U.S. patent application number 15/777905 was filed with the patent office on 2018-11-29 for closure or lock device for a vacuum chamber.
This patent application is currently assigned to Applied Materials, Inc.. The applicant listed for this patent is Applied Materials, Inc.. Invention is credited to Christof KLESEN, Ulrich OLDENDORF.
Application Number | 20180339816 15/777905 |
Document ID | / |
Family ID | 57471881 |
Filed Date | 2018-11-29 |
United States Patent
Application |
20180339816 |
Kind Code |
A1 |
OLDENDORF; Ulrich ; et
al. |
November 29, 2018 |
CLOSURE OR LOCK DEVICE FOR A VACUUM CHAMBER
Abstract
Closure device or lock device for a vacuum chamber comprising a
counter plate, which can be arranged on a vacuum chamber and
surrounds an opening of the vacuum chamber, a frame, which is
supported in such a way that the frame can be moved in relation to
the counter plate and on which a closure cover is movably arranged,
wherein the closure cover closes the opening in sealing manner in a
closed position against the counter plate, at least one magnet
device for producing a closing force acting between the counter
plate and the closure cover, which is in engagement with the
counter plate and with the closure cover.
Inventors: |
OLDENDORF; Ulrich;
(Ober-Ramstadt, DE) ; KLESEN; Christof;
(Modautal-Ernsthofen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Applied Materials, Inc. |
Santa Clara |
CA |
US |
|
|
Assignee: |
Applied Materials, Inc.
Santa Clara
CA
|
Family ID: |
57471881 |
Appl. No.: |
15/777905 |
Filed: |
December 2, 2016 |
PCT Filed: |
December 2, 2016 |
PCT NO: |
PCT/EP2016/079555 |
371 Date: |
May 21, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16K 1/24 20130101; B65D
45/02 20130101; F16K 31/082 20130101; F16K 1/2007 20130101; F16K
37/0041 20130101; F16K 51/02 20130101; F16K 1/2085 20130101; F16K
3/18 20130101; F16K 31/0679 20130101 |
International
Class: |
B65D 45/02 20060101
B65D045/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 10, 2015 |
DE |
10 2015 016 081.8 |
Claims
1. Closure device or lock device for a vacuum chamber, comprising a
counter plate, which can be arranged on a vacuum chamber and
surrounds an opening of the vacuum chamber, a frame, which is
supported in such a way that the frame can be moved in relation to
the counter plate and on which a closure cover is movably arranged,
wherein the closure cover closes the opening in sealing manner in a
closed position against the counter plate; at least one magnet
device for producing a closing force acting between the counter
plate and the closure cover, which is in engagement with the
counter plate and with the closure cover.
2. Closure or lock device according to claim 1, wherein the closure
cover has a level top surface and wherein the closure cover can be
slid in a direction parallel to a surface normal of the top surface
on the frame.
3. Closure or lock device claim 1, wherein the closure cover is
connected to the frame via at least one restoring element and
wherein the restoring element is configured to exert a restoring
force directed against the closing force onto the closure
cover.
4. Closure or lock device according to any one of the preceding
claim 1, wherein the at least one restoring element has at least
one restoring spring.
5. Closure or lock device according to claim 1, wherein the closure
cover is arranged via a plurality of restoring elements on the
frame which are spaced apart from each other and wherein a sum of
all the restoring forces from all of the restoring elements acting
on the closure cover is greater than the weight force of the
closure cover.
6. Closure or lock device according to claim 1, wherein the frame
is arranged between an open position and a contact position on the
counter plate or on the vacuum chamber in a swivelling or slidable
manner, wherein in the open position, the frame and the closure
cover arranged on it release the opening and wherein the frame
abuts the counter plate or the vacuum chamber and the closure cover
substantially covers the entire opening in the contact
position.
7. Closure lock device according to claim 6, wherein the closure
cover, where the frame in the contact position can be transferred
from a rest position into the sealing closed position relative to
the frame by means of the magnet device.
8. Closure or lock device according to claim 1, wherein, in the
contact position of the frame, at the sides of the frame and the
counter plate facing each other, at least one spacer is arranged,
the extension of which, perpendicular to the level of the frame or
perpendicular to the level of the counter plate, is at least just
as large as the sum of an adjustment range of the closure cover
between the rest position and the closed position on the frame plus
the thickness of the closure cover.
9. Closure or lock device according to claim 1, wherein the magnet
device has at least one electromagnetic actuator arranged on one of
the closure cover and counter plate and at least one counterpart
arranged on the other closure cover and counter plate, which
magnetically interacts with the electromagnetic actuator.
10. Closure or lock device according to claim 1, wherein an
elastically compressible seal is arranged on the closure cover or
on the counter plate in an intermediate space between the sides of
the closure cover and the counter plate facing each other in a
closed position of the closure cover, which surrounds the
opening.
11. Closure or lock device according to claim 1, furthermore with:
at least one distance measuring device to measure a distance
between the closure cover and the counter plate, wherein the magnet
device can be regulated depending on the distance measured by the
distance measuring device between the counter plate and the closure
cover.
12. Closure or lock device according to claim 11, furthermore with
at least one electronic control circuit, which is coupled with the
distance measuring device and with the magnet device and is
configured to do at least one of maintaining and setting a
predetermined distance between the counter plate and the closure
cover.
13. Closure or lock device according to claim 1, wherein a
plurality of magnet devices are arranged in a distributed manner,
each provided with its own distance measuring device in across the
extent of the opening.
14. Closure or lock device according to claim 1, wherein the
closure cover can be mounted to a guide in a non-contact manner by
means of one or a plurality of magnetic bearings.
15. Closure or lock device according to claim 2, wherein the
closure cover is connected to the frame via at least one restoring
element and wherein the restoring element is configured to exert a
restoring force directed against the closing force onto the closure
cover.
16. Closure or lock device according to claim 2, wherein the at
least one restoring element has at least one restoring spring.
17. Closure or lock device according to claim 3, wherein the at
least one restoring element has at least one restoring spring.
18. Closure or lock device according to claim 2, wherein the
closure cover is arranged via a plurality of restoring elements on
the frame which are spaced apart from each other and wherein a sum
of all the restoring forces from all of the restoring elements
acting on the closure cover is greater than the weight force of the
closure cover.
