US2775194A - Device for printing in register - Google Patents

Description

Dec. 25, 1956 1 G. DUBUl-r `2,775,194

DEVICE FOR PRINTING IN REGISTER Dec. 25, 1956 L.. G. DUBUIT DEVICE FOR PRINTING IN REGISTER 4 Sheets-Sheet 2 Filed Aug. 24, 1954 Dec. 25, 1956 1 G. DUBUIT 4 2,775,194

DEVICE RoR PRINTING IN REGISTER Filed Aug. 24, 1954 4 sn'eetsheet 5 Dec. 25, 1956 1 G. DUBUIT 2,775,194

DEVICE FOR PRINTING IN REGISTER Filed Aug. 24, 1954 4 Sheets-Sheet 4 laura-LTP im@ (SARL-mi `b KMX,

United States Patent O DEVICE FOR PRINTING 1N REGISTER Louis Gilbert Dubuit,Paris, France Application August 24, 1954, Serial No. 451,897 Claims priority, application France June 9, 1954 9 Claims. (Cl. 101123) The present invention concerns a machine for' printing sheets in register by the silk screen process and it is particularly intended for printing large size sheets, with a perfect marking, with the help of a single operator.

In machines of this type, the squeegee and the screen holder are lifted up for withdrawing the printed sheet and replacing it by another sheet to be printed. Nevertheless, however simple be the machines which vare known to date, it is dicult to ascertain an accurate position of the sheet and it is impossible to print it in several colours by successive steps"^for lack of a suitable method for registering the colours.

The object of the invention is a machine in which the arm -carrying the squeegee, when operated, causes, with a certain delay, both the screen-carrying frame to be lifted and elements to operate, which provide the possible accurate registering of the various printings to be operated on a same sheet While simultaneously ensuring the latter to be framed and immobilized during each printing operation.

The machine according to the invention is characterized in that the arm carrying the squeegee is mounted on `a carriage capable of moving and `pivoting on a rail arranged longitudinally on one of the large sides of the table of the machine, said arm being capable, when it is raised with the squeegee to a certain height, of coming into contact with a bar parallel with the above mentioned rail and carried by the upper arms of two bell crank levers articulated to the two ends of the frame of the machine, said bar causing, under the action of the squeegee-carrying arm, the pivoting, on the one hand, of two bars supporting arms bearing the frame of the screen, and secured substantially to the pivoting point of said side bell'crank levers, and, on the other hand, of a bar carried by the lower arms of the latter and acting, 'by means of rods, on marginsetting elements and on a retaining system which maintains the sheet to be printed motionless during printing operations, the whole being so arranged that when the arrn carrying the squeegee is lifted, a certain delay occurs before the screen-carrying frame is lifted, the margin-setting elements are placed in an active position above the table of the machine and the action of the sheetretaining system is interrupted while the squeegee-carrying arm is lowered and causes successively the retaining system to operate, the margin-setting elements to be erased below the plane of the sheet to be printed and finally the screen-carrying frame to be lowered.

The margin-setting elements are constituted by tappets articulated about an axle carried by gussets sliding along section elements secured under the table, parallel with apertures through which said tappets may pass and provided inthe wall or walls of the table.

Each one of said tappets is constituted by a lever, articulated, at its lower portion, on the axle carried by the gusset and abutting against a stop fixed on said gusset when the tappet is in an active position and emerges from the upper plane of the table, said tappet being called ICC to this position by a spring secured thereon and on the gusset, while it is called to and kept in a position so as to be erased above said plane by a slider secured on one of the rods connected with the bar carried by the lower arms of the side bell crank levers.

The retaining system intended for keeping the sheet to be printed motionless may be pneumatic or mechanical.

In the first case, the table of the machine is formed by two walls between which a chamber is thus realized, capable of being placed under vacuum by means of a conduit opening into said chamber through the lower wall of the table, while the upper wall is provided with holes designed for causing the suction of the sheets placed on the table.

One of the rods connected with the bar carried by the lower arms of the bell crank levers acts on the throttle of a gate placed on the conduit connecting the vacuum chamber of the table with the vacuum machine in such a manner that the gate be open when the sheet is being printed and that it be closed once the printing operations are over, and the printing assemblyis lifted and the tappets are driven to an active position.

