[0001] The present invention concerns a device for supplying thin, piled objects, in particular
envelopes, to a conveying device in an overlapping manner.
[0002] Such devices are used for supplying envelopes to be printed to a printing machine.
[0003] As the envelopes are presented to the printing machine by the conveying device in
an overlapping manner, when they are taken up one by one by the printing machine,
they have to cover a shorter distance than if they would have lain entirely one after
the other on the conveying device, which allows for a higher print speed.
[0004] It is clear that it is important hereby that the successive envelopes overlap one
another at the same, invariable distance or that they are situated at equal distances
from one another with their front side or back side.
[0005] Known devices of the above-mentioned type contain friction belts, whereby the envelopes
are taken one by one from the bottom side of a pile by means of friction.
[0006] Such devices do not allow to obtain the required invariable overlap of the envelopes,
however.
[0007] Other known devices contain a perforated suction belt which can move over an opening
which is connected to a vacuum source via a pipe. Each time a single envelope has
to be taken from the pile, the suction belt with its perforations moves over the opening,
so that the envelope is held onto the belt.
[0008] These devices have a limited supply speed, they cannot be adjusted in a flexible
manner and lead to an irregular supply distance between the envelopes.
[0009] The invention aims a device for supplying thin objects to a conveying device in an
overlapping manner which does not have the above-mentioned and other disadvantages
and which has a relatively simple construction and thus is economical, but which can
nevertheless supply flat objects, in particular envelopes, at a relatively high speed,
in a precise manner, and thus at an invariable mutual distance.
[0010] This aim is reached according to the invention in that it contains a rotor which
can rotate around a stator, and means for driving the rotor, whereby the stator is
equipped with a chamber opening in its outer perimeter which is connected to a vacuum
source, and whereby the rotor is provided with openings which are temporarily situated
opposite to the exit of the chamber during the rotation of the rotor.
[0011] The openings may be provided according to a hole pattern and in particular form axially
directed rows of holes, but the openings are preferably axially directed slots in
the rotor, which makes the manufacturing easier, and as a result of which for example
less deburring is required.
[0012] Not only the rotational speed of the rotor can be adjusted; the stator can also be
adjusted around the axis of rotation of the rotor.
[0013] The means for driving the rotor may contain at least two drive belts. In this case,
these belts can be driven at the same linear speed as the conveying device, so that
they can ensure the conveyance of the objects from the rotor to the conveying device.
[0014] In order to better explain the characteristics of the invention, the following preferred
embodiment of a device for supplying thin objects to a conveying device in an overlapping
manner according to the invention is described as an example only without being limitative
in any way, with reference to the accompanying drawings, in which:
figure 1 schematically represents a section of a device for the overlapping supply
to a conveying device according to the invention;
figure 2 represents the part which is indicated by F2 in figure 1 to a larger scale;
figure 3 shows a side view with partial cut-out of a practical embodiment of the device
according to the invention in a supply device of a printing machine;
figure 4 represents a top view to a larger scale of the part which is indicated by
F4 in figure 3;
figure 5 is a section according to line V-V in figure 4, to a larger scale;
figure 6 is a section according to line VI-VI in figure 5.
[0015] The device represented in figures 1 and 2 is used for supplying envelopes 1 from
a pile 2 in an overlapping manner to a conveying device 3 and mainly consists of a
frame 4, a stator 5 provided upon it which is equipped with a chamber 6 opening in
its outer perimeter, a rotor 7 surrounding the stator 5 and provided with openings
8, means 9 for driving this rotor 7 and a vacuum source 10, for example a vacuum pump,
which is connected to the chamber 6 of the stator 5 by means of a pipe 11.
[0016] In the given example, the stator 5 is a cylindrical body which is horizontally fixed
to the frame 4 with its shaft. The chamber 6 is elongated and axially directed and
it is connected to an axial duct 12 which is part of the pipe 11 on the one hand,
and it opens in the outer perimeter of the stator 5 with an elongated opening on the
other hand, on the top side of the stator 5.
[0017] The rotor 7 is tubular and has an inner diameter which is practically equal to the
outer diameter of the stator 5.
[0018] In the embodiment represented in figure 1, the means 9 for driving the rotor 7 consist
of a motor 13 and belts 14.
[0019] The openings 8 are axially directed slots whose width, measured on the inner side
of the rotor 7, is for example almost equal to the width of the above-mentioned opening
with which the chamber 6 opens in the outer perimeter of the stator 5. The latter
width may be equal to the intermediate distance of the openings 8, measured on the
inner side of the rotor 7 and in the sense of rotation.
[0020] The number of openings 8 depends on the required distance between the successive
envelopes 1 on the conveying device 3 which consists of one or several endless belts
15 which are guided over wheels 16, one of which is driven by a motor in a manner
which is not represented in the figures, which operates synchronously with the above-mentioned
motor 13.
[0021] According to a variant, the drive of the conveying device 3 may also form the above-mentioned
means 9 for driving the rotor 7, which is then driven for example by means of the
belts 15.