19. Closure or lock device according to claim 3, wherein the
closure cover is arranged via a plurality of restoring elements on
the frame which are spaced apart from each other and wherein a sum
of all the restoring forces from all of the restoring elements
acting on the closure cover is greater than the weight force of the
closure cover.
20. Closure or lock device according to claim 2, wherein the frame
is arranged between an open position and a contact position on the
counter plate or on the vacuum chamber in a swivelling or slidable
manner, wherein in the open position, the frame and the closure
cover arranged on it release the opening; and wherein the frame
abuts the counter plate or the vacuum chamber and the closure cover
substantially covers the entire opening in the contact position.
Description
TECHNICAL FIELD
[0001] The present invention relates to a closure or lock device
for a vacuum chamber with a counter plate which can be arranged on
a vacuum chamber and surrounds an opening of the vacuum chamber and
a closure cover, which closes the opening in a sealing manner in a
closed position against the counter plate. In addition, the
invention relates to a method for sealing an opening of a vacuum
chamber by means of such a closure or lock device.
BACKGROUND
[0002] Closure and lock devices for vacuum chambers are adequately
known from the most recent background art. In this respect, for
example, WO 2005/121621 A 1 describes a lock device according to
this class for a lock opening arranged in a wall between a first
and a second recipient as well as a shut-off device arranged in the
interior space of the first recipient and a counter plate assigned
to the shut-off device. The flange-like counter plate surrounding
the opening is provided with a circumferential seal, against which
the shut-off device is pressed in a sealing manner.
[0003] To comply with a required tightness, in particular, in order
to comply with high-vacuum conditions inside the vacuum chamber, it
is desirable that the shut-off device presses in the
circumferential direction as evenly as possible in the areas lying
around the opening in a distributed manner. Applying an even and
homogeneous pressing force across the entire seal is particularly
difficult in the case of seals with a seal diameter of a few
millimetres at a dimension of a shut-off element or a closure cover
in the range of several decimetres or meters from a constructional
and manufacturing-technology point of view.
[0004] The implementation of a lift of approximately 0.5 to 2 mm
over the surface of the closure cover compressing the sealing ring
at a range of 0.5 to 5 m.sup.2, for example, or beyond this, has
been shown to be extremely expensive on a constructional and
technical manufacturing level. In addition, the direct contact of
counter plate and the closure cover, which are typically made of
metal, must absolutely be avoided due to reasons regarding required
clean-room conditions and for reasons regarding a required
particle-free environment of the vacuum chamber associated
therewith.
[0005] In addition, any possible shear movements between the seal
and a metal component ending up resting on it must absolutely be
avoided or kept to a minimum when sealing the closure or lock
device, typically between the seal and the closure cover, also for
reasons of complying with the required clean-room conditions and
being free of particle contamination.
[0006] In addition, the fact that the seal, which is typically made
of an elastomer material, for example, made of rubber, can be
subject to an ageing process and that its elastic properties can
change as the closure or lock device continues to be used.
Furthermore, it is conceivable that the vacuum chamber is operated
with different vacuum or pressure levels. Provided that the closure
or lock device seals the interior space of the vacuum chamber
against the atmosphere or another ambient pressure, for example,
against a deviating pressure of an adjacent vacuum chamber, the
contact pressure on the seal can vary depending on the respective
predominate pressure in the vacuum chamber and can result in
relative movements between the seal and the metal parts of the
closure or lock device.
[0007] In this regard, the object of the present invention is to
provide an improved closure or lock device for a vacuum chamber, by
means of which a particularly even and as exclusively perpendicular
as possible pressing force can be exerted on the seal when closing
the vacuum chamber. In particular, it is an objective to avoid any
shear movements or friction on the seal, which is typically
rubber-elastic, between the counter plate and the closure cover or
to reduce the shear movements or friction to an absolutely required
minimum. With the device, a particularly low level of particle
contamination and high level of purity in the area of the vacuum
chamber should be able to be achieved. Furthermore, the closure or
lock device should be characterized by a comparatively low weight
and by easy and good manageability of its individual components
with regard to manufacturing, assembly and long-term operation.
INVENTION AND ADVANTAGEOUS EMBODIMENTS
[0008] This object is solved by means of a closure or lock device
according to independent Patent claim 1. Favourable embodiments are
the object of the dependent patent claims respectively.
[0009] In this respect, a closure or lock device for a vacuum
chamber is provided. The closure or lock device has a counter
plate, which encloses an opening of the vacuum chamber and which
can be arranged on a vacuum chamber or has been arranged on it, or
if applicable, has been integrated into the vacuum chamber or
connected to a chamber wall. The counter plate is typically formed
to be flange-like. It can protrude from the wall of the vacuum
chamber toward the outside and has or forms a contact surface
extending through the opening of the vacuum chamber approximately
perpendicular to the direction of insertion.
[0010] The closure or lock device furthermore has a frame that is
mounted in a moveable manner against the counter plate. In turn, a
closure cover is arranged in a moveable manner. The closure cover
can be brought to the counter plate into a closed position, in
which the closure cover closes the opening of the counter plate in
a sealing manner. It is particularly the frame, which is movably
mounted to the counter plate between an open position and a contact
position. In the open position, the frame and the counter plate
arranged on it releases the opening of the vacuum chamber so that
substrates to be treated in the vacuum chamber can be introduced
into the vacuum chamber and be removed from it.
[0011] In a contact position, the frame is in mechanical contact
with the counter plate. The closure cover, which is moveably
mounted on the frame, can, in that contact position, abuts the
counter plate in a relatively loose manner, typically abutting a
seal enclosing the opening of the counter plate, however without
exerting notable forces on the seal. It is also conceivable that
the closure cover in the contact position of the frame on the
counter plate is contact-free with respect to the counter plate or
with respect to the seal typically arranged on the counter
plate.
[0012] Sealing the opening and thus the vacuum chamber is achieved
by moving the closure cover relative to the frame from the contact
position of the frame, which is already in the contact position
with the counter plate.
[0013] Furthermore, the closure or lock device has at least one
adjustable and/or controllable magnet device or controllable magnet
device in operable connection with the counter plate and the
closure cover. This is configured to generate a closing force (C)
acting between the counter plate and the closure cover. By means of
the adjustable magnet device, the level and the direction of the
closing force acting between the counter plate and the closure
cover can be varied. Depending on the specific embodiment of the
magnet device, both an attractive as well as repulsive force can be
exerted onto the closure cover in order to optionally open or close
the opening of the vacuum chamber by means of the closure cover
depending on the predominate pressure level in the vacuum chamber
and the vacuum chamber environment.
