US1438460A - Art of lithographic printing - Google Patents

Description

A. S. N. OLSON.

ART OF- LITHOGRAPHIC PRINTING.

APPLICATION FILED MAY14,19I7- 1,488,460, Patented; Dec. 12, 1922.

3 SHEETS--SHEE'I 1- Z' 72 11v VENTOR.

ATTORNEY A. S. N. OLSON.

ART OF LITHOGRAPHlC PRINTING.

APPUCAUON FILED MAY 14, 1917.

1,438,460 Patented Dec. 12, 19220 3 SHEETS-SHEE1 2.

ATTORNEYW A. s. N. OLSON.

ART OF LHHQijHgWHlC PRINI'IHU.

APPLICATION FILED MAY E1, 131]- Patented Dec. 12, 1922.

INVENTOR.

Patented Dec. 12, 1922.

ALBERT S. N. OLSON. OF CHICAGO, ILLINOIS.

'ENT

ART OF LITHOGRAPHIC PRINTING.

Application filed May 14,

T all whom it may concern Be it known that 1, ALBERT S. N. OLSON,

a citizen of the United States, and resident of Chicago, in the county of (00k and in the State of Illinois, have invented certain new and useful Improvements in the Art of Lithographic Printing. and do hereby declare that the following is a full, clear, and exact description thereof. 0 My invention relates to lithographic or planographic printing, that is to say to printing from the etched or engraved surfaces of thin metal sheets-such as zinc or aluminum. \Vith such methods or appli- 5 ances ordinarily used. it is commercially impracticable. to do small jobs in small uantities. because they are not profitable. liy my invention. however it is rendered possible to do jobs of small dimensions. and when small 0 quantities are desired. with use of the ordinary platen letterpress. Generally stated. the object of my invention is to enable lithographic or planographic printing to be done economically so as to render 5 it available in fields from which it has heretofore been excluded, because of cost. and in particular my object is to enable such printing to be done with an ordinary platen letterpress. 0 In the accompanying drawings 1 illustrate one way by which my invention can be carriedoutin connection with. and in the form .of an attachment to an ordinary platen letterpress. in which drawings :5 Fig. 1 is a side elevation of an ordinary Qordon letterpress, provided with an attachment embodying my invention:

Fig. 2 is a front view of the chase and bed for holding the engraved metal sheet:

Figs. 3 and 4: are respectively side elevations thereof, showing the lowered and raised positions respectively of bearers for preventing contact of the ink rollers with the printing form when that is desired;

Fig. 5 is a detail view in vertical section on the lines 55 of Fig 2;

Fig. 6 is a horizontal section on the line 66 of Fig. 2;

Fig. 7 is a detail top plan view of the inking and dampening rollers;

Fig. 8 is a detail view thereof in side elevation;

Fig. 9 is a detail view of one of the bearerprofit and by the 1917. Serial m. 168,516.

bars for controlling the positions of the inking and dampening rollers in passing over the inking plate or disk;

Figjlll is audetail view in side elevation of one of the bracket devices for supporting and attaching the dampening roller to the inking rollers;

Fig. 11 is a front elevation of the water fountain for supplying water to the dampening roller;

Fig. 12 is a side elevation thereof;

Fig. 13 is a vetrical section through the fountain on the. line 1313 of Fig. 11;

Fig. V1% is a detail view in-section of one of two similar devices at each side of the press frame for attaching thev water fountain thereto.

The Gordon pressshown in the'drawing being a well-known construction needs no particular description beyond saying that it comprises a frame 10, a chase 11, an inkdisk 12. the swinging platen 13 and poweroperated platen swinging mechanism which need not be particularly described. The discovery which I have made which results in the attainment of the object of my invention, 1s that by supporting a thin metal sheet having an inked printing face upon a plane or flat surface and pressing thereagainst the sheet to be printed by a flat or plane platen, and with even pressure lithographic or planographic printing can be successfully 5' and satisfactorily done. The im )ortant considerations in the press. there ore. are its possessions of the characteristics of two opposing flat or plane surfaces between which the engraved plate and the sheet to be printed are pressed. Since lithographic or planographic. printing requires the application of water to the printing plate or form. it will be found that my invention provides moistening means, and it will also be found that a special construction of chase is desirable, but no substantial alteration or modification of the press as constructed for ordinary use is required, so that for the practice of my invention the appliances or devices necessary may exist in the form of an attachment to the press.

