US3054346A

US3054346A - Tripping device for printing machine cylinders

Info

Publication number: US3054346A
Application number: US88818A
Authority: US
Inventors: Koch Werner; Preuss Friedrich
Original assignee: ROLAND OFF SETMASCHINENFABRIK
Current assignee: ROLAND OFF SETMASCHINENFABRIK; Roland Off Setmaschinenfabrik Faber & Schleicher Ag
Priority date: 1960-04-09
Filing date: 1961-02-13
Publication date: 1962-09-18
Anticipated expiration: 1979-09-18

Description

p 1962 w. KOCH ET AL 3,054,346

TRIPPING DEVICE FOR PRINTING MACHINE CYLINDERS Filed Feb. 13, 1961 4 Sheets-Sheet l 8r H Mob 1977-0 R/VE Y6 Sept. 18, 1962 w, KOCH T AL 3,054,346

TRIPPING DEVICE FOR PRINTING MACHINE CYLINDERS Filed Feb. 13, 1961 4 Sheets-Sheet 2 Dive/760m V5,? IVER K0 c Ewan/we Pxauss 3/ HM M Sept. 18, 1962 w. KOCH ET AL 3,054,346

TRIPPING DEVICE FOR PRINTING MACHINE CYLINDERS 4 Sheets-Sheet 5 Filed Feb. 13, 1961 v u N w R PWW M RM D E m J TRIPPING DEVICE FOR PRINTING MACHINE CYLINDERS Filed Feb. 13, 1961 4 Sheets-Sheet 4 5/? M5,? A o H Fe/eamur PREUSJ Patented Sept. 18, 1962 3,054,346 TRIPPING DEVICE FOR PRINTING MACHINE CYLINDERS Werner Koch and Friedrich Preuss, Offenbach am Main, Germany, assignors to Roland Offsetmaschinenfabrik Faber & Schleicher AG., Offenbach am Main, Germany, a German body corporate Filed Feb. 13, 1961, Ser. No. 88,818 Claims priority, application Germany Apr. 9, 1960 3 Claims. (Cl. 101-218) This invention relates to a tripping device for use in connection with printing machine cylinders such as are positioned, for example, in the sidewalls of a printing machine for cooperation with one or more similarly positioned cylinders arranged parallel thereto and in relation to which the printing cylinder is movable toward and away in a direction at right angles to its axis.

The invention, more particularly, refers to the controls which, in some types of printing machines, are employed to adjust the distance between two cylinders when materials of varying thicknesses are to be printed, usually paper or cardboard, by the same means by which the printing cylinder is tripped on and off.

In connection with machines of this kind it is known to perform the tripping on and off movements by means of cams or other eccentric members. However, since in the working position of the cylinders the distance between their axes is determined by the thickest material between them, to which must be added the length of the trippingofi stroke, considerable increases in their axial distances are encountered, which result in the engagement of the gear wheels on the tripped cylinders getting out of their pitch circles.

In most printing machines the cylinder which has to be tripped operates in conjunction with a third cylinder whose distance from the tripped cylinder also changes during the tripping operation so that the engagement also of these respective gear wheels is no longer adequate.

It is, therefore, the main object of the invention is to provide a printing machine of the said kind in which the aforesaid disadvantages are avoided. This object is achieved, in accordance with the invention, by an arrangement of the tripping device in which, when the distance between the cylinders in their tripped-on or working position increases, the length of the stroke of the tripping device will decrease by approximately the same amount. In this way the axial distance between the two cylinders in their tripped-off position will always be approximately the same, independently of the thickness of the printing material between them. But in no case will it be larger than would be required for the correct function of the machine.

As a further object the invention provides that in a machine in which the cylinder to be tripped is journaled at each of its ends in an eccentric bushing which can be turned, for instance by means of a connecting rod, from a pivoted lever of which the effective leverage is adjustable from zero, or some other minimum, to a maximum amount preferably in a manner in which at the largest leverage the axial distance between the two cylinders in their tripped-on position will correspond to the smallest distance between them. This minimum is preferably chosen so that it will be obtained when the peripheries of the cylinders just touch each other.

The aforedescribed bearing arrangement of the printing cylinder in eccentric bushings and its tripping by means of a pivoted lever is safe and simple and is particularly suited for use in combination with the tripping means in accordance with the invention.

The accompanying drawings diagrammatically illustrate the invention by way of example. In these drawings:

FIG. 1 shows a printing machine cylinder set for thin paper in its tripped-on position,

FIG. 2 shows the same parts in their tripped-01f position,

FIG. 3 is a view corresponding to FIG. 1 for thick cardboard with the parts in their tripped-on position,

FIG. 4 is a view similar to FIG. 3 with the parts trippedoif,

FIG. 5 illustrates a printing machine in side elevation,

FIG. 6 is a front view partly in section of FIG. 5,

FIG. 7 shows a modified form of the trip lever in side elevation,

FIG. 8 is a front view thereof,

FIG. 9 is an end view of FIG. 7, and

FIG. 10 a front view of the trip lever shown in FIGS. 1-4.