[0014] Thereby, the closure cover can be subject to a comparably
low level of lift or a relatively short or small movement with
relation to the frame. Such small or short movements can be made
separately, and therefore can be especially well controlled or
managed by means of the magnet device. In particular, by means of
this, a defined and especially even deformation of the elastic seal
between the closure cover and the counter plate can be
achieved.
[0015] In further embodiment, the closure cover has a flat top
surface. Furthermore, the closure cover can be slid in a direction
parallel to a surface normal (N) of the top surface on the frame.
Typically, the closure cover is moveably mounted to the frame
between a rest position (U) and the closed position (S). It is
typically translationally or linearly arranged on the frame in a
moveable manner. By means of the closure cover being moveably
mounted to the frame considerably perpendicular to the top surface
and also perpendicular to a level of the frame, the closure cover
can exert a homogeneous pressing force across the extent of the
seal and therefore, also a homogeneous compression on the seal
under the influence of the magnet device.
[0016] In particular, it is provided that the closure cover is
moved by the magnet device only in the direction of the surface
normal with respective to the frame in the case of a frame in the
contact position and starting from a rest position on the frame.
Any shear forces or relative movements rubbing along the seal
between the closure cover and the seal can be considerably avoided
in this way. When closing the closure or lock device, meaning when
transferring the closure cover out of a rest position on the frame
into the closed position compressing the seal, the seal solely or
primarily only experiences a compression that is directed
perpendicular to the level of the closure cover or perpendicular to
the level of the seal. A friction or squashing of the seal in the
transverse direction can considerably be avoided by means of the
mentioned guide of the closure cover on the frame.
[0017] In a further embodiment, the closure cover is connected to
the frame via at least one restoring element. The restoring element
is configured to exert a restoring force onto the closure cover,
which is directed against the closing force, which can be generated
by the magnet device.
[0018] During the sealing closure of the closure or lock device,
the magnet device acting between the counter plate and the closure
cover counteracts the restoring force of the at least one restoring
element. This has the advantage that the magnet device merely has
to generate a force acting in a single direction, namely in the
closing direction.
[0019] Thereby, the magnet device is designed to generate a closing
force that is greater than the restoring force acting on the
closure cover. In particular, the closing force that can be exerted
onto the closure cover by the magnet device is greater than the sum
of the restoring forces of all restoring elements, via which the
closure cover is mounted onto the frame. The magnet device acts, so
to say, against the restoring force of all the restoring elements
to seal the opening. Since the closing force is greater than the
sum of all restoring forces, this leads to a movement of the
closure cover into the closed position when the magnet device is
activated.
[0020] In contrast, in order to open the vacuum chamber, it is
provided to reduce the closing force generated by the magnet device
to at least a predetermined extent so that the effective closing
force is lower than the sum of all the restoring forces of all
restoring elements. As a result, the closure cover is set into the
rest position on the frame via the at least one, typically via a
plurality of restoring elements, in the case of a correspondingly
lower or a completely lacking closure force of the magnet device.
In this, the closure cover is either in a loose contact position to
the seal of the counter plate or, at least one gap between the
closure cover and the seal is available on the counter plate so
that, in the case of the frame being in the contact position, the
closure cover in the rest position is not in contact with the
counter plate or the seal provided on the counter plate.
[0021] In a further embodiment, it is also provided that the at
least one restoring element is an elastic restoring element. In
this respect, the restoring element is elastically deformable and
provides the required restoring force due to its elasticity. An
elastic restoring element can, in particular, be designed as a
single piece in the form of a single component, which is not
subject to any relative movement between the frame or the closure
cover apart from its elastic deformation. The one-piece design of a
restoring element along with its elastic deformability has proven
to be advantageous for adhering to the requirement of being free of
particle contamination. In particular, a friction of the restoring
elements with other components of the closure or lock device are
prevented due to the elastic deformability of the at least one
restoring element.
[0022] According to a further embodiment, the at least one
restoring element has at least one restoring spring. The restoring
spring can, for example, be designed in the form of a leaf spring.
The restoring spring can, for example, extend between the opposite
limbs of the frame. The restoring spring can be connected to the
closure cover at approximately the centre between the frame limbs.
By means of this, a centrical or face-centred mounting of the
closure cover onto the frame can be achieved, which can have a
favourable effect on the linear slidability of the frame.
[0023] According to another embodiment, the closure cover is
arranged on the frame via a plurality of restoring elements spaced
apart from each other. It is been proven beneficial if a plurality
of equal-acting restoring elements and/or a plurality of restoring
springs are arranged in a distributed manner across the surface of
the frame, consequently being arranged across the surface of the
closure cover. In this way, a restoring force that is homogeneous
and defined to the furthest extent possible can be provided across
the surface of the frame or across the surface of the closure
cover.
[0024] According to a further embodiment of this, the sum of all of
the restoring forces exerted upon the closure cover by all of the
restoring elements is greater than the closure cover's weight
force. Such a layout of the restoring elements, for example, makes
a horizontal and, consequently, a reclining alignment of the
counter plate possible, as well as making loading of the vacuum
chamber from above possible. If the sum of all the restoring forces
that can be exerted onto the closure cover is greater than the
closure cover's weight force, the closure cover can also be pulled
upwards by the restoring elements against its own weight force into
the rest position on the carrier. Such a layout of the restoring
forces has proven beneficial for flexibly using the closure or lock
device and, in particular, for a great variety of different
geometrical alignments of the closure or lock device.
[0025] According to another embodiment, the frame is arranged on
the counter plate or on the vacuum chamber between an already
mentioned open position and an already mentioned contact position
in a swivelling or slidable manner. In the open position, the frame
and the closure cover arranged on it release the opening of the
vacuum chamber.
[0026] In particular, a sliding guide is suitable for a
space-saving embodiment and an arrangement of the closure or lock
device in the area of a substrate-treatment process station. Unlike
swivel-mounted closure covers, the area, which is outside of the
opening of the vacuum chamber and, so to say, within an extension
of that opening, can be used to arrange other components of a
process station and does not have to remain free as is the case
with a swivel mount of the closure cover.
