GB2156786A - A sheet delivery control and regulating apparatus - Google Patents

Abstract

In a sheet feeder where sheets are being delivered by a chain conveyor from a processing machine, e.g. a printing machine to a stack with the aid of suction rollers to slow the progress of a sheet and possibly air blowers to assist the deposition on the stack, various elements of the feeder are computer-controlled. Inputs for paper weight (45), sheet length and width (47, 47a) and speed of rotation (49) of the processing machine are fed to a reference value sorting device (42) which includes memory and computing facilities. Suitable values are transmitted over output lines (43) to servo motors or electromagnetic valves controlling position and speed of suction rollers, adjustment of gripper opening cams for the conveyor, and, the vacuum or air pressure sortings. <IMAGE>

Description

SPECIFICATION A sheet feeder control and regulating apparatus This invention relates to a control and regulating apparatus of a sheet feeder, in particular for sheet-processing machines, that is to say for example sheet4ed printing machines.

With sheet feeders of that kind, the individual sheets which have been processed by the machine in some manner, that is to say for example printed, coated or processed in some other way, are removed from the sheet-processing machine by means of gripper arrays which are mounted on two circulating, mutually parallel chains; then, by way of a row, which extends transversely with respect to the direction of movement of the sheets, of suction wheels which apply a braking or a lift-off action to each sheet, or a corresponding continuous suction roller, or another means for applying a braking action, the sheets which have been removed from the machine are braked before they are deposited above a receiving stack, and then deposited on the top of the stack.That operation is effected by the grippers which guide the individual sheets being opened by means of a gripper opening cam, more specifically, the time at which the grippers are opened is adjustable in accordance with certain features and details of the sheets, as set out in detail hereinafter, and also of the machine. For reasons which also depend on the properties of the material being printed and the printing machine, both the peripheral speed of the suction wheels (or suction roller) and the increased or reduced pressure applied at the suction wheels or the suction roller are also adjustable.

If, hereinafter in this specification, reference is only made to sheet feeders for sheet-fed printing machines, that is intended only to be by way of example in regard to the sheet feeders of other machines for processing sheets or reels (in the case of reel-processing machines, the web of material, after being printed or the like, can be cut into sheets and also deposited in sheet feeders). That mode of expression was used only in order for the description to be drafted in shorter and clearer form. However, that is not intended to restrict the scope of protection claimed to sheet feeders for sheet-fed printing machines, but on the contrary, the scope of protection claimed is intended to extend to the feeders and distributor or depositing devices of all machines in which sheets are subject to processing in some manner and then fed out of the machine and deposited or distributed.

In sheet-processing machines, for example sheet-fed printing machines, precautions in respect of safety and programming are taken for almost all parts or elements of the machine. There are defective sheet controls, double sheet controls, sheet checking operations at the individual printing rolls, there is also programming in respect of printing programs which have already been carried out at the inking mechanisms and at the damping mechanisms, there are controls in respect of premature sheets, retarded sheets and defective sheets, side mark controls, there is the control in respect of sheet transfer from roll to roll and from printing mechanism to printing mechanism, crumple or crease sheet safeguards and many more.

Hitherto, there was nothing of that kind for sheet feeders. The correct setting of the various adjustable elements of a sheet feeder involves a whole series of factors, including the quality of the paper (weight of the paper per unit of area), operating speed (rotary speed) of the machine, more specifically during the running-up and running-down phases, compared with the continuous or steady-state printing operation (for example a larger number of sheets are printed until the desired operating printing speed is reached); in addition, a part is also played by the format and also the printed image, that is to say therefore the amount and thus the weight and distribution of the ink on each individual sheet.

Correct presetting and continuous resetting of the feeder, for example when there are changes in the speed of rotation or after any intentional or unintentional stoppage of the machine, which has a whole series of different forms of adjustability, has hitherto been left to the attentiveness, the capability and the skill of the printer. Until the printer has found the optimum setting for all elements of the sheet feeder, more particularly having regard to the large number of possible adjustments and settings available, there may be a considerable amount of wastage, a corresponding loss of material and a drop in the overall productivity of the printing machine.

