US2208043A - Offset printing machine - Google Patents

Description

July 16, 1940.

J. J. ORMQND OFFSET PRINTING MACHINE Filed Nov; 13, 1939 2 SheetS-Sheet 1 M 16, 1940. ,J, ioRMoND 2,208,043

OFFSET PRINTING MACHINE Filed Nov. 13, 1939 2 Sheets-Sheet 2 ,fii 06775212" wpm 7/ a wiat,

Patented July 16, 1940 OFFSET PRINTWG E John J. Ormond, Boston, Mass, assignor to Artugraphic Incorporated,

Boston, Mass, a corporation of Massachusetts Application November 13, 1939, Serial No. 304,186

2 Claims.

This invention relates to printing machines and methods of printing.

It is customary in printing machines to employ gripper mechanism or other means for holding 5 subject matter during the time it is passing into register with and between printing members. The function of these members is to insure a high degree of registration of the subject matter with the printing members and to assist in supporting the subject matter on the printing member when printing operations are being carried out at high speed. In some cases, it is desired to effect application of a printing image over the entire surface of a given sheet of subject matter from edge to edge thereof, an operation known in the printing art as bleeding ofi. It is impossible to employthe gripper mechanism described when carrying out such a printing operation as these members must necessarily take up a part of the surface of the sheet which is engaged. As a result, bleeding off operations are efiected only with great difficulty, and at slow rates of speed such as to prohibit commercial utilization of this type of printing. Reference is particularly had to small sized sheets of subject matter, as for instance envelopes, cards, and similar subject matter. In addition to the difiiculties noted with respect to bleeding off operations, specific problems arise in hanso dling and printing envelopes due to the fact that they are composed of several layers of material which tends to require make ready, and envelopes usually are composed of rough, cheap paper, ill adapted to properly retaining printing ink.

It is a chief object of the present invention to improve printing machines and to devise register and printing mechanisms adapted to eliminate the use of holding or gripper members and make possible bleeding off operations. It is a further object of the invention to effect means particularly suited to facilitating the handling and printing of envelopes, cards and similarly sized subject matter.

These and other objects of the invention will be more readily understood from the following description when read in connection with the accompanying drawings, and the novel features of v the invention will be more particularly pointed out in the appended claims.

In the accompanying drawings:

Figure 1 is a view in side elevation illustratin a printing mechanism of the invention.

Fig. 2 is a cross section taken on the line 2-2 of Fig. l.

Fig. 3 is a detail view more particularly illustrating register mechanism forming a part of the printing machine; and

Fig. 4 is another fragmentary elevational view of the register and printing mechanism of the machine illustrated in greater detail.

In the construction shown, arrow l0 indicates generally the printing machine which is made up with a frame H comprising two upper portions between which is mounted a cylinder E2 on a shaft E3. The cylinder H has on its periphery a blanket l2a which may be formed of a resilient material adapted to receive printing ink and transfer it to the surface of a sheet of subject matter.

Mounted in frame H above cylinder 92 is a carrier M on the shaft Ma for the printing plate l5, which in the operation of the apparatus is brought into rolling contact with the surface of the blanket 82a. it indicates a cylinder similarly mounted in frame ii on the shaft ill and carrying on its periphery a pressure plate is which, in the printing operation, urges the subject matter to be printed against the surface of blanket 52a.

Inking means for the printing plate i 5 is comprised by a trough til extending across the machine and supported at its ends in frame ll. Associated with trough 69 are inking rolls W3 and 65 adapted to apply ink on the surface of printing plate i5 upon rotation of the plate carrier extending across the roll 68 and having its ends recessed. In the top of frame l! i is a doctor bar 7 3 adjustably secured by a screw it on the under side of which is recessed a doctor blade i5.

Radially recessed in the pressure roll it and just ahead of the forward end of the pressure plate it is a guide member fit extending longitudinally of the roll and normally projecting above the surface of the pressure plate It. As the pressure roll rotates, subject matter to be passed between this roll and the transfer blanket 82a. will be laid on to the pressure plate and held against the guide member 86. As pressure roll it continues to rotate, the outer edge of the guide member 86 is depressed after proper registration of the front edge of a sheet of subject matter has been effected.

v The printing means now described is of a type generally employed in the art to effect ofiset printing. It is further customary to rely on gripper mechanism for holding, feeding and. maintaining sheets of subject matter in the printing machinery construction shown, and these gripper means or mechanisms are partly associated with one or the other of rolls such as the rolls I2 and I6.

According to the present invention, registration of subject matter is effected and subject matter is printed from edge to edge in the absence of; any holding or gripping mechanism either located on the printing or pressure roll or any other part of the printing machine. Means for effecting these results comprise in combination with the guide 86 referred to, a register mechanism mounted in the machine on side frames 93 extending frontwardly of the rolls, and supported by brackets extending forward from frame II.