[0027] The closure cover can be mounted to the guide in a
non-contact manner by means of one or a plurality of magnetic
bearings. Thereby, a non-contact, and therefore low-wear and
low-maintenance sliding of the closure cover against and relative
to the counter plate is possible. Unlike a roller-bearing guide of
the closure cover, no abrasion takes place in the case of a
magnetic-bearing-based mounting of the closure cover. Required
clean-room conditions and a required freedom of particle
contamination in the area of the closure or lock device can
therefore be easily maintained.
[0028] The magnetic bearings intended for the guide, similar to the
magnet device provided for the closure or lock device, can each
have an electromagnetic actuator and, hereby, a magnetically
interactive counterpart, as well as a distance measuring device and
a control circuit so that the closure cover is mounted at a
predefined distance from the guide in an almost freely suspended
manner and can be moved along the guide by means of the one or a
plurality of magnetic bearings.
[0029] According to a further embodiment, in the case of a frame in
the contact position, the closure cover can be transferred from a
rest position into the sealing closed position relative to the
frame by means of the magnet device. In the contact position, the
frame abuts the counter plate or the vacuum chamber. Thereby, the
closure cover substantially covers the entire opening. It seals the
opening, however, it is still not gas-tight. In this respect, there
can also be an air gap between the closure cover and the seal,
which is typically arranged on the counter plate.
[0030] Only when the magnet device is activated and by the sliding
movement of the closure cover perpendicular to the level of the
closure cover or perpendicular to the level of the carrier and
therefore typically also perpendicular to the opening level, which
is controlled and managed by the magnet device, can the seal
located between the counter plate and the closure cover be
compressed as evenly as possible in the required manner.
[0031] In another embodiment, at least one spacer is arranged
between the frame and the counter plate. In the contact position of
the frame on the counter plate, there is the at least one spacer
between the sides of the frame and the counter plate facing each
other. Typically, a plurality of spacers are proved across the
extent of the counter plate. Via the spacer or spacers, the frame
braces itself on the counter plate upon reaching the contact
position. The geometric design and arrangement of the at least one,
preferably of a plurality of spacers, defines the contact position
of the frame on the counter plate.
[0032] The extension of at least one or of a plurality of spacers
perpendicular to the level of the frame or perpendicular to the
level of the counter plate is at least as large as the sum of an
adjustment range of the closure cover between the rest position and
the closed position on the frame plus the thickness of the closure
cover. Due to spacers measured in such a way, it is ensured that
the closure cover arranged on the side of the frame facing the
counter plate, for example, is out of contact with the counter
plate or the seal provided on it if the frame with the closure
cover on it in the rest position is transferred out of the open
position into the contact position.
[0033] A premature contacting or sliding along of the closure cover
at an area of the seal due to a swivelling or sliding movement of
the frame can be prevented in this way.
[0034] According to an embodiment, the magnet device has at least
one electromagnetic actuator arranged on one of the closure cover
and counter plate and at least one counterpart arranged on the
other of the closure cover and counter plate, which magnetically
interacts with the electromagnetic actuator. The electromagnetic
actuator can, for example, be arranged on the counter plate or
embedded into the counter plate, while the counterpart can be
arranged on the closure cover. Thereby, it is also conceivable that
the counterpart is integrated into the closure cover or that the
entire closure cover acts as a counterpart.
[0035] The counterpart or the closure cover is either designed to
be ferromagnetic or permanently magnetic to engage in magnetic
interaction with the electromagnetic actuator supplied with a
corresponding control current. In a closed position of the closure
cover on the counter plate, in which the closure cover completely
covers the opening cross-section of the vacuum chamber, the
electromagnetic actuator and a counterpart assigned to it are at
least capable of covering in sections, for example, so that a
sufficient closing force or opening force can be generated.
[0036] It is generally conceivable that the electromagnetic
actuator of the magnet device is arranged on the closure cover,
while the counterpart magnetically interacting with the
electromagnetic actuator is arranged on the counter plate or formed
on the counter plate Regardless of whether the electromagnetic
actuator is arranged on the closure cover or on the counter plate,
furthermore, at least one other permanent magnet can still be
arranged on each component, at which the electromagnetic actuator
is arranged, which can provide further support for the force
generated by the electromagnetic actuator. Thereby, for example,
the closure cover can be kept shut without power so that the coil
of the actuator can be supplied with a considerably lower level of
current strength. Heat loss of the coil and problems associated
herewith with regard to cooling or thermal expansion can thereby be
decreased or even eliminated.
[0037] According to another embodiment, an elastically compressible
seal enclosing the opening can be arranged on the closure cover or
on the counter plate within an intermediate space between the sides
of the closure cover and the counter plate facing each other in a
closed position of the closure cover. The seal can be arranged, for
example, on the counter plate. For this purpose, the counter plate
can have a groove surrounding the opening of the vacuum chamber, in
which the circumferential seal is arranged. In an uncompressed
original state, the thickness or the diameter of a seal section is
greater than the depth of the groove accommodating the seal so that
a part of the seal at least slightly protrudes from the side of the
counter plate facing the closure cover, consequently with the
contact surface formed by the counter plate. By means of that
embodiment, the closure cover can end up resting on the seal in a
sealing manner without the metal components of the counter plate
and the closure cover touching each other.
[0038] The sides of the closure cover and the counter plate facing
each other are typically designed as level of contact surfaces at
least in sections, which, in the closed position, extend
substantially perpendicular to the direction (z) specified by the
geometry of the opening of the vacuum chamber or perpendicular to a
closing direction, in which the closing force generated by the
magnet device acts.
[0039] The seal is typically made of an elastomer and has an
elasticity and/or compressibility suitable for the respective
intended purpose. By means of the distance-dependent regulation of
the closing force of the magnet device, it is also conceivable to
use different seals with regard to their elastic or mechanical
properties, each being used for different applications of the
closure or lock device. By means of the distance-dependent
regulation of the closing force, the closure or lock device can
adapted to different or varying elastic properties of the seal
provided. The seal can be designed as an O-ring-like seal,
consequently being a circumferential sealing ring, which is closed
in the circumferential direction.
[0040] Although the seal is preferably arranged within a groove of
the counter plate and the closure cover, which interacts therewith,
is designed without a seal, reverse embodiments are also
conceivable, wherein the seal is arranged on an inner side of the
closure cover, in particular, within a groove of the closure cover
and wherein the counter plate is designed without a seal.