Referring particularly to Figs. 1 to 4, it will be seen that the chase 11 has the usual flat rectangular frame form. Within it is secured a bed 1 in the form of a solid slab or block, whose'outer face is flat or plane, and is situated substantially type-high. Stretched tightly over the flat outer face of the bed 14 is the sheet metal printing plate 15, its top and bottom edges being clamped securely so that itis stretched tightand smooth over the bed. The bottom edge of said plate is clamped between the bottom of the bed 14 and a clamping bar '16 which at intervals is engaged by several screw adjusting devices 1T,mounted on the bottom bar of the chase l1.

tits a groove 19 of the adjacent side bar of the chase. In a space between the top of the bed 14 and the top bar of the chase, there is a vertically movable clamp that consists of two bars, a lower bar 20 and an upper bar 21 with correspondingly shaped irregular opposing faces between which the upperedge of the printing sheet 15 is gripped and securely held by the aetionof several screws 22. that join the two bars. At intervals the upper bar of the phase has several vertical screws 23 whose lower ends engage threaded holes in the lower clamp bar 20 while passing freely through holes in the upper bar 21, so that by turning said screws 23 in the proper direction to do so the clamping bars gripping the upper edge of the printing plate will be drawn upward, and thus stretched tightly over the flat face of the bed 14.

There are two leather-covered ink rollers journalled as usual at their opposite ends in blocks 2."). that are carried by the usual lever 26 at each side of the press, upon the spindles or stocks of which are mounted bearing rollers 26. that pass over the usual bearers '27 on opposite sides of the press. said" inking rollers 24 as usual passing back and forth over the ink disk and the printing form. In advance of the inking rollers 24 is a felt covered moistening roller 28 which at each end has a stock or spindle that is journalled in a block 29, that is connected with and receives motion from the roller vibrating lever 26. The dampening roller stock or spindle is seated in an open ended slot 30 in the block 29, the open end being closed by a removable plate 31, this arrangement being employed for the application and removal of the bar 29 without removing or disturbing the dampening roller. Each block 29 has on its outer side an arm or extension 32 which has journal holes near its ends for the pintles of two small rollers that lie parallel, and have contact. with the dampening roller, one of each small rollers 33 aids in distributing moisture over the surface of the dampening roller (moisture being supplied thereto as hereinafter described) said roller 33 being preferably felt covered, while the other roller 34 is of metal and performs the function of cleaning ink from the surface of the dam- The clamping bar 1( i i guided at each end by a lug 18 that slit'lably pressed yieldingly against the dan'ipening roller. 28. In the device shown in the drawings, this is accomplished by mounting the arm 32 on a threaded stud 36 fixed at one end to the block 29. and interposing a spring 37 on the stud between a nut 38 on the stud and the lower one of two ears 39 on the arm, through which the stud passes. I

When the dampening roller traverses the ink-disk. it should not touch the inked surface thereof. To secure this result, an arm 40 may be secured to the press, at each side, which extends upward and. rearward, parallel with the inked face of the disk, forming in effect, an extension of each bearer 27, with the top edge of which a roller 41 on the pint-le of the dampening roller will engage. as the adjacent smaller roller 42 which cooperates with the bearer 27. leaves the latter, and thereby the dampening roller lifted enough above the ink-disk to clear the same. 7

The dampening roller is supplied with water from a fountain situated below the chase 11, to and from which said roller is moved by the lever arms 26. Said fountain (see Figs. 11 to 13) comprises an oblong box or tank 42 which has on its front side an opening or slot 43, at which is exposed a portion of an endless band 44 of felt, or other water absorbent material, into contact with which exposed port-ion the roller 28 is brought. The band 44 passes about a roller 45 in the bottom, water holding portion of "the tank, and about a roller 46 at the top thereof, to which motion is imparted to cause the band to pass slowly through the water to take up the latter.- The lower, Watersubmerged roller 45 is hollow so as not to diminish the water-holding capacity of the tank. To support the exposed portion of the band againstthe pressure of the roller 28, at each end of the tank adjacent the exposing slot. is a lip 47 which lies on the inner side of the band adjacent the side edge thereof. Vater is supplied to the tank from a vacuum. reservoir 48 at the back thereof, communication 'between the reservoir and tank being afforded by a pipe 49 that opens into the tank at a point at which it is desired to maintain a constant level in the tank. As soon as the level falls enough to unseal the outlet end of the pipe, air enters the reservoir and a flow of Water therefrom is caused. The pipe has a valve 50 for closing it when the reservoir supply is to be replenished,

bolt between which and said block the arm.

