U.S. patent application number 10/798544 was filed with the patent office on 2005-09-15 for apparatus including a sucker with autoselection function for handling material.
This patent application is currently assigned to G 01.COM Srl. Invention is credited to Marton, Luigi.
Application Number | 20050200069 10/798544 |
Document ID | / |
Family ID | 34920294 |
Filed Date | 2005-09-15 |
United States Patent
Application |
20050200069 |
Kind Code |
A1 |
Marton, Luigi |
September 15, 2005 |
Apparatus including a sucker with autoselection function for
handling material
Abstract
An apparatus for handling material of the type in sheets or
portions of flat sheets, includes at least one device with an
autoselection function for the lifting-release of the material, of
the type with a vacuum that is obtained between the sucker and the
material, by a vacuum forming device through the Venturi effect or
by means of a vacuum pump. This apparatus is made up of a multi-way
pneumatic supply circuit of an auto-selection and auto-relief valve
that includes principal pneumatic commutators. The commutators are
interconnected to a third commutator that is interposed between the
vacuum forming device and the auto-selection valve that supplies
the sucker.
Inventors: |
Marton, Luigi; (Istrana
(TV), IT) |
Correspondence
Address: |
John S. Egbert
Herrison & Egbert
7th Floor
412 Main Street
Houston
TX
77002
US
|
Assignee: |
G 01.COM Srl
Istrana (TV)
IT
|
Family ID: |
34920294 |
Appl. No.: |
10/798544 |
Filed: |
March 12, 2004 |
Current U.S.
Class: |
271/90 |
Current CPC
Class: |
B65H 3/0891 20130101;
H01L 21/6838 20130101; B65G 2249/04 20130101; B65H 2406/42
20130101; B65H 3/0883 20130101; B66C 1/0268 20130101; B65G 2249/045
20130101; B66C 1/0243 20130101; B65H 29/241 20130101; B65H 2701/173
20130101; B65H 2701/175 20130101; B65G 49/061 20130101 |
Class at
Publication: |
271/090 |
International
Class: |
B65H 005/08 |
Claims
1. Apparatus for handling material, comprising: at least one sucker
for lifting-release of the material, providing a vacuum, obtained
between said sucker and the material to be handled, generated by
vacuum forming means by means of Venturi effect or by a vacuum
pump; and a multi-way pneumatic circuit of an auto-selection valve,
having main pneumatic commutators, the commutators being
interconnected to a third pneumatic commutator interposed between
the vacuum forming means and the auto-selection valve.
2. The apparatus according to claim 1, being essentially divided
into blocks, to which at least one sucker is connected; wherein,
respectively, a first block is comprised of a pneumatic
installation for the supply of dependent blocks, the second and
third, comprising an auto-selector valve that interacts with vacuum
generation means, said first block being comprised of pressure
regulators and interacting commutator electro-valves with an
alternative valve; wherein said first block supplies a second block
that includes the auto-selection valve and is comprised of
pneumatic commutators, a relief valve and vacuum generator
means.
3. The apparatus according to claim 1, wherein the block having the
pneumatic installation supplies one or more suckers, just as the
block that having an auto-selector valve that interacts with vacuum
generation means is applied to every sucker or group of
suckers.
4. The apparatus according to claim 1, wherein said auto-selection
valve comprises two pneumatic commutators, each provided with an
axially movable and elastically yielding piston.
5. The apparatus according to claim 1, wherein the circuit, in the
case of activation, through an impulse the electro-valves of the
first block are excited so that by a first electro-valve the air
impulse passes through the pneumatic commutators of the second
block to supply the vacuum generator; while with the second
electro-valve, the airflow supplies a first pneumatic commutator,
in such a way as to determine the movement of the second piston; in
this case the air originating from the electro-valve, passes
through the alternative valve, moves the sphere allowing the supply
of the circuit, which on entering into the second block determines
the movement of said piston.
6. The apparatus according to claim 1, wherein the circuit with the
airflow originating from the first electro-valve of the first
block, entering into the subsequent block for a few seconds,
activates a depression in the circuit and therefore maintains the
piston of the pneumatic commutator in auto-relief.
7. The apparatus according to claim 1, wherein the circuit
comprises at least one pneumatic commutator of the second block
being provided with a more rigid spring.
