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EP 0 815 046 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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13.06.2001 Bulletin 2001/24 |
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Date of filing: 18.12.1996 |
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International Patent Classification (IPC)7: B65H 3/52 |
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International application number: |
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PCT/GB9603/123 |
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International publication number: |
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WO 9724/282 (10.07.1997 Gazette 1997/30) |
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A SHEET NUDGING ASSEMBLY
EINE BOGENANSTUPSEINRICHTUNG
ENSEMBLE SERVANT A POUSSER DES FEUILLES PAR A-COUPS
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Designated Contracting States: |
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DE ES FR GB |
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Priority: |
27.12.1995 GB 9526554
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Date of publication of application: |
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07.01.1998 Bulletin 1998/02 |
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Proprietor: De La Rue International Limited |
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Basingstoke, Hampshire RG22 4BS (GB) |
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Inventor: |
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- BROTHERSTON, Colin, Peter
Emsworth, Hants PO10 7TP (GB)
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Representative: Skone James, Robert Edmund et al |
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GILL JENNINGS & EVERY
Broadgate House
7 Eldon Street London EC2M 7LH London EC2M 7LH (GB) |
| (56) |
References cited: :
EP-A- 0 645 328 US-A- 4 555 103
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WO-A-88/02735 US-A- 5 163 666
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| Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
|
[0001] The invention relates to a sheeting nudging assembly for use, for example, in a sheet
handling system.
[0002] Sheet handling systems are used in a wide variety of fields to feed sheets from a
stack. Examples include banknote dispensing and also photocopy paper dispensing. A
known system for dispensing sheets from a stack is disclosed in EP-A-0645328. The
assembly makes use of a rotatable wheel through which suction is applied selectively
to draw sheets from the stack. The sheets are stacked on their edges in a sheet store,
the store including a sheet exit and a face plate towards which the sheets are urged.
Also provided are a sheet holding device, to selectively prevent sheets being fed,
and a nudging device, to urge the foremost sheet towards the sheet exit. The nudging
device engages with the leading sheet through an aperture in the face plate, the sheet
is then nudged towards the sheet exit and the nudging device then retracts away from
the sheet.
[0003] Generally the nudger eccentric is driven by the same drive that controls the valves
for supplying vacuum to the components of the sheet handling system. Such an arrangement
is disclosed in EP-A-0645328 and is used to maintain the timing of the nudging device
relative to the sheet feed mechanism and the sheet holding device. However, this sometimes
suffers from the disadvantage that when it is not required to feed a sheet, continued
oscillation of the nudging device could cause the sheet to be advanced too much towards
the sheet exit.
[0004] In accordance with the present invention, we provide a nudging assembly for nudging
the leading sheet in a stack of sheets, the assembly comprising a nudging device coupled
to a drive mechanism which causes the device to undergo a reciprocal movement; characterised
in that the assembly further comprises a control mechanism for controllably activating
the nudging device into an operative condition in which the device periodically engages
the leading sheet in the stack of sheets and urges it towards a sheet exit, the control
mechanism including a position controller for moving the nudging device between an
extended operative position in which the device periodically engages the leading sheet
in the stack of sheets and urges it towards a sheet exit and a retracted non-operative
position in which it cannot engage the stack while allowing the device to continue
with its reciprocal movement; and in that the nudging device comprises two sections,
wherein the first section is coupled to the drive mechanism and the second section
is movably mounted to the first section for movement between the retracted and extended
positions.
[0005] The control mechanism may comprise means for controllably activating the nudging
device drive mechanism whereby the device does not undergo the reciprocal movement
when it is not required to feed a sheet or group of sheets.
[0006] Typically, the nudging device comprises part of a sheet handling assembly which further
comprises a sheet holding device for holding the leading sheet in the stack of sheets.
For example, the sheet holding device may comprise means for controllably applying
a vacuum to the leading sheet in the stack of sheets.
[0007] In a first alternative, the mechanism that drives the nudging device and the mechanism
that drives the valves that supply the vacuum to the components of the sheet handling
system may be separate. It is then possible to stop the mechanism that drives the
nudging device when it is not required to feed a sheet or group of sheets and restart
the drive mechanism if sheets are to be fed. This can be done without interfering
with the supply of vacuum to the remainder of the sheet handling system. That is,
the nudging device is controlled independently from the sheet holding device.
