U.S. patent application number 15/603931 was filed with the patent office on 2017-11-30 for method and an appliance for separating individual, flat, flexible products from the lower side of a stack.
The applicant listed for this patent is Ferag AG. Invention is credited to Othmar Brunschwiler, Marcel Ramseier.
Application Number | 20170341891 15/603931 |
Document ID | / |
Family ID | 58709880 |
Filed Date | 2017-11-30 |
United States Patent
Application |
20170341891 |
Kind Code |
A1 |
Brunschwiler; Othmar ; et
al. |
November 30, 2017 |
METHOD AND AN APPLIANCE FOR SEPARATING INDIVIDUAL, FLAT, FLEXIBLE
PRODUCTS FROM THE LOWER SIDE OF A STACK
Abstract
A method and an associated appliance for the cyclically
controlled separating and singularizing of flat, flexible products
from the lower side of a stack of such products and for conveying
the singularized products away from the stack. The method includes
the: gripping the lowermost product of the stack, separating the
lowermost product from the stack lower side and transporting the
product away from the stack. A first process condition is detected
within cycle-linked measuring time window and a second process
condition is detected within at least one further cycle-linked
measurement time window in the same work cycle, by way of a single
sensor in combination with a control device.
Inventors: |
Brunschwiler; Othmar;
(Bettwiesen, CH) ; Ramseier; Marcel; (Wetzikon,
CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ferag AG |
Hinwil |
|
CH |
|
|
Family ID: |
58709880 |
Appl. No.: |
15/603931 |
Filed: |
May 24, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 29/62 20130101;
B65H 2511/515 20130101; B65H 2220/03 20130101; B65H 2701/1932
20130101; B65H 2220/01 20130101; B65H 2220/01 20130101; B65H
2220/03 20130101; B65H 7/14 20130101; B65H 2511/51 20130101; B65H
2511/52 20130101; B65H 2404/2613 20130101; B65H 2511/524 20130101;
B65H 2511/515 20130101; B65H 3/0875 20130101; B65H 2553/414
20130101; B65H 2511/51 20130101; B65H 2511/52 20130101; B65H 5/26
20130101; B65H 1/06 20130101; B65H 2511/524 20130101 |
International
Class: |
B65H 7/14 20060101
B65H007/14; B65H 1/06 20060101 B65H001/06; B65H 3/08 20060101
B65H003/08; B65H 5/26 20060101 B65H005/26 |
Foreign Application Data
Date |
Code |
Application Number |
May 26, 2016 |
CH |
00681/16 |
Claims
1. A method for the cyclically controlled separating and
singularizing of flat, flexible products from the lower side of a
stack of such products and for conveying the singularized products
away from the stack, comprising the steps of: gripping the
lowermost product of the stack, separating the lowermost product
from the stack lower side and transporting the product away from
the stack, wherein a first process condition is detected within
cycle-linked measuring time window and a second process condition
is detected within at least one further cycle-linked measurement
time window in the same work cycle, by way of a single sensor in
combination with a control device.
2. The method according to claim 1, wherein a third process
condition is determined within a further cycle-linked measurement
time window in the same work cycle.
3. The method according to claim 1, wherein in the respective
measurement time window, at least one measured value is determined
by the sensor and evaluated by the control device, and an
extraordinary process step is initiated in a temporally subsequent
process course given a deviation of the determined measured value
from a predefined set value.
4. The method according to claim 1, wherein the sensor is an
optical sensor for detecting a light signal.
5. The method according to claim 1, wherein the sensor is part of a
light barrier with a light signal source and in particular with at
least one reflector.
6. The method according to claim 5, wherein, from the measured
values, it is determined whether the measuring beam path of the
light signal has been interrupted between the light signal source
and the sensor.
7. The method according to claim 5, wherein a reflector is located
in each case in the reflecting position for reflecting the light
signal towards the sensor, within the respective measurement time
window.
8. The method according to claim 1, wherein within the measurement
time window, it is examined whether the measuring beam path is
interrupted by a product, which is correctly held by the transport
element and moved through the measuring beam path.
9. The method according to claim 1, wherein, within the further
measurement time window, in which, with a correct operation, a
product intermediate space between two consecutive products of two
work cycles is moved through the measuring beam path, it is
examined whether the measuring beam path is interrupted, in
particular by a product that is not correctly separated from the
stack.
10. The method according to claim 9, wherein, within the further
measurement time window, it is examined whether the measuring beam
path is interrupted by a pulled-open, multi-page product or a
surplus product.
