FR2620430A1 - FEEDING DEVICE FOR SHEET ITEMS, IN PARTICULAR SHEETS OF PAPER FOR MAKING CORRUGATED CARDBOARD - Google Patents

Abstract

The feed device for sheet articles 6, for example sheets of paper, comprising an oscillating lever 10 which is driven by a rotating crank shaft 9 and an ejector or actuator 7 in the form of a stopper driven following a reciprocating movement by the oscillating lever 10 via a connecting rod 11a, is characterized in that the oscillating lever 10 is associated with at least one shock-absorbing damping element 19, 20 which is active during reversals of the direction of movement of the oscillating movement in synchronism with the course of the oscillating movement.

Description

The present invention relates to a device

  feed for sheet articles, particularly

  sheets of paper used in the cardboard composition

  corrugated. The invention applies to devices of this gen-

  re in which variations in the drive torque occur in the sheet feeding mechanism

are mitigated.

  We will first describe, with reference to Figs. 5 and 6, a device of the prior art. The device, generally designated at 1, is intended to supply a

  printing device 2. In FIG. 5, a stack consisting of

  killed by a large number of leaves 6 is placed on a

  table 3 of the sheet feeding device 1. A bar-

  sliding re 8, which is embedded in the table 3 so that it can slide in the same plane as the table 3 backwards and forwards to deliver the sheets, is

  arranged to have reciprocating movement through the

  diary of an oscillating lever 10 and connecting rods 11a, 11b, under the control of a rotating crank shaft 9. The connecting rod 11a couples the sliding bar 8 with one end of the lever

  oscillating 10, while the connecting rod 11b couples the shaft

  velle 9 with the other end of the oscillating lever 10. An ejection or actuating member 7 in the form of a stop, which is integral with the sliding bar 8, moves jointly with the latter to extract the sheets 6 of the stack from the bottom, in the direction of the arrow in FIG. 5. The ejected sheet 6 is clamped between upper 12 and lower 13 food rollers which are arranged at the front of the table 3, and it is

  sent to printing device 2 for the following operation

  boasts of rotation of rollers 12 and 13.

  In the printing device 2, a cylinder su-

  plate 15 with a plate carrying a printing plate 14 is rotated, as is a lower support roller 16. Printing is carried out when the sheet 6 passes between the rollers 15 and 16. The sheet 6

  is then transported downstream for another

  processing, for example printing with another

  be color or an ejection operation, by rotation of upper output rollers 17 and lower 18 disposed

downstream of rollers 15 and 16.

  In this mechanism, the crankshaft 9, the cylinders 15 and 16 and the rollers 12, 13, 17, 18 are coupled with each other by means of a series of pinions and they

  are driven by a gear train.

  In the above feed system which uses an oscillating or crank type mechanism, such as

  shown in Figs. 6a and 6b, an important force of inertia

  te is exerted on the entire mechanism at the two points for reversing the direction of movement of the oscillating lever 10 and the cranks 11a, 11b, these points corresponding to the positions of the member 7 at the end of its forward stroke and at the end of its back stroke. Therefore, this mechanism

  has the following disadvantages.

  First and foremost, it is necessary to have a drive motor (not shown) which has a large power in order to overcome

  * 20 the important force of inertia mentioned above. Then

  te, due to the fact that significant constraints are generated

  in the respective parts of the machine by this form

  this inertia, we must use organs, in particular

  shaft 9, which have an unnecessarily high resistance

  aunt. In addition, with regard to the rotating elements such as the rollers 12 and 13, the cylinders 15 and 16 and the rollers 17 and 18 coupled to the mechanism by a train

  gear, there is a variation in their movements

  rotation due to the fact that a variation in torque, caused by the force of inertia, occurs each time the crank mechanism oscillates, which affects

  adversely feed and print accuracy

  sheet 6. In addition, due to this vari-

  torque riation, there is also an increase

  significant vibration of the machine, which

  -calls a deterioration in its functioning.

  As described above, in the feeding device

  ment of the prior art, it was necessary, because

  sound of the torque variation caused by the force of inertia

  excessively important tie which is exerted during

  direction of the crank mechanism, increase

  ter the output power of the drive motor and strengthen the mechanical resistance of the parts. In addition, the

  feeding device according to the prior art was ame-

  born to have feeding accuracy and printing accuracy of deteriorated sheets of paper

  due to the variation in the speed of rotation of the

  rotating parts and due to mechanical vibrations.

