EP0545769B2 - Controlling device for fly printing machine and corresponding method - Google Patents

Description

The field of the invention is that of shipping mail, including shipping systems to process a large number of folds high speed.

More specifically, the invention relates to postage mail in such systems.

In general, mail forwarding systems to high speed of known types include at least an insertion machine and a franking machine. The insertion machine folds the sheets to be sent and their enveloping. She deliver these envelopes one after the other to the franking machine, also called machine that prints various information, such as than the postal signs (stamp and home office) and the advertising flames.

The invention therefore relates to these franking machines, and more precisely the optimization of their functioning, and in particular of the franking speed. In other words, the invention relates to a optimized machine control device part of a shipping system mail.

• un tambour d'impression comportant la tête d'impression (sur laquelle on retrouve les informations à imprimer sur les enveloppes);
• un système de sécurité, souvent constitué d'un ensemble comportant une barre d'obturateur verrouillant l'ensemble de commande du tambour d'impression;
• des moyens de transport qui, d'une part, délivrent les enveloppes provenant du dispositif d'insertion au poste d'affranchissement de l'appareil d'impression, et d'autre part, éjectent ces enveloppes après que la tête d'impression ait imprimé les signes postaux et les flammes de publicité.

A printing machine generally includes the following:

• a printing drum comprising the printing head (on which the information to be printed on the envelopes is found);
• a security system, often consisting of an assembly comprising a shutter bar locking the control assembly of the printing drum;
• transport means which, on the one hand, deliver the envelopes coming from the insertion device to the franking station of the printing apparatus, and on the other hand, eject these envelopes after the print head has printed postal signs and advertising flames.

Postal signs and advertising flames are printed while the print drum is moving at a constant speed commonly called "jump speed".

It is clearly understood that, to obtain a correct printing during this printing phase, the tangential speed at the surface of the drum must be equal to that of mail at print location. This is achieved if the speed, called "transport speed", to which the means of transport deliver the envelopes from the insertion machine is equal to the "jump speed" during the entire printing phase.

The rest of the time, i.e. when there is no the drum is usually stopped. When an envelope presents itself, it sets in motion, and accelerates until it reaches the speed of jump.

This first type of printing machines presents the major drawback of limiting the flow of the entire shipping system, because when each print cycle (postage of a envelope), the print drum should be brought to a complete stop and the security system must be engaged and disengaged.

Indeed, it is necessary that the printing drum goes from zero speed to "jump speed" before printing the signs, then be slowed down after printing to the stop position. The shutter bar must then be returned to the rest position (or print inhibit position).

Therefore, to increase the system throughput overall, the insertion machine must increase the mail ejection speed, which requires the increase the "jump speed" of the print drum. Consequently, the amplitudes of the deceleration and of the print drum acceleration are also increased.

A classic solution to this problem is to use more powerful motors, so as to obtain higher speed and provide more torque tall. This leads, in addition to an increase in physical dimensions of the machine, an increase of energy consumption and dissipation of heat, which consequently increases the cost of the system.

In addition, the operation of the postage meter at higher speed and at amplitudes greater acceleration and deceleration results in premature wear of the device and his training set.

In fact, the higher the speed, the more the phases acceleration and deceleration are brutal, same as the shutter movements, which causes many harmful mechanical shocks.

In addition, these shocks cause noise from important operation, very unpleasant for the user the shipping system and its environment, especially in the event of regular operation, or even permanent.

In order to increase the throughput of a machine for sending mail with a device postage while reducing the harmful effects on the wear of the system as exposed previously, a second type of printing machine was designed, presented in particular in the patent document FR-A 2,619,643.

• le transport des plis du courrier,
• la mise en rotation du tambour de l'appareil d'affranchissement,
• et le déplacement de la barre d'obturateur de l'appareil d'affranchissement, sont sous le contrôle d'un micro-ordinateur unique, assurant le pilotage centralisé des différents actuateurs.

In this second type of printing machines, three independent drive mechanisms, each ensuring respectively:

• transport of mail folds,
• the rotation of the drum of the franking apparatus,
• and the movement of the shutter bar of the franking apparatus, are under the control of a single microcomputer, ensuring the centralized control of the various actuators.

