US2112246A

US2112246A - Sheet coating machine

Info

Publication number: US2112246A
Application number: US89195A
Authority: US
Inventors: William W Maher
Original assignee: American Can Co
Current assignee: Primerica Inc
Priority date: 1936-07-06
Filing date: 1936-07-06
Publication date: 1938-03-29
Anticipated expiration: 1955-03-29

Description

March 29, 1938. w. w. MAHER 2,112,246

vSHEET COATING MACHINE Filed July 6, 1936 2 Sheets-Sheef` 1 Fig-.I 36,

42 @SAS/56 4/ B a5 :213 j 1 3Q ,'f a7 1 R:`J: j @U y' -4/ l 2 74 I 46 e@ ,5- 687 fi 7 /Z 2/ 34 l ,7 Q7 ff ,sa i 53 jf z March 29, 1938.

W. W. MAHER SHEET COATING MACHINE Filed July 6, 1936 2 Sheets-Sheet. 2

7V. ATTORNEY Psienied Mar. 29, 193s' PATENT OFFICE f I SHEET coATING MACHINE William W. lMaher, San Francisco, Calif., as-

signor to American Can Company, ,New York, y N. Y., a corporation of New Jersey L Application July 6, 1936, Serial No. 89,195

9 Claims.

The present invention relates to printing presses or coating machines of the off-setprinting type which utilizes a rotatable impression cylinder for applying a film or a design of coating material to a surface of sheet stock such as, for example, tin plate or the like and has particular reference to creating and maintaining an exact and uniform film for printing orv coating by preventing piling up or unevenness or excess accumulation of the coating material on the impression cylinder, such a desiderative being best' obtained by suitable mechanism for rst wiping off the impression cylinder as it rotates to insure a clean surface for each application of such a iilm or design of coating material,

and vsecond for uniformly distributing and smoothing out the coating on the cleaned surface preparatory to its transfer to the sheet.

An object of the invention is the provision of a coating machine which utilizes a rotatable impression cylinder for applying coating material4 to sheets to be coated wherein any residual coating material, which may be left on the impression cylinder after an impression has been made or which may remain on the cylinder because no sheet was presented, is picked up or wiped off before each application of. the film or design to the impression cylinder.

Another object is the provision of such a coating machine wherein the coating material applied to the cleaned surface of the impression cylinder, as for example, by means of the usual transfer roller, is further uniformly distributed on the cylinder and is smoothed out evenly over its surface, any coating material in excess of the required lm as it lies on the impression cylinder, being picked up and carried back onto the transfer roller so that a smooth and exact even lm of the desired thickness will be applied to the sheet.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

Figure 1 is a vertical cross-sectional view of an exemplary type of coating machine embody-l ing the instant injfention, parts of the machine being broken away;

. Flg. 2 is a horizontal section taken substantially along the broken line 2-2 in Fig. 1, with parts removed; and

Fig. 3 is an enlarged perspective detail as viewed substantially froma position indicated by the line 3-3 in Fig.2, certain of the parts being broken back and shown in section while other parts are broken away.

As a preferred embodiment of the inventio the drawings illustrate the principal parts `of a,

conventional off-set printing or coating machine which is utilized in applying a lm or design of coating material which may be varnish, lacquer, ink or the like, to the surface of a' sheet A.

Such a conventional machine comprises suitable side frames I I (Fig. 1) which support a pair of spaced and parallel, constantly rotating cylinders including an impression cylinder I2 and a gripper cylinder I3 between which is passed a sheet A to be coated.

The impression cylinder I2 is -mounted on a horizontal shaft I5 having its ends journaled in suitable bearings formed in the side frames II. This cylinder carries the film or' design of coating material to be impressed upon the sheet A. The cylinder is rotated in the direction indicated by the arrow in Fig. 1 by a driving gear I6 which is mounted on one end of the shaft I5 and which is driven in any suitable manner.