[0008] In a second alternative, the activating means may controllably switch a single drive
mechanism that drives both the valves and the nudging device. In this case, when it
is not required to feed sheets the drive mechanism would be stopped and the motion
of the nudging device and the control valves would cease, thus preventing sheets from
being fed. Reactivation of the mechanism would once again lead to sheets being fed.
[0009] In the preferred embodiment, the nudging device continues to undergo reciprocal motion,
but it no longer engages with the leading sheet of the stack of sheets. As a result,
the foremost sheet is no longer urged toward the sheet exit. This helps prevent the
unwanted feeding of sheets that sometimes occurred with the previous apparatus.
[0010] The advantage of providing the nudging device as two sections is that the section
coupled to the drive mechanism and hence the drive mechanism itself, can remain stationary
with respect to the stack of sheets. This allows for easier construction of the assembly.
[0011] Typically, the position controller comprises a fluid controlled piston cylinder arrangement,
although any suitable means, such as a rack and pinion, could be used. As fluid controlled
mechanisms are typically used elsewhere in the sheet handling system, it is easier
to use a fluid controlled moving means than an alternative system.
[0012] Although it is possible to use any fluid in the piston cylinder arrangement, typically
air is used. This has the advantage that it is readily available and that sources
of compressed air are already used in the sheet handling system.
[0013] In general, the nudging assembly would be associated with a control means for controlling
whether the device is positioned in its extended or retracted position. Where the
position controller comprises a piston cylinder arrangement, the control mechanism
controls the supply of fluid to the position controller. It may be possible to use
a continuous fluid supply and control the pressure in the cylinder using a valve,
although the control of the fluid supply is preferred as any valves are then located
separate from the device. This makes general maintenance and repair work easier to
carry out.
[0014] Preferably, the first section of the nudging device defines a cylinder whilst the
second section defines a piston positioned within the cylinder. Although the reverse
case is possible, the preferred system has the advantage that the cylinder will remain
stationary with respect to the stack of sheets and the remainder of the assembly.
As it is required that the fluid source is coupled to the cylinder, the assembly is
more easily achieved if the cylinder does not retract and extend.
[0015] Generally, the nudging device also includes a means for normally urging the device
into the retracted position. This is preferable to urging the device into the extended
position in that should a fault occur with the system, the nudging device will generally
retract and hence stop urging sheets toward the sheet exit. This helps prevent unwanted
feeding of sheets.
[0016] The urging means is typically a compression spring but an extension spring or similar
means could be used.
[0017] As previously mentioned, the nudging assembly can be used in a sheet handling system.
Such systems can be utilized with various different types of sheets including banknotes
and other paper, card and the like.
[0018] An example of a nudging assembly and a sheet handling system according to the invention
will now be described with reference to the accompanying drawings, in which:
Figure 1 is a cross-section through the nudging device of the preferred embodiment;
Figure 2 is a plan view of the nudging device shown in Figure 1;
Figure 3 is an end view of section one of the nudging device shown in figure 1;
Figure 4 is a diagram of the sheet handling assembly, partly in plan and partly schematic;
Figure 5 is an end view of the face plate through which the nudging device projects;
Figure 6 is a perspective view of the component parts of the nudging device shown
in Figure 1;
Figure 7 is a perspective view of the components of the piston arrangement; and,
Figure 8 is a perspective view of the assembled nudging device of the preferred embodiment
connected to a control means shown in schematic form.
[0019] The nudging device shown in the drawings comprises a first section 1 and a second
section 2. The first section 1 is formed from a support block 3 which defines a cylinder
4. The cylinder 4 is connected to a source of air pressure via an inlet 5. As shown
in Figures 6 and 8, the inlet 5 is connected to an air supply 51 via a spigot 56,
right angle tube 57, nut 58, an air hose or tubing 64 and a solenoid controlled valve
52. In addition, washers 59,60,61 are provided to ensure the assembly remains air
tight. As shown in Figure 8, the solenoid operated control valve 52 is controlled
by a controller 62.
[0020] The drive mechanism for the support block 3 includes a shaft 6 having screwed into
it an eccentrically positioned bolt 7. The bolt 7 extends through bearings 8 which
are mounted in a bore 9. Movement of the support block 3 in response to rotation of
the shaft 6 is constrained to be along an elliptical path by means of a pivot pin
10 supporting a yoke 11. The pin and yoke are shown more clearly in Figure 2. The
yoke 11 is positioned and constrained to move between blocks 12 and 13 which are mounted
on block 3 by bolts 14.