• la "vitesse de saut" du tambour d'impression soit la vitesse minimum requise,
• lors de chaque cycle d'impression, la vitesse de transport soit égale :
  • à la "vitesse de saut" pendant l'impression,
  • et à la vitesse d'arrivée des enveloppes (vitesse supérieure à la "vitesse de saut") avant la décélération et après l'accélération,
• lors de chaque cycle, la vitesse du tambour et donc de la tête d'impression soit :
  • égale à la "vitesse de saut" pendant l'impression,
  • et nulle avant l'accélération et après la décélération, de façon à permettre la mise en place de l'obturateur.

Means for detecting the speed of entry of the envelopes and means for triggering detection as a function of the position of the envelope provide information to the microcomputer, which controls the various mechanisms of the machine so that:

• the "jump speed" of the printing drum is the minimum speed required,
• during each printing cycle, the transport speed is equal:
  • at "jump speed" during printing,
  • and at the speed of arrival of the envelopes (speed greater than the "jump speed") before deceleration and after acceleration,
• during each cycle, the speed of the drum and therefore of the print head is:
  • equal to "jump speed" during printing,
  • and zero before acceleration and after deceleration, so as to allow the shutter to be fitted.

By simultaneous management of the feed speed envelopes and drum speed these machines therefore make it possible to obtain a higher flow rate than those of the first type described above. However, the obligation bring the drum to a complete stop when each cycle is always a limiting factor in debit of the entire mail forwarding system.

Indeed, with this type of machines, it is necessary to handle a shutter at each cycle. The machine is therefore always subject to sudden stops the print head drum and its control which inevitably generate vibrations, wear and noise.

Finally, we will notice that in such machines, in order to have a "jump speed" of the printing drum as low as possible, we force the transport speed to vary between a high speed (the speed envelope entry, i.e. the speed of envelopes at the exit of the inserter) and a lower speed (the "jump speed") that we want the as low as possible. In other words, the speed of transport varies constantly, depending on whether one is in a printing phase or in a feeding phase an envelope. The management of the different speeds is therefore complex, and their optimization not very easy.

Patent application US 4,023,489 describes a device in which the transport speed is constant, and in which the tangential velocity of a print drum varies between zero and the speed of transport, but it does not go down to zero if the rate of arrival of the documents to be printed is not less than a fixed value.

Therefore, variations in drum speed generally have a reduced amplitude compared in the case of machines in which the drum always marks a shutdown period. However this machine has the disadvantages that this amplitude of variation remains high when the rate of arrival is low compared to the maximum rate allowed by this machine because the transport speed, and therefore the drum speed during printing is fixed and remains equal to a value corresponding to the maximum flow of the machine.

In addition, if this transport speed is chosen low it limits the flow of the printing device too much.

The invention particularly aims to overcome these various drawbacks of the state of the art. More specifically, an object of the invention is to provide a control device for printing machine allowing reduce vibrations and shocks by the operation of the drum, so in particular to limit wear and operating noise machine while increasing the throughput of the global mail dispatch system including is part of the printing machine.

The object of the invention is also to provide such a device which is simple, reliable and inexpensive, in particular compared to existing devices, such as previously described.

Another object of the invention is still to provide such a device, which allows optimized operation of the franking machine whatever the envelopes processed, their number and arrival rhythm.

These and other objectives that will appear subsequently, are achieved according to the invention using a control device for a printing machine stolen, especially for franking envelopes as described in claim 1.

In this way, the "jump speed" of the head is as low as possible, and the amplitudes deceleration and acceleration for the head are further reduced.

So the operation of the printing device at a lower speed further reduces the vibrations, wear and noise of the machine, while working at the same speed.

Advantageously, said transport speed optimized is chosen from a finite number of values predetermined.

• détermination de la cadence d'arrivée des documents sur lesdits moyens de transport,
• calcul d'une vitesse de rattrapage à appliquer audit premier moteur lors de ladite phase de rattrapage, en fonction de ladite cadence d'arrivée,
• détermination de l'écart de vitesse entre ladite vitesse de rattrapage et ladite vitesse de transport,
• si ledit écart de vitesse est supérieur à un seuil prédéterminé, correction de ladite vitesse de transport.

