DE2921842A1 - Printing press pull guide - has lever mechanism determining roller and side stop movements against spring action - Google Patents

Abstract

The printing press pull guide head slides along a cross-member for the entire width of the sheet, and is moved periodically by the member towards the sheet for the alignment operation. A spring-loaded roller in the head periodically presses the sheet against a pull rail underneath, while on either side of this roller there are spring-loaded side stops sliding in the head. Depending on the sheet edge to be aligned, one or the other of these slides forward into the working position, in which it acts against a fixed stop on the press. To give multiple sheet monitoring, a lever mechanism (40,42) determines the difference between the periodic movements against spring action of the roller (4) and the active side stop (11 or 12). When this difference exceeds a predetermined value a switch is thrown.

Description

Pull lay head for printing machines with integrated multiple

Shelf Control The present invention relates to a pull tab head for printing machines according to the preamble of claim 1.

Find in offset printing or other paper processing machines use for lateral alignment of sheet drag or slide marks like this z. B. in CH-PS 300 970 is shown of which prior art the present Invention runs out. A pull lay head sits periodically with one or more rollers on the sheet to be aligned, the one below, a pulling motion executing rail is pressed. The bow is thereby sometimes against in the Machine permanently installed stops, but more often against attached to the pulling head Side stops moved, with the pulling head working periodically on a solid surface resiliently touches down, whereby the bow is aligned.

Find on offset printing or other paper processing machines Use of a wide variety of devices for the detection of multiple sheets. So there are, for example, systems that work with transmitted light; such systems fail but with highly reflective or non-translucent sheets. on the other hand there are periodically working buttons that sense the arc thickness. These buttons However, they need a backlash-free and stable suspension in order to avoid the influence of vibration phenomena to be suppressed as far as possible and to avoid false reports. It also affects the additional touch point on the sheet often the reliable function of the pull lays or requires additional downtime of the sheets for the multiple sheet inspection. Mechanical translation mechanisms mostly generate from the different Signals one or more arcs (for example each having a strength of o, o2 mm) an enlarged signal that can be further processed, which if necessary serves to stop the printing press.

The task on which the present invention is based is now with an offset printing or other paper processing machine the advantages a rail or pull lay and the existing devices anyway to use at the same time to check the muufach sheet and the disadvantages to avoid previous multiple sheet control devices. This includes, in particular, the influence of vibration phenomena occurring on the machine on the scanning process to be excluded as far as possible, since relatively small values are measured.

According to the invention, this object is achieved by the characterizing part of claim 1 solved. The components that are already present on the pull lay head like the pressure roller for the pull bar and the side stop for the pulling process are used for the scanning process for multiple sheet control, with over a lever mechanism is only the difference in the inward displacement of the components mentioned is detected. As long as this difference corresponds to the thickness of a printed sheet, no signal is triggered via the assigned switch. If the difference becomes larger, because two or more sheets have been fed in, the switch is switched. There only a difference is measured and not an absolute value, any Vibration processes on the machine do not affect the measurement result.

According to a preferred embodiment, the role can be fixed with be connected to a switch housing in which the one provided with a switch plunger Switch is arranged, the active side stop via one or more Lever engages the switch tappet. Of course, these ratios can also be the other way around, namely that the active side stop with the switch housing is connected, while the role is directly or indirectly connected to the switch plunger attacks.

In the switch housing, which is formed from two parts, which are through Connection with the roller are movable in height, the two housing parts are mutually adjustable and the switch is connected to one part of the housing is, the switching time can be mechanical or preferably electronic Switches can be set to suit the system to the different paper thicknesses set accordingly.

In this context it should be mentioned that there are electronic switching elements with a switching repeatability of + 0.03 mm.

The active side stop when the Pull mark head on the fixed stop of the printing machine resulting inward movement against the spring pressure, a lever mechanism can be used to act on the switch tappet. For this purpose, a pivot lever can be provided in a part of the switch housing by which the inward movement of the active side stop on the switch plunger is passed on.