11. An appliance for the cyclically controlled separation and
singularization of flat, flexible products from the lower side of a
stack of such products and for conveying the singularized products
away from the stack, with a control device for the cyclically
controlled operation of the appliance, wherein the appliance
comprises a sensor, which in combination with the control device,
is designed for detecting a first process condition within a
cycle-linked measurement time window and for detecting a second
process condition with a further cycle-linked measurement time
window in the same work cycle, for the purpose of detecting
irregularities on separating and transporting away the
products.
12. The appliance according to claim 11, wherein the sensor is an
optical sensor.
13. The appliance according to claim 12, wherein the appliance
comprises a light barrier with a light signal source, and the
optical sensor is part of the light barrier for receiving a light
signal emitted by the light signal source.
14. The appliance according to claim 12, wherein the light barrier
is a reflection light barrier which comprises at least one
reflector for reflecting a light signal emitted by the light signal
source, to the sensor.
15. The appliance according to claim 13, wherein the light signal
source comprises a laser diode.
16. The appliance according to claim 11, wherein a transport
device, by way of which the products are transported away from the
stack, and the at least one reflector is arranged on a moved
component of the transport device.
17. The appliance according to claim 13, wherein the light signal
source of the light barrier is arranged such that the measuring
beam path of a light signal emitted by the light signal source is
interrupted by the product with the away-transport, within the
measurement time window.
18. The appliance according to claim 13, wherein the light signal
source of the light barrier is arranged such that the measuring
beam path of a light signal emitted by the light signal source
leads through the product intermediate space of two products within
the further measurement time window.
19. The appliance according to claim 14, wherein at least one
reflector or reflector section is arranged in a manner such that
given an empty cycle, the light signal is reflected from the
reflector or reflector section to the sensor within the measurement
time window.
20. The appliance according to claim 14, wherein at least one
reflector or reflector section is arranged in a manner such that on
moving an intermediate product space through the measuring beam
path, the light signal is reflected from the reflector or reflector
section to the sensor within the further measurement time window.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The invention lies in the field of conveying flat, flexible
products, in particular printed products. The invention relates to
a method for the cyclically controlled separating and singularising
of flat, flexible products from the lower side of a stack of such
products and for the conveying of the singularised products away
from the stack, with the steps: gripping the lowermost product of
the stack, separating the lowermost product from the stack lower
side and transporting the product away from the stack.
Description of Related Art
[0002] The invention moreover relates to an appliance for the
cyclically controlled separating and singularising of flat,
flexible products from the lower side of a stack of such products
and for conveying the singularised products away from the stack,
with a control device for the cyclically controlled operation of
the appliance.
[0003] The flat, flexible products in particular are printed
products such as newspapers, magazines, periodicals, brochures,
advertising supplements, individual sheets, pamphlets, flyers and
advertising leaflets in the widest sense.
[0004] Appliances for separating and singularising printed products
from the lower side of a stack of printed products and for
conveying away the printed products of the aforementioned type are
known from the state of the art. Such appliances are described for
example in the publication documents EP-A-2 700 599 as well as
EP-A-2 128 055 and EP-A-2 690 040.
[0005] The mentioned appliances, amongst others are applied in
co-called collecting appliances, in which different printed
products are compiled into collections along a collecting
stretch.
[0006] In such a collecting device, the appliance is designed as a
so-called feeder, which is arranged along the collecting stretch
and which each feeds singularised printed products from a stack to
the collecting stretch.
[0007] Several such feeders, which feed different printed products
each from a stack to the collecting stretch in a singularised
manner, can be arranged along the collecting stretch. This means
that each of these feeders includes a stack with identical printed
products.
[0008] The collecting stretch includes a plurality of receiving
elements which are movable along the collecting stretch and which
receive the printed products fed by the feeders along the
collecting stretch whilst forming a collection of printed
products.
[0009] Collections of advertising supplements, for example, can be
compiled in such receiving elements which, for example, can be
receiving compartments or receiving grippers. In a subsequent
processing step, the collections are inserted, for example, as a
supplement into newspapers or periodicals or are processed further
as a dispatch unit.
[0010] Disturbances leading to the collection being incorrectly or
incompletely compiled can occur on compiling such collections. One
possible source of such a disturbance could be at the feeder for
example.
[0011] Thus due to a malfunction, it can occur that no printed
product is singularised from the stack of the feeder, so that the
collection, which is complied with the receiving element and to
which the mentioned printed product is to be fed, is
incomplete.
[0012] Moreover, it can also occur that more than one printed
product is simultaneously pulled from the stack, so that several
identical printed products are fed to a receiving element and thus
to a collection.