The invention also relates to a method implemented in such control devices, comprising the following steps:

• determination of the rate of arrival of documents on said means of transport,
• calculation of a catch-up speed to be applied to said first motor during said catch-up phase, as a function of said rate of arrival,
• determination of the speed difference between said catch-up speed and said transport speed,
• if said speed difference is greater than a predetermined threshold, correction of said transport speed.

• la figure 1 présente une vue développée d'une tête d'impression de type connu, telle qu'utilisée généralement dans les machines d'impression ;
• les figures 2a à 2c présentent de façon schématique le cycle d'impression d'une enveloppe ;
• la figure 3 présente un schéma simplifié de la tête d'impression représentée en figure 1 ;
• les figures 4a à 4c présentent la courbe de variation de la vitesse V de la tête d'impression en fontion de la position angulaire  de cette même tête d'impression, dans les cas où, respectivement :
  • le cycle d'impression comprend une phase de compensation avec décélération de la tête d'impression ;
  • le cycle d'impression s'achève par le retour au point d'arrêt de la tête d'impression ;
  • le cycle d'impression comprend une phase de compensation avec accélération de la tête d'impression.
• les figures 5a et 5b présentent la courbe de variation de la vitesse V de la tête d'impression en fonction de la position angulaire  de cette même tête d'impression lors de phases d'apprentissage dans les cas où, respectivement :
  • la cadence d'entrée des enveloppes augmente;
  • la cadence d'entrée des enveloppes diminue ou bien la vitesse de rotation de la tête d'impression est trop élevée par rapport à cette cadence.

Other characteristics and advantages of the invention will appear on reading the following description of a preferred embodiment of the invention given by way of an indicative and non-limiting example, and the appended drawings, in which:

• FIG. 1 presents a developed view of a printing head of known type, as generally used in printing machines;
• Figures 2a to 2c schematically show the printing cycle of an envelope;
• Figure 3 shows a simplified diagram of the print head shown in Figure 1;
• FIGS. 4a to 4c show the curve of variation of the speed V of the print head in function of the angular position  of this same print head, in the cases where, respectively:
  • the printing cycle comprises a compensation phase with deceleration of the print head;
  • the printing cycle ends with the return to the stop point of the print head;
  • the printing cycle includes a compensation phase with acceleration of the print head.
• FIGS. 5a and 5b show the curve of variation of the speed V of the print head as a function of the angular position  of this same print head during learning phases in the cases where, respectively:
  • the rate of entry of the envelopes increases;
  • the envelope input rate decreases or the rotation speed of the print head is too high compared to this rate.

The control device of the invention applies therefore to a printing machine used in particular for frank envelopes in a shipping system of mail.

• des moyens de transport permettant d'amener des enveloppes à une vitesse dite "vitesse de transport",
• des moyens d'impression comprenant une tête d'impression rotative.

This printing machine includes:

• transport means enabling envelopes to be brought to a speed known as "transport speed",
• printing means comprising a rotary printing head.

This print head is presented in developed view in figure 1.

Full length of head circumference is not used for printing. The real area printing corresponds to that of hoop 2 which allows to train the envelope during the whole phase printing.

• au timbre,
• au bureau d'attache,
• et aux flammes de publicité.

In a zone 6 of the same length as the hoop 2 there are generally three printing pads 3, 4, 5, corresponding respectively:

• stamp,
• at the home office,
• and the advertising flames.

As soon as the printing on the envelope is finished, that is to say at the end of zone 6 (therefore of fret 2), the print head continues to rotate but without contact with the envelope.

For a good impression, we understand that during the entire printing phase, i.e. during the contact time of the hoop with the envelope, the speed of the head must be equal to the "transport speed".

A print cycle is presented schematically in Figures 2a to 2c.

In FIG. 2a, the hoop 2 is in contact with a envelope 20. The print head turns in one direction 22 and the envelope advances in a direction 23.

The speed of the head is then equal to the "speed of transport ": this is the start of printing.

The distance between two printing starts (i.e. the length of a letter added to the gap between two successive letters) being larger or larger small than the length of the head circumference print, you will have to slow down or speed up the head to compensate for this difference in length.

• quand la frette de la tête est en contact avec l'enveloppe (longueur L1),
• pendant l'engagement et le dégagement de l'enveloppe de la frette (longueur correspondante L2).

The speed of the head must not vary:

• when the fret of the head is in contact with the envelope (length L1),
• during engagement and disengagement of the hoop envelope (corresponding length L2).