The gripper cylinder I3 is mounted on a horizcntal shaft I8 having its ends journaled in suitable bearings formed in the side frames II. This cylinder is rotated at the same surface speed as the impression cylinder, the cylinders being geared together by spur gears 2|, 22 which are mounted on the respective shafts I5, I8. The gripper cylinder presses the sheet A into tangential contact with the impression cylinder the while advancing the sheet horizontally between them.

The sheet A is fed into the grip of the cylinders I2, I3 from a horizontal table 24 which is secured to the side frames II. 'I'he table carries a feeding device comprising a pair of spaced and parallel feed bars which are disposed in grooves 26 formed in the table and which are reciprocated through a forward and a return stroke by any suitable means moving in time with the other moving parts of the machine. Feed dogs 21 which are carried on the feed bars engage behind the sheet during the forward stroke of the bars and push it into position for feeding. Passage of the sheet between the cylinders impresses the coating material thereon.

The coated sheet as it leaves the cylinders I2, I3 is supported on an endless belt conveyor 3| carried on a pair of pulleys 32 which are mounted on horizontal shafts 33. The shafts are journaled in suitable bearings formed in the side frames I I and are rotated by any suitable means operating in time with the other moving parts of the machine. The conveyor deposits the coated sheets onto a discharge table 34 from which they may be removed as desired. The discharge table is secured to the sides frames II.

The coating material used in coating the sheet A may be supplied to the machine by a pipe 36' (Fig.v 1) from which it ilows as a continuous stream, indicated by the letter B, onto a pair of C Qntinuously rotating rollers. These rollers run in surface contact as

fountain rollers

36, 31 the latter functioning as a transfer roller.

These rollers are carried on

horizontal shafts

38, 39 having their ends journaled in suitable bearings formed in the side frames Meshing gears 4|, 42 (Fig. 2) carried on the ends of the

shafts

38, 39 rotate the rollers in unison in the direction of the arrows shown in Fig. 1 and at the same surface speed as the impression cylinder. The gear 42 meshes with and is driven by the gear 2|.

Transfer roller 31 engages with the impression cylinder |2 and transfers the coating material received by it to the surface of the impression cylinder. The coating material thus applied to the impression cylinder, is spread out or distributed over its `exterior surface by a distributing roller 45.

The distributing roller 45 is located adjacent the transfer roller 31 on top of and engaging the impression cylinder I2. It is mounted on a horizontal shaft 46 (Figs. l and 3) having its ends journaled in bearing blocks 41 which are carried in U-shaped recesses 48 formed in brackets 49 which are secured to the side frames Il. The bearing blocks are supported on springs 5|. Adjusting thumb screws 52 engaging the top of the blocks and carried in bosses 53 formed on the bracket are provided for adjusting the pressure of the distributing roller against the impression cylinder. A gear 54 mounted on the distributing roller shaft 46 meshes with the impression cylinder gear 2| and rotates the distributing roller at the same surface speed as the impression cylinder.

Uneven distribution and excess of coating material on the usual impression cylinder often results from the repeated applications thereon of the coating medium and sometimes causes undesirable streaks and blotches on the surface of the sheet A being coated. This condition is prevented in the present case by the use of a wiper roller 55 which cleans the surface of the impression cylinder at each rotation cycle and by an auxiliary distributing roller 56 which more thoroughly distributes and smooths out the coating material which is applied to the impression cylinder. It is these features to which the present invention is particularly directed.

The wiper roller 55 is located below the transfer roller 31 and is in engagement with the impression cylinder. This wiper roller is mounted on a horizontal shaft 6| having its ends journaled in bearing blocks 62 (Figs. 2 and 3) which are carried in slots 63 formed in brackets 64 secured to the side frames 'I'he bearing blocks are held under spring tension by means of springs 66 located in recesses 61 (Fig. 2) formed in the brackets adjacent one end of each slot.