[0022] Above the top part of the conveying device 3, on the frame 4, is provided a stop
17 for the pile 2 in an adjustable manner.
[0023] The working of the device is as follows.
[0024] The pile 2 of the envelopes 1 to be printed is put against the stop 17, so that the
bottommost envelope 1 is positioned with its back part above the rotor 7, in particular
above the exit of the chamber 6 of the stator 5, and rests with its front part on
the conveying device 3.
[0025] When the device is activated, the rotor 7 is driven by the motor 13 in the direction
represented by arrow P1 in figures 1 and 2, synchronously with the conveying device
3 which is driven in the direction represented by arrow P2, such that the linear speed
of the perimeter of the rotor 7 is equal to the linear speed of the conveying device
3, and a partial vacuum is created in the chamber 6 by the vacuum source 10 via the
pipe 11, so that there is a suction represented by arrow P3 in figures 1 and 2.
[0026] As a result, the envelope 1 which is situated at the bottom of the pile 2 is sucked
against the rotor 7 as soon as an opening 8 of the rotor 7 is situated opposite the
exit of the chamber 6 of the stator 5.
[0027] Thanks to the suction, the envelope 1 is carried along by the rotor 7 and is pushed
further forward on the conveying device 3, under the pile 2.
[0028] In the same manner, a following envelope 1 is sucked up by a following opening 8
and carried along by the rotor 7 as soon as this following opening 8 is situated opposite
to the exit of the chamber 6, which is the case immediately after or even during the
movement of the preceding envelope 1, as the envelopes 1 are only situated with their
back parts above the rotor 7.
[0029] This following envelope 1 is pushed on the conveying device 3 on top of the preceding
one, so that the envelopes 1 overlap on this conveying device 3 and are situated at
an invariable and fixed distance from one another with their back edges, whereby the
last envelope 1 which was carried along lies each time on top.
[0030] If the envelopes 1 lie too far backward in relation to the rotor 7, several successive
openings 8 should carry along the bottommost envelope before it rests completely on
the conveying device 3 and has thus been removed from above the rotor 7.
[0031] The distance between the successive envelopes 1 depends on the distance between the
openings 8 and thus on the number of openings 8 spread over the perimeter of the rotor
7, but also on the position of the bottommost envelope 1 in relation to the opening
8 when it is first carried along.
[0032] Thus, said distance can be adjusted by shifting the pile 2, and thus by adjusting
the stop 17.
[0033] By moving this stop 17, it becomes possible to handle envelopes 1 having different
sizes.
[0034] If we assume that every envelope 1 is sucked up and moved by a single opening 8,
the distance over which a sucked-up envelope 1 is moved, will depend on the size of
the exit of the chamber 6 in the outer perimeter of the stator 5.
[0035] The moment at which an envelope 1 is first sucked up and moved depends on the position
of the exit of the chamber 6 and may possibly be modified by rotating the stator 5
around the axis of rotation of the rotor 7.
[0036] The speed at which the envelopes 1 are put on the conveying device 3 depends on the
speed of the rotor 7 which is for example synchronised with the speed of the conveying
device 3, and is determined by the speed of the printing machine being fed by it.
[0037] Figures 3 to 6 show a more practical embodiment of the above-mentioned device.
[0038] In this embodiment, the frame 4 consists of two side walls 18 and 19 which are connected
by cross connections 20.
[0039] The stator 5 is supported by these side walls 18 and 19 by means of horizontal rods
21 and 22 which extend this stator 5 on both sides and which are provided with one
rotatable end in the side wall 18 or 19. On the rod 21, on the outer side of the side
wall 18 is fixed a button 23 with which the rod 21 and thus also the stator 5 can
be rotated so as to adjust the direction of the exit of the chamber 6, and with which
said rod 21, once it has been adjusted, can also be locked.
[0040] The above-mentioned pipe 11 between the chamber 6 and the vacuum source 10 partly
extends through the rod 22.
[0041] The rotor 7 is bearing-mounted with its ends around the rods 21 and 22 by means of
ball bearings 24. The openings 8 are slots which are directed in the longitudinal
direction of the rotor 7.
[0042] The means 9 for driving this rotor 7 contain two O-belts 25 which are provided in
grooves 26 on the far ends of the rotor 7 on the one hand and over wheels 27 on the
other hand which are fixed on a horizontal shaft 28, next to the above-mentioned wheels
16, which is bearing-mounted with its far ends in the two side walls 18 and 19 by
means of bearings 29.
[0043] The belts 15 are provided around said wheels 16 on the one hand, around a reversing
drum 30 which is driven directly by a motor 31.
[0044] There where the belts 15 touch the reversing drum 30, they are covered by endless
belts 32 which are each guided over three wheels 34 fixed on shafts 33 and a tension
roller 35 which is mounted on the frame 4 in a springy manner. The shafts 33 are bearing-mounted
in the side walls 18 and 19 and are situated such that a part of the belts 32 extends
from top to bottom, over the reversing drum 30, and ends practically horizontally
on an end of an additional conveying device with endless belts 36.