The printing machine which is shown in FIGS. 5 and 6 is of a conventional type which consists of a base 101 to which the side walls of the machine are bolted or otherwise secured. Arranged between these side walls is the plate cylinder 1 with its inking device 104, the blanket cylinder 3 and the impression cylinder 2 although of course any other cylinders may be positioned in the machine in the same or other arrangement. The sheets to be printed are fed from a table 105 and are carried to the stacking device (not shown) by means of a conveyor 106.

At each side of the machine frame the blanket cylinder 3 is journaled with its trunnion 4 in an eccentric bushing 5 which is adapted to be turned about its axis 6 (FIGS. 1-4). This is accomplished at either side of the machine by means of a connecting rod 7 which, with one of its ends is pivoted to an arm 9' of the bushing 5 as by means of a pin 8, while with its other end it is pivoted by a pin 14 to a trip lever 10-7 (FIGS. 5 and 6) which is fixed to the end of the trip shaft 10 outside the

walls

102, 103. A hand lever 108 is provided on each end of the shaft 10 by means of which the said shaft may be rocked through a certain angle in order to trip the cylinder 3 on and off in relation to the cylinders 1 and 2 (FIGS. 1 to 4).

The trip levers 107 are shown in FIGS. 5 and 6 only diagrammatically. The distance of the pivot 14 from the axis of shaft 10 cannot be changed in the conventional printing machines. However, the invention provides that it can be changed in accordance with the thickness of the material which is to be printed. For that purpose, as shown in FIGS. 1 to 4 and 10, a trip linkage 30 is provided which consists of two

individual levers

11 and 13 which are pivotally joined to one another by means of a pin 12, and of which lever 11 is rigidly mounted on shaft 10. J l f,

Lever 13, as aforesaid, is pivoted to one end of the connecting rod 7 which is thus able to move the lever 13 by means of the arm 9 of the bushing 5, while a screw bolt 16 which is fitted to a turnable lug 15 on lever 11, passes through a tapped hole in a lug 17 adapted to swivel on lever 13 about an axis which is vertical to the plane of the lever.

By turning the screw bolt 16 the lever 13 can be swung in relation to lever 11 thereby causing the connecting rod 7 to move lever 9 for instance into the position III in FIG. 3. When the limit of the swinging movement is reached, the axis of pin 14 will coincide with the axis of shaft 10. If through tripping off the cylinder 3 the shaft 10 and, therewith, the lever 11 is turned into the position of FIG. 2, then the bushing 5 as well as the blanket cylinder 3 will take the position II which is shown in broken lines in FIG. 1 and in full lines in FIG. 2, whereby the axis of the cylinder assumes the position 19 causing a gap 20 to be formed between the

cylinders

2 and 3.

In FIG. 3 the

cylinders

2 and 3 are shown to be set for printing on cardboard as by turning lever 13 by means of the screws 16 in relation to lever 11 so that the distance between the axes of pin 14 and shaft 10 becomes shorter than in FIGS. 1 and 2. This causes the bushing to be turned in clockwise direction from the position I in FIG. 1 to the position III in FIGS. 3 and 4. The axis of cylinder 3 moves from the point 18 in FIG. 1 to point 21 in FIG. 3, so that a gap 22 is formed which conforms to the thickness of the cardboard to be printed. When during the tripping-off of cylinder 3 shaft is turned by means of lever 11 into the position of FIG. 4, the gap 22 will be enlarged by only a small amount, since the axis of cylinder 3 is merely shifted from point 21 to point 23 close by, whereby arm 9 of the bushing 5 takes the position IV shown in broken lines in FIG. 4 so as to produce the gap 24 which is of practically the same width as gap in FIG. 2. A graduated scale (not shown) is preferably provided on lever 11 on which the required turning movements for the various thicknesses of printing material are indicated.

FIGS. 7 to 9 illustrate a modified form of variable tripping lever. Rigidly connected to the shaft 10 is a cradle 109 in which a block 111 is displaceable as by means of a screw 110. Provided in said block is a pivot 112 to which the right end of the connecting rod 7 is attached.

What I claim is:

1. In a printing machine having vertical side walls, a

printing cylinder journaled between said side walls, a second cylinder also journaled between said side walls parallel to said printing cylinder, and shifting means for varying the mutual axial distance between said two cylinders and for tripping said printing cylinder on and off, the provision of means in connection with said tripping device by which with an enlargement of the axial distance in the working position of the cylinders the magnitude of the tripping-01f movement becomes reduced by substantially the same amount.

2. In a printing machine having vertical side walls, a printing cylinder and at least one other cylinder journaled between said side walls of the machine, an eccentrically mounted rotatable bushing, an arm extending from said bushing for rotation in unison therewith, a tripping device comprising a pivotal lever, a connecting rod connecting the arm extending from said bushing and said lever, and means for moving said pivotal lever by said connecting rod so that the effective length of said arm is adjustable from Zero to a maximum.

3. In a printing machine a tripping device as claimed in claim 2, in which at the greatest effective length of the arm the axial distance between the two cylinders in their tripped-on position assumes its minimum value, and its maximum value when the etfective length of said arm is zero.

References Cited in the file of this patent UNITED STATES PATENTS 1,816,796 Rossger July 28, 1931