Hitherto, a single and only very partial form of automation of the mode of operation of sheet feeders has been known, more specifically, German patent specification No 818365 disclosing that the adjustable cam onto which the gripper arrays holding the sheet pass and are thereby opened, and therewith also the time of opening of the grippers, may be automatically adjusted by means of a control device, for example by means of a fluid drive means, in dependence on the speed of rotation of the machine. However, the time of opening of the grippers is only one of the many adjustment features of a sheet feeder and, as already indicated, the correct time of opening also depends not just on the speed of rotation of the machine but also on many other influences.

The problem of the present invention is to avoid the above-indicated disadvantages by providing a novel control and regulating apparatus for a sheet feeder, which makes it pos sible for all settings required in respect of the adjustable elements of a sheet feeder to be set in the optimum fashion from a single location, and to be automatically re-adjuted to meet fluctuating conditions in accordance with a predetermined program, and thereby to achieve a very considerable saving in time, avoid wastage of material and at least substantially to eliminate dependency on the skill, capabilityand knowledge of the printer According to the present invention there is provided a sheet feeder control and regulating apparatus, with which feeder individual sheets are removed therefrom by means of gripper arrays mounted on two circulating, mutually parallel chains, and guided above a receiving stack by way of a transversely extending row of suction wheels which apply a braking or a lift-off action to each sheet, or a corresponding continuous suction roller, over which stack the grippers are opened by means of a gripper opening cam which is adjustable to provide for an earlier or later gripper opening action, and with which the peripheral speed of the suction wheels or suction roller and the reduced or increased pressure applied thereat, and the longitudinal setting of the suction wheels or suction roller, are adjustable in the direction of the sheet movement for the purposes of adaptation to different sheet format lengths, wherein, for altering a plurality of the following values (1) to (7):: 1) the speed of rotation of the suction wheels or suction roller; 2) the longitudinal setting of the suction wheels or suction roller; 3) the reduced or increased pressure at the suction wheels or the suction roller and switching roller and switching same on and off and switching over from suction air to blowing air; 4) adjustment of a gripper opening cam for varying the time of opening of the sheet grippers; 5) the speed of rotation and switching on and off of fans which blow downwardly onto the sheet to facilitate the stacking action, or the pressure of another kind of regulatable blowing sources which have the same action and act at a point;; 6) the pressure at pressure blast nozzles (rake-like blowing unit) which are optionally provided, for fixing and thrusting the sheet downwardly upon deposit thereof, and 7) other adjustable elements of the feeder, such as a stack level regulating means, or switching over of the straight thruster motion of an individual stroke movement per sheet, to a shaker motion, there are provided respective separate control motors with feedback of the setting reached to a reference value setting means or electromagnetic valves, and wherein the reference value setting means is provided with a respective input means for the paper weight, for the sheet format and for the speed of rotation of the machine and is connected to or integrated with a computer which computes the reference values for all settings of the feeder, such reference values being determined empirically for each operating condition and being stored in the form of a family of characteristics, said computer outputting said reference values to the reference value setting means which transmits same to control motors or electromagnetic valves.

It should be clearly emphasised that the servo adjustment and automatic control or regulation does not have to be provided for all points or values 1 to 7 set forth in claim 1, but that one setting or the other may also be adjusted in conventional manner, while perhaps three or four others of the points specified are automatically controlled or regulated in the manner characterised in the claim.

The memory and the reference value setting means or generator may be a separate element of the machine, which is only associated with the sheet feeder; however, they may also be combined with or partially or fully integrated into the computer which is provided in the machine in any case for example for inking mechanism or damping mechanism programming and control or with some other computer that is already provided in the machine.

With the reference value setting means and/or the computer, there may be provided a memory having interchangeable memory elements, to which there are connected a switch which can be switched over from manual setting to automatic setting in respect of the adjustable elements of the apparatus, and a second switch for putting into store in the memory element the optimum values which are empirically determined by many setting.

Therefore, in this case also the correct values for the various possible settings of a sheet feeder are determined empirically, but the values are then stored and subsequently, when the same printing operation is carried out again, or when a printing operation which is at least fairly similar is performed, those values can be set again by using the memory element which was previously already prepared for that purpose, without the-printer being required to be particularly attentive in that respect. In fact the operation of changing a memory element into a reference value setting means requires only a very small amount of time.

