US3338149A

US3338149A - Apparatus for printing a plate intended for offset printing, by passing through a photographic developing unit

Info

Publication number: US3338149A
Application number: US401517A
Authority: US
Inventors: Hemery Marc
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-10-11
Filing date: 1964-10-05
Publication date: 1967-08-29
Anticipated expiration: 1984-08-29
Also published as: FR1379093A; DE1447840A1; GB1074476A

Description

Filed Oct. 5, 1964 Au 29, 1967 M HEMERY 3,338,149

APPARATUS FOR PRINTING A PLATE INTENDED FOR OFFSET PRINTING, BY PASSING THROUGH A PHOTOGRAPHIC DEVELOPING UNIT 4 Sheets-Sheet 1 M. HEMERY 3,338,149 APPARATUS FOR PRINTING A PLATE INTENDED FOR Aug. 29, 1967 OFFSET PRINTING BY PASSING THROUGH A PHOTOGRAPHIC DEVELOPING UNIT Filed Oct.

4 Sheets-Sheet z M. HEMERY R O F DH w m N O M m? NT IG E N m TIP A S O L S L P A E P A V E G B D W ,C T G M N N P IIA R T R P N G I R R w 0 P 0 F T H W T F A A F R O A P P A 4 Sheets-Sheet 3 Filed Oct.

Aug. 29, 1967 M. HEMERY 3,338,149

APPARATUS FOR PRINTING A PLATE INTENDED FOR OFFSET PRINTING, BY PASSING THROUGH A PHOTOGRAPHIC DEVELOPING UNIT Filed Oct. 5, 1964 4 Sheetsfiheet United States Patent 3,338,149 APPARATUS FUR PRINTING A PLATE INTENDED FOR ()FFSET PRINTING, BY PASSING THROUGH A PHOTOGRAPH-III: DEVELOPING UNIT Marc Hemery, Rue Pierre Brossolette, Clamart, France Filed Oct. 5, 1964, Ser. No. 401,517 Claims priority, application France, Get. 11, 1963, 950,404 6 Claims. (Cl. 9589) It is known to transfer, by passing through a photographic developing unit, the image of a negative of small size on to a printing form intended for offset printing (a grained metal plate).

The applicants have discovered that the kind of apparatus which lends itself best to this transfer was that in which a central wetting device impregnates the emulsion only of one of the two sheets of sensitive paper employed, the other sheet being conveyed in the developer liquid.

- In an apparatus of this kind, it is not however sufficient to introduce the negative into the single impregnation wetting side and the offset plate into the developer bath in order to obtain completely satisfactory results.

Amongst other adaptations, it was necessary to ensure perfect synchronism in the simultaneous passage in complete agreement of these two elements of very different natures which are the negative consisting of a sheet of sensitive paper and the offset form constituted by a metallic plate.

Failure to observe this condition resulted in offset printing which was fuzzy, out of register, having defects and in a word unsatisfactory.

It will therefore be understood that up to the present time only offset plates of small size have been printed, the printingof offset plates of large dimensions having been considered practically impossible until a satisfactory solution had been found.

This satisfactory solution has been provided by the present invention which is the concurrent point:

of a fiat presentation of the negative and the plate at the exact level of the contact generator line of the intake rollers of the developing apparatus;

of the accurate centering obtained between the negative and the plate;

I of perfect synchronism of the rotation of the intake rollers and the squeeze rollers of the developing unit;

of a considerably increased length or span of the rollers and guiding tracks without the latter getting out of truth or buckling;

of the adjustment of the pressure of the rotating rollers.

The invention resides in the combination of a photographic developer unit and a centering table, the plane of which coincides with the generator contact line of the intake rollers of the developer unit, a common driving device establishing perfect synchronism between the rotation of the intake rollers and the squeeze rollers of the developer unit.

Guiding tracks, of which the essential feature of each is constituted by a series of parallel separate plates, held in position by cross members, permit the simultaneous displacement of the negative and the ofiset plate in perfect agreement.

The upper roller serving for the intake can be raised and lowered so as to permit the introduction of the negative and the offset plate into the developer unit.

The upper intake roller is only lowered on the negative and the plate when the latter have been effectively engaged in their respective guiding tracks.

An adjustable abutment enables a pre-determined position to be adopted for the offset plate on the centering table.

3,338,149 Patented Aug. 29, I967 also adjustable, on the centering positioning the negative with re- A transverse strap, table, is employed for spect to the offset plate.

The developing unit preferably comprises at least one wetting roller, the direction of rotation of which is the same as that of the intake rollers, which facilitates the impregnation of the negative.

