US402772A - Offset mechanism for printing-machines - Google Patents

Description

(No Model.) 3 SheetsSheet 1.-

W. SCOTT. OFFSET MECHANISM FOR PRINTING MACHINES.

Patented May '7, 1889.

Lithographer, Washington D, C.

(No Model.) 3 Sheets-Sheet 2.. W. SCOTT. OFFSET MECHANISM FOR PRINTING MACHINES;

Patented May 7, 1889 (No Model.) 3 Sheets-Sheet 3.

W. SCOTT.

OFFSET MECHANISM FOR PRINTING MACHINES.

Patented May '7, 1889.

ET X 1 N. PEYERS Pmlu'Limognphar. Washington. D. C.

UNITED STATES PATENT OFFICE.

WALTER SCOTT, OF PLAINFIELD, NEW JERSEY.

OFFSET MECHANISM FOR PRINTING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 402,772, dated May 7, 1889.

Application filed April 17, 1888.- Serial No. 270,935. (No model.)

To all whom, it may concern.-

Be it known that LWALTER SCOTT, of Plainfield, in the county of Union and State of New Jersey, have invented an Improvement in OffsetMeohanism forPrinting-Machinespf which .the following is a specification.

I make use of an offset-web and rollers for receiving the same, the parts being arranged so that the web is wound up automatically, and the roller which is full is passed into the place that had before been occupied by the roller from which the web had been drawn, and the offsetweb is then passed through the press in the opposite direction and with the reverse side to the printed matter, so that the ink dries and offsets are prevented.

In the drawings, Figure 1 is a vertical section of a portion of a printing-press with my improvement applied thereto. Fig. 2 is an elevation of a portion of the frame, the winding-roller and its supporting-arm, and the tension device. Fig. 3 is a section of the frictional gear at the end of the winding-cylinder. Fig. 4 is a plan at one end of the winding-rolls, and Fig. 5 is a diagram of a modification in the support for the wind-up roll.

R R are the type-cylinders, and Q Q the impression-cylinders. If there are illustrations to be printed, the plates or blocks are to be placed upon the cylinder R. The cylinders are preferably arranged as shown, so that the second impression-cylinder is below the first, and the web of paper to be printed passes beneath the cylinder R, over the impressioncylinder Q, and around between the cylinders Q Q, and between the second type-cylinder, R ,and the second impression-cylinder,Q', and from these the web of paper is conveyed by the tapes 28 to the cutt er-cylinders S S, where the web is perforated. From thence the web of paper is conveyed by the tapes 3O 31 to the nipping-rollers K L, and the latter act in connection with said tapes 3O 31 to separate the sheets at the places perforated in the web by the cutter-cylinders S S. The belts 3O 31 then convey the separated sheets to the folding or delivery device. The means for inking the type-cylinders are not shown in the drawings, and a reference is hereby made to my-application for patent, No. 251,872, for a description of an arrangement of rollers that may be used for inking the cylinders R R.

The paper, as it passes off from between the type-cylinder R and oifsetwveb, is below such web; hence it falls therefrom by gravity upon the belts or tapes 28, which is a great convenience, especially in entering a fresh 'Web of paper.

The offset web 40 is rolled upon the roller M, the shaft of which rests in the brackets 41, secured to the side frames of the press, and there is a friction-strap, 42,'lever, and weight 43 to apply to the roller M the necessary friction to prevent the roller M revolving too rap idly. 7 The offset-web passes over the rollerN directly to the guide-roller 45, and thence around the impression-cylinder Q, as shown in Fig. 5, or else it may pass up over the guide-rolls 46 47 previous to reaching such roller 45, and after the offset-web has passed around the impression-cylinder Q it passes over the winding-cylinder P and is wound upon the roller N, that is received into jaws at the ends of the arms N upon the shaft N There is a frictional clamp, N applied to a disk upon the shaft N that is adjustable by the screw 50 and prevents the arms N swinging in the line of the dotted arc, except as the offset-web accumulates by being wound upon the roller N, and I remark that the winding-cylinder P is to be driven in such a manner as to maintain a slight tension on the tympan-sheet, which may be accomplished by the actuating-power moving slightly faster than the travel of the offset-web, so as to apply a constant strain to said tympan; or the cylin der P can be slightly larger than the pitchline of the gear-wheel 51, by which it is driven from the gear 64 on the shaft of the cylinder Q, Fig. 5; or the frictional driving mechanism may be of any desired character;'or the cylinder P may slip upon the paper as it is moving slightly faster. With this object in view the gear-wheel 51' at the end of the shaft 52 of the winding-cylinder is pressed against a friction-disk, 53, by an adjustable spring, 54, and this gear-wheel 51 is to .be revolved slightly faster than the cylinder P, so that the cylinder P is driven by the friction between wheel 51 and disk 53, and the offset-web will always be kept under a slight strain and it will be pulled off the roller M by the impression-cylinder Q, and such offset-web will intervene between the printed surface of the web and the impression-cylinder Q, so as to receive any offset from the printed surface.