The invention will be described and explained in greater detail hereinafter with reference to the drawings in which: Figures 1 to 4 are in the form of diagrammatic side views of a sheet feeder showing the influences of the time of opening of the grippers and the speed of the suction wheels, Figures 5 and 6 are views corresponding to Figs. 1 to 4, showing the influence of the blowing air fans, the so-called top air, which are not shown in Figs. 1 to 4, Figure 7 shows the influence of the air blast nozzles which are used in many cases, also being referred to as rake-like blast units.

Figure 8 is a perspective view of a sheet feeder in the region in which the sheets are deposited upon the stack, with the various adjusting means, Figure 9 is a perspective view on an enlarged scale of a means for transverse adjustment in respect of a suction wheel, which may additionally be provided and which can also be remote-controlled, and Figure 10 is a highly simplified view of an electrical circuit diagram for the apparatus according to the invention.

In Fig. 1, the machine is slowly starting up so that the grippers which are carried by the feeder chains 1 and the gripper bars 2 may only open when the leading edge of the sheet has reached a position shortly in front of the paper stop 30. The peripheral speed of the suction wheels 14 approximately corresponds to the speed of the chains 1. The falling sheet indicated by reference numeral 41 then falls without any problems onto the stack of sheets 39 and, as the next gripper array slowly moves towards the stack 39, there is also no collision with the preceding sheet which has already dropped down to a sufficiently low level. The fans (not shown here) which produce the top air may run slowly as only a small amount of top air flow is required. With many kinds of paper, there is no need for a blast of air out of the nozzles of a rake-type blowing unit.

Figs. 2 to 6 do not show the reference numerals set out in Fig. 1 as the same components are involved in all those drawings. In the view shown in Fig. 2, the machine is running quickly. The grippers must already be open when the leading edge of the sheet is still really far from the paper stop 30.

The peripheral speed of the suction wheels 1 5 must be relatively low, compared to the speed of the chains 1, so that the suction wheels produce a greater braking action. By virtue of its own kinetic energy, the sheet gently reaches the paper stop 30 promtly and without suffering damage at its leading edge. It then passes in an orderly fashion and sufficiently quickly downwardly onto the stack 39, more specifically by virtue of the use of a stronger top air flow which causes it to be thrust downwardly and stabilised with a strong blast of air out of the nozzles of a rakelike blowing unit.That ensures that the subsequent gripper system does not catch the sheet still in its path of movement and push it together to form a crease or crumple, which immediately results in the machine being switched off, by virtue of triggering off the means for sufeguarding against crumpled or creased sheets, which is installed in the usual manner.

It will be appreciated that there is an infinite range of variations between the modes of operation shown in Figs. 1 and 2, being primarily dependent on the machine speed, the sheet format size, the sheet weight (we only have to consider the difference between bible paper and heavy cardboard or other materials), the height of drop, the strength of the suction effect at the suction wheels 14, the peripheral speed of the suction wheels 14 in relation to the speed of the chains 1, and thus of the individual sheets, the strength of the action of the fans 38 producing the top air flow (that will be described in greater detail hereinafter with reference to Figs. 5 and 6), the blast jets of greater or lesser strength from the blast pipes 37 of the blowing unit, and also the setting of the blowing air devices, which is a crucial factor.If the blowing or sucking air feed devices are not set in the optimum fashion, that results in stray turbulence phenomena and thus also in undesired stoppages.

In the view shown in Fig. 3, the machine is also running slowly. However, the grippers are opening much too early and the braking action of the suction wheels 14 is too great, because they are rotating at an excessively slow peripheral speed, The result of that is that the sheet comes into contact with the top of the stack 31 a long way in front of the paper stop 30, and thus rolls up, as illustrated. After just one or only a few sheets, that again also results in stoppages, because the sheets then move into the path of the gripper devices. The latter effect may also be caused by virtue of the trailing edges of individual sheets which are to be deposited projecting up in front of the suction roller 1 4.