8. The apparatus according to claim 1, wherein the circuit has the
airflow introduced from a first electro-valve, passing first
through the pneumatic commutators to the piston of the second
block, then through a third pneumatic commutator provided with a
more rigid spring, to supply the vacuum generator that raises the
sphere of the relief valve thus supplying the circuit with a
depression that simultaneously supplies the sucker for the movement
of the material and the piloting of the circuit.
9. The apparatus according to claim 1, wherein the piloting
depression, passing through the perforations of the shaft of the
piston of the first pneumatic commutator, forms an eddy in the
upper chamber of the commutator maintaining said piston in position
0.1, forming an auto-relief circuit.
10. The apparatus according to claim 1, wherein the circuit with
the auto-relief function is activated when the vacuum has reached a
sufficient depression value to maintain the piston of the second
pneumatic commutator in raised position.
11. Apparatus according to claim 1, further comprising a connection
between the lower chamber of the shaft and the upper chamber of the
piston.
12. The apparatus according to claim 1, wherein, in the case that
the sucker should suffer a substantial loss of adherence or
detaches, the auto-relief of the second commutator of the second
block is automatically de-excited, automatically interrupting the
supply of the vacuum generator.
13. The apparatus according to claim 1, wherein in the circuit, in
the stand-by phase, the first pneumatic commutator of the second
block equipped with a sturdier spring than the spring of the second
commutator, by increasing depression allows the movement of the
piston to the high position, subsequently with respect to the first
commutator, placing it into the auto-relief position, in such a way
as to interrupt the airflow originating from the first
electro-valve of the first block, destined to supply the vacuum
generator.
14. The apparatus according to claim 1, wherein during the loss of
depression phase, the piston of the first pneumatic commutator
moves, placing itself in a low position, so that the airflow
originating from the first electro-valve of the first block
supplies the first pneumatic commutator in a high position which in
turn, through the third pneumatic commutator, will supply the
vacuum generator that re-opens the relief valve.
15. The apparatus according to claim 1, wherein in the circuit, the
depression re-activation phase makes provision for the circuit
depression value to return to the maximum on the re-opening of the
relief valve, in this way re-positioning by auto-relief the piston
of the first pneumatic commutator to a high position and thus
re-closing the compressed airflow originating from the first
electro-valve of the first block with similar closure of the relief
valve.
16. The apparatus according to claim 1, wherein in the circuit, the
detachment phase of the sucker from the material, takes place
continuously to maintain the first electro-valve of the first block
excited and exciting a third electro-valve, which makes a higher
air pressure flow to the circuit than the pressure flowing to the
second electro-valve, thus moving the sphere of the alternative
valve; the air with a higher pressure than that exerted for the
activation of the system for the adherence of the materials
maintains the piston of the first pneumatic commutator in high
position, moreover it moves the cursor of the third pneumatic
commutator to a low position, in this way blocking the supply of
the vacuum generator means, bypassing the airflow directly to the
circuit to the sucker.
17. Apparatus according to claim 1, wherein the vacuum generator
means of the type with Venturi effect are used.
18. Circuit and apparatus that carries out handling with suckers,
wherein a vacuum pump is provided that supplies the circuit for the
sucker detachment phase with a pressurized airflow, exciting the
first electro-valve and de-exciting a fourth electro-valve, when
for all the other previous phases the circuit is supplied by a line
in depression rather than under pressure.
Description
RELATED U.S. APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO MICROFICHE APPENDIX
[0003] Not applicable.
FIELD OF THE INVENTION
[0004] This invention refers to an apparatus including at least one
sucker, with a vacuum obtained by means of the Venturi effect or by
means of a vacuum pump, with an auto-selection function for
handling material of the type in sheets or objects that lend
themselves to being handled with this system.
[0005] The invention finds particular application where the vacuum
is used non-exclusively in the metal plate moving sectors.
BACKGROUND OF THE INVENTION
[0006] In the field of industrial automations, for example,
installations working <<unmanned>> or "lights off",
namely without human presence, the invention assumes particular
interest.
[0007] One of the characteristics that distinguishes said
installations, is the fact that each installation is prepared
during day hours for functioning without human presence during
nocturnal hours.