[0041] According to another embodiment, the closure or lock device
has at least one distance measuring device to measure a distance
between the closure cover and the counter plate. By means of the
distance measuring device, a distance, at least at points, can be
measured between the closure cover and the counter plate in the
direction of the closing force generated by the magnet device. The
distance between the closure cover in the counter plate is a
measurement for the currently predominant compression or elastic
deformation of a seal provided between the counter plate and the
closure cover, provided that the closure cover rests above the seal
on the counter plate. Consequently, the degree of elastic
deformation of the seal can be measured by means of the distance
measuring device.
[0042] Furthermore, for the closure or lock device, it is provided
that the magnet device can be regulated by the distance measuring
device depending on the distance measured between the counter plate
and the closure cover. By means of the distance-dependent
regulation of the magnet device provided in this respect, different
closing forces depending on the distance at hand can be generated
so that, for example, the seal provided between the counter plate
and the closure cover can be compressed to the required extent. By
means of the distance measuring device and the back-coupling to the
at least one magnet device provided in this respect, a variety of
different states of the closure or lock device can be detected.
[0043] For example, by means of the distance measuring device, it
can be measured if and to what extent the counter plate and the
closure cover abut each other in a sealing manner. If the distance
should be approximately above a maximum value provided for an
adequate seal, by means of the adjustable magnet device, the
closing force can, for example, be incrementally increased until
the distance falls below the maximum permissible maximum
distance.
[0044] In the opposite case, it is also conceivable that, in the
case of detecting or measuring a distance between the counter plate
and the closure cover that is too small, a direct contact of the
counter plate, which is typically made of metal, and the closure
cover must be feared. In particular, due to reasons of a required
freedom of particle contamination in the ambient environment of the
vacuum chamber, this must absolutely be avoided. In such a case,
the closing force level can be incrementally reduced until a
minimum permissible distance between the closure cover and the
counter plate is exceeded.
[0045] Thereby, by means of the distance-dependent regulation and
control of the magnet device, different or temporally varying
pressure levels within the vacuum chamber can also be responded to.
By means of a pressure differential between the interior space of
the vacuum chamber and the ambient environment or by means of a
pressure differential on the side of or beyond the closure cover, a
closing force or opening force per se can already be present on the
closure cover. By means of the distance-dependent adjustable magnet
device, varying pressure differentials on the opposite sides of the
closure cover can be compensated for.
[0046] Furthermore, according to a further embodiment, at least one
electronic control circuit is provided, which is coupled with the
distance measuring device and with the at least one magnet device
and is configured to maintain and/or to set a predetermined
distance between the counter plate and the closure cover. The
control circuit typically has a setpoint device, by means of which
the distance signals, which can be generated by the distance
sensor, are compared with a predetermined target value. By
comparing the target value and the current value, a controller
downstream from the setpoint device can generate a control signal
to control the magnet device, in particular, to control the
electromagnetic actuator.
[0047] Each control signal that can be generated by the controller
can be supplied to the electromagnetic actuator, typically via an
amplifier. By means of the electronic control circuit, an active
and automatic regulation of the closing force can be implemented.
In this way, a dynamic and situation-related response to any sudden
or continuous changes of the operating or ambient conditions can be
carried out, such as a change of the pressure differential between
the interior space of the vacuum chamber and the ambient
environment. By means of the control circuit coupling the distance
measuring device and the magnet device with each other, a required
distance between the counter plate and the closure cover and
thereby, also a required pressing force of the closure cover as
well as a compression of a seal provided between the counter plate
and the closure cover associated therewith can be brought about and
maintained in a controlled manner.
[0048] According to another embodiment, a plurality of magnet
devices, each provided with their own distance measuring device,
are arranged in a distributed manner across the extent of the
opening and the extent of the flange-like counter plate, for
example. By providing a plurality of magnet devices arranged in a
distributed manner across the extent of the opening, a particularly
even pressing and closing force can be set between the counter
plate and the closure cover. Furthermore, by means of this, it
makes it possible to compensate for any deformations or
manufacturing inaccuracies of the counter plate and/or the closure
cover in a system-controlled manner.
[0049] Each of the distance measuring devices coupled with a magnet
device respectively can, so to say, self-sufficiently maintain and
set a predetermined distance between the counter plate and the
closure cover at the location of the corresponding distance
measuring device or magnet device. Pressure-dependent and
inevitable very minimal deformations of the closure cover, which
would otherwise lead to an uneven pressing or closing force of the
seal can thereby be compensated for in an effective manner and an
uneven gap size with respect to a varying distance across the
extent of the opening between the closure cover and the counter
plate can be countered.
[0050] Any load-dependent or manufacturing-related deformations or
component tolerances can be compensated for in a system-controlled
manner. By means of a plurality of magnet devices, each
respectively provided with its own distance measuring device,
different closing forces and contact pressures can be generated on
a local level across the extent of the opening or across the extent
of the counter plate so that, as a result, a homogeneous
compression of the seal is achieved to the furthest extent possible
and can be set in a controlled manner, which leads to a required
tightness of the closure or lock device. Within the scope of
practical application, that embodiment is particularly beneficial,
namely, in particular, if at least one of the closure cover and the
counter plate are not designed to be absolutely rigid and/or are
subject to local load-dependent deformations.
[0051] By means of a plurality of magnet devices, each provided
with a distance measuring device respectively, such effects can be
eliminated and compensated for in a system-controlled manner. Even
comparably large component tolerances or mechanical deformations
can be accepted for the construction of the closure cover and/or
counter plate so that for even comparably large-scale embodiments
of the closure cover and the counter plate a comparably filigree
construction can be provided with a comparably lower weight.
[0052] According to another embodiment of the closure or lock
device, it is provided that magnet devices arranged in a
distributed manner across the extent of the opening of the vacuum
chamber or across the extent of the counter plate or across the
extent of the closure cover are each coupled with their own control
circuit. Thereby each of the magnet devices can, independently of
each other, set and regulate the present distance or gap size
between the closure cover and the counter plate at their respective
positions. As a result, a processing of the obtainable distance
signals from the respective distance measurement devices can take
place at a local level within the area of the magnet devices and
control circuits. By means of this, any data and signal lines can
be reduced to a minimum, which can prove to be particularly
beneficial for applications in the vacuum sector.