In the view shown in Fig. 4, the machine is again operating at speed. In this case however the grippers are opening much too late so that the leading edge of the sheets strikes hard against the sheet stop 30, and suffers damage, and the entire sheet, depending on its structure, is concertina-ed together to a greater or lesser degree. That then also immediately results in stoppages. However, the even much worse case may occur, more particularly when the sheets are nonetheless properly aligned above the stack, but the leading edge, as already mentioned, retains deformation of greater or lesser magnitude. In that case, more particularly, in a possible second installation, the sheets can no longer be properly aligned in register, with the result that the entire print or substantial parts of a print are finally and completely wastepaper.

Little can be done to change any of that, even by altering the peripheral speed of the suction wheels, quite apart from the fact that, if the paper has a sensitive surface, it will be damaged due to an excessively severe braking action at a low peripheral speed and high vacuum in respect of the suction wheels 14, due to the rubbing or scouring effect at that point. It will be appreciated that that can also occur under all other conditions if the suction wheels are not at their optimum setting in regard to their peripheral speed.

With the setting of the fans 38 shown in Fig. 5, namely, with the fans producing flows of air directed against the sheet chiefly in the leading and trailing regions of the sheet in question, an air cushion of a bell-like configuration is very quickly formed under the sheets as they drop down onto the stack, and cannot escape sufficiently quickly. As soon as the cushion of air begins to project into the region of the path of the grippers, the machine once again comes to a stop, especially as the capacitive stack level regulating means 40 which is arranged between the paper stops can only produce any control action at the edge of the stack 39 and not at the centre where the highest point of the bell-shaped air cushion is to be found.

The setting in respect of the top air as shown in Fig. 6 is correct in principle. The air between the downwardly moving sheets can escape in an outward direction, and no bellshaped air cushion is formed under the sheets as they drop down onto the stack. However, the necessary condition here is also that the strength of the blowing action is not excessive at the centre as otherwise the sheets may possibly not be straightened out on the top of the stack if they are premature in coming into excessive contact with the sheet which is disposed therebelow. That is then a consequence of friction and adhesion of the printing ink which is still not entirely dry and/or also an electrostatic charge.

At the leading and trailing ends of the sheets, the air flow directed thereonto should as far as possible only be of such a strength that the sheets are also held out of the path of movement of the grippers, but nonetheless still tend towards the position shown in Fig.

6.

It should be noted at this point that, in place of the fans 38, it is also possible to provide other kinds of blowing air sources which have the same action and which are regulatable and which act at a point.

Fig. 7 shows the arrangement of the blowing pipes 37 of the rake-like blowing unit, more specifically, in contrast to Figs. 1 to 6, viewing in the direction of movement of the sheets. This arrangement can also be seen in Fig. 8 which will be described hereinafter.

The blowing pipes 37 of the blowing unit, which each have air nozzles that are arranged close together over the entire length thereof and which are directed downwardly are to perform the function of stabilising and in addition urging downwardly particularly unstable or unsteady sheets when they have reached the stack chamber, by means of a suitably strong blast of air. The stabilisation effect is produced by a wavy or corrugated configuration, as shown, being temporarily imparted to the sheet. In that respect, all possible variations can be used; more particularly, such are also dependent on the sheet format. When the present invention is used, the blowing pipes can be individually cut in or cut out by means of electromagnetic valves.

The foregoing examples, which are only a few, showing the individually required settings on the feeder in the correct combination in relation to the respective print carrier in accordance with its format, its weight per unit of area, its structure, its speed, its tendency to roll, its speed of drop, its height of drop, etc, clearly show how much the printer on the machine is required to preset the sheet feeder and also always to keep it in optimum adjustment while the machine is running.

A problem also occurs whenever the machine is in the start-up or run-down phase (rising or falling speed). In such phases, the overall adjustment which has once been set for steady-state or continuous printing speed may not be the proper adjustment and may therefore also not function properly, so that the start-up and run down phase very often involves a whole pack of waste sheets, which must be removed, and to be accurate that may occur during each of those periods of time during which the printer should actually be devoting himself to the quality of printing of the printed product. In that connection, the start-up and run-down phases are also repeated in the event of any stoppage which in turn is generally caused by the individual adjustable elements of the feeder not being at the optimum settings.

