Sliding door assembly for ICP torch box

Abstract

A sliding door assembly (50) for an inductively coupled plasma torch box (40) reduces the risk of heat-related injuries and facilitates handling of the torch box. The door assembly (50) includes a door and a guide mechanism (6) for allowing the door to move along an opening (45) of the torch box (40) in a first direction so as to enable opening and closing of the torch box, and allowing the door to move in a second direction substantially perpendicular to the first direction so as to move the door or at least a portion thereof toward the opening when closing the torch box. The door may include an inner door panel interconnected with an outer door panel so that only the inner door panel moves in the second direction toward the opening (45) of the torch box (40) to tightly close it, while the outer door panel can maintain a safe temperature during operation.

Description

Technical Field

[0001] The present invention relates to a sliding door assembly for a plasma source chamber or torch box of a spectrometer, such as an ICP torch box used in an ICP emission spectrometer. Background Art

[0002] Plasma sources are commonly used in optical emission and mass spectrometers. In a plasma source, such as an inductively coupled plasma (ICP) source, a plasma is generated at high heat, in which atoms and molecules can be ionized. In such plasmas, extremely high temperatures may occur, such as temperatures of 8,000 K or even 10,000 K.

[0003] In optical emission spectroscopy, vaporized atoms and ions in a plasma are brought to a high energy state. The atoms and / or ions then relax to their ground state, during which they emit electromagnetic radiation at a wavelength that is characteristic of the element involved and that depends on the quantized energy level structure of each atom or ion.

[0004] The detection of emitted photons can be performed by radial or side observation of the plasma or by axial or end observation of the plasma. Radial observation is the typical operating mode of an optical emission spectrometer. The optical path toward the detector generally involves an optical periscope that directs the incident radiation toward the detector. The periscope has an internal mirror that deflects the incident electromagnetic radiation toward the detector. Due to the close proximity of the periscope to the plasma and the strong heat and radiation from the plasma, the optical mirror inside the periscope may need to be replaced. Moreover, the plasma source requires regular maintenance. Therefore, the user needs to be able to regularly approach the interior of the plasma source chamber. Due to the high temperatures involved, care must be taken whenever the ICP source or source chamber is handled after the source has been used. Therefore, any mechanism for opening and closing the source chamber must be heat-proof not only during use but also when the chamber is opened for any type of maintenance or adjustment after use, and all parts that the user interacts with, such as door handles and external surfaces, should be thermally isolated from the heated interior. In addition, the source chamber and door mechanism must also prevent UV light and electromagnetic radiation from going out and entering, so that the instrument as a whole meets the electromagnetic compatibility requirements of laboratory standards.

[0005] An example of an ICP chamber is disclosed in US 4,664, 477. Prior art ICP chambers have hinged doors which are less practical because the open door, which may be hot, extends towards the operator of the instrument. Summary of the invention

[0006] The present invention seeks to provide a solution to the above challenges by providing a sliding door assembly for use with an ICP torch box / source chamber. The sliding door assembly reduces the risk of heat-related injuries because it eliminates the possibility of accidentally touching the inner surface of the door. It further enables smooth and reliable opening and closing of the torch box and improves accessibility to the chamber because the door moves out of the way when fully opened and does not restrict the space in front of the opening for operation and access.

[0007] In one aspect, the present invention relates to a sliding door assembly for use with an inductively coupled plasma (ICP) torch box, the door assembly comprising a door, a guide mechanism for allowing the door to move in a first direction along at least one access opening of the ICP torch box to allow the torch box to be opened and closed, and allowing the door or at least a portion thereof to move in a second direction substantially perpendicular to the first direction so as to move the door or at least a portion thereof toward the at least one access opening when closing the torch box.

[0008] By using a sliding door to close the access opening of the torch box, space in front of the torch box is saved and the risk of touching hot parts is significantly reduced. By using a sliding door that can preferably move parallel to the opening and towards (and away from) the opening in a single movement, a good sealing of the opening can be achieved in a simple manner. The sliding door assembly of the present invention is preferably arranged for essentially linear movement in two directions. In addition, the sliding door assembly of the present invention is preferably without hinges and can be arranged to avoid rotational movement of the door parts.

[0009] Hence, the guide mechanism is preferably arranged for enabling substantially linear movement in both the first direction and the second direction.

[0010] Typically, the torch box has a single opening, which may be referred to as an access opening, as it provides access to the torches. However, embodiments are envisioned in which the torch box has two or more openings, which may be closed by a single sliding door or multiple sliding doors.

[0011] The second direction can be completely perpendicular to the first direction, so the 90 0 angle, but smaller or larger angles, such as 45 0 , 60 0 or 80 0 angle.