Let LT be the length of the head circumference, the speed of the head can therefore vary over the length: ΔL = LT- (L1 + L2)

These lengths L1, L2, LT and ΔL are shown in figure 1.

Rather than reason with distances and at using an expanded view of the print head, subsequently uses an angular notation, corresponding to a circular representation of the head.

Figure 3 shows such a diagram of the head, the diameter 31 is constant whatever the machine. Indeed, the diameter of the print heads is generally 80 mm.

Fret 2 corresponds to an angle 1. We design by T the angle corresponding to the circumference of the head (of course equal to 360 degrees).

• 1=214°50'
• 2=36°10'
• 1+2=251°
• Δ =T - (1 + 2) = 109°

Let 2 and Δ be the angles corresponding to L2 and ΔL respectively. The normalized values of these angles are:

• 1 = 214 ° 50 '
• 2 = 36 ° 10 '
• 1 2 = + 251 °
• Δ = T - (1 + 2) = 109 °

This means that the rotation of the head at speed constant during the printing phase corresponds to a rotation of 251 °.

Distance compensation must therefore absolutely be done while the head travels the remaining 109 degrees.

Thus, in FIG. 2b, the impression of the envelope 20 being completed, the head continues to rotate but at an different speed so as to be synchronous with the next envelope 21. Figure 2c shows the beginning of the following print: the beginning of envelope 21 is well facing the beginning of the fret 2.

• lors de chaque cycle, suite à la phase d'impression, la tête doit ralentir de façon à bien positionner la frette par rapport à l'enveloppe suivante,
• l'enveloppe à affranchir est la dernière et la tête doit ensuite revenir en position d'arrêt,
• lors de chaque cycle, suite à la phase d'impression, la tête doit accélérer de façon à bien positionner la frette par rapport à l'enveloppe suivante.

When the printing machine is in regular operation, three cases can arise:

• during each cycle, following the printing phase, the head must slow down so as to correctly position the hoop relative to the next envelope,
• the envelope to be franked is the last and the head must then return to the stop position,
• during each cycle, following the printing phase, the head must accelerate so as to properly position the hoop relative to the next envelope.

These three cases are respectively discussed below in conjunction with Figures 4a to 4c. For that, we have represented the curve of variation of the speed V of the print head according to angular position  of this same print head, over one or two cycles printing.

In these figures, the position  = 0 degrees corresponds to the start of the first printing phase. For each of these figures, the curve begins with the printing phase 41 _A of the (k + 1) ^th / cycle.

In the first case, FIG. 4a, the speed of the head during this (k + 1) ^th printing phase 41 _A is equal to v _i . This speed v _i is necessarily the transport speed since, as already explained, during printing, the transport and print head speeds must be equal.

The different values of this transport speed v _i (i varying from 1 to 5) will be explained in conjunction with FIGS. 5a and 5b.

After 251 degrees of head rotation, printing is complete. As we are in the case where the distance between two starts of printing is greater than the length of the circumference of the head, we must slow down the head (phase 42). Then, in order to compensate for this distance difference, the head rotates at a lower speed (v _i - Δv) (phase 43). And finally, it is accelerated (phase 44) to return to speed v _i and thus be at the right speed for the next printing 41 _B (that of the (k + 2) ^th cycle).

In the second case, FIG. 4b, there is no next envelope and the (k + 1) ^th impression 41 is therefore the last.

The head is therefore slowed down (46) and arrives in position stop 45. This stop position is not arbitrary, but is such that the fret and the printing pads are not accessible. The deceleration phase 46 has the maximum possible slope.

In the third and last case, figure 4c, the distance between two start of printing is smaller than the length of the circumference of the head, it is therefore necessary to accelerate the head (phase 47). Then, in order to compensate for this distance difference, the head rotates at a higher speed (v _i + Δv) (phase 49). And finally, it is decelerated (phase 48) to return to the speed v _i and thus to be at the right speed for the next printing 41 _B (that of the (k + 2) th cycle).