When the sheet-retaining system is a mechanical system, it is constituted by pincers each one of which is formed by a plate secured at the end of a rod carried by a gusset sliding underneath the table and traversing an aperture provided therein, a bell crank lever articulated on said gusset being actuated through one of its arms by a rod `connected with the bar carried by the lower arms of the two lateral bell crank levers of the machine and said lever articulated on the gusset acting, by its other arm, on said rod, for placing it in a sheet-retaining position as soon as the squeegee-carrying arm is lowered and conversely for releasing the sheet when said arrn is lifted, at the end of the rund thereof only.

The rod in the form of pincers may, in some cases, serve also as a margin setting element and replace the pivoting tappets mentioned above.

On the two parallel bars secured on the lateral bell crank'levers the arms carrying the screen frame may slide or be secured at any desired point and the dimensions of said bars may vary from the smallest to the largest allowed -by the machine and their location may be determined at the operators Will.

The arms carrying the screen frame are provided, at their free end, with pincers which provide for seizing and supporting said frame by two of its opposite sides.

The squeegee is of the rocking type and automatically assumes the inclination corresponding to the direction of its displacement when the operator, acting on the arrn which carries it, causes the carriage to slide on its supporting rail.

Finally, the lifting of said control arm and of the printing assembly which it carries is facilitated by a counterweight and is automatically limited by the abutment of the upper arms of the lateral lbell crank levers against the rail carrying the control arm, the latter then being in contact with the transverse bar connecting the upper arms of said bell crank levers.

Said characteristics, as well as other secondary features are described in detail in the following description with reference to the appended drawings, wherein:

Fig. l is an elevational view in profile, with partial sections, of a printing machine provided with a device according to the invention;

Fig. 2 is a plan view of said machine;

Fig. 3 is a front elevational view of the machine, with partial sections;

Fig. 4 is a partial transverse section of the machine, showing a mechanical sheet-retaining system;

Fig. 5 is a section along the line V-V of Fig. 4.

In one of its embodiments, mentioned by `way cf example, the improved printing machine according to the invention is constituted as follows:

On a metal frame 1 (Figs. 1 to 3) is ixed a table consisting of a frame 2, formed out of flat iron, for instance, the larger sides of which are connected together by cross pieces 3 made out of solid bars or section irons such as channel irons.

On both sides of the frame 2 and of the cross pieces 3 sheet iron plates 4 and 4 are welded, thus forming a hollow table.

In the cross pieces 3 and the iron sheets 4 and 4, apertures are cut o ut for allowing the passage of the frame ing elements described hereinafter.

Tightness is ensured between the metal sheets 4-4 and the frame 2 as well as at the location of the apertures 5 so as to make it possible to provide a vacuum in the hollow chamber formed between said sheets.

Passages are provided in the cross pieces 3 for establishing a communication between the various compartments created by them inside said chamber.

At one end of the smaller sides of the table, on the frame 1, two anges 6 are attached, between which a shaft 7 is arranged, having a round section, the ends of which are threaded for receiving attachment nuts 8. The threaded portions of the shaft are slightly excentered so as to allow an adjustment of the position thereof.

Between the anges 6 and below the shaft 7 are mounted two bell crank levers 9 pivoting around two trunnions 10 secured in the anges.

The hubs of the two bell crank levers 9 are connected together by two bars 11 and 11 of flat iron.

Each lever 9 comprises, at its upper portion, an arm 9a, and at its lower portion an arm 9b cast integral with the hub of the lever or attached thereto.

Between the ends of the upper arms 9a of the levers 9, a tubular cross piece 12 is secured, and the ends of the lower arms 9b are connected by a round section bar 13b.

On the shaft 7, serving as a rail, a carriage 14 can move, provided with two wheels 15 arranged in a vertical plane and with four wheels 16 arranged horizontally, said wheels bearing on the rail 7, in groups of three along two perpendicular diameters of said rail.

On the carriage 14 is secured, by means of two screws 17, a bar 18 with a rectangular section, terminating, at

one of its ends, into a handle 19 and carrying, at its other end, a counter-weight 20, the position of which may be adjusted by means of a clamp 21 carrying it and sliding on the bar 18, a screw 22 making it possible to immobilize said clamp on the` latter.