Fig. 8 shows a feeder according to the invention with various centrally controlled servo or control motors and electromagnetic valves. The individual, centrally-controlled remote adjustments with feedback to the reference value generator or setting means (generally by way of potentiometers) are carried out, in detail, as follows: Format setting: That is effected by means of a drive motor 20 by way of a connecting shaft 21, a pair of bevel gears 23 and two screwthreaded spindles 22 which are respectively mounted at both ends in supports on the side walls. The screwthreaded spindles 22 carry the complete suction wheel slider or carriage 1 3a which, withcorresponding screwthreaded nuts, moves the suction wheel shaft 1 3 or the suction roller forwards or backwards in the direction of movement of the paper, thereby setting the arangement to the format size. The rear sheet stops for precise paper stacking are also disposed on the complete suction wheel carriage 1 3a. Format width can be set in the same manner, by way of the lateral straight thrusters or push members.

Hitherto, that adjustment had to be effected by means of a hand wheel and a detecting device, both operating by way of the connecting shaft 21, and individual adjustment of the lateral sheet pusher members on both sides of the sheet feeder.

Speed of rotation of the suction wheels (peripheral speed in relation to the speed of the feed chains): A drive motor 27, by way of a drive stub portion 28 and a chain wheel 26, drives a roller chain 26a which also passes over a further chain wheel 25. A chain wheel 24 which is fixed on the suction wheel shaft 1 3 meshes in all format settings in the upper run of the roller chain 26a and entrains the suction wheels 14. The speed of the suction wheels can be regulated at the drive motor 27, more specifically, not only in proportion to the speed of rotation of the machine but also in accordance with any other procedures or interrelationships. It would also be possible for example to vary the speed of the suction wheels while each individual sheet is passing through.

Strength of the suction at the suction wheels: A control valve in the control housing 31 is rotated by way of a control or servo motor 32, whereby the suction or reduced pressure is altered in the delivery or output conduit 35.

The reduced pressure feed conduit 34 (of the two conduits 34, one is for reduced pressure and the other for increased pressure) and the reduced pressure region of the control housing 31 are always under maximum reduced pressure.

Hitherto, that adjustment had to be made by means of a separate hand valve with rotary wheel or knob and scale, and continuous readjustment was required.

Feed of compressed air to the suction wheels: In first form and perfecting printing, that is to say, when the sheets are freshly printed on both sides, it is not possible to use the suction wheels 1 4 as a braking means, without smearing the fesh ink on one side of the sheet. Without the braking action of the suction wheels however, the machine can only be operated relatively slowly, and it is therefore advantageous for the suction wheels to be displaceable laterally so that they can be positioned in print-free spaces of the overall print image. In situations in which individual suction wheels do not have such print-free spaces, then compressed air is blown out of the vacuum nozzles of the suction wheels and the sheet is locally held away from the suction wheel in order to prevent the above-mentioned smearing from occurring.In the case of a fully continuous print form which does not have any free space at all, it may be necessary for air to be blown out of all suction wheels. In that case, a reduced printing speed must be accepted.

Hitherto, this operation of individually converting from reduced pressure to compressed air, in regard to all or individual ones of the suction wheels, was effected manually and in a really uncomfortable position, with the machine stationary (because of the risk of accidents).

By virtue of using electromagnetic valves, in accordance with the invention, which are fited into the feed conduit to each of the suction wheels 14, that entire procedure can be caried out under remote control and can even be programmed for repeat orders.

The valves and some conduits are not shown in Fig. 8.

Adjustment of the gripper opening cam: A drive motor 11, by way of a worm 10 and a worm gear 9, rotates a control shaft 8 and thereby a flange 7 carrying an eccentrically positioned control pin 5 which is disposed in a slot 6 in the gripper opening cam 4 and which, when the control motor 11 is set in operation, causes adjustment of the cam 4.

Hitherto, instead of a remote-controllable transmission motor of that kind, the machine had a hand wheel for adjusting the gripper opening cam.

Speed of rotation of the fans (local variations in top air): The fans 38 are chiefly driven individually or in longitudinal or transverse series or in a diagonal row or in any mix, at a higher or lower speed, or however are also switched off entirely.