[0053] According to another embodiment, the magnet devices arranged
in a distributed manner across the extent of the opening and/or the
distance measuring devices assigned to the magnet devices are
coupled with a central control system. The central control system
can be provided instead of a local control circuit or, however, in
addition to the respective magnet device and to the related control
circuit assigned to the distance sensor. By means of a central
control system, which is, for example, coupled with all control
circuits of all magnet devices with data connections, a synchronous
control of the control circuits can take place in a particularly
simple manner.
[0054] For example, the central control system can be coupled with
the setpoint device of the individual control circuits respectively
so that, by means of the central control system, a distance to be
maintained between the counter plate and the closure cover can be
simultaneously transferred to all control circuits. By means of the
central control system, the user of the closure or lock device
obtains an operating element that is particularly easy to operate,
with which a distance to be maintained or a corresponding gap size
between the closure cover and the counter plate can be
synchronously or simultaneously set for all control circuits and
magnet devices.
[0055] For each of the various embodiments of the closure or lock
device, diverse distance measuring devices can be provided. The
distance measuring device can, for example, have one or a plurality
of distance sensors based on an optical, magnetic or capacitive
measurement principle. In particular, sensors are used that are
based on an inductive measurement principle or based on eddy
currents. The distance sensor is particularly arranged in close
proximity to the magnet device, in particular, in direct proximity
to the electromagnetic actuator or to the counterpart of the magnet
device so that a higher degree of co-location can be achieved to
the furthest extent possible. The directly adjacent or even
covering arrangement of the distance measuring device and the
magnet device contributes to improving measurement and control
accuracy. The distance sensor can, in particular, be arranged on
the counter plate and therefore measure a distance, in particular,
a gap size between the counter plate and the closure cover. A
distance sensor arranged on the counter plate is, in particular,
configured to measure the distance from a defined reference surface
or a reference point of the closure cover in a precise manner,
typically with an accuracy within the sub-millimetre or in the
micrometre range.
SHORT DESCRIPTION OF THE FIGURES
[0056] Other objectives, features as well as favourable embodiments
of the invention are explained in the following description of the
exemplary embodiments taking the drawings into consideration. In
the figures:
[0057] FIG. 1 a simplified schematic illustration of the closure or
lock device with the frame supporting the closure cover in the
contact position and a closure cover in the rest position on the
frame;
[0058] FIG. 2 a perspective representation of the closure or lock
device with an open closure cover;
[0059] FIG. 3 the closure or lock device in accordance with FIG. 2
in the closed position;
[0060] FIG. 4 another embodiment of the closure or lock device with
a slidable frame mounted to the counter plate or the vacuum chamber
in the open position;
[0061] FIG. 5 the closure or lock device in accordance with FIG. 4
with the frame and with the closure cover in the closed
position;
[0062] FIG. 6 a cross-section of the closure or lock device
according to FIG. 2 in the open position;
[0063] FIG. 7 a representation in accordance with FIG. 6, however,
with the frame in the contact position and the closure cover in the
rest position on the frame; and
[0064] FIG. 8 a representation in accordance with FIG. 7, however,
with the closure cover in the closed position with respect to the
frame.
DETAILED DESCRIPTION
[0065] The closure and lock device 10 shown as a cross-section in
FIG. 1 is provided for arrangement at an opening 14 of a vacuum
chamber 12. The closure or lock device 10 has a counter plate 16,
which is typically connected to the wall 11 of the vacuum chamber
12 schematically indicated in FIG. 1. The counter plate 16 can be
arranged flush with the opening 14 of the vacuum chamber 12 on the
wall 11 or as an integral component of the vacuum chamber 12. In
this respect, the counter plate 16 can also have an opening 14,
which can typically coincide with the opening of the vacuum chamber
12.
[0066] As is evident in the overview in FIG. 2, 3, as well as 6 to
8, the considerably level closure cover 18 in this embodiment is
mounted to a frame 15 by means of a plurality of restoring elements
82 in a slidable manner. Thereby, the slidability and the
deflection of the restoring elements 82 result from a comparison of
FIGS. 7 and 8. The frame 15 itself is, for example, swivel-mounted
to the counter plate 16. In FIGS. 2 and 3, a corresponding swivel
or hinge axis 80 is shown. In the embodiment in FIGS. 4 and 5, the
frame 15 is linearly mounted to the counter plate 16 in a sliding
manner.
[0067] The side 19 facing the counter plate 16 of the closure
cover, consequently the inner top surface 81 is substantially
level. In the rest position U of the closure cover 18 relative to
the frame 15 shown as an example in FIG. 7 and in the case of the
frame 15 in the contact position K located on the counter plate 16,
the top surface 81 is aligned substantially parallel to a level of
the seal 22, which is located in the groove 20 on the side 17 of
the counter plate 16 facing the closure cover 18.
[0068] In a closed position 28 shown in FIG. 8, the closure cover
18 seals the opening 14 in a gas-tight and vacuum-tight manner.
Furthermore, the counter plate 16 and the closure cover 18 are
provided with at least one magnet device 30, by means of which a
closing force (C) can be exerted on the closure cover 18.
[0069] The counter plate 16 can have a flange-like geometry and, in
particular, have a seal 22 on a side 17 facing the closure cover 18
and acting as a contact surface, which extends around the opening
14, typically in the area of an opening boundary of the counter
plate 16. In the present disclosure, the seal 22 made of an elastic
and deformable material is arranged in a surrounding groove 20 of
the counter plate 16. However, it can also be arranged within a
corresponding groove of the closure cover 18 or in an intermediate
space 25 between the closure cover 18 in the counter plate 16.
[0070] Upon reaching a closed position S shown in FIG. 8, the seal
22 is deformed between the closure cover 18 in the counter plate 16
and squashed in such a way that the opening 14 is sealed in a
gas-tight manner.
[0071] By means of the magnet device 30, a closing force (C) on the
closure cover 18 can be exerted in the insertion direction or
closing direction (z). The closing force (C) is typically aligned
perpendicular to the level (x, y) or perpendicular to the contact
surface or to the side 17 of the counter plate 16. The closure
cover 18 also has a side 19 facing the counter plate 16, which also
acts as a contact surface. The sides 17, 19 facing each other in
the closed position 28 of the counter plate 18 and the closure
cover 19 are aligned parallel to each other, at least in
sections.
[0072] The respective contact surfaces of the sides 17, 19
corresponding to each other extend in an x-y plane.