On the bar 18 forming a control arm, a sheath 23 can slide which may be secured thereon by means of two screws 24. The sheath is provided at its lower portion with a stud 25 at the center of which a screw 26 is secured, serving as an axle for a cradle 27 which can rock about it.

At the two ends of the cradle 27 are screwed two screws 28 serving as pivots for a U-shaped mounting 29, in which is held, by means of screws 30, part 31 carrying the squeegee 32. The oscillations of said squeegee are limited on both sides of the vertical axis by two screws 33 going through two lugs 34 associated with the cradle 27. The squeegee alters its inclination at each change in the direction of displacement of the arm 18.

On the bars 11 and 11 may be immobilized two other bars 35 and 35 by means of clamps 36 and 36' clamped by two bolts 37 and two nuts 38. The bars 35 and 35" may thus be placed at any desired point along the bars 11 and 11', at the desired degree of depression and at the desired orientation in a direction perpendicular to the latter.

At the end of each bar 35 and 35' is secured, by means of a screw 39, a square-angled part so as to pivot about said screw. A second screw 39 makes it possible to lock part 40 in a suitable orientation.

In partt40 are providedthreebores, in, two of which can slide two spindles 41 carrying a jaw 42 while inside the third one is screwed a screw 43 associated with said jaw. The vise thus formed by part 4t) and jaw 42 makes it possible to clamp the frame 44 carrying the silk screen 45.

Said screen may be of any size, since the bars 35 and 35' are capable of sliding on the bars 11 and 11 and since they pinch the frame of the screen at the middle of two of its sides. This arrangement is of interest, particularly when it is desired to print in several colours, since each colour may then represent only a very small area and require only small screens of very low cost.

Under the metal sheet 4' of the table are secured, parallel with the apertures 5 thereof, angle irons 46, the vertical web of each of which comprises a long slot 46a in which can slide two screws 47 carrying a gusset 48. On this gusset is secured an axle 49 about which a margin cleat 50 pivots and it carries a stop 51 against which the cleat may come in abutment so as to be held in a vertical position.

The unit is so arranged that the cleat 50 can pass through the aperture 5, to which it corresponds and protrudes above the table when it is in its upper or active position. j

The margin tappet is provided with a wing 50a through which passes a rod assembly on which may slide on one side of wing 50a, a slider 54, the immobilization of which on the rod is ensured by a screw 54a. A spring 52 connecting the cleat 50 with a pin 53 secured on the gusset 48 acts constantly on said tappet so as to cause it to emerge from the upper plane of the table.

The rod 55 is screwed at its rear end in a yoke 56 through which passes the bar 13b.

On the bar 13b is mounted, in the same manner, a rod 57 on which is secured a slider 58 secured thereon by a screw 59. This tappet acts on a lever 60 through which passes the rod 57 and associated with an aXle 61 journalled in a boss 62a, of a duct 62 for sucking the air contained in the enclosure created between the two plates 4 and 4 of the table.

The axle 61 is associated with a throttle 63 capable of closing the duct 62. A spring 64, fastened, on the one hand, to the tail piece 60a of the lever 60 and, on the other hand, to a pillar 65 associated with the duct, tends to keep the throttle constantly in its closed position.

A piping 66 connects the duct 62 with the vacuum conduit, in such a manner that the depression created in the enclosure of the hollow table may, through holes 67 drilled in the upper plate 4 thereof, cause ya suction of the sheet placed on the table for being printed.

The operation of the machine is as follows:

An aperture 5 is provided, at oney yend of the table and over almost theentire length thereof, so that. a margin tappet 50 may be arranged at any desired location on the small side of the table and against which may bear one edge ofthe sheet to be printed, while apertures 5, shorter than the rst one, are provided so that other tappets 50 may serve as supports for the sheet through another edge perpendicular on the first one.

The margin tappets 50 are brought to the desired locations by the operator by sliding the gussets 48, which carry them, along apertures 46a of the angle irons 46, thereafter locking the screws 47.

The frame of the screen carrier 44 having been seized in the pincers 40-42 located at the ends of the bars 35, the latter are placed in position on the bars 11-11, by means of tianges 36-36 in such a manner that the screen is applied, on the margined sheet, at the desired location by the operator.