[0021] The second section 2 is formed from a metal block 15 having a U-shape so as to define
arms 16 and 17 (Figure 6). Rubber ends 18 and 19 are bonded to arms 16 and 17 respectively.
Block 15 is connected to an actuating rod 20, which has a shaped end piece 21, via
bolt 22. The actuating rod 20 forms part of a piston assembly and is mounted inside
the cylinder 4.
[0022] The piston assembly comprises a compression spring 23, a piston 24, a seal 25, and
nuts 26. The components of the piston assembly are mounted on the actuating rod 20
as shown in Figure 7. The piston assembly is held in cylinder 4 by a sealing piece
27, which in turn is held in place by bolts 27a and 27b. The positioning of these
bolts is shown in Figure 3.
[0023] To provide additional support for section 2, a guide piece 28 is provided. This is
mounted on support block 3 by a bolt 29. The guide piece 28 engages with slot 30 defined
by the nudging block 15 as shown in Figure 2.
[0024] Extension of the nudging device is achieved by supplying air under pressure through
the inlet 5 to the cylinder 4. The increase in pressure in the cylinder 4 causes the
piston to move outwards thus compressing the spring 23. As the piston 24 is fixed
to the rod 21 this also moves, and as a result the second section 2 moves away from
the first section 1, increasing the overall length of the nudging device.
[0025] Figure 4 shows the nudging assembly in use in a sheet handling system. The sheet
handling system comprises a face plate 31 and an end wall 35 on adjacent sides of
a base 33. The sheet handling system also includes a sheet feed device 36 and a sheet
holding device 37. The sheet feed device 36 comprises a peeler wheel 38, a pinch roller
39 and a contra roller 40, which are positioned adjacent to a sheet exit 41. The sheet
holding device 37 comprises a manifold 42 connected to the face plate 31 by pins 43
and urged against the plate 31 by compression springs 44. Air or vacuum is supplied
to bore 45 in manifold 42 from which it passes through a conduit 46 to an outlet 47
for communication with sheet 32 through apertures 53 in the face plate 31. These apertures
are shown in Figure 5. Operation of such a sheet handling system is described in more
detail in EP-A-0645328.
[0026] Further features of the sheet handling system include a rear wall 48 which supports
a motor 49 connected via a follower block 50 to a guide wall 34. Upon activation of
the motor 49, the guide wall 34 vibrates to aid sheet feeding. The guide wall 34 and
the end wall 35 have shaped end pieces 36 and 37' respectively, these end pieces being
shaped towards the sheet exit 41 to further aid sheet feeding. The ends 18 and 19
of the nudging device project through apertures 54 and 55 respectively.
[0027] Operation of the sheet handling system will now be described.
[0028] When in use, a stack of sheets is placed upon the base 33 between the guide wall
34 and the end wall 35. These sheets are urged towards the face plate 31 by an urging
means, not shown, such as a sprung loaded plate. If operating correctly, the controller
62 will respond to signals on a line 63 from the sheet handling mechanism to cause
a vacuum to be supplied to the bore 45 from a vacuum source (not shown). This communicates
with the sheets 32 via apertures 53 in the face plate 31 (Figure 5). This sucks the
leading sheet onto the face plate 31. The controller 62 also actuates the valve 52
so that air pressure is supplied from the pump 51 to the nudging device, causing the
device to extend in length as previously described. As the shaft 7 rotates the rubber
ends 18 and 19 of the nudging device will undergo reciprocating motion as indicated
by arrow 53. During this motion the rubber ends 18 and 19 project through the apertures
54,55 in the face plate 31 and engage with the leading sheet 32, this situation being
shown in Figure 1. As the arms move from right to left (the feed direction), according
to Figure 4, air pressure is supplied to the bore 45 and vacuum is supplied to the
peeler wheel 38 using a system as illustrated in Figure 1 of EP-A-0645328. This causes
the leading sheet in the stack to be released from the face plate 31. The nudging
device nudges the sheet towards the sheet exit 41, where it is sucked on to the peeler
wheel 38. As the peeler wheel rotates, the sheet is removed from the assembly through
the sheet exit 41. As the arms of the nudging device begin to retract, due to the
reciprocal motion, the vacuum is once again applied to bore 45. This attracts the
next sheet to face plate 31. By the time the first sheet has been removed through
the sheet exit 41, the arms of the nudging device are fully retracted behind the face
plate 31, they then return to their initial position and the cycle begins again. The
vacuum applied through the apertures 53 and counter rotation of the roller 40 prevent
more than one sheet being fed at the same time.