The offset-web being drawn through the press by the action of the impression and type cylinders, its speed of movement is uniform, and such speed is not influenced by the speed of the wind-up cylinder; hence the speed of the latter can be slightly greater to prevent any slackness or wrinkles in the offset-web as wound up; and. by using the separate winding-cylinder l? the offset-web is wound up with the offset side outwardly, but when the offset-web is being drawn off the roll the innerside is presented for the offset; hence the alternate sides of the offset-web are used to receive the ofisets from the impressions.

The roller N is revolved by contact with the winding-cylinder P, and it will be observed that as the diameter of the offset-web increases upon the roll N it decreases upon the roll M;hence when the offset-web has been all drawn off the roll M the roll N will be of the largest diameter and occupy the position shown by dotted lines, Fig. 1, and it is only necessary to open the journal-bearing 41 and take out the roll M and turn aside the friction-strap and then swing the crank-arms N and turn the rock-shaft N so as to bring the projecting ends of the shaft of the roll N upon the inclined upper surface of the brackets 41, and the roll N containing the offsetweb will roll down to place in the bearings upon the brackets 41, and the end of the offset-web is then to be passed beneath the roll 45 around the impression-cylinder Q and winding-cylinder P to the roll M, which is now placed into the forked ends of the arm N, (in place of the roller N,) the arms N and shaft N being then turned so as bring the roller carried by it into contact with the offset-web upon cylinder P, so that the winding operation commences when the press is again started.

I11 changing the offset-Web and rolls itwill be apparent that the press can be stopped. and the empty roll removed before the last end of the sheet reaches the roll. The full roll of oifseteweb is now transferred to the brackets 41, and the web of paper out across, leaving a short length in the press, and then the end of the web can be pasted upon the rear end of the offset-web in the press, so as to be drawn through the press when again started.

By my improved arrangements the offsetweb is turned over each complete movement thereof, so that one side thereof receives the offset when running through the press, and then the other side receives the offset when the web is run through the second time, and

slide back with the roller and its shaft as the offset-web increases in diameter, as shown in Fig. 5. In either form the roller upon which the offset-web is wound is moved laterally toward the bearings 41 by the accumulation as the winding progresses, so that the roller has to be moved but a small distance when the roll is transferred.

I claim as my invention- 1. The combination, with the type-cylinders R R and impression-cylinders Q Q, of the winding-cylinder P, a tympan or offset sheet, two rollers for the same, fixed bearings for one of the rollers, arms N and shaft N for the other roller, and a frictional mechanism upon the shaft N for insuring the proper pressure between the winding-cylinder and the roll as the tympan-sheet is wound up, substantially as set forth.

2. The combination, with the offset-Web and the rolls M N, of thebrackets 41, having inclines upon which the journals of the roll (M or N) are received and boxes into which the journals are received, and the arms N or equivalents for moving the full roll to the inclines, substantially as specified.

3. The combination, with the printing and impression cylinders, of an offset-web passing around the impression-cylinder, one roll for the ofiset-web and stationary bearings for the same, a second roll on which the offset-web is wound, and moving bearings for the same that are moved laterally by the accumulation of the offset-web as'wound up, so that the roll and its bearings are carried bodily toward the stationary bearings, to be subsequently transferred thereto, as set forth.

4. The combination, with the offset-web and the rolls on which the same is wound, of a roller or cylinder for drawing off the said web and a wind-up cylinder and a frictional connection to the motive power, whereby the wind-up cylinder causes a constant strain to keep the offset-web sufficiently tight, substantially as set forth.

5. The combination, with the printing and impression cylinders, of an offset-web pass ing in above the impressioncylinder and wind-up mechanism for drawing the web up from below the impression cylinder, and mechanism for receiving and cutting the web of paper as it falls away from the oifsetweb, substantially as specified.

6. The combination,with'the rolls for the offset-web, and the printing and the impression cylinders, of a winding-cylinder against which the web as it is wound up into a roll rests, and mechanism for rotating the winding-cylinder so that its surface is moved slightly faster than the web for keeping the latter under tension as rolled up, substantially as specified.

Signed by me this 13th day of April, 1888.

\VALTER SCOTT.

Witnesses:

GEo. T. PINCKNEY, WILLIAM G. Mom.

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