US2667120A - Cylinder interrupter for offset lithographic printing machines - Google Patents

Description

Filed June 27, 1952 C. G. KING 2,667,120 CYLINDER INTERRUPTER FOR OFFSET LITHOGRAPHIC PRINTING MACHINES 2. Sheets-Sheet l INvFNTeR Cm. Gwshvs Kine Z Mam/J4 11347.4)

Jan. 26, 1954 c, 3, KING 2,667,120

CYLINDER INTERRUPTER FOR OFFSET LITHOGRAPHIC PRINTING MACHINES Filed June 27, 1952 2 Sheets$heet 2 Patented Jan. 26, 1954 CYLINDER INTERRUPTER FOR OFFSET LITHOGRAPHIC PRINTING MACHINES Carl Gustave King, Kenton, England, assignor to Kayes Rotaprint Agency Limited, London, England, a British company Application June 27, 1952, Serial No. 296,006

Claims priority, application Great Britain July 16, 1951 8 Claims.

This invention relates to improvements in and relating to offset lithographic printing machines.

More particularly the invention relates to machines of the kind having a form cylinder, a blanket cylinder and an impression cylinder wherein the blanket cylinder is rotatably mounted on a shaft having eccentric end portions adapted to be rotated, relative to the machine frame in which they are mounted, to vary the position of the blanket cylinder and move it into contact with the impression cylinder. The final position of the blanket cylinder is determined by a stop which is engaged by link means connected with the eccentric end shaft portions. With this known construction, when the various cylinders are set up in the machine, the contact pressure to be exerted by the blanket cylinder relative to the impression cylinder is preset and cannot be varied without resetting the cylinders in the machine frame. This entails careful adjustment of both ends of the cylinder to ensure that the cylinders are correctly aligned in the adjusted position. The contact pressure however has to be adjusted in accordance with the thickness of the paper passing through the machine and with the prior machines it meant that the machine was necessarily out of use during the time required to reset the cylinders.

It is an object of the present invention to provide a machine of the type referred to with means whereby the contact pressure may be readily adjusted by a simple manual control.

To enable the invention to be fully understood it will now be described with reference to the accompanying drawings, in which:

Fig. 1 shows in diagrammatic form the cylinders of an ofiset printing machine in inoperative position; and

Fig. 2 is a similar view but showing the cylinders and associated mechanism in the preliminary position just prior to their reaching full printing position.

.As shown in the accompanying drawings I represents the form cylinder of an offset printing machine, 2 represents the blanket cylinder and 3 the impression cylinder. The ends of the shaft of the blanket cylinder are freely rotatable in a bearing member mounted in the machine frame by means of eccentric shaft portions 4.

The eccentric end shaft portions 4 are themselves rotatably mounted in the frame of the printing machine, whereby when they are rotated the cylinder 2 will be moved in a plane parallel to its axis into engagement with the form and impression cylinders l and 3 for printing.

The eccentric shaft 4 at one end of the cylinder 2 carries a bracket 5 attached thereto having a pair of parallel movement links 6, l pivoted thereto, the links being connected by a pivoted cross link 8 adjacent to their free ends. A lever 9 is secured to the link I to extend axially thereof, one end of the lever carrying a roller l0 and the other end forming a manually operable handle portion H.

A bracket member I2 is mounted on the adjacent portion of the machine frame and carries a fixed abutment plate [3 over which the roller I0 is adapted to ride when the lever 9 is moved into operative position. A second abutment I4 is slidably mounted on the bracket l2 and is formed with an arcuate end face IS. The abutment i4 is mounted for slidable movement in guides on the bracket I 2 and a spring or the like is provided for urging the abutment I upwardly into engagement with a cam l6 fixed to the lower end of a rotatable rod H which extends through aperture guides 18, I9. The upper end 20 of the rod is adapted to be rotated by suitable means to adjust the cam and is preferably provided with a pointer 2| adapted to move across a dial or index plate 22.

Before the start of printing, the lever 9 is in its lowered or inoperative position as shown in Fig. l and the eccentric shaft is in a position wherein the blanket cylinder 2 is spaced from the form and impression cylinder. When printing is to be started the operator first raises the lever 9 to the position shown in Fig. 2 to engage the roller with the fixed radiused abutmentwhereby the eccentric is rotated to bring the blanket cylinder into contact with the form cylinder; this corresponds to the blanket inking position. When the machine is now started up and the cylinder 2 rotates, mechanism in the machine causes the eccentric shaft portions 4 and the attached bracket 5 to rotate therewith whereby the roller i0 is caused to ride along the fixed abutment i3 and finally ride on to the adjustable abutment face l5. This is the final or printing impression position and it Will be understood that the position of the adjustable stop determines the degree to which the eccentric shaft can be rotated and accordingly the final position of the blanket cylinder and thereby the pressure it exerts on the impression cylinder.

To vary the contact pressure it is only necessary to rotate the rod l'i so that the abutment I5 is moved by the action of the cam I6 to any desired adjusted position. The dial or index plate 22 is calibrated according to different paper thicknesses so that it is merely necessary to rotate the rod I! to a given scale reading as indicated by the pointer 2! to ensure the desired cylinder contact pressure for a known paper thickness. The abutment i5 is accordingly adjustable by a single manual control which can be operated if desired while the machine is running. Further the position of the blanket cylinder is adjusted Without changing the relationship that cylinder has with the form cylinder in the blanket inking position.