Thumb screws 68 threaded into the brackets at the opposite ends of the slots provide adjustment for holding the wiper roller against the impression cylinder with the desired amount of pressure. A gear 1| mounted on the wiper roller shaft and meshing with the impression cylinder driving gear 2| rotates the wiper roller at the same surface speed as the impression cylinder.'

The wiper roller picks up residual coating material which may be left on the impression cylinder after a preceding impression has been made. Also, if no sheet is passed through the machine the lm of coating material remaining on the impression cylinder as a result of such failure of printing is entirely wiped oi by the wiper roller. In this manner the impression cylinder.

is always cleaned off before a new lm of coating material is applied. Thus accumulation of repeated applications is prevented and streaking and blotching of printed sheets are avoided.

Coating material picked up by the wiper roller 55 is removed by a scraper blade 13 which bears against the wiper roller. The scraper blade is held by a clamping plate 14 to an angle iron frame 15 which has bearing blocks 16 secured to its ends. These blocks are formed with inverted U-shaped slots 11. Projecting ends of stationary shouldered pins 18 carried'in the wiper rol1er.bearing blocks 62 t within the slots 11 of the bearing blocks 16 and thus support the scraper frame. Adjusting set screws 19 threaded into the scraper frame and the bearing blocks 16 bear against the side of the projecting ends of the pins 18 and hold the frame and scraper in adjusted position against the wiper roller.

The residual coating material picked up by the Wiper roller 55 is thus scraped off as it is collected. This coating material falls into a hopper 8| secured to the side frames and is discharged to a suitable place of deposit by a pipe 82 one end of which is connected to the hopper.

The auxiliary distributing roller 56 is located between the transfer roller 31 and the distributing roller 45 and frictionally engages both of these rollers. It is mounted on a horizontal shaft 85 having its ends journaled in bearing blocks 86 which are carried in inverted U-shaped recesses 81 formed in the brackets 48 adjacent the U-shaped recesses 48. This roller picks up excess coating material from the distributing roller which has functioned to distribute the freshly applied coating received on the cleaned surface of the impression roller by the transfer roller, This excess is carried back by the auxiliary roller and deposited onto the transfer roller for re-use. In this manner the auxiliary roller relieves the distributing roller of any excess material picked up by it from the impression cylinder and assists the distributing roller to more uniformly spread out, in a smooth even lm of desired thickness, the coating material applied to the impression cylinder.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. In a machine for coating sheets, the combination of an impression cylinder for applying the coating material to a sheet, a transfer roller engaging said impression cylinder, said transfer roller receiving the coating material and depositing the same on the impression cylinder, a distributing roller also engaging the impression cylinder for distributing the coating material thereon, and an auxiliary distributing roller disposed between and engaging the distributing roller and the transfer roller for smoothing out the coating material on said impression cylinder and for carrying back to said transfer roller any excess material applied to said impression cylinder.

2. In a machine for coating sheets, the combination of an impression cylinder for applying the coating material to a sheet, a transfer roller engaging said impression cylinder, said transfer roller receiving the coating material and depositingthe same on the impression cylinder, a distributing roller also engaging the impression cylinder for distributing the coating material thereon, means for driving said rollers and said cylinder at equal surface speed, and an auxillary. distributing roller engaging the distributing roller and the transfer roller and driven by frictional contact therewith, for smoothing out the coating material on said impression cylinder and for carrying back to said transfer roller any excess material applied to said impression cylinder.

3. In a machine for coating sheets. the combination of an impression cylinder for applying the coating material to a sheet, a gripper cylinder disposed adjacent said impression cylinder for conveying a sheet therebetween to effect the application of the coating material to the sheet, feeding devices for presenting a sheet between said cylinders, a plurality of contacting fountain rollers adapted to first receive the coating material, one of said rollers engaging said impression cylinder to transfer and deposit a film of the coating material on said impression cylinder, a distributing roller also engaging the impression cylinder for distributing the coating material thereon, and an auxiliary distributing roller engaging the distributing roller andthe transferring roller for smoothing out the coating material on said impression cylinder and for carrying back to said transfer roller any excess material applied to said impression cylinder.