[0073] In the present disclosure, the magnet device 30 has at least
an electromagnetic actuator 32 arranged on the counter plate 16 as
well as a counterpart 34 arranged on the closure cover 18, which
magnetically interacts with the electromagnetic actuator 32. The
counterpart 34 is designed as a permanent magnetic or ferromagnetic
component, which is either arranged on the closure cover 18 or
embedded into the closure cover 18. It is also conceivable that the
closure cover 18 itself includes a permanent magnetic or
ferromagnetic material, at least in sections, or at least in areas
or is completely made of such a material.
[0074] By powering or by applying electrical power to a coil 33 of
the electromagnetic actuator 32, an attractive or repulsive force
can be exerted on the closure cover 18. By regulating the current
strengths or by varying the control signal, the closing force (C)
generated by the magnet device 30 can be varied according to the
requirements at hand.
[0075] Furthermore, the closure or lock device 10 optionally has a
distance measuring device 40, by means of which a distance 41
between the closure cover 18 and the counter plate 16, in
particular a distance between the sides 19, 17 of the closure cover
18 and the counter plate 16 facing each other can be measured in a
determinable and quantitative manner. In the present disclosure,
the distance measuring device 40 has a distance sensor 42 arranged
on the counter plate 16, which measures a distance 41 in the
closing direction (z) between the counter plate 16 and the closure
cover 18. By means of the distance measuring device 40, thereby,
the magnet device 30 can be regulated, in particular the closing
force (C) generated by it, depending on the distance. In
particular, it is provided that, by means of a distance-dependent
regulation of the magnet device 30, the distance 41 between the
closure cover 18 and the counter plate 16 can be set to a
predetermined extent in a precise manner.
[0076] For the distance-dependent regulation, in particular, a
control circuit 45 is provided, which couples the magnet device 30
with the distance measuring device 40. The control circuit 45 has a
setpoint device 44, which is connected to the distance sensor 42 on
a data/technical level. The setpoint device 44 receives the
distance signals provided by the distance sensor 42 and compares
these with a predefined or a variably specifiable target value from
a central control system. The actual and target value are compared
with each other in the setpoint device 44.
[0077] A comparison signal resulting from this is then supplied to
a controller 46, which generates a control signal provided to
control the electromagnetic actuator 32. That control signal that
can be generated by the controller 46 can be supplied to the
electromagnetic actuator 32 via an amplifier 48.
[0078] The amplified control signal, which can be supplied to the
coil 33 of the electromagnetic actuator 32 is calculated and
determined in such a way that a predetermined distance 41 between
the counter plate 16 and the closure cover 18 is maintained and
that, in the case of deviations of a required distance, the force
generated by the magnet device 30 can be dynamically adapted to
maintain the distance 41.
[0079] All electronic components of the control circuit, meaning
the amplifier 48, the controller 46, the setpoint device 44, and,
if applicable, also the distance sensor 42 can be accommodated
altogether on a single PCB, for example, in the form of an
integrated control circuit. The space required for a corresponding
electronic unit and the wiring effort associated therewith can be
minimized in this respect.
[0080] In addition to the coil 30, to which electrical signals can
be applied, the electromagnetic actuator 32 typically has a
ferromagnetic core, for example an iron core. The electromagnetic
actuator 32 can be designed as an electromagnet, however in a
variety of different ways, for example, also as a Lorentz or
voice-coil actuator. In contrast to an electromagnet, the latter
can generate not only attractive, but also repulsive forces between
the electromagnetic actuator and the counterpart.
[0081] The groove 31 intended to hold the electromagnetic actuator
32 or its coil 33 has to be covered and/or sealed facing the
counterpart 34 for reasons relating to vacuum suitability. A cover
21 provided for this is typically made of a magnetically permeable
material or out of the non-magnetic or only weakly magnetic
material. The cover 21 can act almost as a closure for the groove
31 and can be designed as such. By means of separate seals, which
are not explicitly shown in the present disclosure, the cover 21 is
arranged over or in the groove 31 in a sealing manner. The cover 21
can, in particular, be integrated into the side 17 facing the
counterpart 34 in a flush manner, consequently into the contact
surface of the counter plate 16 or the closure cover 18. For the
sake of clear illustration, the cover 21 in FIG. 1 is only shown on
the right side of the counter plate 16. Each of the magnet devices
30 arranged in a distributed manner across the extent of the
opening 14 can be regulated according to the distance 41
predominant within their range between the counter plate 16 and the
closure cover 18 so that a distance 41 remaining the same or
maintained within slight tolerances can be set across the entire
outer extent of the opening 14.
[0082] As is furthermore shown in FIG. 1, there is at least one
spacer 24 between the side 17, 19 of the counter plate 16 and the
closure cover 18 facing each other, which acts as an end-stop for
the frame 15.
[0083] In the uncompressed state of the seal 22, as shown in FIG.
7, the seal 22 protrudes from the side 17 of the counter plate 16
at least slightly.
[0084] In the rest position U of the closure cover 18 relative to
the frame 15 and the contact position K of the frame 15 relative to
the counter plate 16 shown in FIG. 7, there is an air gap between
the closure cover 18 and the counter plate 16 or between the
closure cover 18 and the seal 22. It can also be provided that the
closure cover 18 abuts the seal 22 in that rest position U without
being compressed and therefore in a relatively loose manner.
[0085] Upon activating the magnet device 30, the components of
which are only schematically shown in FIG. 6-8 in comparison to the
illustration according to FIG. 1, the closure cover 18 experiences
a shifting movement compressing the seal 22 according to a closing
force C acting upon it. The compressed seal 22' is indicated in
FIG. 8. In the present embodiment, the closing force C interacts
with the weight force G of the closure cover 18. The closing force
C acts against a restoring force R of individual restoring elements
82. The restoring elements 82 are, as is evident in FIG. 3,
designed as leaf springs 83 in the present disclosure.
[0086] The frame 15 is designed as a circumferential closed frame.
It has two longitudinally extending limbs 85, 86, which run
substantially in parallel, which are connected to each other at
their longitudinal ends via had sections 87, 88 on the end sides.