Pivotally mounted in the frames 98 is a shaft 08a on which are fixed stop members 95 for holding subject matter passing along the supporting I plates 95 on belts 98 driven by rollers 0i more clearly shown in Fig. 2". The supporting plates 96 are slotted to receive the stop members 05 therethrough and are further formed with vertical side portions for supporting both edges of a sheet, as shown in the figure referred to. At the front of the plate 96 is a chute 06b for supporting a sheet as it becomes engaged between the printing rolls. Fixed at the ends of shaft 08a adjacent and inside of frame 98 are finger members 99. Supported by shaft 00a are vertical plates I00 and fixed on shaft 00a adjacent plate I00 is a cam link IOI at the lower end of which is a cam roller I02. I03 indicates supporting arms pinned to plates I00 for supporting a driven shaft I00 on which are mounted rollers I05. Adjustment of shaft I00 may be efiected by screws I040 in supporting arms I03. Rotation of shaft 98a moves the fingers 99 against the drivenshaft I00, freeing it from its supporting arms I03, allowing the rollers I05 to drop down into engagement with the conveyor belts 90. At one end shaft 98a is provided with a collar mm and the retaining spring I022; for maintaining the shaft in the position shown in Fig. 2.

At one end of pressure roll 56 there is mounted a cam plate I06 havinga cam surface adapted to be in register with cam roll I02, so that upon rotation of roll it cam link I0i will be forced inwardly, rotating shaft 98:; to drop the fingers 98 and engage the rolls I05 with subject matter passing along the belts. At the same time stop members 95 are so arranged on shaft 08a with respect to the fingers 'that they fall away from the front edge of subject matter on the conveyor 'belts and allow the subject matter to pass ahead in a highly accurate registered position.

The surface speed of the rolls I05 is greater gaged at the nip of the rolls, thereby partly obviating the need for gripping mechanism.

Shaft 94, as viewed in Fig. 2-, has mounted at its right-hand end a gear I01 which meshes with other driving parts of the printing machine. At its other end shaft 94 is provided with a sprocket wheel I09 which drives a sprocket wheel IIO by chain I II. Sprocket H0 is mounted on a stub shaft mounted through frame 93 and has at its outer end another sprocket II3, which in turn drives a sprocket Ill by a chain I I5. Chain III passes from sprocket I I0 to drive sprocket I Ilia. mounted on shaft H8 in the rear end of frame 03, and there may be provided a tension roller as III mounted on shaft II 8 supported adjacent bracket 00. By arranging supporting plates 96 to support both sides of a sheet and by timing the stops with the lifting bars 09, driving rolls I05 and guide plate 86 in proper relation to one another, such as has been described and illustrated in Figs. 3 and 4, it becomes possible to secure suitable register of a small sheet of subject matter with such degree of accuracy that no holding or gripping mechanism is employed, and as a result the sheet is free to be printed over its entire face. The resilient character of the transfer member I2a may be such as to readily adapt itself to conforming to unevennesses in the surface of a sheet of subject matter such as an envelope, which it is particularly desired to print by the means described.

This position of the register mechanism with respect to the depressible guide 85 assists in making possible high-speed register and passage of envelopes between the printing members without sticking occurring, hence no gripping mechanism is necessary to be employed for stripping the sheets after they are printed.

It will be seen by the construction now shown and described, a printing operation over the entire side of a'sheet of subject matter, or bleeding off," may be carried out, with a good grade of printing being effected and no smurring or ink transfer occurring. The means shown are particularly adapted to the treatment of envelopes, cards and similarly sized subject matter, which may be printed at high speeds and at a very cheap cost.

While I have shown a preferred embodiment of my invention, it should be understood that various changes may be desired to be effected therein, in accordance with the spirit of the invention as defined by the appended claims.

Having described my invention, I claim:

1. In a printing machine, the combination of a pressure roll and a printing roll adapted to apply an image to subject matter passing between said rolls, an endless carrier for delivering subject matter to be printed to said rolls, said carrier supported on a shaft adjacent said rolls, stop means fixed on a second shaft for receiving said subject matter, means for rotating said second shaft, said means being operatively connected to a cam plate on said pressure roll for releasing said stop member, and means located above said first shaft and adapted upon rotation of said second shaft to engage subject matter on said carrier and advance same to the rolls at a speed greater than the surface speed of the rolls, and additional-stop means on said pressure roll for receiving the front edge of said subject matter and effecting register of same relative to the image on the printing roll as the subject matter passes between the rolls.

2. In a printing machine, the combination of a pressure roll and a printing roll adapted to apply an imageto subject matter passing between said rolls, a frame and an endless carrier received therein for delivering subject matter to be printed on said rolls, said carrier supported on a shaft in the frame adjacent the printing roll and pressure roll, driving roller means adjustably supported in the frame over said shaft, a second shaft member pivotally received in the frame rearwardly of'the said'firstshaft, cam means associated with said second shaft for rotating the shaft, finger members for raising the said roller means, the finger members being fixed on said second shaft and stop means for subject matter also fixed on said second shaft in such position relative to the finger members that upon rota- 5 tion of the second shaft, the stop means will drop down into a non-operative position, and the carrier and driving roller means being adapted to then advance the subject matter to the printing roll and pressure roll at a speed greater than the surface speed of these rolls.

JOHN J. ORMOND.

Images