[0029] If feeding of the notes is to be stopped, or should any fault occur with the mechanism,
such as a note becoming permanently stuck to the peeler wheel or the sheet exit 41
becoming blocked, then the control valve 52 is controlled by the controller 62 to
stop the supply of air from the supply 51 to the nudging device. As a result the nudging
device retracts in length under the influence of the spring 23 and, although it is
still undergoing reciprocating motion, the ends 18 and 19 no longer project through
the face plate 31 and cannot engage with the leading sheet of the stack. This situation
is shown in Figure 2. With the nudging means no longer engaging sheets, the leading
sheet will not be urged towards the sheet exit 41 and feeding of the sheet will cease.
When the blockage in the feed mechanism is removed, the valve 52 will again be operated
to supply air to the nudging device and feeding of sheets will once again commence.
1. A nudging assembly for nudging the leading sheet in a stack of sheets, the assembly
comprising a nudging device coupled to a drive mechanism which causes the device to
undergo a reciprocal movement, characterised in that the assembly further comprises
a control mechanism for controllably activating the nudging device into an operative
condition in which the device periodically engages the leading sheet in the stack
of sheets and urges it towards a sheet exit, the control mechanism including a position
controller for moving the nudging device between an extended operative position in
which the device periodically engages the leading sheet in the stack of sheets and
urges it towards a sheet exit and a retracted non-operative position in which it cannot
engage the stack while allowing the device to continue with its reciprocal movement;
and in that the nudging device comprises two sections, wherein the first section is
coupled to the drive mechanism and the second section is movably mounted to the first
section for movement between the retracted and extended positions.
2. A nudging assembly according to claim 1, wherein the position controller comprises
a fluid controlled piston cylinder arrangement.
3. A nudging assembly according to claim 2, wherein the fluid is air.
4. A nudging assembly according to claim 2 or claim 3, wherein the first section of the
nudging device defines a cylinder and the second section of the nudging device defines
a piston that is positioned within the cylinder.
5. A nudging assembly according to any of claims 2 to 4, wherein the control mechanism
includes means for controlling the supply of fluid to the piston cylinder arrangement.
6. A nudging assembly according to any of the preceding claims, wherein the nudging device
further comprises means for normally urging the device into the retracted position.
7. A nudging assembly according to claim 6, wherein the means for normally urging the
device into a retracted position comprises a compression spring.
8. A nudging assembly according to any of the preceding claims, wherein the control mechanism
comprises means for controllably activating the nudging device drive mechanism.
9. A sheet handling assembly comprising a sheet store for holding a stack of sheets;
a sheet exit towards which individual sheets are urged from the stack of sheets; a
sheet feed device for carrying individual sheets away from the sheet exit; and a nudging
assembly according to any of the preceding claims for urging the sheets from the stack
towards the sheet exit.
10. A sheet handling assembly according to claim 9, when dependant on any of claims 2
to 7, the sheet store including a face plate against which sheets in the stack are
urged, the face plate having one or more apertures through which the nudging device
can protrude, wherein the control mechanism causes the nudging device to retract through
the aperture(s) when the sheet feed device is not to feed sheets and to extend through
the aperture(s) when the sheet feed device is to feed sheets.
11. A sheet handling assembly according to claim 9 or claim 10, comprising a sheet holding
device for holding the leading sheet in the stack of sheets, and wherein the sheet
holding device is driven and controlled independently from the nudging assembly.
12. A sheet feeding assembly according to claim 11, wherein the sheet holding device comprises
means for selectively applying a vacuum to the leading sheet in the stack of sheets.