[0013] Moreover, such a printed product superfluously pulled off
can also move through the appliance in an unguided manner and lead
to a disturbance.
[0014] A huge significance is placed upon an at least early
detection of such errors or disturbances--inasmuch as they cannot
be avoided--so that suitable measures can be undertaken already at
an early point in time, in order to avoid extensive consequential
measures. This is due to the fact that a fault or disturbance in a
feeder of a collecting device on compiling a collection can have
far-reaching consequences.
[0015] If a collection of printed products, for example, is faulty
or incomplete, then this must either be ejected and newly created,
or corrected or completed, at a later stage.
[0016] The first-mentioned procedure demands an ejecting station
for ejecting the incomplete collections, as well as a return device
for feeding back the printed products of the incomplete collection
into the processing circulation.
[0017] The second-mentioned procedure demands a circulatory
apparatus, in which the receiving elements with the incomplete
collections can be led back into the collecting stretch for the
purpose of completing or correcting the collection.
[0018] If the complied collections of printed products even need to
be arranged in a certain sequence along the conveying path, then
the effort for correcting a faulty collection at a later stage
becomes even greater.
[0019] Faulty collections thus basically lead to an increased
return stream of printed products. This requires much effort and is
also expensive with regard to logistics.
[0020] Moreover, one is also confronted with similar problems in
other applications of the further processing of the printed
products, in which printed products are singularised from a stack
for the further processing.
[0021] Indeed, it is known to detect irregularities by way of
sensors during the processing of printed products, so that suitable
measures can be immediately initiated. However, if the further
processing of the products is to be comprehensively monitored,
which is to say a plurality of process conditions is to be
monitored, then as a rule a plurality of sensors becomes
necessary.
[0022] The application of sensors and the evaluation of the sensor
data by way of a control device however entail an additional
effort. The more sensors are applied, the larger does this
additional effort become and the complexity of the sensor
monitoring increases.
[0023] The published document EP-A-2 279 974 hence describes a
method for the control of a paper-processing machine, according to
which individual sheets are pulled from the lower side of a stack.
Given the occurrence of a fault, this is automatically ascertained
by a detection means. After determining the fault, a measure is
automatically undertaken, in order to counteract the fault. Here
however, it is only a single process condition that is
determined.
SUMMARY OF THE INVENTION
[0024] It is now the object of the invention, to suggest a method
and an appliance of the initially mentioned type, by way of which
irregularities of different types on separating and transporting
products away from the lower side of a stack can be determined as
early as possible and with as little as possible effort.
[0025] Cascading errors in the further processing, which amongst
other things lead to the feeding-back of printed products, shall be
avoided due to the early detection of such irregularities.
[0026] Any occurring operational interruptions given the occurrence
of irregularities during the singularisation and the transport of
the printed products away from the stack shall be avoided or
possibly reduced thanks to the method according to the invention
and to the associated appliance.
[0027] According to the invention, a first process condition is
detected within a cycle-linked measurement time window and a second
process condition is detected within at least one further
cycle-linked measurement time window in the same work cycle, by way
of a single sensor in combination with control device.
"Cycle-linked" is to be understood as being related to the
respective work cycle.
[0028] The first process condition in particular relates to the
correct transporting-away of a product within a work cycle. In the
associated measurement time window, the sensor has the task of
detecting whether a product is correctly transported away in the
respective work cycle, or whether it is the case of a so-called
empty cycle. The empty cycle is a work cycle in which no product is
transported way. This, for example, is because no product has been
pulled from the stack or no product is present in the stack space
of the appliance.
[0029] Such an empty cycle has effects upon the subsequent further
processing with regard to this processing cycle.
[0030] As already initially mentioned, the products in the
appliance are singularised from the stack. The term "singularising"
is to be understood in that the products are detached individually
from the lower side of the stack and are distanced to one another,
which is to say are transported away whilst forming a product
intermediate space. For this, the stack in particular is arranged
in a standing manner. I.e., the products are arranged lying in the
stack. The products are transported away from the stack in
particular downwards.
[0031] The products are accordingly transferred individually and in
a manner spaced from one another to an onward-conveying appliance
or further-processing appliance.
[0032] The second process condition in particular now relates to
the product intermediate space between two consecutive products of
two work cycles. In the associated, further measurement time
window, the sensor in particular has the task of detecting whether
the product intermediate space between two consecutive singularised
products is free or is covered by an incorrectly singularised, in
particular surplus product or products.