Around the pull mark head both to the right as well as to the left to use, i.e. to each of the two side stops use to be able to do without a separate transmission mechanism for the inward movement for each case the respective side stop, the switch housing is in the middle arranged between the side stops, with a lever the two side stops rocker-like connects, so that the inward movement of the active side stop with a fixed inactive side stop (rest position) in the middle of this lever This can be done, for example, by means of the pivot lever mentioned, which rests in the middle of the aforementioned lever. The device is like this designed that when switching from the left to the right stop or vice versa, depending on whether the sheet has to be aligned on the left or on the right, the relationship between the stops and the rollers of the pull lay head the rocker is retained.

The pull lay head with the integrated multiple sheet button can open be arranged displaceably on a rod with a fine and coarse adjustment.

An embodiment of the present invention is referred to on the accompanying drawings.

Fig. 1 shows a pull lay head according to the prior art, such as it is used on planographic printing machines.

2 to 5 show the pull lay head according to the invention in different ways Views or sections.

The well-known pull mark head has a roller that the sheet periodically presses on an underlying rail executing the pulling movement and thereby pulls the bow against a fixed, adjustable stop. The well-known pull tab head can optionally be used as a right or left pull tab because it has a right or has a left pull tab, one of which is used, each according to whether the pull lay head for a right-hand lay or a left-hand lay of the head bow is set.

With the pulling head 1 works a bar executing the pulling movement or rail 2 together, which is transverse to the direction of travel of the sheet of paper 3 in the vicinity the leading edge of the sheet is under the paper. A periodically moving up and down Roller 4 of the pulling head presses the sheet 3 to be aligned onto the bar or rail 2, so that the sheet through this roller 4 against the one side stop (pull lay) 12 is pulled. The periodic up and down movement of the pulling head 1 takes place through a cam disk, not shown, via an angle lever which is attached to a Traverse 8 attacks. The pulling movement of the bar 2 is carried out by a further cam disk 16 from, which by means of an inclined surface 17, the arm 18 of the bar 2 in the horizontal Direction shifts.

The housing 9 of the pulling head 1 is on the traverse 8 above the front lay 15 slidably mounted so that the housing moved over the entire width of the paper and can be clamped in any position by means of a clamping screw 1o can.

In a printing machine on which the pull-mark head described so far Can be used, as already mentioned, a multiple sheet control must also be performed take place so that two or more sheets are not accidentally the actual printing process are fed. This multiple sheet control can be done in different ways or be made by different devices, for example by separately buttons to be attached. In the subject matter of the present invention, as shown in the Fig. 2 to 5 is shown, this sensing device is now in the pull tag head integrates and uses already existing elements.

The pull tab head according to the invention is essentially the same Way arranged in a printing machine, as shown with reference to FIG of the prior art was explained in more detail. However, the pull lay head takes over As already indicated, the functions of the button of the multiple sheet control simultaneously and has a special structure for this purpose, as described in more detail below should be described.

The rollers 4 (one or more) are in the housing 9 via one perpendicular displaceable, spring-loaded slide 14 downwards against the pull bar 2 applied. The compression spring 16 is supported on the one hand on the slide 14, on the other hand on an angle lever 19 pivotably mounted on the housing 9, the angular position of which and thus the spring pressure on the slide 14 can be adjusted by means of an adjusting screw 20 is, which in turn can be fixed by a lock nut 22. The slide 14 can can only be adjusted by a certain amount in its axial direction, as indicated by the in a longitudinal slot engaging stud screw 24 is determined.

The spring 16 is at its upper end via a pin 26 with the Angle lever 19 connected. The switch housing consists of a lower part 28 and an upper part 30 is connected to the slide 14. Part 30 of the switch housing 32 can be pivoted about the pivot point 34, both parts being supported by a spring 36 be pressed against an adjusting screw 38.

The distance between the two housing parts 28 and 30 is determined by this adjusting screw 38 determined, the rotational position of which is determined by a locking plate 41 which is attached to the Attacks circumferential knurling of the adjusting screw.

From Fig. 2 a position of the pull lay head can be seen, in which the right side stop 12 is in the working position, while the left side stop 11 is in the rest position. The two side stops are via a rod 40 mounted on a ball 48 in the manner of a rocker connected, wherein the center of the rod 40 engages a pivot lever 42, which is mounted on the housing 9 and at the opposite from the pivot point The end of the switch tappet of an electrical switch 44 engages, which at the top Part 30 is attached. The active side stop is activated by a compression spring 54 pressed into the lowest position, while the other side stop one exactly assumes a defined rest position in which it is firmly locked.

