US1517969A - Direct and offset lithographic rotary machine - Google Patents

Description

A. B. EVANS ET m.

DIRECT AND OFFSET LITHOGRAPHIC ROTARY CHINE Filed Aug. '28, 1922' Patented Dec. 2, 1924.

u N i re ARTHUR BURROUGHES EVANS, OF CHAPELTOVT N, LEEDS, AND RAYMOND PERCIVAL PAYNE, 0F LEEDS, ENGLAND.

DIRECT AND OFFSET LITHOGRAPHIC ROTARY MACHINE.

Application filed August 28, 1922; Serial No. 584,905.

T 0 all whom it may concern:

Be it known that we, ARTHUR BUnnoUcHEs EVANS and RAYMOND PEROIVAL PAYNE, sub jects of the King of Great Britain and Ireland, residing, respectively, at 7 Woodland Grove, Ghapeltown, Leeds, England, and 169 Spencer Place, Leeds, England, have invented certain new and useful Improvements in Direct and Offset Lithographic Rotary Machines, of which the following is a specification.

This invention relates to direct and offset lithographic rotary machines adapted for printing upon sheets of paper or the like in which the sheets are fed directly from a feed board to a series of grippers or the li is carried by the main impression or offset cylinder disposed between the design cylinder and a delivery and auxiliary impression cylinder of approximately one-half the diameter of the main impression or offset cylinder and provided with a series of grippers, the printing surfaces being less than one half the periphery of the main impression or offset cylinder. In such machines it is usual for two revolutions of the main impression or offset cylinder to take place for each sheet printed, the sheet being taken in the first revolution from the feed board by the grippers on the said cylinder and being carried past the design cylinder without impression, and thence to the delivery and auxiliary impression cylinder where the impression is effected and the grippers upon which cylinder remove the sheet from the main impression or offset cylinder, the second revolution of the said cylinder serving for the reception of the succeeding offset from the design cylinder.

According to the invention the main auxiliary or offset cylinder, adapted to receive the sheets to be printed directly from a feed board, is provided with a set of grippers, diametrically opposed in position to the grippers used in direct printing and following the offset surface, the surface diametrically disposed to the offset surface serving as a sheet receiving surface.

According to the invention, moreover, in the operation of the machine for offset print ing the sheet is received by the grippers of the offset cylinder and is carried round by the revolution of the said cylinder upon the receiving surface, without impression, to the delivery and auxiliary impression cylinder,

cylinder is connected also to the journals of the delivery and auxiliary impression cylinder in such manner that the operation of the mechanism also removes the said cylinder from or into contact with the offset cylinder.

According to the invention, moreover, a second design surface may be carried by the design cylinder and a corresponding surface on the offset cylinder, so that the sheet may receive a direct lithographic impression, by impression from the second design plate be fore it receives an offset impression from the offset surface, such'two impressions being upon opposite sides of the sheet.

According to the invention, moreover, the design cylinder may be of a diameter approximately one half that of the offset cylinder, such a relation not altering the uses of the machine save that in the case of a direct impression on one side and an offset impression 011 the other side of the sheet, these two impressions are of one design and in the form of a transparency.

The accompanying diagrammatic drawing represents a lithographic rotary machine constructed according to the invention.

The cylinders a Z) represent respectively the design cylinder, the main impression or offset cylinder, and the delivery and auxiliary impression cylinder of a direct and offset lithographic rotary machine, in which a series of grippers d are provided on the impression cylinder 6 immediately in front of the offset surface 6 and are operated to take the sheets from the feed board e, in the use of the machine for direct printing, the surface 79 being in this case prepared as an impression surface. A series of grippers f, carried by the delivery cylinder 0 are.

operated to receive the sheets, after impression, and to pass them forward to the delivery mechanism.

In carrying the invention into effect, for the operation of the machine for offset printing, the cylinders (a, Z), 0 serve respectively as the design cylinder, offset cylinder, and impression cylinder of such a machine when used for single-side offset printing. In this case a series of grippers g is disposed diametrically opposite to the series of grippers cl and a surface on the cylinder 6- (the offset cylinder) is provided or adapted to support the sheets carried by the grippers 9, but without impression from the design cylinder (t or the impression cylinder 0, so that the sheets are carried forward to the impression cylinder 0, and, at or about the contact line, transferred to the grippers and carried in this way by the cylinder 0 for one complete revolution of this cylinder. On the second revolution of the cylinder 0 printing contact is obtained between the sheet and the offset surface on the offset cylinder Z) which has received already an impression from the design cylinder a, after which contact the sheets are carried forward to any known form of delivery, that in most common use for direct lithographic rotary machines being of the type exemplified in the drawing. In the drawing is shown also a part of a known tripping mechanism for lithographic rotary machines, and in this the shaft h is operated by a cam motion, so that the mechanism is moved from the full to the dotted position by the operator, as and when required, for instance, when sheets are not fed to the machine. On the shaft 72 are levers z carrying pins on which are pivoted the lower ends of connecting links is, the upper ends of which are pivoted on -pins Z carried by eccentric journals m in which rotate the spindles 71 of the cylinder Z). The action of the trip mechanism and the eccentricity of the journals m are such that the cylinder 7) is drawn out of contact with the cylinder a and in the direction of the cylinder 0. In order to break printing con tact between the cylinder 0 and the cylinder 5 at the same time as the cylinder Z) is tripped, we provide extensions 2) upon the eccentric journals m, carrying pins 9 on which are pivoted the ends of the connecting links 1", the other ends of which are pivoted on pins 8 carried by eccentric journals t in which rotate the spindles of the cylinder 0.