[0008] A typical case is illustrated by the installations in which
automatic systems are provided for loading, on the construction
line, and unloading of materials to be submitted to processing,
such as metal sheets, plastic material plates, ceramic and glass,
with the aim of allowing processing to be carried out continuously
without the need to intervene at the end of every operative cycle.
Said systems, for example, are required in sheet cutting
installations, those employing laser or plasma techniques, oxygen
cutting, water techniques and also others.
[0009] Generally, therefore, it is possible to consider that this
concerns installations subdivided into at least two working areas,
respectively an upstream unit, including the group loader-feeder of
the material in sheets, an intermediate station, for instance made
up of the cutting apparatus, and a possible downstream adjacent
unit including a stacker-ejector of the sheet processed in this
way.
[0010] With respect to these installations, certain drawbacks have
been observed by operators in this sector, above all with reference
to the most common grill or bench material loading systems in the
intermediate station.
[0011] Among the most well-know systems, proposed for loading and
unloading the sheeting, for example using a cutting apparatus grill
or a bench for a folding press, it is possible to cite
substantially five techniques.
[0012] The first of the four, the primary technique is known for
manual removal of pieces cut from a grill or bench with the
subsequent loading of the new sheet, by means of an overhead crane,
fork truck, purchase block or sucker frame mounted on a fixed
oscillating arm.
[0013] A second solution consists in providing two grills or
benches, operating on the cutting or processing installation, in
such a way as to be operated alternatively on a grill for loading
and unloading, while the other is functioning. A third solution,
for sheet cutting installations, is intended to optimize the system
which in the previous point provided a carousel with a certain
number of grills, collected in a vertical warehouse.
[0014] A fourth solution, suitable for interacting with one of the
systems described previously with respect to the unloading of the
grill, provides a vertical warehouse upstream of the cutting unit,
with more shelves, where the sheets to be processed are
pre-arranged, in such a way that, according to the program, an
extractor or handler with suckers can pick up and transfer the
material on the grill of the intermediate unit so it can be
processed.
[0015] Prior Art
[0016] Therefore, suckers are known the in the field of assistance
for machine tools and in other sectors, which, supported by
conventional systems, are made to adhere the peripheral border of
the circular flange to the flat surface of the underlying material
to be handled. Once placed in contact, a temporary depression is
produced, substantially, which causes the material to remain in
contact with said suckers. In this way the suckers, raising
themselves from the support base of the material, will determine
the subsequent transfer of the material to an adjacent station.
Once placed in the release position, a device provides the
re-balancing of the pressure on the interior of the cups of the
suckers, allowing the detachment of the material. It is therefore
evident given that said suckers are connected to systems that allow
depression generation and re-balancing of the sucker once certain
conditions have been reached. More particularly, said devices
utilize the Venturi effect or in some cases a common vacuum
pump.
[0017] Therefore, for example in U.S. Pat. No. 5,979,889
(Klopfenstein), a practical application of the Venturi effect for
generating a depression in the sucker cup is described. In detail,
the sucker is mounted with the tubular connector along a main rod
that is channelled to intersect it on the bias. A second connector
is coaxial to the main channelled rod and develops until passing
beyond the interconnection point with the tubular pin. In this way,
by introducing a fluid through the second connector, the air
present in the cup in contact with the material is sucked again, so
that the sucker remains in very close contact or adhered to the
surface of the material to be handled.
[0018] Also U.S. Pat. No. 5,928,537 (Fortune) describes a system
that uses the Venturi effect to generate a vacuum on the interior
of a sucker. In more detail, a tool for lifting small portions of
materials is proposed, which is provided on one side with a sucker
and is connected on the other side to a vacuum generator. Said
vacuum generator is connected on one side to a first ON/OFF valve
that allows the emission of compressed air and on the other side,
downstream of the circuit, to a second valve that connects with the
exterior. Operating with the first valve in open position, the
compressed airflow crosses the vacuum generator that is in contact
by means of a connector with the tool provided with a sucker. The
compressed airflow finds a vent in a downstream position set apart
with respect to the tool's connector and continues through the
second valve in open position. In this way, the necessary
re-suction is produced along the tool's connector, so that the
sucker remains in the position of being adhered to the material.