Other particular features and advantages of the present invention will be brought out in the description which follows below, reference being made to the accompanying drawings, in which:

FIGURE 1 shows a perspective view of an apparatus according to the invention permitting the printing of plates intended for offset printing;

FIGURE 2 is also a view in perspective, but partial, so as to show the guiding track of the offset plate;

FIGURE 3 is a view in perspective of the apparatus showing the guiding track of the negative, together with the device for driving in synchronism the intake rollers and the squeeze rollers;

FIGURE 4 is a view in partial perspective of the squeeze rollers of the developer unit;

FIGURE 5 shows the application device of a pressure roller, inserted under a squeeze roller.

In the form of construction shown, the developer unit or developer is of the type comprising two guiding tracks, one upper, the other lower, with respect to two central wetting cylinders 3 and 4.

Intake rollers A and B are provided at the inlet of the developer, and two squeeze rollers C and D are arranged at the outlet of this same developer. The roller A has the special feature that it can be raised and lowered (arrows f and f This movement of the roller A is advantageous ly obtained by mounting the roller A on two pivoted levers 5 and 6 with an operating handle 7.

The wetting rollers 3 and 4 preferably rotate in the same direction as the intake rollers, which facilitates the wetting of the negative which comes into contact with them. In fact, the negative is not soaked but simply moistened, which contributes to its conveyance in perfect agreement with the plate, in view of its flexible nature as compared with the more rigid plate.

In front of the developer unit is arranged a centering table 8. This is intended to support, in a plane coincident with the contact generator line of the rollers A and B, a metal offset plate (positive) and a negative sensitive support.

While they are resting on the table, the plate and the negative support are sufiiciently engaged in their respective guiding track of the developer (lower track for the plate and upper track for the negative support). This engagement of the negative and the plate naturally implies the lifting of the roller A (h).

The relative position of the plate and the negative can be modified by adjusting the respective positions of two abutment means provided on the centering table. The offset plate rests directly on the table and its position is set by means of a cylindrical abutment 9.

The position of the negative, which rests in turn on the plate, is adjusted by means of a transverse strap 10.

The cylindrical abutment 9 passes across the table 8 by a longitudinal slot 11 formed in the table. A knurled nut 12 is screwed on the abutment 9 so as to be capable of immobilizing it at a selected point along the length of the slot 11 (arrow 3).

The strap 10 can pivot (arrow f about a longitudinal rod 13 parallel to the table and fixed thereto by studs 13a. A knurled screw 14 permits the strap to be fixed at any desired point on the length of the rod 13 (arrow f In this way, the offset 15 is prevented from sliding in any direction opposite to that of its introduction into the developer unit. This immobilization may be different, de-

3 pending on the position occupied by the adjustment stop 9 in the slot 11.

In its turn, the strap 10 swung back on the plate, also prevents the negative 16 from moving in the direction opposite to that of its introduction into the developer unit. The position of the strap 10 along the rod 13 enables the negative to be immobilized on the plate, while leaving more or less space between the edges of these latter.

The lateral movement of the strap 10 enables this space to be varied at the beginning of the operation. This spacing between the negative and the plate is not capable of varying between the beginning and the end of the operation because of the perfect synchronism established between the rotation of the intake rollers and the squeeze rollers. A system comprising a belt 17 and motor 18 drives in synchronism the pulleys 19 keyed on the shafts of the roller B, of the wetting rollers 3 and 4 and the squeeze roller D.

The essential element 1 of the upper guiding track and the essential element 2 of the lower guiding track are both constituted by profiled parallel plates 20, main tained at regular spacing by means of the cross members 21.

This construction enables the guiding tracks to be given a substantial length, capable of receiving negatives and offset plates of large dimensions.

The negative passes between the element 1 of the upper track and the wetting rollers 3 and 4, while the offset plate travels between two plates 22 and 23 facing each other, and the element 2 of the lower track. The plates 22 and 23 can be fixed by the screws 22a, 2311, on the end plates a of the element 2, which are slightly higher than the profiled plates 20.

The lower track rests in a tank 24 supplied with developer liquid by a deformable pocket 25 intended to be compressed by a pressure device 26 with an operating handle 27. A bag for recovering the spent bath (not shown) may be provided in the apparatus.

The intake rollers may be provided with a clutch 28 having a handle 28a, which enables these rollers to be released before the roller A is lifted, and prevents any displacement between the teeth of the pinions a and b of the rollers A and B (the roller A being driven by the roller B) when the drive is re-applied.

The fiat presentation of the negative and the plate at the level of the contact generator line of the intake rollers is effected in a strictly accurate manner by means of a water-level 29 provided on the centering table.

