EP0241358B1 - Printer equipped with a device for selectively feeding printing sheets distributed in two magazines - Google Patents

Description

The present invention relates to improvements made in the printing sheet feeding part of a printing machine, and more particularly to the invention relates to a printing master comprising a removable unitary modular device for feeding sheets of printing medium. printing comprising: at least two removable loading trays; extraction means, driven by a single main motor, for extracting the sheets from one of the trays and propelling them in the machine towards printing means; selection means for selectively cooperating the extraction means with one of these tanks; and movement sampling means which are able to cooperate by simple contact with a rotating member forming part of the mechanism for driving the sheets in front of the printing means and driven by the aforesaid main motor located outside the supply device, in the remaining part of the printing machine, and which are further arranged to transmit this movement inside the device; the aforesaid selection means comprising movement distributing means associated with said movement taking and transmission means for directing the movement towards the sheet extraction means from the selected tray.

It is common, at present, to equip printing machines or the like with two print sheet feeders, either to facilitate the supply of the machine with sheets of the same type, or to selectively use specification sheets ( formats and / or colors in particular) different.

The systems for extracting sheets from the loading trays and for selecting the appropriate tray are, in these known machines, driven by an electric motor which is specific to them, that is to say which is different from the feed motors of the sheets and printing in particular; the motor with two directions of rotation is associated with a transmission train including two free wheels so as to selectively drive the rollers for extracting the sheets or loosening rollers respectively in the two tanks. The motor used has a very high speed of rotation, which means that the movement transmission pinions also rotate quickly, hence the generation of significant noise; in addition, the pinions, to be sufficiently resistant, must be metallic, which increases their cost and, taking account of the high rotational speeds, they must be mounted on ball bearings or the like, resulting in an additional increase in costs.

Document GB-A 2 132 591 presents a modular unitary removable sheet feeding device comprising several trays and arranged as indicated in the preamble. However, the power take-off on the leaf drive mechanism and the selection of the feed tray calls for complex mechanical means including clutches and large gear trains. These organs are generally subject to wear and require constant maintenance.

In addition, these members are very noisy in operation due to the noise and vibrations generated by the clicking of the clutches and by the cooperation of the teeth of the gears. Such an arrangement therefore goes against current trends in the design of printing machines which it is sought to make as silent as possible for the comfort of the users.

In addition, the transmission of movement by gear train as is done in the known device assumes that the rotating member from which the movement is taken is located, in the machine, in an easily accessible location and in the immediate vicinity of the cowling. receiving the removable modular sheet feeding device. As a result, this arrangement with transmission of motion by gear is ill-suited for devices having to equip machines where the power take-off must be made more deeply, since it is then necessary to increase the length of the gear train, and therefore the number of these gears, hence a consequent increase in noise, friction, etc. In addition, such a gear transmission lends itself rather poorly to the production of various variants arranged respectively to equip printing machines with various structures in which the rotary member on which the power take-off is carried out can be located at locations ( especially at different depths under the hood).

The object of the invention is essentially to remedy the drawbacks presented by known printing machines, and to arrange the selective sheet feeding device so as to reduce its cost and make it more silent to operate. The invention also proposes to take advantage of this arrangement to improve access to the various organs of the selective sheet feeding device, or even to the organs of the rest of the printing machine, so that maintenance and possible replacement of parts they are facilitated, simplified and therefore less expensive.

• - en ce que les moyens de prélèvement et de transmission de mouvement comprennent: un bras, saillant au moins partiellement à l'extérieur du dispositif; une roue de prise de mouvement, portée par l'extrémité libre du bras, apte à coopérer avec l'organe tournant du mécanisme d'entraînement de feuilles dans l'imprimante; un lien sans fin supporté par deux poulies ou analogue dont l'une est coaxiale à la roue de prise de mouvement et solidaire de celle-ci en rotation et dont l'autre est coaxiale à l'axe d'articulation du bras sur le dispositif; et des moyens de rappel élastique associés au bras agencés de manière que la roue de prise de mouvement soit appliquée élastiquement contre l'organe tournant,
• - et en ce que sont prévus des moyens moteurs pour commander lesdits moyens répartiteurs de manière que ceux-ci puissent occuper au moins trois positions, à savoir au moins deux positions fonctionnelles dans lesquelles ils coopèrent sélectivement respectivement avec les moyens d'extraction des deux bacs et une position neutre dans laquelle ils ne coopèrent avec aucun des moyens d'extraction des bacs.