[0012] The sliding door assembly may include a sealing mechanism for sealing the door to the torch box in an accurate and fully closed position. Preferably, the sliding door assembly includes at least one resilient member for applying pressure to the door or door component in a second direction when the door is closed. The sealing mechanism may advantageously be elastic, for example comprising a silicon strip protruding from a groove surrounding the at least one access opening of the torch box or a door frame surrounding the at least one opening closed by the door mechanism and / or protruding from a groove on the inside of the door.

[0013] The sliding door assembly preferably includes a locking mechanism for locking the door in a closed position. 'Locked' as used herein indicates that the door slides to a specific final closed position and a force is required to move it out of the locked position, so it "locks" into the specified final closed position, preferably with a click and / or noticeable tactile feedback indicating to the user that the position has been reached.

[0014] In some embodiments, the door of the door assembly comprises an inner door panel and an outer door panel, which are preferably interconnected so that the inner door panel is moved by the outer door panel. The configuration of the inner door panel and the outer door panel provides enhanced thermal insulation to ensure that the outer side of the door does not get too hot. The guide mechanism is preferably arranged so that it only allows the outer door panel to move in a first direction (forward and backward) parallel to the plane of the opening of the torch box, while allowing and guiding the inner door panel to move in both the first direction and the second direction (and the corresponding opposite direction). Therefore, this can be configured so that the outer door panel engages with the first sliding mechanism to allow the outer door panel to move longitudinally in the first direction forward and backward (opening and closing direction) in a manner that the inner door panel follows the outer door panel, and wherein the inner door panel and the outer door panel are interconnected via a second sliding mechanism to allow the inner door panel to move relative to the outer door panel in both the first direction and the second direction. With this mechanism, when the door is placed in a fully closed and locked position, the distance between the inner door panel and the outer door panel can be increased so that the door is pressed against the chamber, thereby providing an effective seal. Preferably, moving the outer door panel in the first direction will cause the inner door panel to be in the second direction at the same time. In some embodiments, the inner door panel moves over a portion of its trajectory in the first direction and the second direction at the same time.

[0015] In one embodiment, the inner door panel is configured so that the door assembly has a first closed position and a second closed position, the first closed position being achieved by longitudinal movement of the door along the first sliding mechanism toward the inner door stop in a first direction, and the second closed position being achieved by the inner door panel moving longitudinally and transversely (i.e., in the first direction and the second direction, respectively) relative to the outer door panel within the door assembly along the second sliding mechanism after reaching the first closed position. This can be suitably arranged so that when the inner door panel reaches the inner door stop, the inner door panel cannot move further in the first direction (longitudinal direction), but the outer door panel can move further, and by doing so, the second sliding mechanism guides the inner door panel in the second direction. Therefore, as the outer door panel moves further in the first longitudinal direction, the inner door panel moves not only in a perpendicular (or second) direction relative to the plane of the opening of the torch box, but also in two directions relative to the outer door panel.

[0016] Thus, in one embodiment of the door assembly of the present invention, the outer door panel and the inner door panel are interconnected so that after the door has reached the first closed position, as the outer door panel moves further in the first direction / closing direction and the inner door panel moves inwardly toward the torch box opening, the spacing (distance) between the outer door panel and the inner door panel increases. In other embodiments, after the door has reached the first closed position, both the outer door panel and the inner door panel move inwardly, resulting in the same functional result, i.e., the inner door panel moves closer to the torch box opening. Thus, if a seal is placed between the inner door panel and the torch box, the seal is compressed as the inner door panel moves closer to the opening.

[0017] The second closed position is defined as the final position when the inner door panel is in the desired final position, which is moved inwardly toward the torch box opening to create a seal. Typically, when the second closed position has been reached, the door cannot be moved further.

[0018] The inner door stop may be suitably located on the ICP torch box on which the door assembly is to be mounted, or on the door frame of the assembly, or associated with the assembly to be mounted on the torch box. This door frame may be considered part of the door assembly, but may also be considered a separate optional component associated with the torch box but configured to operate with the door assembly.

[0019] As will be appreciated from the above, the second sliding mechanism may be suitably actuated by applying a force to the outer door panel in a first direction after the inner door panel has met the inner door stop. This may be arranged, for example, by providing the second sliding mechanism with at least one pair of parallel inner guides arranged longitudinally (along the first direction) between the inner door panel and the outer door panel, and at least two pairs of bearings interconnected with the inner guides. The inner guide member may be fastened to the outer door panel and a pair of bearings mounted on a support fastened to the inner door panel, or vice versa, meaning that the inner guide member may be fastened to the inner door panel and a support holding the bearings mounted in this case on the outer door panel in an alternative embodiment. Therefore, when a force in a first direction is applied to the outer door panel, after it has reached the first closed position and the inner door panel stops at the stopper, further moving the outer door panel will cause the bearing to move along the inner guide component (because the inner guide component or the bearing is moving in the first direction with the outer door panel, but the inner door panel cannot move further in said direction), thereby applying a lateral force on the inner door panel, and thereby causing the inner door panel to move in an inward direction toward the opening of the torch box, and ultimately into the second closed position.