In that connection, the choice of the mode of operation depends on the properties of the respective print carrier (sheet or material).

It may be for example that the sheet is being printed over its full area on the righthand half or on the left-hand half, while the other half remains entirely or predominantly free. Due to the weight of the ink, the sheet falls more quickly on the side which has the more heavily printed area, so that it is necessary for the top air flow generated by the fans to be set at a higher value, over the half which is not printed or which is more slightly printed, or possibly the fans over the half which is more heavily printed must be entirely switched off. With the apparatus according to the invention, all that can be done centrally in accordance with the values stored for the respective application of printing.

If the printing machine has an automatic ink zone control means, including a computer, in accordance with individual zones, then those values can also be utilised for the adjustment of the fans referred to herein, because the crucial distribution of the ink is stored in the computer for the inking mechanism.

Another problem arises when very small formats are to be dealt with. Although the fans are displaceable in a lateral direction and also in the direction of movement of the sheets, some of them are however outside the format; that also applies moreover in regard to the blowing pipes 37 of the blowing unit.

However, blowing air flow outside the format results in interference in the movement of the paper and in the deposit thereof because such air flow gives rise to vagrant or stray air flows and turbulence, with its attendant problems.

Therefore, in accordance with the invention, switching on and switching off of the fans and the blowing pipes are coupled to automatic format adjustment.

Hitherto, the fans were regulated by means of their own, independent control transformers, in part also in series, by means of rotary knobs, which was a fairly time-consuming operation just by virtue of the relatively large number of fans involved.

Control of the pressure blast from the blowing pipes of the blowing unit: This adjustment is made by means of a control motor 33 and the transverse pipe 36 of the rake-like blowing unit, to which the blowing pipes 37 are connected. The term rake-like blowing unit means the complete array of individual blowing pipes 37 on the transverse pipe 36. Cyclic control of the respective short-term air blasts is effected in known manner by means of a control cam on a single-revolution shaft and an electomagnetic valve.

Hitherto, adjustment of the strength of compressed air blast was effected by a separate manual valve with a rotary knob and a scale.

Axial displacement of the individual suction wheels: It has already been briefly mentioned here it before that, if the freshly printed side of a sheet (more particularly, in perfecting printing) is drawn over the suction wheels 14, the suction wheels are displaced laterally in order to gear against the sheet as far as possible in regions which do not bear any printing. A further embodiment of the invention, which relates to that concept, substantially curtails the overall pre-setting of the feeder in that setting of the individual suction wheels in the axial direction thereof is also remote-controlled and the precisely correct positions of the suction wheels can be stored, for repeat orders The mechanism provided for that purpose is shown in Fig. 9.The suction wheel carriers 1 5 each carry a drive motor 19, the pinion of which is engaged with a transversely extending toothed rack 1 8 which is fixed to the suction wheel slide or carriage 13a.

In comparison, hitherto the suction wheels could only be displaced when the machine was stationary, because of the risk of an accident, and also in a really uncomfortable position. Re-setting is also frequently required because the space without any printing thereon is too small and does not pass through the machine entirely on the proper and correct line. For that purpose however, the machine must then be stopped again.

Fig. 10 shows the heart of the electricalelectronic control and regulating apparatus, namely the reference value storage means or memory with characteristic computing means and possibly memory and computer generally denoted by reference numeral 42. Therefrom respective lines 43 go to the individual control motors or electromagnetic valves, wherein associated with those feed lines 43 which go to control motors are respective lines 44 for the actual values in respect of the various settings, such actual values generally being produced by potentiometers.

Connected to the reference value memory, the characteristic computing means, the computer and the memory with interchangeable memory elements is an input means 45 for paper weight, with a corresponding scale, being connected thereto by way of a line 46, and also an input means 47 for the sheet format length, also with a scale, by way of line 48, an input means 47a for sheet format width, with scale, by way of line 48a, and also a tachogenerator 49 which supplies 42 with an analog signal corresponding to the speed of rotation of the machine, by way of a line 50. Alsoconnected to 42, if provided therein is a memory with interchangeable memory elements, is a switch 51 for switching over from manual to automatic mode, being connected by way of a line 52, and a switch 53 for putting data into storage, being connected thereto by way of line 54.When the arrangement is set with the switch 51 to the manual mode and with selection of the element to be adjusted in the feeder, at 42, the respective element is set to the optimum setting and that setting is then put into store into the respective storage element used, by actuation of the switch 53. In that way, all adjustable elements are first successively moved into the optimum position by hand, or valves are switched on or off, and the values relating thereto are then all put into store by actuation of the switch 53.