[0033] A first cause of a covered product intermediate space can be
due to a multi-page printed product having been opened during the
separation from the stack. It can thus occur that such a multi-page
product is arranged in the stack the wrong way round and this not
being detached from the stack with the fold in front but with the
cut edge in front. This leads to the product concerned being pulled
open, which is to say being opened, when being pulled from the
stack. The pulled-open or opened printed product, which is then
accordingly enlarged with regard to the surface area, now covers
the product intermediate space, which is subsequent in the
transport direction. Such an overlapping is detected in the further
measurement time window.
[0034] A further cause of an overlapped product intermediate space
can lie in several products being simultaneously released from the
lower side of the stack in one work cycle. This can arise, for
example, if high electrostatic attraction forces counteracting a
singularisation of the products arise between two products of a
stack.
[0035] Consequently, it is possible for the surplus separated
product in the associated work cycle to be transported away in an
unguided manner, in particular in a manner in which it is not held
by a transport element and accordingly also transported away in an
uncontrolled manner. Such products are also called "straying"
products. The straying product then covers the product intermediate
space, which is subsequent in the transport direction, and is thus
detected in the further measurement time window.
[0036] In a further development of the invention, a third process
condition can be determined in a further cycle-linked measurement
time window in the same work cycle. As a whole, three measurement
time windows are present in this case.
[0037] Basically, one can also set more than three measurement time
windows within a work cycle, within which time windows a further
process condition is each determined.
[0038] According to a further development of the invention, in the
respective measurement time window at least one measured value is
determined by the sensor and evaluated by the control device.
[0039] In particular, an extraordinary process step is initiated in
a temporally subsequent process course given a deviation of the
determined measured value from a predefined set value.
[0040] According to the invention at least two process conditions
are thus determined within a work cycle by way of a single
sensor.
[0041] The sensor is then arranged in particular in a stationary
manner relative to the appliance.
[0042] The sensor in particular is an optical sensor for detecting
a light signal. The associated measured variable is accordingly a
light signal, which can be detected by the sensor. The light signal
can be emitted periodically or permanently on operation of the
appliance and in particular in one of the mentioned measurement
time windows.
[0043] The detection of measured values by the sensor for the
purpose of evaluation, in particular by way of the control device,
is however effected in only one of the predefined cycle-linked
measurement time windows of a work cycle.
[0044] In particular, an incorrect course of the measuring beam
path of the light signal in the associated measurement time window
is determined by way of the measured values detected by the
sensor.
[0045] According to a further development of the invention, the
optical sensor is part of a light barrier with a light signal
source for emitting a light signal. The optical sensor serves for
receiving the light signal emitted by the light signal source.
[0046] The light signal source and the sensor in particular are
arranged on a common side according to this further
development.
[0047] The light signal source and the sensor thus in particular
form a construction unit. The light signal source and the sensor in
particular can be arranged in a common housing.
[0048] The light signal source and the sensor are arranged on the
appliance in particular in a stationary manner.
[0049] The sensor in particular is part of a reflection light
barrier with a light signal source and at least one reflector.
[0050] The light signal source can include a laser diode. A laser
diode permits the implementation of an extremely reliable
measurement within a very narrow time window
[0051] The term "measurement" here means the emitting of a light
signal by the light signal source and the detecting of the
reflected light signal or the non-detecting of the non-reflected
light signal by the sensor, for the purpose of evaluation, in
particular by the control device.
[0052] In particular, it is determined from the measured values of
the sensor as to whether the measuring beam path of the light
signal between the light signal source and the sensor was
interrupted.
[0053] If the sensor is part of the reflection light barrier, then
a reflector is located in the reflecting position within the
respective measurement time window in each case. Reflecting
position means that the reflector is capable of reflecting a light
signal emitted by the light signal source to the sensor in the case
of an uninterrupted measuring beam path. In its reflecting
position, the reflector is arranged in particular lying opposite
the light signal source and the sensor.
[0054] According to a further development of the invention, within
one of the measurement time windows it is examined as to whether
the measuring beam path is interrupted by a product, which is
corrected transported away and moved through the measuring beam
path, or whether possibly an empty cycle is present, which is to
say a work cycle, in which no product is separated from the stack
and transported away.
[0055] In the latter case, the measuring beam path is not
interrupted and detected by the sensor in this measurement time
window. "Correctly transported away" in particular means that the
product is correctly held by a transport element.
[0056] In this measurement time window, a reflector is thereby
arranged in a manner such that the light signal is reflected
towards the sensor given an empty cycle.