The squeegee carrier is also adjusted by sliding the sheath 23 on the arm 18.

Printing is then effected, in the known manner, by exerting on the arm 18 a suicient pressure so that the squeegee 52 causes the ink to gok through the stencil of the silk screen 45, and in simultaneously displacing the carriage 14 along its carrier rail 7.

The weight of the arm 18 and of the squeegee carrying assembly should, as seen from the operators side, be balanced by the counter-weight 20 placed on the other side of the carriage 14, supporting the whole and serving as a pivot for the two lever arms thus created, which saves the operator any useless fatigue.

`When a sheet has been printed, the operator raises the arm 13 which has the etfect, `irst, of separating the squeegce from the silk screen, then as the arm comes in contact with the bar 12, of raising the latter until the arms 9a of the two bell crank levers 9 come, on each side oi the machine, and abut against the rail 7.

in this rotating motion olf the levers 9, the arms 11 and 11 pivot about the trunnions 10 and the bars 35 rise, carrying along with them the screen-carrying frame 44 which clears the table of the machine.

p On `the other hand, the arms 9b of the levers 9 drive the bar 13b frontwards, and, due to this, the rods 55 are driven in the direction of the arrow f, shown in Figure l, and since the slider 54 no more maintains tappets 50 in their lowered positions, the latter are subjected to the action of spring 52. The tappets are then caused to protrude above the upper metal sheet 4 of the table, i. e. in their active position.

Simultaneously, rod 57 is pushed towards the front of the machine by bar 13b and slide 58 releases lever 60 which, pulled by spring 64, drives in rotation axle 61 on which is mounted the throttle 63 which is then brought to a position for closing the duct 62. The suction through the holes 67 of the table ceases and the operator may remove the sheet which has just been printed.

lt will be noted that the rail 7 serving as a stop for the bar 12 limits the rising the squeegee and of the` screencarrying `frame.`

The operator places a new sheet to be printed, by bringing the two perpendicular edgesthereof in contact with the tappets 50 and he lowers the arm 1S.

T he bar l2 being released, the bell crank levers 9 rock t under the weight of said bar and of the screen-carrying unit and the arms 9b bring the bar 13b back towards the rear of the machine. This bar exerts a traction on the rods`55, the sliders 54 of which act on the tappets 50 lowering them below the level lower than that of the upper` sheet iron plate 4, so that they are prevented from coming into contact with the screen.

Simultaneously, the rod 57 is actuated by the bar 13b and the lever 60, released by the slider 58, is brought back by the spring 64. The throttle 63 then opens the duct 62 and a vacuum is again created in the table. The

, sheet to be printed is subjected to the resulting suction and immobilized underthe silk screen, for the entire duration of the printing operation and while the silk screen is being raised; it is thus not lifted from the table.

lt will be` seen that it is thus possible to obtain a mark for several colours printed successively on one sheet by always bringing the sheet against the margin tappets 50, said sheet then being held in a fixed position upon each printing operation and, in particular, while the screen in being lifted.

It should be noted, however, that the double walled table and a suction system for the sheet to be printed may be considered astoo costly in some cases. it may be convenient, therefore, to replace the pneumatic system by mechanical elements for immobilizing the sheet and which operate in an identical manner.

In this form of embodiment, the table of the machine may then consist of a frame 2 and cross pieces 3 (Figure 4) on which is welded a single sheet iron plate 4.

In this plate 4 (Figs. 4 and 5) are cut, along the `cross pieces 3', rectilinear slots 5 designed for allowing a passage for the elements which maintain the sheet to be printed, each one of them consisting of a rod 70 going 6 through the two webs of a U shaped piece 71. This part is secured on the cross piece 3' corresponding to the slot through which passes the considered rod 70, by means of bolts 72 going through a rectilinear slot 3a provided in said cross-piece.

The part 71 may thus be brought to a desired position along said cross piece.

At the upper portion of the rod 70 is provided a plate 73 for pinching the sheet against the table 4.

On the rod 70 is secured a collar or ring 74 serving as a support for a spring 75 which, bearing against the upper web of the part 71, constantly tends to urge the rod 70 downwards, i. e. in the position in which the plate 73 pinches the sheet to be printed.