Operating inversely, thus closing the second valve, which is
downstream of the circuit, the compressed airflow passes across the
tool's connector and therefore re-balances the pressure on the
interior of the cup obtaining the detachment of the material.
[0019] State of the Art Most Similar to the Invention
[0020] U.S. Pat. No. 4,750,768 (Kumar), describes an adhering
device. This substantially concerns a pneumatic vacuum generator
that uses an amp fluid sensor that senses the presence of an object
when said object is in contact with the sucker cup. This
circumstance activates the main Venturi effect vacuum generator
that provides for forming the vacuum necessary that makes it
possible for the object to be lifted. An external release signal
determines the arrest of the vacuum to release the object. The
energy for the vacuum, in this case, is to be generated only when
the object is lifted, in such a way as to suppress energy
consumption and noise. Furthermore, it is possible to adjust the
level of force necessary for lifting. The fluid logic circuit,
automatically blocks the vacuum in the sucker, while the supply to
the main Venturi is placed in the OFF position after a
pre-established period of time.
[0021] U.S. Pat. No. 5,795,001 (Burke) describes a device for
manipulating articles. The small hand contains a sucker that
cooperates with a circuit that includes an electric motor coupled
to a vacuum pump. An electronic circuit allows the operator to
control directly the application of vacuum to the sucker.
Furthermore, an electronic circuit detects the prolonged vacuum
between the sucker and the object to be handled and if this reaches
a predetermined low level, the electronic circuit informs the
operator of the condition and automatically re-starts the motor of
the vacuum pump until the depression level is re-established. An
alternative solution to this invention provides for a Venturi
effect vacuum generator that can substitute directly the module
that includes the vacuum pump.
[0022] In conclusion it is correct to affirm that at present it is
known that for the formation of the vacuum in said suckers, a
Venturi for each sucker or a Venturi for several suckers is
applied, and if a depression greater than that which can be
generated by a Venturi was necessary, it is possible to resort to a
vacuum pump that, also in this case, can be applied to one or
several suckers.
[0023] Drawbacks
[0024] In terms of the systems described with the Venturi effect,
these present an economical advantage and are simple to apply. For
example, in the case of the use of several suckers and one Venturi
for each of these, it is guaranteed that if one or several suckers
does not completely adhere to the object, the depression in the
other suckers is maintained, thus ensuring the lifting or
transportation of the piece. In this case it is evident that the
suckers that are not able to create the vacuum continue to be
supplied thus giving rise to the wastage of compressed air. To
compensate for the air loss problem, manual taps can be applied
that block the Venturi supply of the sucker to be excluded.
However, it is evident that this solution appears inconvenient
since manual intervention is required. From a practical point of
view, this circumstance involves the stoppage of the installation
causing increased down times, in one case, it can require
processing on flat material pieces that often present different
dimensions or are not perfectly aligned and coplanar.
[0025] Others systems, to avoid the air loss problem and to manage
the valves manually, provide the application of electro-valves.
These systems involve the use of management software, of electric
wiring or, in the more economic version, a series of switches. From
a practical point of view, the proposal causes considerable
complexity in the installations with the relative implementation
and maintenance costs. However, to this can be added the fact that
the proper positioning of the piece to be lifted is necessary in
order to avoid the useless supply to the suckers that are not
involved.
[0026] In the case in which, unlike the Venturi system, it is
possible to opt for an installation with a vacuum pump, or with a
Venturi for the entire installation, it is necessary to define from
the start of processing the suckers that activate the adhering
function and those that do not. In this hypothesis, in the event
that a good adherence is not provided or the sucker detaches, it
would cause the depression to decline in the entire installation,
thus provoking the detachment of the object from the other suckers
(and eventually the stoppage of the installation).
[0027] Other systems, not mentioned previously include a relief
valve where given the possible unsuccessful adherence of the
object, the aspirated airflow will close the passage thus
eliminating the vacuum supply. It is the opinion of the applicant
that this system is not reliable, since it requires an ample
aspiration flow in order for the device to in turn be able to stop
the it. In a second system a small hole would always remain,
through which air from the exterior continues to be sucked, thus it
is not airtight.