I claim:

1. An offset printing machine including a form and an impression cylinder having fixed axes of rotation, a blanket cylinder, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing members fixed on said machine for said eccentric shaft portions, a support attached to said eccentric shaft portions, link means pivoted to said support, a fixed abutment secured to said machine, an adjustable abutment mounted on the machine adjacent to said fixed abutment, a device on said link means engageable with said fixed and adjustable abutments, means for manually rotating said support and link means to position said device for engagement with said fixed abutment and means operable on the rotation of the blanket cylinder to further rotate the said support and link means to cause the said device to ride along the fixed abutment on to said adjustable abutment, the consequent rotation of the link means effecting a corresponding rotation of the eccentric shaft portions to cause the blanket cylinder to be moved into engagement with the form and impression cylinders.

2. An offset printing machine as claimed in claim 1 wherein manually operable means is provided for adjusting said adjustable abutment.

3. An offset printing machine including a form and an impression cylinder having fixed axes of rotation, a blanket cylinder, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing members fixed on said machine for said eccentric shaft portions, a support attached to said eccentric shaft portions, link means pivoted to said support, a fixed abutment secured to said machine, an adjustable abutment slidably mounted on the machine adjacent to an end of said fixed abutment, a device on said link means engageable with said fixed and adjustable abutments means 1'01 manually rotating said supports, and link means to position said device for engagement with said fixed abutment and means operable on the rotation of the blanket cylinder to further rotate the said support and link means to cause the said device to ride along the fixed abutment on to said adjustable abutment.

4. An offset printing machine including a form and an impression cylinder having fixed axes of rotation, a blanket cylinder, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing members fixed on said machine for said eccentric shaft portions, a support attached to said eccentric shaft portions, link means pivoted to said support, a fixed abutment secured to said machine, an adjustable abutment slidably mounted on the machine adjacent to said fixed abutment, a device on said link means engageable with said fixed and adjustable abutments, means for manually rotating said support and link means to position said device for engagement with said fixed abutment and means operable on the rota tion of the blanket cylinder to further rotate the said support and link means to cause the said device to ride along the fixed abutment on to said adjustable abutment, and manually operable cam means for adjusting said slidably mounted abutment relative to the fixed abutment.

5. An offset printing machine including a form and an impression cylinder having fixed axes of rotation, a blanket cylinder, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing members fixed on said machine for said eccentric shaft portions, a support attached to said eccentric, link means pivoted to said support, a fixed abutment secured to said machine, an adjustable abutment mounted on the machine adjacent to said fixed abutment, a roller mounted on said link, means for manually rotating said support and link means to position said roller into engagement with said fixed abutment and means operable on the rotation of the blanket cylinder to further rotate the said support and link means to cause the said device to ride along the fixed abutment on to said adjustable abutment, and effect the simultaneous rotation of said eccentric shaft portions to move the blanket cylinder into engagement with the form and impression cylinders.

6- An offset printing machine including a form and an impression cylinder having fixed axes of rotation, a blanket cylinder, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing members fixed on said machine for said eccentric shaft portions, means for rotating said eccentric shaft portions to effect movement of the blanket cylinder into operative engagement with said form and impression cylinders, said means comprising a support secured to one of said eccentric shaft portions, link means pivoted to said support, a fixed abutment secured to said machine, an adjustable abutment slidably mounted on the machine adjacent to an end of said fixed abutment, a device on said link means engageable with said fixed and adjustable abutments, means for manually rotating said support and link means to position said device for engagement with said fixed abutment and means operable on the rotation of the blanket cylinder to further rotate the said support and link means to cause the said device to ride along the fixed abutment on to said adjustable abutment.

7. An offset printing machine including a form and an impression cylinder having fixed axes of rotation, a blanket cylinder, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing members fixed on said machine for said eccentric shaft portions, means for rotating said eccentric shafts portions to effect the adjustment of said blanket cylinder into operative engagement with said form and impression cylinders, said means comprising a support secured to one of said eccentric shaft portions, link means pivoted to said support, a roller mounted on said link means, a stop element engageable by said roller to limit the pivotal movement of said link means, said stop element comprising fixed and adjustable abutments, means for manually rotating said support and link means to position said roller for engagement with said fixed abutment and means operable on the rotation of the blanket cylinder to further rotate the said support and link means to cause the said roller to ride along the fixed abutment on to said adjustable abutment.

8. An olTset printing machine including a form and an impression cylinder having fixed axes of rotation, a blanket cylinder, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing members fixed on said machine for said eccentric shaft portions, means for rotating said eccentric shaft portions to efiect the adjustment of said blanket cylinder into operative engagement with said form and impression cylinders, said means comprising a support secured to one of said eccentric shaft portions, link means pivoted to said support, a roller mounted on said link means, a stop element engageable by said roller to limit the pivotal movement of said link means, said stop element comprising fixed and adjustable abutments, means for manually rotating said support and link means to position said roller for engagement with said fixed abutment and means operable on the rotation of the blanket cylinder to further rotate the said support and link means to cause the said roller to ride along the fixed abutment on to said adjustable abutment, and manually operable cam means for adjusting said slidably mounted abutment relative to the fixed abutment.

CARL GUSTAVE KING.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 913,119 Ford Feb. 23, 1909 2,568,761 Peyrebrune Sept. 25, 1951 2,578,700 Harrold et a1 Dec. 18, 1951

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