  The object of the invention is therefore to provide a

  device for feeding sheet articles, in particular

  sheets of paper, in which, for the points of reversal of the direction of the oscillating movement, the variations in torque caused by the large inertia force are eliminated, so as to be able to maintain feeding precision and printing accuracy for sheet items at a high level without it

  be necessary to increase the output power of the mo-

  drive tor and the mechanical resistance of the parts

of the machine.

  To this end, according to the present invention, the provision

  feed for sheet articles has a

  swing lever which is arranged to swing under the

  control of the rotation of a rotating crankshaft, and an ejection or actuation member in the form of a stop which is driven in an alternating movement by the oscillating arm, by means of a connecting rod, characterized in that the oscillating lever is associated with a shock absorbing shock-absorbing element which is active at the points of reversal of the direction of movement of the oscillating movement, in

  synchronism with the movement over time

oscillating.

  According to three practical embodiments of the present invention, the shock absorbing element can consist of a pair of coil springs, leaf springs or pneumatic cylinders

  which are arranged on either side of the swing lever.

  In the feeding device according to this

  invention, thanks to the above arrangement, the cushioning element

  weaver, at the points of reversal of the direction of movement of the oscillating movement of the mechanism, acts in the direction to

  which it compensates for the significant and reduced force of inertia

naked the force of inertia.

  The above object, as well as others, as well as the features and advantages of the present invention,

  will appear on reading the description which follows

  and with reference to the accompanying drawings in which:

  Fig. 1 is a schematic side view of an arrangement

  feed for sheet articles in a fashion

  preferred embodiment of the present invention, this provision

  feed sitive being associated with a device for im-

  pressure; Figs. 2a and 2b are partial side views with

  larger scale showing the states of the mechanism used

  is in the device during the two reversal points of the direction of movement of the oscillating movement; Fig. 3 is also a larger side view

  scale showing a second embodiment of the element

  shock absorber; Fig. 4 is still a side view at a larger

  scale showing the third embodiment of the element

shock absorber;

  Fig. 5 is a side view of the feeding device

  tation of sheet articles and of the printing device according to the prior art; and Figs. 6a and 6b are partial side views on a larger scale showing the states for which the ejection element is located the furthest back and foremost respectively under the control of the mechanism

  drive in the device of FIG. 5.

  In what follows, modes of reaction will be described.

  preferred reading of the invention with reference to Figs. 1 to 4.

  Fig. 1 schematically shows the main elements

  of a device established according to the first embodiment. The device 1 for supplying sheet articles and the printing device 2 are shown in side view. In this figure, the feed device 1 is actuated to eject sheet articles 6, for example sheets of paper, which are stacked in a hopper comprising a front stop element 4 and a

  rear support element 5. The sheets, which are

  placed on table 3, are ejected from the stack by the

  alternative ejection or actuation element

  7 in the form of an abutment which projects upwards from the sur-

  upper face of table 3. Element 7 is subject to

  a sliding bar 8 arranged to slide in the ta-

  ble 3, to move together with the sliding bar

  health 8 in a reciprocating motion. The sliding bar

  8 is driven in its reciprocating movement by a mechanism

  oscillating nism located under the sliding bar 8 and com-

  bearing an oscillating crank shaft 9, an oscillating lever

  , a connecting rod 11a connecting the sliding bar 8 to an ex-

  - end of the oscillating lever 10 and a connecting rod 11b connecting

  the shaft 9 at the other end of the lever 10.

  A sheet 6 ejected by the element 7 is pinched in

  be upper 12 and lower 13 food rollers disposed at the front of the table 3, and it is delivered

  in the printing device 2 for the next step.

  In this printing device 2, printing is carried out while the sheet 6 passes between a rotating cylinder 15 with a plate which carries a printing plate 14, and a support roller 16. Next, the sheet of paper 6 is delivered downstream for the next step by being

  pinched between upper output rollers 17 and lower

  laughing 18 which are arranged behind the cylinders 15,16.

  The device described at this point is the same as the known device which has been described with reference to the

Fig. 5.

  In the preferred embodiment of the present invention which is shown in Figs. 1, 2a and 2b,

  two helical springs 19 and 20 constitute elements

  characteristic features. One end of the springs 19 and 20 is subject to fixed points X and Y, on either side of the oscillating lever 10, and the other end

  of these springs is subject to a point of the lever oscil-

  lant 10 which is close to the point of articulation of the biel-

11a on this lever.

