing table and the pasting arrangement, the pressure cylinder I0 is utilized for pasting Fig. 5 shows in front elevation the gearing on the web 1. To enable the web to be nxed 45 and the raising and lowering device for the on the printing Support 2 in stretched condition stencils, l as little paste as possible is applied on the sup- Fig. 6 is a top plan'view of the doctor mechport 2 in stripes Il by a ribbed cylinder I2 (Fig. anism, 2). This cylinder I2, which is composed of parts Fig. 7 shows the doctor reversing mechanism which rest loosely between the printing Support 50 in side elevation, 2 and a paste feeding roll dipping into the paste Fig. 8 is a top plan view of Fig. 7, box I3 and connected by toothed gear wheels Fig. 9 shows the ne adjustment device in with the roll l, is guided laterally only by adtop plan view, justable levers I5, and is rotated by friction by Fig. 10 is a side elevation oi.' Fig. 9, the movement of the printing support and the 55 roll I4. The ribs of the body I2 are preferably so narrow; and spaced so far apart that the paste stripesll applied to the printing support 2 do not contact after being rolled out. In the pasting arrangement I a squeezing cylinder I6 is also arranged which is adjustable in its bearings and prevents Athe roll I4 from taking up too much or too little paste. As paste, dextrine has for example been found suitable, as it becomes glasshard when dried by heat, but rapidly re-dissolves in warm water, so that it is possible to remove it without difflculty from the printing support in the washing arrangement III. On the other hand the rolled-on paste only penetrates slightly into the fabric and thus keeps the fabric in a state perfectly capable of taking up ink.

Above the pasting arrangement I adjusting levers I1 and guide plates I8 are arranged at the two sides of the band 2, the plates I8 having flaps I9 extending vertically downwards and bearing against the edges of the band, so that the band 2 is positively guided on to the printing table in the correct position. The band 2 runs along the printing table without clearance between two guide bars 20 fixed at the sides ofthe printing table, and from these bars 20 a resilient holding clown element 2|, for example a thin sheet metal, rubber, reinforced fabric strip or the like, extends across the printing support so that the latter is enclosed as in a groove. The two guide plates I9 exert a resilient pressure on the yieldable band also from above and facilitate its passage on to the printing table by pushing the band inwards. Guide rollers or similar means might be employed instead of guide plates.` The printing support is preferably supported in the gap between the roll 4 and the printing table I by a transverse support 22. The positive lateral guiding of the upper side of the band counteracts diagonal and lateral displacements thereof which may be caused by the band structure, heating and cooling, and so forth, so that the printing support 2 circulates Wit-h its central longitudinal axis exactly in register with the longitudinal axis of the printing table. A uniform running of the printing support is also ensured in that the feed and guide rolls.3 and 4 are interconnected by a stretchable driving chain 23 which runs over the driving shaft 5 of the machine.

The iilm printing stencils 6 required for the printing are mounted on a pair of rigidly interconnected vertically shiftable bars 24 arranged parallel to the printing support 2, this pair of bars being guided with frictional contact by guide rods 25 in one or more guides 26 mounted vertically on the printing table I, so that longitudinal and lateral displacementsof the pair of bars 24 cannot occur and consequently in the case of multicolour printing the stencils are always accurately in register the one above the other. The raising and lowering of the stencils takes place when the printing support 2 is at a standstill and is effected by a lever 21 which is constructed as a bell crank lever and actuated by hand. 'Ihe lever 21 is connected by a connecting rod 28 with a lever system 29 by whose movements the pair of bars 24 and consequently the stencils 6 are moved up and down. A second rod 36 connects the lever 21 with a crank disc 3l of the motor C, so that the stencils 6 can also be raised and owered by motive power. The stencils 6 are iixed by front and rear riders 32 and 33, adapted to be clamped on the two bars 24. The front riders 32 engage behind abutment bolts 34 mounted on the longitudinal sides of the stencils and press the stencils by clamping screws 36 with hand operable head against the front bar serving at the same time as abutment bar for the pressure table `I. Thus, the front end of the stencil is unshiftably fixed in the longitudinal and transverse direction of the printing table. In order that also the rear end of the stencil cannot shift laterally, the rear riders 33 are constructed as lateral stops between which the stencil is stretched. On one of the narrow sides of the stencils there is an abutment Vbolt 36, by means of which any turning of the stencil around the vertical axis can be noticed and its lateral fitting is rendered possible. The number .of stencils to be fixed depends upon the number of colours to be printed and may vary within limits as desired. In the example described and illustrated two stencils are provided, each stencil prints a separate color,