The input means in respect of paper weight, format length and format width, as well as in respect of the speed of rotation of the machine, may operate in analog fashion, for example using potentiometers, adjustable capacitors or adjustable throttle or choke means, or however they may operate digitally.

When dealing with many more or less normal print orders, there will be no need for storage of all possible settings. On the contrary, in that case, when altering the speed of rotation or the machine or adjusting the paper weight or the sheet format, the various adjustable elements of the feeder are set and regu lated in accordance with a family of characteristics, once it has been introduced.

In the case of repeat orders (reproductions), if the printer, in the case of the first order, put the optimum values into store in a storage element, the printer can use that storage element and call up the stored values, in which respect all functions are then automatically preset to their optimum values and however are still automatically re-adjusted, to correspond to the speed of rotation of the machine.

For longitudinal adjustment of the suction wheels 14, there is no need to go by way of the reference value setting means 42; on the contrary, that may be coupled directly to the format setting for the format length. In substance, the same considerations also apply in regard to transverse setting of the lateral pusher members, which may be directly coupled to the format width setting; it will be appreciated that a necessary condition for that purpose is the provision of control motors for transverse setting of the lateral pusher members.

Obviously, selector keys or buttons must be provided on the reference value setting means 42, for the individual settings that are provided. They are used both wnen the correct values which have been empirically determined are put into store in a memory, but also when, in the case where, although a stored program is being otherwise used in its entirety, there are some altered external factors that are to be taken into account, for example altered air temperature, air humidity, paper qualities or the like, and for that purpose, a particularly defined setting (or some settings) are to be modified in comparison with the values which were previously stored as a complete program for the same print operation.

The manual setting means for the individual adjustable elements of the arrangement should certainly not be omitted in any case, so that for example in the event of failure of a control motor, production can be continued by making the associated adjustment by hand, possibly by way of an interposed releasable coupling means, so that the manual adjustment can be separated from the control motor. The same could then obviously also be used to modify individual settings, deviating from the program which has just taken place, by hand instead of by way of the reference value setting means, in comparison with that program.

Claims (3)

1. A sheet feeder control and regulating apparatus, with which feeder individual sheets are removed therefrom by means of gripper arrays mounted on two circulating, mutually parallel chains, and guided above a receiving stack by way of a transversely extending row of suction wheels which apply a braking or a lift-off action to each sheet, or a corresponding continuous suction roller, over which stack the grippers are opened by means of a gripper opening cam which is adjustable to provide for an earlier or later gripper opening action, and with which the peripheral speed of the suction wheels or suction roller and the reduced or increased pressure applied thereat, and the longitudinal setting of the suction wheels or suction roller, are adjustable in the direction of the sheet movement for the purposes of adaptation to different sheet format lengths, wherein for altering a plurality of the following values (1) to (7): 1) the speed of rotation of the suction wheels or suction roller; 2) the longitudinal setting of the suction wheels or suction roller; 3) the reduced or increased pressure at the suction wheels or the suction roller and switching same on and off and switching over from suction air to blowing air; 4) adjustment of a gripper opening cam for varying the time of opening of the sheet grippers; 5) the speed of rotation and switching on and off of fans which blow downwardly onto the sheet to facilitate the stacking action, or the pressure of another kind of regulatable blowing sources which have the same action and act at a point;; 6) the pressure at pressure blast nozzle rake-like blowing unit) which are optionally provided, for fixing and thrusting the sheet downwardly upon deposit thereof, and 7) other adjustable elements of the feeder, such as a stack level regulating means, or switching over of the straight thruster motion of an individual stroke movement per sheet, to a shaker motion, there are provided respective separate control motors with feedback of the setting reached to a reference value setting means or electromagnetic valves, and wherein the reference value setting means is provided with a respective input means for the paper weight, for the sheet format and for the speed of rotation of the machine and is connected to or integrated with a computer which computes the reference values for all settings of the feeder, such reference values being determined empirically for each operating condition and being stored in the form of a family or characteristics, said computer outputting said reference values to the reference value setting means which transmits same to control motors or electromagnetic valves.