[0057] According to a further development of the invention, within
the other measurement time window it is examined as to whether a
product intermediate space, which is moved through the measuring
beam path, is covered by a product that has not been correctly
separated from the stack and the measuring beam path of the light
signal is therefore interrupted and does not reach the sensor.
[0058] In particular it is examined as to whether the measuring
beam path in this measurement time window is interrupted by a
pulled-open, multi-page printed product or by a straying
product.
[0059] The light signal is not interrupted and reaches the sensor
with correct operation, in which the product intermediate space is
not covered.
[0060] A reflector in this measurement time window is thereby
arranged such that a light signal is reflected to the sensor.
[0061] The invention moreover relates to an appliance for the
cyclically controlled separating and singularising of flat,
flexible products from the lower side of a stack of such products
and for conveying the singularised products away from the stack,
with a control device for the cyclically controlled operation of
the appliance.
[0062] The appliance includes a sensor that, in combination with
the control device, is designed for detecting a first process
condition within a cycle-linked measurement time window and for
detecting a second process condition within at least one further
cycle-linked measurement time window in the same work cycle, for
the purpose of detecting irregularities on separating and
transporting away the products.
[0063] In particular, the appliance forms a stacking space for
receiving a stack.
[0064] According to a further development of the invention, the
appliance includes at least one transport device for transporting
the product away from the stack.
[0065] The transport device is arranged in particular below the
stack or the stacking space.
[0066] The sensor and possibly also the light signal source in
particular are arranged below the stack or stacking space. The
sensor and possibly also the light signal source are arranged in
particular in the region of the transport device.
[0067] The at least one reflector of a light barrier is arranged in
particular on a moved component of the transport device.
[0068] According to a further development of the invention, the
transport device includes at least one transport element.
[0069] The transport element is movable in particular along a
conveying path leading past the sensor.
[0070] The at least one transport element can be movable along a
closed circulating path of a transport circulatory apparatus.
[0071] The transport element can be a gripper.
[0072] If the sensor is part of a reflection light barrier, then
the at least one reflector can be arranged on the transport element
or on a component of the transport device, which is synchronously
co-moved with the transport element, e.g. on a transport
circulatory apparatus.
[0073] The appliance can include one or more reflectors, which are
synchronously co-moved with the transport element.
[0074] The reflector or reflectors can also be arranged in a
stationary manner relative to the appliance.
[0075] In particular, a reflector or a section of a reflector can
be assigned to each measurement time window. Thus, a first
reflector or reflector section can be assigned to one of the
measurement time windows, a second reflector or reflector section
to a further measurement time window and possibly a third reflector
or reflector section to yet a further measurement time window.
[0076] The light signal source of a light barrier in particular is
arranged such that the measuring beam path of a light signal
emitted by the light signal source is interrupted by the product on
transporting away within the measurement time window of a work
cycle, in which empty cycles are to be detected.
[0077] If the transport device includes transport elements such as
grippers for holding the products, then in the respective
measurement time window the emitted light signal in particular is
directed to the transport element or the gripper of the respective
work cycle.
[0078] A reflector or reflector section in particular is arranged
in a manner such that the light signal is reflected from the
reflector to the sensor in the respective measurement time window
given an empty cycle.
[0079] The light signal source of a light barrier in particular is
moreover arranged such that the measuring beam path of a light
signal emitted by the light signal source leads through the product
intermediate space of two consecutive products of two work cycles,
within the further measurement time window of the same work cycle,
in which pulled open or surplus products are to be detected.
[0080] A further reflector or reflector section in particular is
arranged in a manner such that on moving the product intermediate
space through the measuring beam path, the light signal is
reflected from the reflector to the sensor in this further
measurement time window.
[0081] The appliance is operated in a cyclically controlled manner
according to the invention. This means that the products are
separated and transported away from the lower side of the stack in
a predefined cycle. The appliance is thereby operated in particular
in a cyclically synchronous manner with a subsequent processing
appliance, such as a collecting appliance.
[0082] If, for example, an empty cycle, which is detected e.g. in
one of the measurement time windows, is now present, then this
product is missing from the work cycle of the subsequent processing
appliance.
[0083] If the processing appliance is a collecting appliance with
receiving elements for collecting different products into a
collection, then finally this product is missing from the
collection belonging to the cycle.
[0084] The collection is thus incomplete and must be rejected or
completed at a later stage.
[0085] Extraordinary process steps can be initiated in good time in
a subsequent process course thanks to the sensor, which detects an
empty cycle already directly after the separation or more precisely
after a non-separation of the product.
[0086] The extraordinary process steps, for example, can lie in
appliances which are subsequent in the process course likewise
delivering no products to the respective receiving element
including the incomplete collection.