  We will now describe the operation of this mode

  of achievement. Fig. 2a shows the state for which the element

  ejection ment 7 is in its rearmost position, that is to say at a point of reversal of the direction of movement of its oscillating movement under the control of the mechanism; if

  it is assumed that the springs 19 and 20 do not exist, com-

  me in the prior art, an excessively large inertial force acts on the upper half of the oscillating lever

  in the direction of arrow A during operation

  machine, that is to say when the mechanism

  ve at this end position.

  On the contrary, due to the existence of springs

  helical 19 and 20, the spring 19 is stretched by the

  the oscillating lever 10, while the helical spring

  coidal 20 is compressed, which gives rise to

  these return which are exerted on the oscillating lever 10 in the direction of arrow B to compensate at least

  partly the inertial force exerted on this lever.

  Furthermore, FIG. 2b shows the state of the mechanism for which the ejection element 7 is in its most forward position, at the end of the ejection stroke, and, for this position, on the contrary, the recall forces

  caused by springs 19 and 20, which are respective

  compressed and elongated, act on the lever

  blinking 10 in the direction of arrow A to compensate for the inertial force which exists at the end of the stroke

in advance for ejection.

  For example, springs 19 and 20 are two springs

  identical traction spells that perform actions

  equal and opposite for the middle position of the lever os-

shining 10.

  As is clear from the above, the force of inertia

  important tie that exists in the mechanism during in-

  versions of the direction of movement of the oscillating movement can be attenuated by the action of the two springs 19 and 20 and, therefore, the variations in torque, vibrations and the like mentioned above are also reduced, which eliminates the adverse effects indicated previously

all over the machine.

  Although the preferred embodiment above has been described assuming that one end of each spring 19 and 20 was fixed in X or Y, since the force of inertia increases in proportion to the square of

  the angular speed of the oscillating movement, we can pre-

  see, in some cases, adjustment means arranged to move the anchor point of one of the ends of the springs 19 and 20 according to the operating speed of the machine, these means not being shown for clarity drawings. This arrangement allows, whatever

  regardless of the operating speed of the machine,

  balance the inertial force and the restoring forces.

  According to the second embodiment of the invention, it is possible to use a system with two springs Z1

  leaf instead of two coil springs 19 and 20, com-

  shown me in fig. 3. According to the third mode of reaction

  reading, shown in FIG. 4, one can use a

  pressurized system using two pneumatic cylinders

  that 21 'which exert a reaction force created by the

air compression.

  As appears from the above, according to the pre-

  invention, we can reduce or even eliminate the

  fluence of the force of inertia existing at the points of

  version of the direction of movement of the oscillating movement of the

  canism, rotation of the feeding device and other rotating parts which are coupled to the device

  in advance through a gear train from-

  comes soft, improves feed precision and pressure accuracy of sheet items,

  which provides excellent quality products.

  In addition, thanks to the present invention, since the variations in torque also become small, the re-

  mechanical resistance of the component parts of the device, -

  tif can be reduced throughout the machine, which saves material and, overall,

a reduction in the cost price.

  Of course, the invention is not limited to mo-

  of implementation, no more than the mode of application which

  have been described; we could on the contrary conceive di-

  Verses variants without departing from its framework.

Claims (5)

  1. Feeding device for sheet articles, in particular sheets of paper, comprising an oscillating lever (10) which oscillates under the control of a shaft   rotating crank (9), and an ejection or acceleration member   actuation (7) in the form of a stop which is driven in an alternating movement by the oscillating lever (10) by means of a connecting rod (11a), characterized in that the oscillating lever (10) is associated with at least one shock absorbing element (19,20,21,21 ') which is   active at the points of reversal of the direction of the movement of the eye-   lation in synchronism with the course of the os-   bright. 2. Device according to claim 1, characterized in that said damping element is constituted by a pair of helical springs (19,20) cooperating with the oscillating lever and being located on either side thereof, these springs being for example equal tension springs exerting equal and opposite actions   for the middle position of the swing lever.   3. Device according to claim 1, character-   in that the damping element consists of two   leaf springs (21) which are arranged on either side be of the swing lever.   4. Device according to claim 1, characterized   in that the damping element is constituted by two   pneumatic rinses (21 ') arranged on either side of the swing lever.   5. Device according to one of claims 1 to 4,   characterized by the fact that the damping element is   adjustable, especially for adapting to operating speed   operation of the feeding device.