• lorsque la machine démarre, la vitesse de transport prend obligatoirement sa valeur maximale possible. Par conséquent, lors de l'impression la tête va aussi tourner à cette vitesse qui est très rapide. Or si la cadence d'arrivée des enveloppes n'est pas très rapide, la tête va devoir s'arrêter pendant la période angulaire de compensation de distance pour que la frette soit bien positionnée par rapport à l'enveloppe suivante ;
• lorsque la vitesse de transport a une valeur v_i élevée, la cadence d'arrivée des enveloppes diminue. On est alors ramené au cas prédédent : il va falloir arrêter la tête pendant la phase de compensation ;
• lorsque la vitesse de transport a une valeur v_i faible, la cadence d'arrivée des enveloppes augmente. On est alors obligé d'accélérer la tête pendant la phase de compensation.

When starting the machine, or when changing the value of the rate of arrival of envelopes from the system located upstream of the franking machine, we are faced with different types of problem:

• when the machine starts, the transport speed must take its maximum possible value. Therefore, when printing the head will also rotate at this speed which is very fast. However, if the rate of arrival of the envelopes is not very rapid, the head will have to stop during the angular period of distance compensation so that the hoop is correctly positioned relative to the next envelope;
• when the transport speed has a high value v _i , the rate of arrival of the envelopes decreases. We are then brought back to the previous case: we will have to stop the head during the compensation phase;
• when the transport speed has a low value v _i , the rate of arrival of the envelopes increases. We are then forced to accelerate the head during the compensation phase.

In order to avoid these disadvantages which constitute stopping or accelerating the print head during the compensation phase, or changes the speed of transport, and therefore the speed of the head, thanks to lifelong learning.

Figures 5a and 5b illustrate this learning which avoids stopping (Figure 5a) and accelerating of the head (Figure 5b) during the compensation phase.

Figures 5a and 5b show, like the figures 4a to 4c, the variation curve of the speed V of the head depending on the angular position  of this same printhead over three printing cycles.

For each of these figures, the curve begins with the printing phase 51 of the (k + 1) ^th cycle.

FIG. 5a presents the case where the speed of the head during the (k + 1) ^th printing 51 is V _o , which is also the transport speed (equality of the two speeds during the printing phase) and corresponds to the speed maximum machine transport.

The transport speed can take a value from a choice of possible values, from V _o to v _i where the index zero corresponds to the highest speed and the largest index corresponds to the lowest speed.

In the rest of the presentation, we consider that six choices v _o to v ₅ are possible.

In the case of FIG. 5a, the rate of arrival envelopes is low.

The head must therefore stop (phase 52). During the following cycle, the head always rotates at the speed V _o during the (k + 2) ^th printing 53. On the other hand, thanks to learning, it does not stop during the compensation phase: it rotates, after deceleration 54, at a constant speed v ₁ - Δv (phase 55). Then it re-accelerates 56 to rotate at speed v ₁ during the (k + 3) ^th printing 57. This speed v ₁ is also the transport speed.

In the same way, learning continues on the following cycles by further decreasing this transport speed if necessary (from v ₁ to v ₂ for example) until this value is optimized and the head does not stop more if possible.

FIG. 5b presents the other case, that is to say that where the speed of the head during printing (it is also the transport speed) is low and has for example the value v ₅ .

In the case of this figure, it is assumed that the envelope arrival rate increases.

The head must therefore accelerate 59, rotate at a speed v ₅ + Δv during the compensation phase 58, before decelerating 60 to rotate at speed v ₅ during the (k + 2) ^th printing.

On the other hand, thanks to learning, at the end of this (k + 2) ^th impression 61, the head accelerates to a speed V _o - Δv which is a compensation level 63.

If the rate of arrival of the envelopes has increased moderately, the head accelerates only to a lower speed v _i - Δv taking a value of greater i.

When this stage is finished, the head is accelerated (64), and the (k + 3) ^th printing 65 can be done at the speed v _o (or v _i with i greater than 0).

In subsequent cycles, the head is no longer accelerated during the compensation phase.

These two examples illustrate the role of learning which allows a decrease in the value of the transport speed over several cycles (example of Figure 5a: from v _o to v ₁ ), or an increase of this value over a single cycle (example of figure 5b: from v ₅ to v _o ).

• une première valeur pendant toute la phase d'impression (qui est égale à la valeur de la vitesse de transport),
• une seconde valeur pendant une partie de la phase de compensation.