By reason of this flat presentation and of the synchronism of rotation, the centering. selected between the negative and the plate is maintained from the beginning to the end of the printing operation of the offset plate.

The intake rollers, the wetting rollers and the squeeze rollers may be mounted on a cradle 30 composed of parallel end-plates 30 and 31, resting on a base 32.

The position of the cradle on the base can be regulated by means of level screws 33, which contribute to a perfect adjustment of the simultaneous travel of the negative and the offset plate in perfect agreement.

The parallelism between the squeeze rollers C and D in particular (which are of great length) may possibly not be absolutely accurate, and in this case an extremely simple expedient can be employed, consisting of an auxiliary pressure roller E inserted under the lower roller D.

The pressure can be applied by means of a lateral lever 34 coupled by a rod 35 to a second lever 36 which carries the shaft 37 of the pressure roller E.

A receiving table can be provided at the outlet of the squeeze rollers for the offset plate.

Finally, a cover 39 may be provided to close the developer unit and the tank 24 may be provided with a level indicator 40.

In a general way, the description above has only been given by way of explanation and not in any limitative sense, and the invention is capable of numerous alternative forms in conformity with its scope.

I claim:

1. Apparatus for printing a metallic offset plate from a sensitized paper negative comprising a centering table having leveling means,

a pair of intake rollers located at one end of said centering table with their generator contact line aligned in a plane with the top surface of said centering table,

two guiding tracks aligned to receive plate and negative from said intake rollers,

a mounting means suporting said pair of intake rollers and said guiding tracks,

wetting rollers and squeeze rollers also supported on said mounting means,

auxiliary pressure means to maintain said squeeze rollers in parallel alignment to each other,

and motor and belt means attached thereto with said belt means in synchronized driving connection with said intake and squeeze rollers,-

said mounting means including a base,

a cradle resting on said base, and

leveling screw means to regulate the position of said cradle on said base.

2. The apparatus for printing an offset plate in claim 1 further characterized by said auxiliary pressure means including a pressure roller located for contact pressure with one of said squeeze rollers.

3. The apparatus for printing an offset plate in claim 1 further characterized by said leveling means on said centering table being a water level attached thereto.

4. The apparatus for printing an offset plate in claim 1 further characterized by said centering table having adjustable abutment means to adopt a predetermined position for the offset plate on said centering table.

5. The apparatus for printing an offset plate in claim 4 further characterized by said centering table having an adjustable transverse strap means to position the negative with respect to the offset plate.

6. The apparatus for printing an oifset plate in claim 1 further characterized by at least one of said wetting rollers having a direction of rotation the same as that of said intake rollers thereby faciliating the wetting of the negative.

References Cited UNITED STATES PATENTS 2,775,933 1/1957 Malone et al 89 XR 2,786,401 3/1957 Briggs et al 95-89 3,107,596 10/1963 Arnold et a1 95-89 3,257,927 6/1966 De Belder 95-89 NORTON ANSHER, Primary Examiner,

FRED L. BRAUN, Assistant Examiner.

Claims

1. APPARATUS FOR PRINTING A METALLIC OFFSET PLATE FROM A SENSITIZED PAPER NEGATIVE COMPRISING A CENTERING TABLE HAVING LEVELING MEANS, A PAIR OF INTAKE ROLLERS LOCATED AT ONE END OF SAID CENTERING TABLE WITH THEIR GENERATOR CONTACT LINE ALIGNED IN A PLANE WITH THE TOP SURFACE OF SAID CENTERING TABLE, TWO GUIDING TRACKS ALIGNED TO RECEIVE PLATE AND NEGATIVE FROM SAID INTAKE ROLLERS, A MOUNTING MEANS SUPPORTING SAID PAIR OF INTAKE ROLLERS AND SAID GUIDING TRACKS, WETTING ROLLERS AND SQUEEZE ROLLERS ALSO SUPPORTED ON SAID MOUNTING MEANS, AUXILIARY PRESSURE MEANS TO MAINTAIN SAID SQUEEZE ROLLERS IN PARALLEL ALIGNMENT TO EACH OTHER, AND MOTOR AN BELT MEANS ATTACHED THERETO WITH SAID BELT MEANS IN SYNCHRONIZED DRIVING CONNECTION WITH SAID INTAKE AN SQUEEZE ROLLERS, SAID MOUNTING MEANS INCLUDING A BASE, A CRADLE RESTING ON SAID BASE, AND LEVELING SCREW MEANS TO REGULATE THE POSITION OF SAID CRADLE ON SAID BASE.