52 has a slot 57 for purposes of adjustment, and to give a rigid support, the block 55 has on its side next the arm an elongated lug 58 that enters the slot.

The band driving roller 46 is rotated intermittently. At one end it has a gear 59 that meshes with a gear 60 loose on a shaft 61 to which a bell-crank lever 62 is pivoted. One arm of the latter carries a pawl 63 that engages the teeth of the gear 60. The other arm is connected to an end of a rod 64, whose other end has an eye 65 that engages a pin or stud 66 on the stationary member or part of the frame 10. The frame member 53 to which the arm or bracket 52 is connected. is pivoted so that it imparts a short to and fro swing to the form, and therefore, a rocking movement is imparted to the bell-crank lever 62 by reason of the connection between it and the stationary frame member formed by the rod 64 and the pin 66. One end of the pinengaging eye 65 is formed by an adjustable cross bar 67, which being shifted to different distances from the other end of the eve. enables the degree of travel of the band 44. to be varied.

In starting up the press, when the plate or form is dry, it is necessary to moisten the form before applying ink thereto. This may be accomplished by preventing contact of the inking rollers with the form before the dampening roller has passed over it. That may be done by providing. as best shown in Figs. 2 to 4:. at each side of the chase 11, a plate 68 that is shiftable to place its outer edge into or out of the path of the bearer rollers 26 on the inking rollers 24, at the time the latter traverses the form.

\Vhen in their raised or elevated positions,

said plates keep the inking rollers from touching the form. Each plate 68 is slidably attached to one side of the chase by several screws 69 that, respectively pass through upwardly and outwardly slanted slots 70, in the plate, and each plate, near its top has a triangular slot 71, which is engaged by the out-turned lower end of a bolt 72 vertically slidable in a hole in the chase. The two bolts 72 are connected by a cross bar 73 that forms a handle by which the two bolts may simultaneously be lifted and thereby both bearer plates lifted and at the same time caused to move laterally to 'project their outer edges in the path of the rollers- 26. The triangular slots 71 form a loose connection between the bolts 72 and the plates 68 which permits the dropping of the bolts after the plates have been lifted unaccompanied by the dropping of the plates.

Each plate 68 after being lifted as explained,

'a downwardly and outwardly inclined hole in the side bar of the chase. and anotch 75 in the rear side of the plate 69, into which an outturned end 76 of the pin His adapted to enter when by the lifting of the plate notch 75 is brought into alinement with said pinend 7 6, which engagement of latch-pin and notch takes place automatically by the action of gravity on the pin 74, which causes it to slide downward and outward in its inclined hole. The latch-pin H has such length thatwhen it is in notch-engaging or latching position, its outer end projects beyond the plane of the outer edge of the plate 68, and, therefore, in position to be engaged by the platen of the press. when the latter moves toward the former, and thereby. the automatic release of the plate 68, effected and it is assured that no injury will come .to the parts when the plates 68 are in their raised position. and the platen is moved towards the printing form. hen

thus released, plates 68 automatically move sufficiently pointed out. Perhaps it may be well to add that as usual. a make-ready is applied to the platen. It is built up of card-board. and thin sheet of rubber. until a solid and even impression is obtained when the platen is placed against the form. the make-ready being of such size as to conform approximately to the size of the surface to be printed without interference with the paper gripper and guides. The change in the same press from letterpress to litho graphic printing and vice versa can quickly be made. and the provision of an attachment embodying my invention to a platen letterpress in nowise impairs or affects the efliciency of the press for letterpress work.

It is evident that my invention may be embodied in different forms and applied to other forms of printing presses than the one illustrated in the drawings. and .it is, therefore. to be understood that what I have shown and described is not restrictive of the scope of my invention, but illustrative to and fro moving platen, a thin flat ongraved plate. and a bed supported within the chase that forms a'sllpport for'the engraved plate type-high.

3. In an ordinary platen letter press C0111- prising a chase support and a flat platen mounted to swing towards and from the vhase. the combination of a chase a thin metal impression iving surface stretched over the ehase.'an a support for such snr- 1O fat-e within the chase holding it type-high. In testimony that I claim the foregoing I have hereunto set my hand.

' ALBERT S. N. OLSON.

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