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.

Description

TECHNICAL FIELD

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

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.

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.

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 m², 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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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:

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;

FIG. 2 a perspective representation of the closure or lock device with an open closure cover;

FIG. 3 the closure or lock device in accordance with FIG. 2 in the closed position;

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;

FIG. 5 the closure or lock device in accordance with FIG. 4 with the frame and with the closure cover in the closed position;

FIG. 6 a cross-section of the closure or lock device according to FIG. 2 in the open position;

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

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

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.

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.

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.

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.

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.

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.

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.

The respective contact surfaces of the sides 17, 19 corresponding to each other extend in an x-y plane.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.