Under the bracket part 71 is secured a square angle 76 on which is articulated, by means of an axle 77, a bell crank lever 78, the two arms of which are pierced, for allowing a passage, one for the rod 70, the other one for a rod 79 connected with the lower bar 13b.

A slider 80, movable over the rod 79, may be secured in a suitable position by a screw 81 in such a manner that when the squeegee-carrying arm 18 in raised and carries along with it the bar 12 connecting the two lateral bell crank levers 9, the bar 13b, connecting the arms 9b of said levers, pushes the rod 79 and, compressing the spring 75, obliges, through the lever 78, the rod 70 to rise above the table 4 as shown in Fig. 1.

At the same time, the bars 11 and 11', carried by the levers 9, rock with the latter and pivot the bars 35 upwards, carrying the screen-carrying frame.

Conversely, when the arm 18 is being lowered, the rod 79 being brought towards the rear of the machine, the spring 75 will act freely on the rod 70, the plate of which 73 will be applied against the table, pinching the sheet to be printed.

As shown by the position of one of the lateral levers represented in mixed lines in Figure l, the action of the rod 79 on the lever 78 is delayed with respect to the raising motion of the screen carrying frame 35 with the result that the printed sheet is released by the pincers 73 only towards the end of the pivoting of the arm 18. Thus the sheet cannot be carried along by the screen holder and thus be in danger of being fouled.

It should be noted, further, that in some cases and, if necessary, at the cost of some modications, the immobilizing element 70-73 may be very easily used, both for rst setting the margin for the sheet to be printed and secondly, for immobliziing it as soon as the arm 18 is lowered.

What I claim is:

l. In a machine for the printing of materials in sheets, in register, by the silk screen process and comprising an arm carrying the squeegee, moving and pivoting on a rail arranged longitudinally on one of the larger sides of the table of the machine, a round section rail, a carriage for carrying the squeegee-holding arm, moving and pivoting on said rail, two bell crank levers articulated at the two ends of the machine for pivoting about an axle parallel with said rail, an upper control bar connecting the two upper arms of said bell crank levers, two bars parallel with said rail connecting the central articulation portion of said bell crank levers, two adjustable arms on said parallel bars and carrying the frame for the silk screen, a lower control bar connecting the lower arms of said bell crank levers, margin setting elements connected with said lower control bar by rods, a system for holding the sheet to be printed, a control element for said holding system connected by a rod with said lower control bar, the unit being so arranged that the squeegee-carrying arm, when raised to a certain height, cornes in contact with said upper control bar and drives it along with it thereby causing a pivoting movement of the two bell crank levers as well as of the parallel bars and of the lower control bar they carry for successively causing the screen carrying frame to raise, the margin setting elements to be set in an active position and the action of the system for holding the printed sheet to be interrupted, the squeegee-carrying arm causing all the converse effects when being lowered.

2. A machine according to claim 1, in which said system for holding the sheet, comprises a table formed of two walls between which a tight chamber is obtained, capable of being placed under a vacuum, a conduit opening through the lower portieri of the table for providing a vacuum in said chamber, holes in the upper portion of the table through which suction is applied to each sheet placed on said table, the control element consisting of a gate located in said conduit, the throttle of said gate being actuated by said rod connected to the lower control bar.

3. A machine according to claim 1, in which said system for holding the sheet comprising apertures provided in the wall of the table, perpendicularly to the guiding rail for the squeegee-carrying arm, cross pieces arranged under the wall of the table along said apertures, slides provided in said cross pieces, supports sliding in said slides, a rod carried by each one of said supports and going through the wall of the table through one of the above apertures, and a control element constituted by a bell crank lever articulated on said support acting by means of one of its arms' on the rod, while the other arm of said lever is actuated by a rod connected with the lower control bar, said rod being provided at its upper portion with a plate acting as pincers for pressing the sheet to be printed when the squeegee-carrying arm is being lowered.