and the second stencil prints over the first. By employing stencils correctly cut according to color, a large range of shades can be produced with only three or four stencils, and the length of the printing table can be relatively short. A great number of stencils with which only one colour can be printed are necessary for producing a multicolour print and consequently require a machine of relatively long construction, in which case merely the printing table with printing support requires to be changed, whereas the two head endslof the machine remain unchanged. 'I'he machine may also be of a width, to allow the printing of wide webs or single pieces such as table cloths, or the like in a single process.

The printing, which takes place whenl the printing support is at a standstill and the* stencils are lowered, is effected either by means of the automatically operating doctor mechanism II or by hand by moving'the printing ink backwards and forwards on the stencils 6. In the case of automatic operation the printing ink is spread by means of a spreader or doctor through the stencils on to the web 1 which is moved to and fro by a motor D independent from the mo.- tor C: In the case of hand operation, the doctors are moved to and fro by hand. The latter method only comes intoquestion, when stencils with coarse and ne patterns are used at the same time or when little ink is required at one portion of a print section and a lot of ink at another portion. The heat radiated rby the printing table exerts a favourable effect on the print- ,ing operation in that the ink after being applied on to the web at the same time gives up moisture, which deposits on the open portions of the stencils with a. gauze ground, whereby the printing ink is continually maintained in soft condition and the meshes in the pattern of the stencil are kept open. Thus, it is possible to print without interruption, or to wash out the stencils only when the service is stopped for a relatively long time, for example, over night. After the printing operation the stencils 6 are raised automatically by the lever 21 or by hand, whereupon the printing operation is terminated. The printed web 1 then passes at the next feedinto the drying arrangement IV into which it is drawn by means of a winding cylinder 38 on which an end strip 39 connected with the beginning of the web 1 is i'lxed. The Winding cylinder 38 is driven by a belt 40 or the like through the intermediary of the driving shaft 5 of the machine. A driving shaft not shown may be mounted in the bearings of the winding cylinder 38 instead of this cylinder, and this shaft drives a mechanism by which the nished material is run out of the drying arrangement IV, to a folding and collecting device.

While a length of web 1 equal to the length of a repeat is being pulled off the printing support 2, the lower side of the band 2 moves through the washing arrangement III. This arrangement comprises a vessel 4l, through which a heating medium passes, rotary brushes 42 dlpping i nto the water in the vessel, laterally shiftable stricklers 43 arranged under the printing support and counter pressure rollers 44 mounted above the printing support 2 and the stricklers 43, by which elements any paste softened by the warm water while the printing support is standing still, and also ink'smears, are washed and scraped off the support as it is moved on. The brushes 42 and stricklers 43 receivel their' drive ,from a gear B through the intermediary of a chain drive or the like and a rod system 43a actuated by a grooved cam 43b on the end of the shaft 5. The cleansed printing support 2 is stretched on its travel to the pasting arrangement I by a stretching roller 46 and dried by the heat radiated downwards from the printing table.

If the support 2 is fed at a low speed the output of the machine will be too small, and if itis fed at a high speed the impetus will be too great at the end of the feed to ensure accurate registering. Consequently the band must run at a high speed at the commencement of its feed and be slowed down so that it moves into its extreme end position at a creeping spee'd. l

The feed of the printing support 2 from one printing position to the next may be produced by the motor A or by hand. The motorA is connected with the driving shaft 5 by the gear B which can be alternately engaged and disengaged by electric clutches E and F or by a hand-actuated clutch G. The clutches E and F serve to quickly and slowly move the printing support 2 in the case of electric drive, and the clutch G, which is only actuated when the clutches E and F are currentless, serves for the quick movement and, in combination with a brake H, for the creeping movement, whereas a hand wheel J mounted on the countershaft 41 of the gear B makes it possible to move the printing support y 2 by hand.