To this end, a printing machine of the type mentioned in the preamble and arranged in accordance with the invention is characterized:

• - in that the means for picking up and transmitting movement comprise: an arm, projecting at least partially outside the device; a power take-off wheel, carried by the free end of the arm, capable of cooperating with the rotating member of the sheet driving mechanism in the printer; an endless link supported by two pulleys or the like, one of which is coaxial with the power take-off wheel and integral with the latter in rotation and the other of which is coaxial with the axis of articulation of the arm on the device ; and elastic return means associated with the arm arranged so that the power take-off wheel is applied elastically against the rotating member,
• - and in that motor means are provided to control said distributing means so that they can occupy at least three positions, namely at least two functional positions in which they cooperate selectively respectively with the extraction means of the two tanks and a neutral position in which they do not cooperate with no means of extracting the trays.

The arrangement in accordance with the invention makes it possible to dispense with a specific motor for picking up the sheets from the loading trays, hence a new source of significant savings.

Furthermore, the arrangement of the device in the form of a removable module provides, after extraction thereof from the printing machine, greater ease of access to the mechanisms and simplifies the maintenance work. A damaged device can be immediately replaced and the machine is thus only immobilized for a short time. In addition, maintenance of the rest of the printing machine can be facilitated, since the extraction of the module provides easy access to the other internal organs. Finally, this arrangement multiplies the working possibilities of the machine, because it is possible to provide modules of different types, equipped for example for sheets of particular format and / or composition.

In addition, it is particularly advantageous that the necessary movement is taken from a rotating member forming part of the mechanism for moving the sheets line by line during printing and that the aforementioned main drive motor is the interlining animating this mechanism: in fact, such a motor rotates very slowly (for example 1 revolution per second) and the drive mechanism can then be produced using pinions and plastic parts, obtained by molding, and therefore inexpensive; moreover, the assembly operates with an extremely low noise level; so, this uniqueness of the motor means for extracting the sheets from the trays and the displacement of the sheets being printed in front of the printing means leads to a synchronization of the advance of the sheets throughout their journey from the storage tray until it leaves the printer after printing.

Finally, the fact that the movement sampling means can cooperate by simple contact and without precise adjustment with the rotating member secured to the motor makes the positioning tolerances of the module in the printing machine less critical.

In a preferred embodiment, the distributing means comprise a pendulum supported in rotation coaxially with the articulation axis of the arm and carrying at least one satellite wheel which interacts with a driven wheel, integral with the pulley for supporting the endless link coaxial with the axis of articulation of the arm and which is capable of coming into contact selectively with one or the other of the means for extracting sheets from the trays.

Advantageously, the motor means for controlling the balance comprises a drive member coupled to the pivoting balance and an electric motor whose output shaft cooperates in rotation with the edge in an arc of a circle of the balance drive member.

In the case of a printing machine equipped with two trays, the balance advantageously supports two satellite wheels capable of cooperating selectively with the sheet extraction means associated respectively with the two trays and the electric motor is controllable in both directions of rotation for cause the pendulum to cooperate respectively with one or the other bin.

• - les figures 1 et 2 sont des représentations schématiques, respectivement en vue partielle de face et en vue de côté, d'une partie de machine imprimante agencée selon l'invention, et
• - la figure 3 est une vue partielle de côté d'une partie de machine agencée selon l'invention, constituant une variante de la disposition de la figure 2.

The invention will be better understood on reading the following detailed description of a preferred embodiment given solely by way of non-limiting example; in this description, reference is made to the single drawing in which:

• FIGS. 1 and 2 are schematic representations, respectively in partial front view and in side view, of a part of the printing machine arranged according to the invention, and
• FIG. 3 is a partial side view of a part of the machine arranged according to the invention, constituting a variant of the arrangement of FIG. 2.

Referring now first of all more specifically to FIGS. 1 and 2, there is shown a part (generally the rear part or a side part) of a printing machine 1 shown by its cover 2, the part considered of the machine being the one where the supply of printing sheets (for example sheets of paper) is located. Of the rest of the machine only are shown schematically the motor 3 or line spacing motor intended to move a sheet (not visible) in front of line by line printing means (not shown), as well as a toothed wheel 4 wedged on the axis of this engine.