2. Apparatus according to claim 1, in which control motors with feedback to the reference value setting means are also provided for transverse adjustment of the suction wheels.

3. Apparatus according to claim 1 or claim 2, having a memory with interchangeable memory elements, which is connected to the reference value setting means and/or the computer, a switch which is connected to the memory and which can be switched over from manual setting to automatic setting of the adjustable elements of the delivery device, and a second switch which is also connected to the memory for putting into store in the memory element, as a family of characteristics, the optimum values which were empirically determined by hand setting.

3. Apparatus according to claim 1 or claim 2, having a memory with interchangeable memory elements, which is connected to the reference value setting means and/or the computer, a switch which is connected to the memory and which can be switched over from manual setting to automatic setting of the adjustable elements of the feeder, and a second switch which is also connected to the memory for putting into store in the memory element, as a family of characteristics, the optimum values which were empirically determined by hand setting.

4. Apparatus according to claim 3, in which the reference value setting means, the computer and optionally the memory is combined with or partially or entirely integrated into the computer which is provided for inking device programming and/or for damping device programming and control or another computer which is provided in the machine in any case.

5. Apparatus according to claim 3, in which the operations of cutting in and cutting out given longitudinal and transverse rows of the fans for generating the top air and longitudinal pipes of the rake-like blowing unit are coupled to the format adjustment.

6. Apparatus according to claim 1, in which the longitudinal setting of the suction wheels is coupled to the formal adjustment for the format length.

7. Apparatus according to claim 1, in which the transverse setting of the lateral straight-line thruster means is coupled to the format adjustment for format width.

8. A sheet feeder control and regulating apparatus, substantially as hereinbefore described with reference to the accompanying drawings.

CLAIMS Superseded claims 1, 3.

New or amended claims:

1. An apparatus for control and regulating a sheet delivery device, with which delivery device individual sheets are removed therefrom by means of gripper arrays mounted on two circulating, mutually parallel chains, and guided above a receiving stack by way of a transversely extending row of suction wheels which apply a braking or a lift-off action to each sheet, or a corresponding continuous suction roller, over which stack the grippers are opened by means of a gripper opening cam which is adjustable to provide for an earlier or later gripper opening action, and with which the peripheral speed of the suction wheels or suction roller and the reduced or increased pressure applied thereat, and the longitudinal setting of the suction wheels or suction roller, are adjustable in the direction of the sheet movement for the purposes of adaptation to different sheet format lengths, wherein for altering a plurality of the following values (1) to (7): 1) the speed of rotation of the suction wheels or suction roller; 2) the longitudinal setting of the suction wheels or suction roller; 3) the reduced or increased pressure at the suction wheels or the suction roller and switching same on and off and switching over from suction air to blowing air; 4) adjustment of a gripper opening cam for varying the time of opening of the sheet grippers; 5) the speed of rotation and switching on and off of fans which blow downwardly onto the sheet to facilitate the stacking action, or the pressure of another kind of regulatable blowing sources which have the same action and act at a point;; 6) the pressure at pressure blast nozzles rake-like blowing unit) which are optionally provided, for fixing and thrusting the sheet downwardly upon deposit thereof, and 7) other adjustable elements of the feeder, such as a stack level regulating means, or switching over of the straight thruster motion of an individual stroke movement per sheet, to a shaker motion, there are provided respective separate control motors with feedback of the setting reached to a reference value setting means or electromagnetic valves, and wherein the reference value setting means is provided with a respective input means for the paper weight, for the sheet format and for the speed of rotation of the machine and is connected to or integrated with a computer which computes the reference values for all settings of the feeder, such reference values being determined empirically for each operating condition and being stored in the form of a family or characteristics, said computer outputting said reference values to the reference value setting means which transmits same to control motors or electromagnetic valves.