[0087] With this, one avoids further products from being fed to an
already incompletely present collection. Specifically, these
products need to be ejected out of the processing process and led
back at a later point in time.
[0088] Moreover, the extraordinary process steps can also lie in
the respective, incomplete collection being ejected at the next
opportunity or, e.g. via a circulatory apparatus, being led back
into the collecting stretch.
[0089] Extraordinary process steps in a subsequent process course
can likewise be initiated in good time by way of the control device
thanks to the same sensor, which also detects incorrectly or
surplus pulled-off products already directly after the separation
from the stack.
[0090] The extraordinary process steps in this case for example can
lie in ejecting the respective product at a subsequent ejecting
station. The extraordinary process steps can also lie in the
control device initiating an emergency stop which permits the
respective product to be manually removed from the appliance before
this causes an even greater operational interruption. Moreover, the
extraordinary process step can also lie in a warning notice being
brought to the attention of operating personnel or technical
personnel.
[0091] The appliance according to the invention has the advantage
that different process conditions can be determined with a single
sensor, by way of the control device determining sensor measured
values only within a defined measurement time windows which are
each directed to the detection of a specific process condition.
[0092] The appliance according to the invention moreover permits
the early detection of irregularities, specifically already
directly subsequent to the singularising of the products. Suitable
measures can therefore be initiated by way of the control device
already in good time.
[0093] Moreover, no large computation capabilities for evaluating
the sensor data are required thanks to the simplicity of the sensor
and the concept of the cycle-linked measurement time windows. This
permits a processing of the sensor data, and from this, the
derivation of control commands by way of the control device in real
time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0094] The subject-matter of the invention is explained in more
detail by way of one embodiment example which is represented in the
accompanying drawings. There are shown in:
[0095] FIG. 1 is a lateral view of an appliance according to the
invention, at a first point in time of the cycle,
[0096] FIG. 2 is a lateral view of the appliance according to FIG.
1, at a second point in time of the cycle;
[0097] FIG. 3 is a lateral view of the appliance according to FIG.
1, at a third point in time of the cycle;
[0098] FIG. 4 is a further lateral view of the appliance according
to FIG. 1, at the first point in time of the cycle,
[0099] FIG. 5 is a further lateral view of the appliance according
to FIG. 1, at the second point in time of the cycle;
[0100] FIG. 6 is a lateral view of the appliance according to FIG.
1, with an empty cycle;
[0101] FIG. 7 is a lateral view of the appliance according to FIG.
1, with a pulled-open product;
[0102] FIG. 8 is a lateral view of the appliance according to FIG.
1, with a surplus pulled-off product.
DETAILED DESCRIPTION OF THE INVENTION
[0103] Basically, in the figures the same parts are provided with
the same reference numerals.
[0104] FIGS. 1 to 8 show an appliance 1 for singularising flat,
flexible printed products 2 from a stack 3 of such products. The
appliance 1 is controlled by way of a control device 61.
[0105] The appliance 1 forms a stack space 4 for receiving a stack
3 of printed products 2. The stack 3 is arranged in a standing
manner, which is to say the flat sides of the printed products 2
are orientated perpendicularly to the gravitational direction G.
The product 2 of the stack 3 which is at the very bottom in the
gravitational direction G lies with a flat side on the support
surface device 6 supporting the stack 3 from below.
[0106] The appliance moreover includes a takeover circulatory
apparatus 10 with a carrier wheel 13, which is rotatable in the
circulating direction D about a rotation axis A. The carrier wheel
13 is arranged below the support surface and is driven via a
drive.
[0107] The takeover circulatory apparatus 10 includes separating
elements in the form of suction elements 11. These serve for
detaching the products 2 from the lower side of the stack. The
suction elements 11 are arranged on the carrier wheel 13 and are
moved along a closed circulatory path by the rotating carrier wheel
13.
[0108] The suction elements 11 along their circulatory path are
moved towards the lower side of the stack 3 and away from this
again in a cyclically controlled manner by way of the rotating
carrier wheel 13, for each gripping the lowermost printed product 2
in the stack 3.
[0109] The takeover circulatory apparatus 10 moreover includes
transport elements in the form of grippers 12, which are likewise
arranged on the carrier wheel 13. The grippers 12 as the suction
elements 11, are moved along a closed circulatory path by way of
the rotating carrier wheel 13.
[0110] A suction element 11 cooperates each with a gripper 12 and
forms a pairing with this. In the present embodiment, in total four
pairings of suction elements 11 and grippers 12 are arranged in a
manner distanced from one another along the outer periphery of the
carrier wheel 13.