The rear or lateral face 5 of the cowling 2 is removable in order to allow passage (installation or extraction) to a device 6 for feeding sheets formed in the form of a removable module. The device 6 is arranged to support, in any manner known per se for this purpose, two trays 7 superimposed and loaded with sheets 8, the trays being removable through corresponding openings on the face 5. Above each tray is located a roller or unwinding wheel 9, wedged on an axis 10 driven in rotation, which extracts the sheet 8 located on top of the corresponding stack.

To drive the appropriate roller 9, use is made of the following means. The device 6 is provided with an arm 11, partially projecting outside, which, at its internal end (right end in fig. 2), is pivotally mounted on an axis 12. At its other end (end on the left in Fig. 2), the arm 11 carries a toothed wheel 13 capable of cooperating with the toothed wheel 4 driven by the motor 3. In addition, an endless link, such as a toothed belt 14, is supported d 'one side by a pulley 15 coaxial with the wheel 13 and integral in rotation with the latter, and by a pulley 16 turning madly on the axis 12 of the opposite end of the arm. A toothed wheel 17 is mounted on the axis 12 and is integral in rotation with the pulley 16. In addition, a balance 18 is also supported for free rotation on the axis 12, this balance having the shape of a circular sector centered on axis 12 and supporting at its two ends two toothed wheels idlers or satellite wheels 19 meshing with the toothed wheel 17. The circular periphery, or part of it, of the balance 18 is toothed (at 20) to cooperate with a toothed wheel 21 driven by a motor 22 with two directions of rotation controlled by an appropriate selection means (change-over switch) not shown.

In the operating position of the printing machine shown in the figures, the toothed wheel 13 carried by the external end of the arm 11 is held in abutment against the driving toothed wheel 4 under the action of an elastic return force due to a spring 23 interposed between the arm 4 and a fixed part of the device. The movement is thus transmitted to the toothed wheels 19 which are continuously driven.

The selection of the upper or lower tray 7 is carried out by controlling the appropriate direction of rotation of the selection motor 22 which drives the balance 18; for example in the direction of arrow 24, as shown in the figures, to bring the upper toothed wheel 19 into contact with a toothed wheel 25 wedged on the upper shaft 10 (the lower toothed wheel 19 then being released from the toothed wheel 25 wedged on the lower shaft 10): it is then the sheets 8 of the upper tray which are delivered to the printing machine during printing.

The selection of the lower tray is carried out by reversing the direction of rotation of the motor 22 so as to release the upper wheels 25 and 19 and to make the lower wheels 25 and 19 cooperate.

Furthermore, a return spring 26 is associated with the balance 18 to return the latter to the neutral position in the absence of control of the selection motor 22: the wheels 25 and 19 both lower and upper no longer cooperate.

In the assembly which has just been described with reference to FIGS. 1 and 2, it can be seen that, for a given direction of rotation of the wheel 17, the cooperation of one or other of the satellite wheels 19 with the wheels 25 corresponding is not carried out in the same way: for one of the pairs of wheels 19-25, this cooperation is "engaging" (that is to say that the forces exerted on the satellite wheel 19 tend to force it into contact with the wheel 25), while for the other pair of wheels 19-25 this cooperation is "disengaging" (that is to say that the forces exerted on the satellite wheel 19 tend to separate it from contact with the wheel 25). Consequently, it is necessary for the motor 22 to generate a sufficiently high torque to maintain the required engagement of the wheel 19 with the wheel 25, including in the case of "disengaging" cooperation, which risks leading to a excessive engine fatigue and rapid wear, or oversize the engine which is more expensive.

To overcome this drawback, the alternative embodiment shown in FIG. 3 (in which the same reference numerals designate members identical to those of the device in FIGS. 1 and 2). In this embodiment, the toothed wheel 21 of the motor 22 acts on the balance 18 ', not directly, but by means of a pivoting drive member 27. The member 27 is shaped in a circular sector mounted freely on its central axis 28 and meshing, by its toothed edge in an arc of a circle 20, with the driving wheel 21. Opposite the toothed edge 20, the drive member 27 carries a finger 29 projecting laterally and engaged in a elongated light 30 of a part opposite the pendulum 18 '. Furthermore, the member 27 is provided with stop studs 31 projecting laterally, capable of coming against corresponding fixed stops 32 (for example carried by the frame). Finally a stop 33, erasable against a return force due to a spring 34, can engage in a notch 35 of the drive member 27 to materialize the neutral position (position shown in fig. 3). In general, the arrangement is such that the pivot axis 12 of the arm 11, the pivot axis 28 of the drive member 27, and the axis of the toothed wheel 21 are aligned, l finger axis 29 is also located in this alignment in the neutral position of the device.