By this mechanism, or any other known form of connection between the journals of the cylinders 7) and 0 including such connections as may be put out of operation at the will of the operator, the tripping mechanism operates also to trip the cylinder 0.

The grippers 7 may alternatively be disposed in the position occupied by the grippers (Z and the surface b be given all the characteristics of the surface 6 such different arrangement only demanding a different timing position of the cylinder 6 from that hereinbefore described.

hen the design cylinder carries a second design surface disposed at or about a position in opposition to the second surface Z) of the cylinder Z2, this surface is utilized as hereinafter described.

The sheets carried by the grippers 9 re ceive in this case a direct impression (not offset) from the second design surface before they reach the impression cylinder 0 and on the opposite side of the sheets to the later offset impression, hereinbefore de scribed. For this purpose the surface 72 is formed as an impression cylinder. Such impressions may be in the same or different colours according to the construction of the accessories of the design cylinder at.

For printing on both sides of the sheet, as described, but with two identical designs in register in the form of a transparency, the two designs on the design cylinder at are similar to one another, so that in the case of such printing being required in the same colour on each side a varying form of construction may be used in which the design cylinder is one half of the diameter of the offset cylinder 6 and carries one design only, which gives its impression in turn to the sheet and to the offset surface 6 We claim:

1. A lithographic rotary machine for offset printing upon sheets of paper, comprising in combination a design cylinder, a delivery and auxiliary impression cylinder, an offset cylinder disposed between said design cylinder and said delivery and auxiliary impression cylinder, an offset surface upon said offset cylinder, a sheet receiving surface upon said offset cylinder, a series of grippers disposed upon said offset cylinder in advance of said sheet receiving surface, a feed board co-operating with the offset cylinder and from which said grippers take a sheet and carry it round upon said sheet receiving surface to said delivery and auxiliary impression cylinder, and a series of grippers upon said delivery and auxiliary impression cylinder adapted to receive the sheet from the series of grippers upon said offset cylinder and to carry the sheet round wit-h said delivery and auxiliary impression cylinder for one revolution thereof before delivery of the sheet.

2. A lithographic rotary machine for direct and offset printing upon sheets of paper, comprising in combination a design cylinder, a delivery and auxiliary impression cylinder, an offset cylinder disposed between said design cylinder and said delivery and auxiliary impression cylinder, an offset surface upon said offset cylinder, a direct impression surface upon said offset cylinder, a series of grippers disposed upon said offset cylinder in advance of said direct impression surface, a feed board co-operating with the offset cylinder and from which said grippers take a sheet and carry it round upon said direct impression surface to said delivery and auxiliary impression cylinder, and a series of grippers upon said delivery and auxiliary impression cylinder adapted to receive the sheet from the series of grippers upon said offset cylinder and to carry the sheet round with said delivery and auxiliary impression cylinder for one revolution thereof before delivery of the sheet.

3. A lithographic rotary machine for offset printing upon sheets of paper, comprising in combination a design cylinder, a delivery and auxiliary impression cylinder, an offset cylinder disposed between said design cylinder and said delivery and auxiliary impression cylinder, an offset surface upon said offset cylinder, a sheet receiving surface upon said offset cylinder, a series of grippers disposed upon said offset cylinder in advance of said sheet receiving surface, a feed board co-operating with the offset cylinder and from which said grippers take a sheet and carry it round upon said receiving surface to said delivery and auxiliary impression cylinder, a series of grippers upon said delivery and auxiliary impression cylinder adapted to receive the sheet from the series of grippers upon said offset cylinder and to carry the sheet round with said delivery and auxiliary impression cylinder for one revolution thereof before delivery of the sheet, and trip mechanisms applied to said offset cylinder and said auxiliary impression cylinder, said trip mechanisms being operatively connected.

4:. A lithographic rotary machine for direct and offset printing upon sheets of paper, comprising in combination a design cylinder, a delivery and auxiliary impression cylinder, an offset cylinder disposed between said design cylinder and said delivery and auxiliary impression cylinder, an offset surface upon said offset cylinder, a direct impression surface upon said offset cylinder, a series of grippers disposed upon said offset cylinder in advance of said direct impression surface, a feed board co-operatmg with the offset cylinder and from which said grippers take a sheet and carry it round upon said direct impression surface to said delivery and auxiliary impression cylinder, a series of grippers upon said delivery and auxiliary impression cylinder adapted to receive the sheet from the series of grippers upon said offset cylinder and to carry the sheetround with said delivery and auxiliary impression cylinder for one revolution thereof before delivery of the sheet, and trip mechanisms applied to said offset cylinder and said auxiliary impression cylinder, said trip mechanisms being operatively connected.

ARTHUR BURROUGHES EVANS. RAYMOND PERCIVAL PAYNE.

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