4. A machine according to claim l, in which said system for holding the sheet comprising apertures provided in the wall ot the table perpendicularly to the guiding rail ot the squeegee-carrying arm, cross pieces arranged under the wall of the table along said apertures, slides provided in said cross pieces, supports sliding in said slides, a rod carried by each one of said supports and going through the wall of the table through one ot the above apertures, a spring acting on said rod for urging it constantly downwards, and a control element constituted by a bell crank lever articulated on said support acting by means of one of its arms on the rod while the other arm of said lever is actuated by a rod connected with the lower control bar in such a manner that the rod be subjected to the action of said spring when the squeegee-carrying arm is lowered and that said rod be raised by said bell crank lever when said squeegee-carrying arm is raised, said rod being provided, at its upper portion, with a plate acting as pincers for pressing on the sheet to be printed.

5. ln a machine according to claim 2, apertures provided in the walls of the table perpendicularly to the guiding rail of the squeegee-carrying arm, solid bars secured in a tight manner between the two walls oi the table opposite said apertures, apertures pierced in said bars, corresponding with the apertures in the two walls, cross pieces secured under the lower wall of the table along said apertures, margin-setting elements constituted by articulated tappets Vgoing through the table through the apertures in the walls or the table and in the solid sealing bars, said tappets being articulated about axles carried by supports, said supports sliding on said cross pieces, each tappet being actuated by one of said rods connected with the lower control bar for causing the tappet to protrude above the upper plane of the table or for bringing the tappet underneath said plane according to whether the tappet carrying arm is raised or lowered.

CFI

r carrying the 6. In a machine according to claim 5, each tappet constituted by a lever articulated at its lower portion on the axlecarried by a sliding support, a stop secured on said support for the tappet to bear against when it protrudes above the upper plane of the table, a spring secured on the tappet and on the gusset for causing the tappet to protrude above the upper plane of the table and a rod connecting said tappet with the lower control bar for bringing and holding the tappet in its inactive position under the plane of the table when the squeegee-carrying arm is lowered.

7. A machine according to claim 1, in which said system for holding the sheet comprises apertures provided in the wall of the table perpendicularly to the guiding rail tor the squeegee-carrying arm, cross-pieces arranged under the wall of the table, along said apertures, slides provided4 in said cross-pieces, supports sliding in said slides, a rod carried by each one of said supportsy and going through the wall of the table through one of said apertures, a spring acting on said rod for urging it constantly downwards, and a control element .constituted by a bell crank lever articulated on said support acting by means of one of its arms on the rod while the other arm of said lever is actuated by a rod connected with the lower control rod in such a manner that the rod be subjected to the action of said spring when the squeegeecarrying arm is lowered and that said rod be' raised by said bell crank lever when said squeegee-carrying arm is raised, said rod being provided, at its upper portion, witha plate forming pincers for pressing the sheet to be printed, the sheet to be printed and said'rod constituting also a margin-setting element when said sheet is positioned.

8. In a machine according to claim 1, said two arms carrying the screen-frame being adjustably secured on the two parallel bars associated with th bell 4crank levers for adjusting said arms to the dimensions of the screen and placing the latter in position at the operators will, the ends of said arms being provided with pincers making it possible to seize and support said frame by two of its opposite sides.

9. ln a machine for the printing of materials in sheets, in register, by the silk screen process and comprising an arm carrying the squeegee, moving and pivoting on a rail arranged longitudinally on one of the largs sides of the table of the machine, a round section' rail, a carriage for carrying the squeegee--holding arm, moving and pivoting on said rail, two bell crank levers articulated at the twoends of the machine, a shaft constituted by two bars parallel with said railfor pivoting with said bell crank levers, an upper control bar connecting the two upper arms of said bell crank levers, two adjustable arms on said shaft constituted by two parallel bars and frame for the silk screen, the unitbeing so arranged that the squeegee-carrying. arm, when being raised to a certain height, comes in contact with said upper control bar and causes a pivoting movement ot the two bell crank levers as well as of the shaft constituted by two parallel bars for causing the screen carrying frame to raise, the squeegee-carrying arm causing the converse eiect when being lowered.

References Cited in the le of this patent UNITED STATES PATENTS 1,922,710 Owens u Aug. 15, 1933 2,207,818 Perry July 16, 1940 2,411,475 Stockman Nov. 19, 1946 2,571,685 DAutermont Oct. 16, 1951

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