4. In a machine for coating sheets, the combination of an impression cylinder for applying the coating material to a sheet, a transfer roller engaging said impression cylinder, said transfer roller receiving the coating material and depositing the same on the impression cylinder, a wiper roller also engaging said impression cylinder for picking up residual coating material left on said impression cylinder to prevent its accumulation, and means interposed between said impression cylinder and said transfer roller for returning to the latter excess coating material deposited on said impression cylinder.

5. In a machine for coating sheets, the combination -of an impression cylinder for applying the coating material to a sheet, a transfer roller y engaging said impression cylinder, said transfer \ro11er receiving the coating material and depositing the same on the impression cylinder, and a wiper roller also engaging said impression cylinder for picking up residual coating material left on said impression cylinder to prevent its accumulatiom instrumentalities for removing said residual coating material from said wiper roll, and means interposed between said impression cylinder and said transfer roller for returning to the latter excess coating material 4deposited on said'impression cylinder.

6. In a machine for coating sheets, the combination of lan impression cylinder for applyingthe coating material to a sheet, a transfer roller-engaging said impression cylinder, said transfer roller receiving the coating material and' depositing the same on the impression cylinder, a wiper rollei also engaging said impression cylinder for picking up residual coating material left on said impression cylinder toprevent its accumulation, means driving said rollers and said cylinder at equ'alsurface speed. instrumentalities for removing said residual coating material from said wiper roll, and means inter'- posed between said impression cylinder and said transfer roller for returning to the latter excess coating material deposited on said impression cylinder.

7. In a machine for coating sheets, the combination of an impression cylinder for applying the Acoating material to a sheet, a gripper cylinder disposed adjacent said impressio cylinder for conveying a sheet during coating, eding devices for presenting the sheet to said cylinders, a` transfer roller engaging said impression cylinder, said transfer roller receiving the coating material and depositing the same on the impression cylinder, a wiper roller also engaging said impression cylinder for picking up residual coating material left onthe latter after an impression has been made or for picking up the coating material left on said cylinder when no sheet is fed for an impression, a scraper instrumentality engaging the periphery of said wiper roller for removing therefrom its collected residual coating material, and means interposed between said impression cylinder and said transfer roller for returning to the latter excess coating material deposited on saidimpression cylinder.

8; In a machine for coatingsheets, the combination of an impression cylinder for applying an impression of the coating material to a sheet, a transfer roller engaging said impression cylinder, said transfer roller receiving the coating material and depositing the same on the impression cylinder. a distributing roller also engaging the impresion cylinder for distributing the coating material thereon, an auxiliary distributing roller engaging both the distributing roller and the transfer roller for smoothing out the coating material on said impression cylinder and for carrying back to said transfer roller any excess material applied to said impression cylinder, and a wiper roller also engaging said impression cylinder for picking up residual coating material left on said impression cylinder after an impression has been made or for picking up the coating material on said cylinder when no sheet is presented to receive an impression.

9. In a machine for coating sheets, the combination of an impression cylinder for applying an impression of the coating material to a sheet, a transfer roller engaging said impression cylinder, said transfer roller receivinglthe coating material and depositing the same on the impression cylinder, a distributing roller also engaging the impression cylinder for distributing the coating material thereon, an auxiliaryl distributing roller engaging both the distributing roller and the transfer roller for smoothing out the coating material on said impression cylinder and for carrying back to said transfer roller any excess material which was applied to said impression cylinder, a wiper roller also engaging said impression cylinder for picking up residual coating .material left on said impression cylinder after an impression has been made and also for picking up the coating material on said cylinder when no sheet is present to receive an impression, and instrumentalities for removing from said wiper roller the coating material collected thereon.