The operation of the clutch G is conditional upon the raising and lowering of the stencils 6 and the doctoring of the printing ink being carried out by hand, and the motors C and D, and

`fixed point, and thus couples this pulleywith the counter shaft 41, this causing the feed of the printing support 2 at high speed through the intermediary of the wheels 53, 54, 55, 56 ofthe gear B, which produce a reductionof the speed oi. rotation of the motor shaft. When the hand lever 5l is swung back, the clutch G is disengaged again and at the same time the 4cheek brake I-I is.applied and the printing support stopped. The cheek brake H is arranged in the gear wheel 56 forming a casing and mounted on the driving shaft 6, and is actuated by a cam 51 controlled by a cam disc 58 arranged on the rear end of the control shaft 50. The rotation of the counter shaft 5 can then be carried out by hand by the hand wheel J, in order to attain particularlyne adjustments of the printing support in its repeat` position.

Manual adjustments, which are necessary in the case of' semi-automatic service, are carried out with the ald of a fine adjusting device K which comprises a magnifying indicating device, consisting for example of a bipartite, unequal armed indicator 59, 60, whose short arm 69 is cillated through a small angle by the contact witha catch L adapted to be clamped on the printing support 2. whereas the arm 60 connected with the short arm 59 by intermeshing teeth, swings out against the action of a spring through an angle many times greater than that of the deflection of arm 56 until it strikes against an adjustable electric contact 6| or the like by which the feed of the printing support is very accurately limited and optically or acoustically indicated or, in the case of electric drive, one

or several electric switches are actuated which y will be hereinafter described.

The catch L, which has a clamping plate 63 adapted to be clamped on the printing support 2 electromagnetically or by hand with the aid of a removable lever 62, is pushed back by hand or mechanically up to a stop 64 adjustably fitted in the initial position or to the beginning of the repeat when the printing support reaches its extreme end'position. The mechanical return of upon it is carried along until it encounters the short lever arm 59 of the ne adjusting device K.' By turning the hand wheel J the fine adjusting device allows the smallest movements of the printing support to be read, so that it can vbe adjusted absolutely in register below'the stencils 6 which are in the raised position.

When the printing support 2 has been vadjusted, the stencils 6 are lowered by means of the two armed lever 21, whereupon the printing ink is distributed on the web 1 mechanically or by hand through the stencils. After the printing ink has been stirred the stencils are again raised by means of the two armed lever 21.

In the case of electric drive the motors A, C and D become operative in succession. The three motors are connected to a common supply main M and, like the other driving means of the stencil printing machine, they can be switched on and off alternately or partly simultaneously by switches a, b, c, d, e, f, connected up in a low or high tension circuit N, and thus effect the uninterrupted drive of the machine. The clutch G and brake I-I are disengaged during the electric drive and the lever 62 of the catch L is removed, so that the catch can now be electrically clamped on the printing support 2 and mechanically returned by the screw spindle 65. This screw spindle only lserves for the idle return of the catch, but rotates continually. A belt 65a extends from the shaft 12 of the transmission gear 66 to a shaft 65h on which a Abevel wheel 65e is mounted which permanently meshes with catch L is effected bya screw spindle 65 which extends through the catch and Ais continually.

a bevel wheel 66d on the screw spindle. The electric clutches E and F in the gear B and the electromagnets 61 and 69 in the catch L- now become operative which have been switched in by the switches a-f of the plant. The clutches E and F effect successively the quick and slow rotation of the driving shaft 5 of the machine and consequently the quick or creeping feed of the printing support 2. The counter shaft 41 carries a second pulley 18 with the clutch E and a third pulley 1| with the clutch F. The pulley 10 is directly connected with the shaft of the motor A by a belt and the pulley 1| with the shaft 'l2 of the transmission gear 66 alsov by a belt. Both pulleys 10 and 1| i'lrst run idle. When the clutch E is engaged, that is the pulley 18 is coupled with thel counter shaft 41, the printing support 2 moves forward at high speed through the intermediary of the wheels 53, 54, 55, 56 of gear B. If the clutch F is engaged and the pulley 1| coupled with the counter shaft 41, the number of revolutions of this counter shaft is reduced by the reduction gear 6E so far, that the printing support is moved by the gear wheels 53, 54, 55, 56 only at a creeping pace intoits extreme repeat position, which is determined by the iine adjusting device K, whereas in the case of hand operated driving shaft 5 the extreme repeat position of the printing support, as stated, is only indicated magnied by the deflection of the indicator 68 up to the electric contact 6|. At the same time when the printing support 2 comes toa standstill, in the f plate 63 of the catch L is loosened and the pin 68 remaining permanently in the aperture of the hollow magnet 61 is caused to drop, and thus effects the return of catch L through the intermediary of the screw spindle 65. 'Ihe screw spindle has at one end an annular groove 13 into whichvthe pin 68 glides when the catch is in its initial position, and is held in this groove until the magnet 61is reexerted. The annular groove 13 and the abutment 64 allow the catch to pass into the initial position at the same height. During this time the motor C; which participates in the electric controls by means of a switch disc 14 connected with the crank disc 3|, effects the lowering of the stencils 6 by a half-revolution. A pinion 15 on the shaft of the motor C transmits the rotations of the shaft to the crank disc 3| constructed as a spur wheel and connected with the stencil holding bars 24 by the