[0111] A suction element 11 is led up to the free lower side of the
lowermost printed product 2 of the stack 3 by way of rotating the
carrier wheel 13, for separating a printed product 2 from the stack
3. The suction element 1 sucks or holds itself firmly on the front
end section of the lowermost printed product 2 and bends this
downwards away from the stack lower side. The lowermost product 2
is thus released or detached from the stack 3.
[0112] The bending-away and release of the printed product 2
downwards is effected via a superimposed movement, consisting of a
pivot movement of the suction element 11 about a pivot axis as well
as of a rotation movement of the suction element 11 with the
carrier wheel 13, which continues to rotate.
[0113] In the further course of the separating procedure, the
suction element 11 now transfers the product 2 onto the gripper 12
of the above-mentioned pairing, the gripper likewise being co-moved
in a rotating manner with the carrier wheel 13.
[0114] The gripper 12 then pulls the gripped printed product 2
downwards away from the stack 3 in a complete manner.
[0115] The movement of the suction elements 11 and of the grippers
12 along their circulatory path, as well as any pivot movements of
the suction elements 11 and of the grippers 12 about a pivot axis
and the closure and opening movement of the grippers 12 is effected
in each case in a cyclically synchronous manner.
[0116] If the printed products 2, which are pulled from the stack
3, are printed products 2 of several pages, each with a fold edge
and a cut edge, then these are each bent away downwards and
transported away with the fold in front.
[0117] The printed products 2 that are transported away from the
stack 3 are subsequently transferred from the gripper 12 onto a
belt conveyor 31.
[0118] According to the present embodiment example, an ejecting
device 41 via which printed products 2a, 2b incorrectly pulled from
the stack 3 can be ejected as yet described further below is
integrated into the belt conveyor 31.
[0119] The ejecting device 41 is designed as a clamping conveyor
with a first and a second conveying belt, which form a discharge
gap. The printed products 2 are discharged from the belt conveyor
31 via the discharge gap.
[0120] The discharge gap is now adjustable between at least two
positions. In a first position of the discharge gap, a printed
product 2 is transferred to the takeover belt conveyor 51 (see
FIGS. 4 and 5). In a second position of the discharge gap, a
printed product 2 is ejected downwards (see FIGS. 1 to 3).
[0121] The position of the discharge gap can be adjusted by
mechanical means, which are controlled by the control device
61.
[0122] The appliance 1 moreover includes a reflection light barrier
for detecting irregularities on singularising the printed products
2 from the stack 3. The reflection light barrier is connected to
the control device 61.
[0123] The reflection light barrier includes a light signal source
71 for emitting a light signal, as well as a sensor 72 for
detecting the emitted light signal. The light signal source 71 and
the sensor 72 are designed as a construction unit and are arranged
on the appliance 1 in a stationary manner in a common housing. The
light signal source 71 and the sensor 72 are arranged below the
support surface of the support device 6 and above a horizontal
plane leading through the rotation axis D of the carrier wheel
13.
[0124] The reflection light barrier moreover includes several first
reflectors 73a, which are arranged on the carrier wheel 13. A first
reflector 73a is each assigned to each gripper 12, wherein the
first reflector is arranged in each case in the proximity of the
gripper 12. As is explained further below, the first reflectors 73a
serve for detecting an empty cycle.
[0125] The light barrier moreover includes several second
reflectors 73b, which are likewise arranged on the carrier wheel
13. A second reflector 73b is assigned to each gripper 12 in a
trailing manner. As is yet explained further below, the second
reflectors 73b serve for detecting a product intermediate space 9,
which is covered over by a printed product 2a, 2 which has not been
correctly pulled from the stack 3.
[0126] The light signal source 71 of the light barrier is thus
arranged such that a product 2, which is correctly transported away
from the gripper 12, is moved through the measuring beam path 74 of
the light signal and interrupts this, within a first cycle-linked
measurement time window.
[0127] The light signal source 71 of the light barrier is moreover
arranged such that a product intermediate space 9, which is
correctly formed between two consecutive printed products 2 of two
work cycles, is moved through the measuring beam path 74 of the
light signal in a second, cycle-linked measurement time window.
[0128] In particular, three forms of irregularities can occur on
singularising printed products 2 from a stack. According to a first
form, no product 2 is separated from the stack 3 in the respective
work cycle. This means that no product 2 is transported away in the
respective work cycle. A so-called "empty cycle" is thus
present.