1. Anstupseinrichtung zum Anstupsen des vordersten Blattes in einem Bogenstapel, mit
einer Anstupsvorrichtung, die mit einem Antriebsmechanismus verbunden ist, der eine
Hin- und Herbewegung der Vorrichtung bewirkt, dadurch gekennzeichnet, daß die Einrichtung
ferner einen Steuermechanismus zur gesteuerten Aktivierung eines Betriebszustands
der Anstupsvorrichtung aufweist, in dem die Vorrichtung periodisch mit dem vordersten
Bogen des Bogenstapels zur Anlage kommt und ihn zum Bogenausgang drückt, wobei der
Steuermechanismus eine Lagesteuerung zum Verschieben der Anstupsvorrichtung zwischen
einer vorgeschobenen Betriebslage, in der die Vorrichtung am vordersten Bogen des
Bogenstapels anliegt und ihn zum Bogenausgang drückt, und einer zurückgezogenen Außerbetriebslage,
in der sie nicht mit dem Stapel zur Anlage kommen kann, es der Vorrichtung jedoch
weiterhin möglich ist, ihre Hin- und Herbewegung fortzusetzen, aufweist; und daß die
Anstupsvorrichtung zwei Abschnitte aufweist, von denen der erste Abschnitt mit dem
Antriebsmechanismus und der zweite Abschnitt am ersten Abschnitt beweglich angebracht
ist, so daß er zwischen der zurückgezogenen und der vorgeschobenen Lage bewegbar ist.
2. Anstupseinrichtung nach Anspruch 1, bei der die Lagesteuerung eine fluidgesteuerte
Kolben-Zylinder-Anordnung aufweist.
3. Anstupseinrichtung nach Anspruch 2, bei der das Fluid Luft ist.
4. Anstupseinrichtung nach Anspruch 2 oder Anspruch 3, bei der der erste Abschnitt der
Anstupsvorrichtung einen Zylinder und der zweite Abschnitt einen Kolben bildet, der
in dem Zylinder angeordnet ist.
5. Anstupseinrichtung nach einem der Ansprüche 2 bis 4, bei der der Steuermechanimus
ein Mittel zum Steuern der Zufuhr des Fluids zur Kolben-Zylinder-Anordnung aufweist.
6. Anstupseinrichtung nach einem der vorhergehenden Ansprüche, bei der die Anstupsvorrichtung
ferner ein Mittel aufweist, das die Vorrichtung normalerweise in die zurückgezogene
Lage drückt.
7. Anstupseinrichtung nach Anspruch 6, bei der das die Anstupsvorrichtung normalerweise
in die zurückgezogene Lage drückende Mittel eine Druckfeder aufweist.
8. Anstupseinrichtung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet,
daß der Steuermechanimus ein Mittel zur steuerbaren Aktivierung des Anstupsvorrichtungs-Antriebsmechanismus
aufweist.
9. Bogenhandhabungseinrichtung mit einem Bogenspeicher zum Halten eines Bogenstapels;
einem Bogenausgang, zu dem einzelne Bögen vom Bogenstapel weggedrückt werden; eine
Bogenvorschubvorrichtung zur Wegbeförderung einzelner Bögen vom Bogenausgang und eine
Anstupseinrichtung nach einem der vorhergehenden Ansprüche zum Wegdrücken der Bögen
vom Stapel zum Bogenausgang.
10. Bogenhandhabungseinrichtung nach Anspruch 9, zurückbezogen auf einen der Ansprüche
2 bis 7, bei der der Bogenspeicher eine Anlageplatte aufweist, gegen die Bögen im
Stapel gedrückt werden, wobei die Anlageplatte eine oder mehrere Öffnungen aufweist,
durch die die Anstupsvorrichtung hindurchragen kann, wobei der Steuermechanismus bewirkt,
daß die Anstupsvorrichtung durch die Öffnung(en) zurückgezogen wird, wenn die Bogenvorschubvorrichtung
keine Bögen vorschieben soll, und durch die Öffnung (en) hindurchragt, wenn die Bogenvorschubvorrichtung
Bögen vorschieben soll.
11. Bogenhandhabungseinrichtung nach Anspruch 9 oder Anspruch 10, mit einer Bogenhaltevorrichtung
zum Festhalten des vordersten Bogens im Bogenstapel und bei der die Bogenhaltevorrichtung
unabhängig von der Anstupseinrichtung angetrieben und gesteuert wird.
12. Bogenhandhabungseinrichtung nach Anspruch 11, bei der die Bogenhaltevorrichtung ein
Mittel zum wählbaren Anlegen eines Unterdrucks an den vordersten Bogen im Bogenstapel
aufweist.