lever system

30, 21, 28, 29. The half revolution of the crank disc 3| is automatically controlled by switches a-f of the plant and by the control disc 14 over which the motor C is automatically switched out after the lowering of the stencils. The stencils being lowered, the switched oi motor C effects through the switch disc 14 and switches a/-f of the plant the switching in of the motor D, which actuates the doctor device II for distributing the printing ink through the stencils on to the web 1. 'I'he doctor device II (see Figs. 1 and 6) consists of two endless pulling elements for example chains 11, driven by a chain 11a through the intermediary of ashaft 11b (Fig. 6). 'I'he chains 11 carry a cam 18 and a bolt 19. 'I'his bolt 19 circulates with the chains 11 about the axles of this driving wheel and moves a carriage 88 to and fro, whereas the cam 18, in` circulating with the chains 11, feeds the control disc 8| through a part revolution. This control disc 8| has contacts 82 arranged in star shape which are brought into contact with a spring 83, thereby closing one of the switches a-f and stopping the motor D. 'I'he ends of a pull rope 84 are connectedv to the ends of the carriage 8|), so thatl thisrope constitutes an endless pulling means. This pull rope is guided over pulleys 81 in such a manner that it extends across the printing table at three j l points as a double pulling rope, one of whose sides always runs in the direction in which the this pulling rope and is consequently moved to and fro across the table in synchronism with the to and fro motion of the carriage. The stencils 6, adjusted and xed according to register over the printing support by front and rear abutment means 32 and 33 lie between the outer guide bars 86 with guide or rope pulleys arranged on their ends. A third guide bar 88 is preferably provided between the stencils and also carries a guide pulley so that the Apullingv element extends from one end of the carriage 80 and is guided several times across the printing table between the end guide bars 86 before reaching the other end of the carriage 88. The doctor holder 85 is carried at each end by a vertically shiftable spring bolt 89 mounted in a carriage 98 (Figs. 7 and 8) and provided with a roller 93 resting on a cam bar 9| slidable along the end guide bars 86, 88 between abutments 92. Each caml bar 9| has two abutments 94, one at each end. As the doctor holder 85 moves to and fro, it shifts the cam bars 9| by means of the bolts 89 whose rollers 93 bear against the abutments 94 at the front end of the cam bars 9| in the direction of movement. At the reversal of the doctor holder 85 the cam' bars 9| first remain stationary and the rollers 93 run along' the cam race thereof and vertically shift the spring bolts 89, before reaching the abutments 94 at the actually inner end of the cam bars, whereupon these cam bars are shifted to the abutment at the other end of the guide bars 86, 88 where, at the reversal of the doctor holder 85'.the operation is repeated. The doctor holder 85 is carried by the bars 24 and consequently ascends and descends with the stencils. The

doctor holder 85 consists of a bar Iwith longitu- 9|, to behind the heap of ink and push it before them in the opposite direction as the doctor holder continues its movement. 'I'he number of to and fro motions can be regulated by the switch discv 8| which switches oi the motorv D either the first time the cam 18' contacts or only after it has contacted several times. The contacts 82 of the switch disc 8| may be either adjustable or unadjustable, or can be separately adjusted for each kind of movement. When the advancing cam 80 contacts with one of the abutments of the switch disc 8|, of which asl many are provided as there are contacts 82, it moves the switch aisaoov to and fro movement of the doctor holder.-

If two cams 18 are arranged on the catch chain spaced at a certain distance, the motor D is stopped after a single to or fro motion. If, however, there is only one cam on the chain 11 and six or less contacts 82 are provided on the switch disc 8|, in the case of twelve abutments, v

the contact spring 88 only comes into contact with a contact 82 after the cam 18 has circulated two or more times, so that the motor D is cut out only after the doctors have performed two or more reciprocating movements.