[0129] According to a second form of an irregularity, the printed
product 2a is arranged in the stack 3 the wrong way round, so that
this is separated and transported from the stack 3 with the cut
edge in front. This results in the product 2a being "pulled open",
i.e. being opened on separating from the stack 3.
[0130] According to a third form of an irregularity, two printed
products are simultaneously separated from the stack 3, wherein
only one printed product 2 is taken over by the gripper 12 and held
by this. The product 2b, which is not held by the gripper 12, as a
so-called "straying product" 2b is therefore transported away
together with the product, which is correctly held by the gripper,
however this being the case in a unguided and accordingly also
uncontrolled manner.
[0131] The light barrier now serves for detecting at least the
three forms of irregularities, which have been mentioned above.
[0132] On transporting away a printed product 2 separated from the
stack 3, by way of the gripper 12, the product is moved downwards
through the measuring beam path 74 of the light barrier. The
product thereby interrupts the light signal, which is emitted by
the light signal source 71.
[0133] A first cycle-linked measurement time window, in which
measured values with respect to the detection of the light signal
are determined by way of the sensor 72, is now set by the control
device 61 during this procedure.
[0134] The first reflector 73a is arranged on the carrier wheel 13
in a manner such that this is located in a reflecting position in
the first measurement time window. This means that the reflector
73a lies in the region of influence of the measuring beam path in
the first measurement time window.
[0135] If the measuring beam path 74 is now interrupted by the
correctly transported-away product 2 in the first measurement time
window, then the sensor 72 accordingly receives no light signal.
From this, the control device 61 recognises that a product 2 was
correctly singularised from the stack 3 in the respective work
cycle.
[0136] Since the measuring beam path 74 is led close to the gripper
12 in the first measurement time window, then it can also be
deduced from the sensor measurement that the detected product 2 is
also indeed correctly held by the gripper 12.
[0137] In the first measurement time window, the light signal is
reflected back to the sensor 72 by the first reflector 73a if an
empty cycle is now present, which is to say the gripper 12 includes
no product 2.
[0138] The control device 61 recognises that an empty cycle is
present by way of the receipt of the reflected light signal within
the first measurement time window. Accordingly, the control device
61 can initiate, e.g., the ejection of an incomplete collection of
a collecting device arranged downstream, the collection belong to
the cycle.
[0139] A second, cycle-linked measurement time window during the
movement of a product intermediate space 9 through the measuring
beam path of the light barrier is set by the control device. The
second reflector 73b is arranged on the carrier wheel 13 in a
manner such that this reflector is located in the reflecting
position within the second measurement time window.
[0140] If a product intermediate space 9 is now moved through the
measuring beam path of the light barrier, then a light signal
emitted within the second measurement time window is reflected back
to the sensor 72 via the second reflector 73b.
[0141] On account of the receipt of the reflected light signal by
the sensor 72, the control device 61 recognises that the product
intermediate space 9 between two singularised printed products 2 of
two consecutive work cycles is free.
[0142] If the product intermediate space 9 is now covered by a
pulled-open or straying product, then the measuring beam path is
interrupted by this product 2a, 2b. Accordingly, the light signal
is not reflected to the sensor 72.
[0143] FIG. 7 by way of example shows how a pulled-open printed
product 2a transported away by a gripper 12 of the takeover
circulatory apparatus 10 covers the product intermediate space 9,
which is subsequent in the transport direction F and thus covers
the measuring beam path 74 of the light signal.
[0144] FIG. 8 by way of example shows how a so-called straying,
surplus printed product 2b, which is transported away together with
a printed product 2 of the same work cycle and which is correctly
held by a gripper 12 of the takeover circulatory apparatus 10,
covers the product intermediate space 9, which is subsequent in the
transport direction F and thus covers the measuring beam path 74 of
the light signal.
[0145] If the sensor 72 now detects no light signal and thus no
product intermediate space 9 within the second measurement time
window, then the control device 61 recognises an operational
disturbance, such as the presence of a surplus printed product 2b
or a pulled-open printed product 2a. The control device 61 can now
initiate one or more of the steps, which have already been
mentioned further above, such as an emergency stop, ejection of the
printed product 2a, 2b concerned, or production of a warning
notice.
[0146] Basically, yet further reflectors can be arranged on the
carrier wheel 13, and these can detect yet further process
conditions within further measurement time windows, in cooperation
with the light signal source 71 and the sensor 72.
[0147] A continuous reflector can also be arranged on the carrier
wheel 13, wherein a reflector section is assigned in each case to a
measurement time window of a work cycle.
* * * * *