In the embodiment which has just been described, the rotation of the wheel 21 causes the pivoting of the member 27 which, in turn, by means of the finger 29 engaged in the slot 30, causes the rocker to tilt 18 'in the appropriate direction. The reaction forces to which the balance 18 'is subjected are taken up and compensated by the drive member 27, and the motor 22 then only has to provide a relatively low holding torque, allowing the use of a low power motor.

Given the low rotation speed (of the order of 1 revolution per second) of the line spacing motor 3, the entire kinematic chain of the device 6 also operates at low speed and therefore remains silent. Another consequence of this low speed is the possibility of using plastic gear wheels which are less expensive and less noisy than the metal gear wheels.

In addition, the use of an elastic return arm 11 ensures effective cooperation of the toothed wheels 4 and 13, whatever the longitudinal positioning (within a certain range) of the device 6 relative to the motor 3, which makes the tolerances of said positioning.

In addition, this arrangement makes it possible to save on the engine traditionally used for extracting the sheets from the trays.

Finally, this arrangement provides synchronization of the advance of the sheets both when they are extracted from the tray and when they pass in front of the printing means of the printing machine.

As goes without saying and as it already follows from the foregoing, the invention is in no way limited to those of its modes of application and embodiments which have been more especially envisaged; on the contrary, it embraces all its variants.

Claims (5)

1. A printing machine (1) comprising a removable unitary module device (6) for the supply of sheets to be printed comprising: at least two removable charging trays (8); extraction means driven by a single principal motor (3) to extract the sheets from one of said trays and to move them in the machine towards printing means; selection means to cause the extraction means to cooperate selectively with one of said trays; and motion take-up means (11-17) which are adapted to cooperate only by contact with a rotary member (4) belonging to a mecanism moving sheets in front of said printing means and driven by said principal motor (3) situated outside of the supply device, in the remaining part of the printing machine, and which are arranged in addition to transmit this motion to the inside of the device; said selection means comprising motion distributing means (18, 19) associated with said motion take-up and transmission means (11-17) to direct the motion to means (9, 10, 25) for extraction of sheets from the selected tray; characterized in that said motion take-up and transmission means comprise: an arm (11), projecting at least partly outside the device; a motion take-up wheel (13) supported by the free end of the arm, adapted to cooperate with the rotary member (4) of the mechanism for driving sheets into the printer; an endless belt (14) supported by two pullies or the like (15, 16) of which one (15) is coaxial with the motion take-up wheel and rotatively fixed to the latter and of which the other (16) is coaxial with the axle for the articulation of the arm (11) on the device; and elastic return means (23) associated with the arm arranged so that the motion take-up wheel is applied elastically against the rotary member, and in that drive means (22) are provided to actuate said distributing means so that the latter can occupy at least three positions, namely at least tow operational positions in which they cooperate selectively respectively with the means for extraction from said two trays and a neutral position in which they do not cooperate with the means for extraction from the trays.

2. A machine according to claim 1, characterized in that the distributing means comprise a balance wheel (18) supported for rotation coaxially with the articulation axle (12) of the arm (11) and supporting at least one satellite wheel (19) which coacts with a driven wheel (17) fast to the endless belt supporting pulley (16) which is coaxial with the arm articulation axle and which is adapted to coact selectively with the one or the other of said sheet extraction means.

3. A machine according to claim 2, characterized in that said drive means for the actuation of the balance wheel comprise a drive member (27) coupled to the balance wheel (18') and shaped as a pivoting circular sector and an electric motor (22) of which the output shaft cooperates in rotation with the circular arcuate edge of the drive member of the balance wheel.

4. A machine according to claim 3, in which the sheet supply device comprises two trays, characterized in that the balance wheel supports two satellite wheels (19) adapted to cooperate selectively with the sheet extraction means associated respectively with the two trays and in that the electric motor (22) can be actuated in both rotation directions to result in the cooperation of the balance wheel respectively with one or other tray.

5. A machine according to any of claims 1 to 4, characterized in that the elastic return means (26, 34) bring back the distributing means into their neutral position when their drive means (22) are not in operation.

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