After sufficient doctoring or after the motor D is cut out, the motor C is again connected in the circuit through the switch disc 14 and switches c-f of the plant so that after the shaft of the motor has performed another half revolution lifts the stencils and at the same time closes the circuit of the catch magnets 61, 69 and of clutch F. The pin 68 is thus drawn into the hollow magnet, that ofthe catch L is unlocked, the clamping plate 63 is clamped on the printing support 2 and the catch advanced by the printing support 2 which is fed at high-speed through the clutch E. Just in advance of the fine adjusting device K a travel stop 91 `is arranged with two contact levers 98 and 99, which stop is laid down by the advancing catch L against the action of a spring |00, and through the intermediary of contacts |0| and |02, successively actuates two of the electric switches a-f by which the disengagement of the clutch E and a moment later the engagement of the clutch F is effected. As soon as the printing support has arrived at theV end of the repeat feed, the catch L knocks over the lever 59 of the fine adjusting device K which swings the pointer 60 up to the contact 6I, whereby throughv the intermediary cf three switches of the plant a-f the circuit of the clutch F is opened and at the same time the circuit of the catch magnets 61, 69 and of the motor C is closed.

'Ihe electric drive of the machine takes place in the following manner: First the main switches |03l and |04 of the supply mains M and the secondary circuit N are closed and the main driving motor A is switched on by closing the circuit by a press button switch |05 or the like, the driving shaft 5 being declutched. Current then flows through the wire |06 across the press button switch |05, a protecting device g series'connected with the motor A and whose switch is closed and conducts the current through the return wire |01 to the mains M and through the wire |08 to the motor A and thence over the return wire I1 back to the mains M. It is supposed that the catch L has turned over the lever 59 ofthe fine adjusting device K. Across the pointer 60 and contact 6| of this device the switches e and f of the secondary circuit N are opened, the magnets 61 and 69 of the catch L and the creeping motion clutch F are rendered currentless and at the same time the switch d is closed and the gear motor C is switched on and now effects the lowering of the stencils 6. When the circuit is closed by the pointer 60 and the contact 6|, the current flows .along the following path: source of current |09, feed wire IIB, pointer 60, contact 6| of the iine adjusting device K, wire |29, switch f which isopened, return wire I I I, switch e which is likewise opened, return wire III, switch d which isclosed, return wire III to source of current |09.` The mains current flows over the closed switch d along the followingpath: feed wire |06, closed switch d, wire II2, relay i, whose switch is closed over the return wire |01, wire |80, gear motor C, return wire |01 to the. mainsM. Whilst the gear motor C is running the spur wheel 8| performs a half revolution, whereupon two friction contacts |I3, V| I4 arranged on the periphery of the switch disc 14 connected` with the spur wheel 3| open the switch d and close the switch c by contacting with the contact |8I 'of the switch disc 14, and thus open the mains circuit of the gear motor C and close that of the gear motor D for the doctoring. After the spur wheel has performed half a revolution the secondary current flows along the following path: source ofcurrentv |09, feed wire IIO, spring contact |8I of spur wheel 3I, friction contacts |I3, ||4 and their wires H5, II6, switch d, which is opened, return wire III, switch c, which is closed, return wire I, source of current |09. By the opened switch d the switch of the relay i series connected with the motor AC is opened and this motor C stopped. By the closed switch c the switch -of a relay h series-connected with the motor D is closed and the doctor motor D switched on. As the doctor motor D rotates the mains circuit is as follows: feed wire |06, switch c, wire ||1, relay h, which is kept closed over the return wire |01, wire H8,