[0028] Here there is the need for the companies to determine
alternative and more effective systems not including those
described previously.
[0029] One aim of this invention is also to avoid the
above-mentioned drawbacks.
BRIEF SUMMARY OF THE INVENTION
[0030] This and other aims are reached with this invention
according to the characteristics as in the included claims, solving
the arising problems, by means of an apparatus for handling
material of the type in sheets or portions of flat sheets,
including at least one device with an autoselection function for
the lifting-release of the material, of the type with a vacuum that
is obtained between the sucker and the material, by vacuum forming
means through the Venturi effect or by means of a vacuum pump; this
apparatus is made up of a multi-way pneumatic supply circuit of an
auto-selection and auto-relief valve that includes principal
pneumatic commutators, said commutators being interconnected to a
third commutator that is interposed between the vacuum forming
means and the auto-selection valve that supplies the sucker.
[0031] Aims of the Invention
[0032] The considerable creative contribution, verified in the
proposal now described, constitutes an immediate technical progress
in order to obtain different advantages.
[0033] First of all, one aim consists in conferring additional
safety to the system described. The principle is based
substantially on the autorelief of the formation of the vacuum
created in the sucker, so that in a series of suckers those that
are not adhered are excluded automatically. For example, in the
event that in an installation a sucker is positioned close to the
edge of the piece to be raised (ref. FIG. 13) and thus experiences
a small loss of air, causing the detachment of the adherence, the
vacuum is aspirated through this sucker and also serves to reduce
the depression in the other suckers thus letting the piece fall (if
the installation has the Venturi effect or a centralized vacuum
pump). With the above-described system this situation would not
occur since the sucker in adherence would automatically be excluded
without compromising the proper functioning of the others. From a
practical point of view, consequently, operator intervention and
control as well as the use of complex management software would be
avoided, providing the installation with particular inexpensiveness
and reliability. Therefore, almost no maintenance with the implied
costs is required, relative to the construction and the
installations, rather than contents.
[0034] A further aim consists in considering a notable saving of
energy, both because the suckers not involved in the lifting
exclude themselves automatically as well as because air consumption
is suppressed since the supply is not required until the sucker is
maintained within the values of the established depression.
[0035] These advantages have the quite relevant value of producing
apparatus with a good technological, multi-functional and extremely
reliable content, even if submitted to particular working
loads.
[0036] Others advantages will appear from the following specific
description of some preferred embodiments, with the aid of the
enclosed schematic drawings, whose implementation details are not
to be considered limitative, but only illustrative.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0037] FIG. 1 is a diagram of the apparatus that is the object of
this invention in the rest position, which represents a plan of the
pneumatic installation for the supply of the autoselection valve
and of the sucker connected to it, cooperating with a Venturi
effect vacuum generator, as well as the connecting circuit between
them.
[0038] FIG. 2 is a diagram of the apparatus that is the object of
this invention as in FIG. 1, in active position.
[0039] FIG. 3 is a diagram of the apparatus that is the object of
this invention, as in previous Figures in auto-relief position.
[0040] FIG. 4 is a diagram of the apparatus that is the object of
this invention, as in previous Figures in stand by/economy
position.
[0041] FIG. 5 is a diagram of the apparatus that is the object of
this invention, as in previous Figures in a position of depression
loss in the sucker.
[0042] FIG. 6 is a diagram of the apparatus that is the object of
this invention, as in previous Figures in a depression reactivation
position.
[0043] FIG. 7 is a diagram of the apparatus that is the object of
this invention, as in previous Figures in a position of detachment
from the piece.
[0044] FIG. 8 is a diagram of the apparatus that is the object of
this invention in the rest position, that represents a plan of the
pneumatic installation for supplying the autoselection valve and
sucker connected to it, cooperating with a vacuum pump, as well as
the connecting circuit between the them.
[0045] FIG. 9 is a diagram of the apparatus that is the object of
this invention in rest position, that represents one variant of the
plan of the pneumatic installation for supplying the auto-selection
valve and sucker connected to it, cooperating with a Venturi effect
vacuum generator, as well as the connecting circuit between
them.
[0046] FIG. 10 is a diagram of an apparatus with several suckers,
supplied by a vacuum pump.