Roughly centred between the head sections 87, 88 a connection
bridge 89 is provided, which connects both limbs 85, 86 again on a
structural level and, in this respect, increase the stability and
the stiffness of the frame 15. The leaf springs 83 are arranged in
pairs. Opposite ends of the leaf springs 82 are arranged on the
opposite limbs 85, 86. The leaf springs 83 are connected to the
closure cover 18 at approximately the centre between the limbs 85,
86. A deflection of the closure cover 18 perpendicular to the level
of the frame 15, consequently parallel to the surface normal N of
the closure cover 18 by means of the magnet device 30 therefore
takes place against the restoring force R generated by the
restoring springs 83.
[0087] As is best evident from FIGS. 6 and 7, a plurality of
spacers 24 are arranged in a distributed manner across the extent
of the opening 14 on the side 17 of the counter plate 16 facing the
closure cover 18. The spacers 24 are typically made of plastic, in
particular, made of a high temperature resistant plastic, for
example, out of polyether ether ketone (PEEK), which has only a
slight or unnoticeable tendency to outgas, even under vacuum
conditions.
[0088] In the contact position K of the frame 15 on the counter
plate 16, the frame 15 rests on the spacers 24 with its underside
facing the opening 14. Thereby, the spacers 24 form a type of
end-stop for the swivel movement of the frame 15. Corresponding to
the arrangement of the spacers 24 on the counter plate 16, on the
outer edge of the closure cover 18, corresponding recesses 23 are
provided, which are interspersed with spacers 24 when assuming the
contact position K. The recesses 23 allow for large-scale covering
of the opening 14 by the closure cover 18 without obstructing a
frame support arranged as close as possible on the opening 14, or
the frame 15 resting on the counter plate 16.
[0089] As is evident from FIG. 7, there is a defined gap between
the closure cover 18 in the seal 22 in the contact position of the
frame 15 and the rest position U of the closure cover 18 shown
there. By activating the magnet device 30, the closure cover 18 is
pulled toward the counter plate 16 according to the closing force
C. As a result, the restoring elements 82 are deflected toward the
counter plate 16. They provide a restoring force R, which
permanently acts on the closure cover 18. In the case of decreasing
closing force or in the case of deactivating the magnet device 30,
the restoring elements 82 and the restoring springs 83 lead the
closure cover 18 out of the sealing closed position S, as is shown
in FIG. 8, thereby compressing the seal 22, back into the rest
position U again.
[0090] Movably mounting the closure cover 18 to the frame 15 is of
an advantage in this respect, thereby being able to exert
relatively high closing forces onto the closure cover 18. Due to
movably mounting the closure cover 18 against the frame 15, those
forces are however not transferred to the frame 15. As a
consequence, a hinge 90 formed by the swivel access 80 does not
have to be able to absorb any of the closing forces generated by
the magnet device 30. The mechanical stress on the frame 15 is
primarily only present due to the restoring force R which is
transferred from the deflected restoring elements 82 between the
closure cover 18 in the closed position S onto the frame 15. Once
the closure cover 18 is in the closed position S shown in FIG. 8,
an increase of the closing force C only has slight or no mechanical
effects on the frame 15. In FIGS. 4, and 5, an alternative
embodiment of the present invention is shown. In contrast to the
embodiment according to FIGS. 2, 3 and 6, the frame 15 there is
mounted in a slidable manner against the counter plate 16 and
against the vacuum chamber 12. FIG. 4 shows the frame 15 with the
closure cover 18 arranged on it in an open position, while FIG. 5
shows the frame 15 and the closure cover 18 in the contact position
K or the closed position S. The frame 15 is mounted in a slidable
manner along the extended guides 62, 64 above and below, or on the
opposite head sections 87, 88.
[0091] The guides 62, 64, which are designed as linear sliding
guides, extend parallel to the level of the counter plate 16 of the
frame 15 and/or of the closure cover 18. Due to the closing
movement of the closure cover 18 the guides 62, 64 are arranged a
sufficient distance away from the counter plate 16 in order to
allow for a non-contact sliding of the closure cover 18 against the
counter plate 16, in particular also against the seal 22 provided
on the counter plate 16, which at least slightly protrudes from the
level of the counter plate 16.
[0092] The linear guides 62, 64 can be designed as non-contact
guides. A plurality of magnetic bearings 60 can be arranged in the
area of the guides 62, 64.
[0093] Similar to the magnet devices 30, the individual magnetic
bearings 60 can each have a distance sensor (not shown separately
in the present disclosure), a control circuit, as well as an
electromagnetic actuator 61, which can be controlled via the
distance sensor and the control circuit which magnetically interact
with a counterpart 63. In this way, a required suspended state of
the closure cover 18 on the guides 62, 64 can be achieved. A
non-contact mounting of the closure cover 18 on the guides 62, 64
is of a particular advantage in avoiding contamination and wear in
the area of the vacuum chamber 12. In this case, a plurality of
electromagnetic actuators 61 are provided along the guide 62, which
successively engage with the counterparts 63 arranged on the frame
15 in the case of sliding the frame 15.
[0094] Thereby, reverse arrangements are both equally within the
scope of the present invention. For example, one or a plurality of
actuators 62 can be arranged on the frame 15 or on the closure
cover 18 while counterpart 63 magnetically interacting therewith is
arranged in a stationary manner on the linear guide 62, 64 designed
as a guide rail.
[0095] In FIG. 4, the frame 15 and the closure cover 18 are shown
in the open position O, in which the closure cover 18 is outside of
the area of the opening 14 of the counter plate 16.
[0096] Thereby, the mounting of the closure cover 18 to the frame
15 has the effect of providing support for a type of parallel
displacement of the closure cover 18 from the rest position U into
the closed position S so that no relative movements of the closure
cover 18 and the seal 22 occur in the plane of the closure cover
(X, Y) to the furthest extent possible. Such shear movements could
otherwise lead to the wear of the seal 22 and at least minor
contamination of ambient environment of vacuum chambers 12.
[0097] The non-contact mounting of the closure cover 18 to the
guide 62, 64 takes place via the frame 15 designed in a slide-like
way and connected to the closure cover 18. One of the components of
the respective magnetic bearing 60, i.e. a component of
electromagnetic actuator 61 and a counterpart 63, is arranged on
the guide 62, 64 in a stationary manner while the other component
of the actuator 61 and the counterpart 63 is arranged on the frame
15. For example, a linear motor 68 is provided to shift the closure
cover 18 and the frame 15 along the guide 62, 64, by means of which
the closure cover 18 can be moved between the open position 0 and
the contact position K against the counter plate 16.
* * * * *