doctor motor D, return wire' |01. After suiiicient doctoring with the doctor device II has beenl done the doctor motor D is stopped again by the star switch 8|. The secondary circuit then flows along the following path: source of current |09, feed wire l| I0, contact Aspring 83, star contact 82, wire I|9, switch c, which is opened, wire III, switch b which is closed, returned through source of current |09. By the opening of the switch c the relay h is also opened and the doctor motor D stopped. By the closing of switch b the relay i is closed 'and the gear motor C restarted. The motor C receives its current from the mains M through feed wire |06, switch b, Wire II2, relay i which is held closed over'the return wire |01, wire |30, motor C, return wire |01, mains M. The motor C now running again rotates the spur wheel 3| through half a revolution with the result that the stencils 6 are raised. In this raised position the motor C is again switched oil by the switch disc 14 and at the same time the magnets 61, 69 of the catch L receive mains current over the switch f and the clutch E for the quick forward movement of the printing support A2 through the switch a. The secondary current then flows from the source of current |09 through wire I| 0, spring contact |3I, friction contacts ||4, |20, I2I, their wires I|6, |22, |23, switch ,f which is-clo'sed, wire ||I, switch b which isopened,

wire I I I, switch a, which is closed, back through wire III, .source of current |09. The current now ows from thevmains through the feed wire |06, switch f and switch a, wire |24, magnets 61, 69 of the catch L, return wire |01 and wire |25, clutch `E for the quick feed movements of the printing supportV 2, back throughv wire |01 to the mains M. The clutch L under current clamps tightly on the printing support 2 by which it is movedforward with theaid of the clutch VE. The oncoming catch Lknocks over the abutment 91 arranged in the path of the printing support 2 and by means of its contacts 98, 99 successively closes two spring contacts Il ll, |02 the first of which |0| breaks the circuit of the clutch E for the high-speed, whereas the second contact |02 closes 'a moment later the circuit of the clutch F for the creeping speed. The opening and closing oi' the circuits `of both clutches E and F is effected again over the switches e and y d. The 'secondary circuit extends as follows:

source of current |09, Wire ||0, path contact 98, contact spring I0|, its wire I 2B, switch a which is opened and a moment late source of current |09, wire IIO, path contact 99, contact spring |02, its wire |27, switch c which is closed, back through wire source of current |09. From the mains wire M the current now flows through the feed wire |06, switch e, wire |28, clutch F for the creeping speed, return wire |07. The printing support 2 now brings the catch L at creeping speed up to the second abutment lever 59 which is also knocked over and thus oscillates the hand 60 of the iine adjusting device K, which movement is considerably magniiled so that the end of this hand brushes over the contact 6|, whereby the switches d, e, f in the secondary circuit H0, are simultaneously aotuated, so that the mains circuit M of the creeping motion clutch F and of the magnets 61, 69 of the catch L are opened and that' of the gear motor C is closed for the purpose of lowering the stencils 6. The sequence of operations then commences afresh. -By switching off the-motor A by the press button switch 91 the machine is brought to a standstill. Clutches may be employed instead of the auxiliary motors C andl D which clutches may also be controlled by switches similar to the switches a-^f, so that all movements of the machine can be controlled by a single driving motor.

I claim:

1. An electric stencil printing machine comprising in combination an intermittently travelling laterally unshiftable and unstretchable printing support, stencils arranged above said support, a device for heating said support, heated printing and washing devices, a continuously rotating motor, va controlled gearbetween said motor and said support, two clutches one for rapid speed and the other for creeping speed, a catch adapted to'clamp on said support during the forward motion of said support to successively disengage the clutch for rapid speed, engage and disengage the clutch for creeping speed, a iine adjusting device for indicating the register position and actuated by said catch and adapted to release said catch for theY return movement, an auxiliary motor controlled by said device, a toothed wheel adapted to be rotated through half a revolution by said auxiliary motor, a switch disc connected to said toothed wheel adapted to lower said stencils, a second auxiliary motor controlled by said disc, a doctor mechanism above said support moved to and fro by said second auxiliary motor, said second auxiliary motor adapted to again switch on said auxiliary motor to raise said stencils and engage the clutch for rapid speed and clamp said clutch on said printing support.

2. In a stencil printing machine as speciiied in claim 1, the iine adjusting device comprising an indicator indicating on a larger scale and havf ing two arms of diierent lengths, the short arm aisaoov magnet adapted to hold said pin in raised inoperative position, said magnet rendered currentless with that oi the catch when the catch reaches its end position.