[0047] FIG. 11 is a diagram of an apparatus with several suckers,
supplied by a single Venturi effect vacuum generator.
[0048] FIG. 12 is a diagram of an apparatus with several suckers,
supplied by a corresponding number of Venturi effect vacuum
generators.
[0049] FIG. 13 is an illustrative plan of certain possible sucker
working positions.
DETAILED DESCRIPTION OF THE INVENTION
[0050] With reference also to the Figures, it is observed that in
an installation for handling/lifting of flat material, for example,
in sheets or pieces of sheet M, an apparatus S1, S2 is provided
that includes at least one sucker 1 on the interior of which, when
adhered in correspondence to the material M, is to form the
vacuum.
[0051] More particularly, the apparatus S1, S2 can be divided into
three blocks, respectively A, B and B1 to which at least one sucker
is connected I. The block A is made up of a pneumatic installation
for supplying the blocks B-B1, which are made up respectively of an
auto-selector valve that cooperates with means to generate the
vacuum F1, F2. In this case, said means for generating the vacuum
can include a solution with Venturi effect F1 or a vacuum pump
F2.
[0052] The block A, is essentially made up of:
1 A pressure regulator 1.1 A first rotary converter electro-valve 1
A pressure regulator 2.1 A second rotary converter electro-valve 2
A pressure regulator 3.1 A third rotary converter electro-valve 3
An alternative valve 4
[0053] In terms of the second and third block B-B1, that includes
the auto-selection valve, it is substantially made up of:
2 A first pneumatic commutator C A second pneumatic commutator D A
third pneumatic commutator F A relief valve G A vacuum generator
F1, F2 Portions of the valves groups C, D, E 0,1 high 0,0 low
[0054] As a rule, while the block A serves to supply one or several
suckers 1, the block B-B1 can be applied to every sucker or group
of suckers according to the needs of the installation.
[0055] Apparatus Activation Phase
[0056] In FIG. 2 the activation of the circuit of the
auto-selection valve (V.A.S.) through a compressed air impulse is
represented. This impulse occurs through the excitation of valve 1
and 2 of block A. In terms of the impulse of the air conferred from
the electro-valve 1 it is observed that, passing through the
pneumatic commutator C, D and E, it is intended to supply the
Venturi effect vacuum generator F1. On the contrary, the airflow,
whose concurrence is provided by an impulse from the electro-valve
2, will supply the pneumatic commutator D in such a way as to
establish the movement of the piston D1 in the position 0.1. More
particularly, the air originating from the electro-valve 2, passing
through the alternative valve 4, moves the sphere 4.1 to position
(b), allowing the supply of the circuit P1, which on entering block
B determines the movement of said piston D1 in position 0.1 for the
duration of the pulse.
[0057] In terms of airflow originating from the electro-valve 1
entering into the block B-B1 through the circuit P, it is observed
that this will supply the Venturi F1 and open the relief valve G to
activate a depression in the circuit L and therefore maintain the
piston D1 in auto-relief position (0.1) maintaining this position
only if the sucker I is well positioned.
[0058] The block B-B1 forms part of a third pneumatic commutator E
that is connected to said circuit P1 and P. In this position said
commutator E does not move, as it requires higher pressure since it
is provided with a more rigid spring E2.
[0059] Consequently, the airflow introduced by the electro-valve 1,
along the circuit P passes first across the pneumatic commutator C
and D, then across the commutator E to supply the Venturi effect
vacuum generator F1. The Venturi F1 forms the vacuum that will thus
lift the sphere of the relief valve G in this way supplying the
circuit L with a depression that will simultaneously supply the
sucker I for the movement of the material M and the piloting of the
circuit L. The depression of the piloting on circuit L, passing
through the perforations D3 of the shaft of the piston D1, forms an
eddy in the upper chamber of the commutator D maintaining the
piston D1 in position 0.1, forming an auto-relief circuit. The
depression created in the circuit L involves one or more suckers I.
The suckers, adhered to the piece to be moved, even in the event of
a small intake of air from the exterior, cause a rapid depression
increase in the circuit L until tripping the auto-relief phase of
the system (piston D1).