[0045] The stop 17 can be adjusted above the conveying device 3 and can be moved to this
end over guides 37 provided on the inside of the side walls 18 and 19, and it can
be locked upon the latter by means of clamps 38.
[0046] On the side of the rotor 7, auxiliary stops 39 are provided which can be moved crosswise
and which can be locked in one position so as to position the envelopes 1 in the cross
direction as well.
[0047] On the other side, two pressure wheels 40 are provided on the stop 17 which press
on the top side of the conveying device 3 in a springy manner.
[0048] As represented in figures 2 and 3, a number of fingers 41 are situated at the end
of the device, i.e. on the other side of the rotor 7 than the stop 17, which can be
shifted over and which can be rotated around a cross rod 42, but which can be locked
on this cross rod 42 by means of a tightening screw 43.
[0049] This cross rod 42 has been fixed to the side walls 18 and 19 with its far ends and
forms one of the above-mentioned cross connections 20, and it is situated somewhat
higher than the rods 21 and 22, such that the fingers 41 are situated above these
rods 21 and 22.
[0050] The working of this embodiment is analogous to the working described above, with
this main difference that the pile 2 is supported in a different manner and that the
bottommost envelope 1, which is sucked up by the rotor 7, is moved further to the
conveying device 3 by the O-belts 25 after it has been moved by the rotor 7.
[0051] The pile 2 which has been positioned with its back side above the rotor 7 with the
help of the stop 17 and the additional stops 39, rests on the O-belts 25 and, next
to the rotor 7, on fingers 41.
[0052] By means of the belts 14, the rotor 7 is driven by the conveying device 3 and, of
course, synchronously with it.
[0053] When a slot of the rotor 7 is situated opposite the chamber 6, the bottommost envelope
1 is sucked up, as a result of which it bends in between the O-belts 25.
[0054] As soon as this envelope 1 is released again, it is conveyed further by these 0-belts
25, and subsequently by the belts 15, it is turned around by the reversing drum 32
and taken up further by the belts 32 and transmitted to the belts 36.
[0055] According to a variant of the above-described embodiment, the exit of the chamber
6 on the outer surface of the stator 5 does not consist of a slot but of a hole pattern,
preferably an axially directed row of holes.
[0056] Also the openings 8 may consist of a hole pattern instead of of axially directed
slots, in particular an axially directed row of holes.
[0057] The invention is by no means limited to the above-described embodiments represented
in the accompanying drawings; on the contrary, such a device for supplying thin objects
to a conveying device in an overlapping manner can be made in all sorts of variants
while still remaining within the scope of the invention.
1. Device for supplying piled, thin objects, in particular envelopes (1), to a conveying
device (3) in an overlapping manner, characterised in that it contains a rotor (7)
which can rotate around a stator (5) and means (9) for driving the rotor (7), whereby
the stator (5) is equipped with a chamber (6) opening in its outer perimeter which
is connected to a vacuum source (10), and whereby the rotor (7) is provided with openings
(8) which are temporarily situated opposite to the exit of the chamber (6) during
the rotation of the rotor (7).
2. Device according to claim 1, characterised in that the openings (8) are axially directed
slots.
3. Device according to claim 1, characterised in that the openings (8) form a hole pattern
and are preferably axially directed rows of holes.
4. Device according to any of the preceding claims, characterised in that the exit of
the chamber (6) on the outer surface of the stator (5) is an elongated opening which
is directed parallel to the axis of the rotor (7).
5. Device according to any of claims 1 to 3, characterised in that the exit of the chamber
(6) on the outer surface of the stator (5) forms a hole pattern and preferably consists
of a row of holes directed parallel to the axis of the rotor (7).
6. Device according to any of the preceding claims, characterised in that the width of
the exit of the chamber (6) on the outer surface of the stator (5) is almost equal
to the distance, measured on the inside of the rotor (7) and according to the sense
of rotation, between the openings (8) in the rotor (7).
7. Device according to any of the preceding claims, characterised in that the stator
(5) can be adjusted around the axis of rotation of the rotor (7).
8. Device according to any of the preceding claims, characterised in that the means (9)
for driving the rotor (7) contain at least two belts (15) which extent over this rotor
(7).
9. Device according to any of the preceding claims, characterised in that the conveying
device (3) is itself part of the means (9) for driving the rotor (7).
10. Device according to claims 8 and 9, characterised in that the conveying device (3)
contains belts (15) extending over wheels (16), and in that the above-mentioned belts
(15) which extend over the rotor (7) also extend over wheels (27) which are coupled
to the first-mentioned wheels (16).
11. Device according to any of the preceding claims, characterised in that it contains
a stop (17) for the pile (2) which is erected above the conveying device (3).
12. Device according to claim 11, characterised in that the stop (17) can be adjusted,
so that objects (1) having different sizes can be supplied to the conveying device
(3).
13. Device according to any of the preceding claims, characterised in that the conveying
device (3) contains a reversing drum (30) and an additional conveying device guided
over the conveying device (3) near this reversing drum (3) to stop the objects (1)
as they are turned and to subsequently take them over.