The rocker-like connection of the two side stops 11 or 12 the pull lay head can work either as a right stop or left stop, whereby only the unneeded side stop in the raised one for conversion Rest position and the active side stop in the lowered working position must be moved. Since the rocker formed from the rod (lever) 40 in both positions works in the same way, the same arrangement can be used in each case.

The device described so far operates in the following way: First, by turning the adjusting screw 38, depending on the strength of the to The correct switching time of the switch 44 is set for the printing paper. Here it should be noted that the switch 44 has a very high switching repeatability what about using electronic components instead of mechanical components is possible.

It is assumed that the pull lay head serves as a right stop, this operating state is shown in FIG.

When the printing sheet to be aligned comes under the rollers 4 to to be pressed on the pull bar 2, which the sheet against the right side stop 12 pulls, there is a difference in height between the lowest foot point of the side stop 12 and that of the rollers 4. This is the case because the side stop 12 rests on a solid component of the printing machine, while the rollers 4 to a Amount to be raised from the position initially assumed when the print sheet is inserted between the rollers 4 and the pull bar 2. By lifting the Rollers 4, the slide 14 is moved upwards, what the entire switch housing 32 in Fig. 4 lifts slightly. At the same time, the inward movement of the side fence 12 of the lever 40 tightened somewhat. As a result, the pivot lever 42, which is on the housing 9 is articulated, raised because it rests on the lever 40, which the rocker between the two side stops 11 and 12, respectively. Depending on the setting of the device the difference between the two shifts of the Roll 4 resp.

of the side stop 12 and depending on the setting on the adjusting screw 32 there is a switching signal at switch 44 or not. For the Operation, the adjustment screw 38 must be adjusted so that the switch 44 then does not switch when the rollers 4 are raised by an amount that is one sheet thickness is equivalent to. However, if the double or greater sheet thickness between the Rolls 4 and the abutment is scanned, of course, the switch 44 generate a switching signal that leads to stopping the printing press.

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Claims (5)

I patent claims 1. Pull lay head for a printing machine, the longitudinal a traverse is displaceable over the entire width of the printed sheet and through the Traverse periodically movable towards the arch for the alignment process is, with a roller mounted in the pull sash head and displaceable against spring pressure, which periodically presses the sheet against a colored pulling rail provided on the sheet, and with two side stops, which are mounted in the pull lay head and can be moved against spring pressure, which are arranged in the pulling direction on both sides of the roll and depending on which to be aligned sheet edge one or the other from a retracted rest position in an advanced working position can be advanced by this side stop periodically comes to rest against a fixed stop on the printing machine, thereby characterized in that for multiple sheet control via a lever mechanism (40, 42; 32, 34) the difference between the shifts that occur periodically against the spring pressure the roller (4) and the active side stop (12 or 11) can be determined and that when a predetermined difference is exceeded, a switch (44) can be triggered. 2. pull mark head according to claim 1, characterized in that the Roller (4) is firmly connected to a switch housing (32) in which the with a Switch plunger (50) provided switch (44) is arranged, and that the active side stop (11 or 12) engages the switch plunger (50) via one (40) or more levers (40, 42). 3. pull mark head according to claim 1 or 2, characterized in that that the switch housing (32) consists of two parts (28, 30) around the pivot point (34) are pivotable, the relative position of the two housing parts to one another is adjustable (adjusting screw 38, spring 36), the switch (44) with the one part (30) and the roller (4) is connected to the other part (28). 4. pull mark head according to claim 3, characterized in that on the housing (9) a pivot lever (42) is mounted, the opposite of which is free The end of the switch plunger (50) of the switch (44) engages, the lever (40) between the pivot point (25) and the switch plunger (50) rests. 5. pull mark head according to one of the preceding claims, characterized characterized in that the switch housing (32) is centered between the side stop (11, 12) is arranged, wherein the lever (40) the two side stops (11, 12) connects rocker-like and the pivot lever (42) in the middle of the lever (40) this attacks.