4. In a stencil printing machine as specified in' claim 1, means for returning the catch from its end position into its initial position, said means comprising a screw spindle driven bythe ,main driving motor, a pin in said catch adapted to engage in the thread of said screw spindle, and a magnet adapted to hold said pin in raised inoperative position, said magnet rendered currentless with that of the catch when the catch reaches its end position, said spindle having an annular groove in which the pinv and consequently the catch are held in their initial positions until their magnets are again excited.

5. A stencil printing machine as specified in claim 1, in which the doctoring device. comprises a motor-actuated pull aggregate, at least bolt, a pull rope fixed at both ends to said carriage, a plurality of pulleys continually guiding said rope on a tortuous path, and a doctor holder attachedto several sections of said rope moving in the same direction.

6. A stencil printing machine as specified in claim '1, in` which the doctoring device comprises guide bars, a carriage shiitable on said guide bars, vertical pins resiliently mounted on said carriage. a doctor holder vertically shiftable on said pins, cam races slidable at the side of said carriage, rollers supporting said doctor holder on said cam races, doctors mounted on said holders, abutments at the ends of said guide bars, cam noses at their ends, and a nose ascending towards the middle, said noses adapted to cooperate with said abutments to transport said doctor holder into its extreme positions and in each of these positions to raise said holder and bring the doctors behind the heap of ink on the stencils.

7. A stencil printing machine as specified in claim l, in which the doctoring device comprises a motor-actuated pull aggregate at least one pin in said pull aggregate, an an'chor bolt in said pull laggregate, a carriage mounted on said bolt, a pull rope i'lxed at both ends to said carriage, a .plurality of pulleys continually guiding said rope on a tortuous path, and a doctor holder attached to several sections of said rope moving in the same direction, contacts on the switch disc cooperating with the cams on said pull aggregate to close the circuit of the third motor and Astop this motor after said disc has performed rotary movement determined by the position oi' said contacts and by the number of said cams, to determine the number of to and i'ro movements of the doctor holder.

8. A stencil printing machine as specified in claim 1, in which the machine comprises a printing table, a pasting apparatus, a pressure cylinder, a washing apparatus, and a'drying apparatus all arranged in the path of travel of the endless printing support, and a heating plant adapted to feed heating `medium through said printing table, pasting apparatus, pressure cylinder, washing apparatus and drying apparatus.

9. In -a stencil printing machine as speciiied in clai 1, a pasting apparatus comprising a 5 multipartite ribbed body adapted to apply stripes of paste on to the printing support, a paste i'eed roll, said ribbed body and said paste roll frictionvally driven by said printing support, a squeegee roller bearing on said paste feed roll to determine 10 the amount of paste fed, and a pressurecylinder adapted to press the paper web on to the pasted printing support, the ribs on said -ribbed body being oi such width and so spaced that the pasted stripes remain separate even after pressure has 15 been excited by said pressure cylinder.` v

10. In a stencil printing machine as specified v in claim 1. said washing apparatus i'or the printing support, comprising a container for hot water, brushes rotating partly submerged in the water 20 in said container, laterally reciprocatable strippers mounted above said brushes, and counter pressure rollers cooperating with said brushes and strippers to b rush and scrape the printing support.

u 11. In a stencil printing machine as speciiied in claim 1, means for xing the stencils, compris-- ing iront and rear bars, front and rear riders adapted to iix said stencils to said bars, abutment bolts on said stencilst he front riders adapted to engage behind the abutment bolts on said sten- 5 cils. the front. bars serving as abutments for the printing table, and hand operated screws on the front riders adapted to press tightly against said front bars, and laterally adjustable abutment bolts on the rear riders adapted t0 laterally se- 10 cure the rear ends oi' the stencils.

12.' A stencil printing machine as specified in claim 1, in which the driving motors, the controlled gear, the toothed wheel, the doctor mechaniam and the catch are controlled by switches 15 in a secondary circuit.

13. In a stencil printing machine as specified in claim 1, means for raising and lowering the stencils comprising stencil holding bars and a rod system connecting said bars with the toothed 20 wheel, the switch disc being only operative when the stencil holding bars are in their extreme positions to switch oit said auxiliary motor and switch on the third motor.

JOSEF KESSEL. 26