1. Ensemble de poussée par à-coups destiné à pousser par à-coups la feuille avant dans
une pile de feuilles, l'ensemble comportant un dispositif de poussée par à-coups relié
à un mécanisme d'entraînement qui amène le dispositif à subir un mouvement alternatif;
caractérisé en ce que l'ensemble comprend en outre un mécanisme de commande destiné
à activer de manière pouvant être commandé le dispositif de poussée par à-coups dans
une condition active dans laquelle le dispositif engage de manière périodique la feuille
avant dans la pile de feuilles et la pousse vers une sortie de feuilles, le mécanisme
de commande comprenant un dispositif de commande de position destiné à déplacer le
dispositif de poussée par à-coups entre une position active sortie dans laquelle le
dispositif engage de manière périodique la feuille avant dans la pile de feuilles
et la pousse vers une sortie de feuilles et une position inactive rétractée dans laquelle
il ne peut engager la pile tout en permettant au dispositif de poursuivre son mouvement
alternatif; et en ce que le dispositif de poussée par à-coups comprend deux sections,
la première sect:.on étant reliée au mécanisme d'entraînement et la deuxième section
étant montée de façon mobile sur la première section pour un déplacement entre les
positions rétractée et sortie.
2. Ensemble de poussée par à-coups selon la revendication 1, dans lequel le dispositif
de commande de position comporte un agencement piston-cylindre commandé par fluide.
3. Ensemble de poussée par à-coups selon la revendication 2, dans lequel le fluide est
de l'air.
4. Ensemble de poussée par à-coups selon la revendication 2 ou la revendication 3, dans
la première section du dispositif de poussée par à-coups définit un cylindre et la
deuxième section du dispositif de poussée par à-coups définit un piston qui est positionné
à l'intérieur du cylindre.
5. Ensemble de poussée par à-coups selon l'une quelconque des revendications 2 à 4, dans
lequel le mécanisme de commande comprend des moyens destinés à commander l'alimentation
en fluide vers l'agencement piston-cylindre.
6. Ensemble de poussée par à-coups selon l'une quelconque des revendications précédentes,
dans lequel le dispositif de poussée par à-coups comprend en outre des moyens destinés
à pousser normalement le dispositif dans la position rétractée.
7. Ensemble de poussée par à-coups selon la revendication 6, dans lequel les moyens destinés
à pousser normalement le dispositif dans une position rétractée comprennent un ressort
de compression.
8. Ensemble de poussée par à-coups selon l'une quelconque des revendications précédentes,
dans lequel le mécanisme de commande comprend des moyens destinés à activer d'une
manière pouvant être commandée le mécanisme d'entraînement de dispositif de poussée
par à-coups.
9. Ensemble de manipulation de feuilles comportant un magasin à feuilles destiné à maintenir
une pile de feuilles; une sortie de feuilles vers laquelle des feuilles individuelles
sont poussées depuis la pile de feuilles; un dispositif d'alimentation en feuilles
destiné à transporter des feuilles individuelles à l'écart de la sortie de feuilles;
et un ensemble de poussée par à-coups selon l'une quelconque des revendications précédentes
destiné à pousser les feuilles depuis la pile vers la sortie de feuille.
10. Ensemble de manipulation de feuilles selon la revendication 9, lorsqu'elle est rattachée
à l'une quelconque des revendications 2 à 7, le magasin de feuilles comprenant une
plaque de face contre laquelle des feuilles dans la pile sont poussées, la plaque
de face ayant une ou plusieurs ouvertures à travers lesquelles le dispositif de poussée
par à-coups peut dépasser, dans lequel mécanisme de commande amène le dispositif de
poussée par à-coups à se rétracter à travers la ou les ouvertures lcrsque le dispositif
d'alimentation en feuilles n'avance pas des feuilles et sortir à travers la ou les
ouvertures lorsque le dispositif d'alimentation en feuilles avance des feuilles.
11. Ensemble de manipulation de feuilles selon la revendication 9 ou la revendication
10, comportant un dispositif de maintien de feuilles destiné à maintenir la feuille
avant dans la pile de feuilles, et dans lequel le dispositif de maintien de feuilles
est entraîné et commandé indépendamment de l'ensemble de poussée par à-coups.
12. Ensemble d'alimentation en feuilles selon la revendication 11, dans lequel le dispositif
de maintien de feuilles comprend des moyens destinés à appliquer de manière sélective
une dépression sur la feuille avant dans la pile de feuilles.