[0060] Apparatus Autorelief Phase
[0061] (Ref. FIG. 3) At the point when the vacuum has reached a
sufficient depression value to maintain the piston D1 in position
0.1 the electro-valve 2 of the block A is to be de-excited. To
maintain itself in this position a minimum depression is
sufficient; this allows the installation to remain primed even if
there are tolerable losses on the suckers themselves. The
detainment of the piston D1 in position 0.1 takes place through the
depression of the circuit L transmitted across the perforation D3
in the shaft of the piston D1, (that is normally found in position
0.0 pushed by the spring D2) which is held in position 0.1 until
the sucker(s) I maintains a tolerable depression hold on the
material M. If the sucker I should suffer a heavy loss due to
perforations and positioning close to the edge of the material M or
completely outside of the latter, by automatically de-exciting the
electro-valve 2 of block A, the supply of the Venturi F1 is
interrupted. The interruption of the supply of the Venturi F1 can
also take place if the sucker I separates from the material M, thus
interrupting the auto-relief of piston D1 by blocking the flow and
eliminating useless air consumption.
[0062] Apparatus Stand-By Economy Phase
[0063] (Ref. FIG. 4) The depression to be created will continue to
increase until reaching the maximum allowed or pre-established. At
this point, the piston C1 equipped with a spring C2 (adjustable)
sturdier than the spring D2 of the commutator D will be placed in
position 0.1 subsequently (reaching the maximum or established
depression allowed) with respect to the commutator D. The movement
of the piston C1 of the commutator C in position 0.1 will interrupt
the airflow originating from the electro-valve 1 of the block A,
destined to supply the Venturi F1. In this way, useless air
consumption is avoided, while the circuit L in maximum depression,
will maintain the sucker I in adherence on the material M and this
thanks to the tightness of the relief valve G.
[0064] Intervention Phase in Case of Depression Loss
[0065] (Ref. FIG. 5) If the depression of the circuit L, due to
small losses, should fall below the maintenance value in position
0.1 of the piston C1 of the commutator C, placing itself in
position 0.0, the airflow originating from the electro-valve 1 of
the block A will supply the commutator D in position 0.1 which in
turn, through the commutator E, will supply the Venturi effect
vacuum generator F1. The latter, creating the depression flow
again, re-opens the relief valve G.
[0066] Reactivated Depression Phase
[0067] (Ref. FIG. 6) On re-opening the relief valve G the
depression value of the circuit L returns to the maximum, thus
re-positioning the piston C1 of the commutator C to auto-relief in
position 0.1 and in this way re-closing the compressed airflow
originating from the electro-valve 1 of the block A with the
similar closure of the relief valve G.
[0068] Detachment Phase of Sucker I From Material M
[0069] (Ref. FIG. 7) The detachment of the sucker I from the
material M takes place while continuing to keep electro-valve 1 of
the block A excited and exciting the electro-valve 3 which causes a
higher air pressure to flow through circuit P1 than that which
flows through the electro-valve 2, in this way moving the sphere
4.1 of the alternative valve 4 into position (a). The air with a
higher pressure than that exerted for the activation of the system
for the adherence of the sheet will maintain the piston D1 of the
commutator D in position 0.1, moreover it will move the cursor E1
of the commutator E into position 0.0, thus blocking the supply of
the Venturi effect vacuum generator F1 means, bypassing the airflow
directly to the circuit L to the sucker I. The latter, on receiving
the blast of compressed air, rather than a depression, will detach
from the material M rapidly, subsequently the entire system will
remain in an apparatus rest position (ref. FIG. 1) to be ready for
another cycle.
[0070] The apparatus described above can be utilized even without
vacuum generator means of the type with Venturi effect F1. In this
case, instead of supplying the apparatus through the line P with
air pressure, it can be supplied directly by a vacuum pump (ref.
FIG. 8), or from a single vacuum generator of the type with Venturi
effect (FIG. 9), both with dimensions for consumption proportional
to the number of suckers employed. The difference with respect to
the description of previous functioning (a vacuum generator of the
type with Venturi effect for each auto-selection valve) consists in
supplying the line P for the sucker detachment phase with a
pressurized airflow, exciting the electro-valve 1 and de-exciting
the electro-valve 5, when for all the other previous phases it is
supplied by a line in depression rather under pressure.
* * * * *