During each print cycle, the speed of the print head takes two distinct constant values:

• a first value during the entire printing phase (which is equal to the value of the transport speed),
• a second value during part of the compensation phase.

Acceleration and deceleration phases allow to go from the first to the second value the speed of the print head.

• une phase où la vitesse de la tête prend la seconde valeur,
• une phase d'accélération,
• une phase de décélération.

The compensation phase therefore includes:

• a phase where the speed of the head takes the second value,
• an acceleration phase,
• a deceleration phase.

In the embodiment which has just been described, acceleration and deceleration phases are chosen of the same duration.

• une portion de courbe assimilable à une portion de droite ayant une certaine pente, et
• une portion de courbe assimilable à une portion de droite ayant la même pente en valeur absolue mais de signe opposé.

In addition, the curve representing the variation in speed of the print head as a function of the angular position of this same print head corresponds respectively during the acceleration and deceleration phase to:

• a portion of the curve similar to a straight portion having a certain slope, and
• a portion of curve comparable to a straight portion having the same slope in absolute value but of opposite sign.

• de forme triangulaire, la phase à vitesse constante étant supprimée, en ajustant de façon adéquate les accélérations et décélérations,
• de forme "adoucie" (présentant par exemple un profil de cuvette), toujours dans l'objectif de réduire les chocs et les bruits. En effet, il n'y a alors aucune variation brusque de vitesse.

It is clear that many other embodiments of the invention can be envisaged. One can in particular provide for compensation phases whose curve representing the variation of the speed of the head as a function of the angular position would no longer consist of three straight portions (corresponding respectively to the deceleration phases, at constant speed, and d 'acceleration) but could be for example:

• triangular in shape, the phase at constant speed being eliminated, by adequately adjusting the accelerations and decelerations,
• "softened" in shape (for example having a bowl profile), always with the aim of reducing shock and noise. Indeed, there is then no sudden variation in speed.

More generally, the invention relates to all devices to reduce variations in the speed of the print head, which never stops in normal operating regime.

Claims (6)

1. Control device for on the fly printing machines, especially for franking envelopes fed at a varying but determined arrival rate, of the type comprising:

   printing means comprising a rotary print head actuated by a first motor running at a rotation speed (V), said print head carrying on a portion of its surface a printing active part (6);

   conveyor means for conveying said envelopes actuated by a second motor feeding said envelopes into contact with said printing means at a given conveyor speed (Vi) and evacuating the franked envelopes;

   characterized in that it further comprises:

   means for optimizing the conveyor speed (Vi) in order to vary the conveyor speed according to the arrival rate of the envelopes such that said conveyor speed be as low as possible while preventing overlapping of said envelopes; and

   means for optimizing the rotation speed (V) in order to adapt, during each print cycle, the rotation speed to the conveyor speed such that the rotation speed is held equal to the conveyor speed during a printing phase corresponding to the period during which an envelope is in contact with said active printing part and as close as possible to said conveyor speed during a complementary catch-up phase.
2. Device according to claim 1, characterized in that said conveyor speed is selected from a finite number of predetermined values.
3. Device according to any one of claims 1 to 2, characterized in that said means for optimizing the conveyor speed take account of at least one of the parameters belonging to the group comprising:

   the envelope conveying speed,

   the rate at which envelopes arrive on the conveyor means,

   the distance between two successive envelopes,

   the length of the envelopes.
4. Device according to claim 1, characterized in that said means for optimizing the rotation speed of said first motor cause said rotation speed to vary between two constant speeds respectively corresponding to the printing phase (41; 41A, 41B; 51, 53, 61, 65) and the catch-up phase (43; 49; 52; 55; 58, 63) and in that said means operate such that the transition phases between said constant speeds are as short as possible.
5. Device according to claim 1, characterized in that said means for optimizing the rotation speed (V) of said first motor are operative such that, in the event of stopping of said first motor, said active printing part (6) is not accessible.
6. Control method implemented by a device according to any one of claims 1 to 5, characterized in that it comprises the following steps:

   determining the rate of arrival of the envelopes on said conveyor means,

   calculating a catch-up speed to be applied to said first motor during said catch-up phase according to said arrival rate,

   determining the speed difference between said catch-up speed and said conveyor speed,

   correcting said conveyor speed if said speed difference is greater than a predetermined threshold.

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