[0020] The inner guide member may preferably be provided with a slot and the bearing holding the bearing is positioned so that the bearing is placed in and cooperates with the slot and can move within the slot when the door panels move relative to each other, each slot having an open end and a closed end and being shaped so that when the door moves toward the second closed position, the bearing moves along the slot in a longitudinal and inward direction toward the closed end of the slot until they reach the closed end and the door is in the final closed position. The closed end of the slot is further away from the outer door panel than the open end of the slot so that when the bearing is in the closed end, the door panels are further apart than when the bearing is in the open end of the slot. In embodiments where the inner guide member is fastened to the inner door panel and the bearing holding the bearing is arranged on the outer door panel, the same applies, but in said embodiments the bearing has a fixed distance to the outer door panel and the slot is therefore shaped so that the closed end of the slot is further away from the outer door panel than the open end so that when the bearing is in the closed end of the slot the distance between the inner door panel and the outer door panel is greater than when the bearing is in the open end of the slot.

[0021] The slot may suitably have a gradient geometry so that as the door moves towards the second closed position, the inward movement of the inner door panel decreases in magnitude relative to the simultaneous (relative) movement in the first direction. In other words, this means that as the outer door panel moves towards the second or final closed position, the inner door panel moves inwardly with a progressively decreasing movement relative to the unit length of movement of the outer door panel as the outer door panel approaches the final closed position. Typically, the force required to move the door from the first position to the second position is thus progressively reduced.

[0022] The sealing mechanism mentioned above can be advantageously disposed on the inner door panel for firmly sealing the inner door to the ICP torch box or its door frame. The sealing mechanism can be provided by a heat-resistant elastic seal extending around or near the outer periphery of the inner door panel, so that when in the closed position, the elastic seal meets the outer surface of the IPC torch box (the surface having the opening closed by the door assembly) or the door frame tightly fixed to the torch box to generate a seal therebetween.

[0023] Preferably, the resilient seal is compressed by the inward movement of the inner door panel during the guided movement of the inner door panel by the second sliding mechanism. It can be seen that the outer door panel is connected to the guide mechanism so that it cannot move laterally, and therefore, as the outer door panel moves towards the final closed position, the second guide device acts to push the outer door panel and the inner door panel apart, and when the outer door panel remains substantially fixed in its plane, the inner door panel is pressed inwardly and cannot move laterally.

[0024] Preferably, the locking mechanism as mentioned above is arranged in the door assembly, which is used to lock the door assembly in the second closed position as described above. The locking mechanism can be arranged with a groove in the groove of the inner guide near the closed end of the groove, so that when the door moves toward its second closed position, the corresponding bearing matching the groove is pushed into the groove, thereby locking the door in the second closed position.

[0025] The locking mechanism may also be of other types, such as any of a variety of suitable latch embodiments or a spring-action male and female locking mechanism that becomes engaged when the door is pushed into the locked position. Preferably, the locking mechanism provides a tactile feel when the locking mechanism locks and preferably "clicks" into position so it is not inadvertently almost closed but not fully closed.

[0026] In some embodiments, the door assembly is further provided with an electronic closing sensor which senses whether the door is fully and properly closed and is connected to the instrumentation system so that the torch box cannot be operated unless the sensor gives a positive signal that the door is closed.

[0027] It follows that the groove is preferably formed to have a main direction that is generally inclined relative to the opening / closing movement direction of the door (first direction), which forces the bearing (and the inner door panel) downward when the door moves from the first closed position to the second closed position, and forces the bearing (and the inner door panel) upward when the door is opened from the second closed position to the first closed position.

[0028] Preferably, the groove of the mentioned slot providing the locking function holds the bearing slightly closer to the outer door panel than halfway through an edge point where the bearing must pass defining a boundary point between the groove and the main area of ​​the slot. The edge point is thus the point of highest sealing pressure and is preferably shaped to form a tactile barrier, i.e. to provide a tactile sensation when the bearing falls into the groove and the door thus falls into the locked position.

[0029] In a useful embodiment, the slots and grooves thereon are so shaped and interact with the bearings that when the bearings are not pushed enough past the edge point, they will pivot away from the edge point, which means that if the door is not fully closed and has not reached the locked position (the bearings are not pushed past the edge point), the bearings will pivot back and thus the door will slide back. In some embodiments, one or more springs are arranged to provide a force that pulls the springs back from the almost closed position to a more open position. Similarly, if the door is pushed slightly from the closed locked position, but not enough to push the bearings out of the grooves and past the edge point, they will pivot back and the door will return to the fully closed and locked position.

[0030] In some embodiments, one or more springs are disposed and arranged between the inner door panel and the outer door panel to provide a force to pull the door into a final closed position or to provide a force to pull the door open from a position that is never fully closed. Thus, in some embodiments, if the door does not reach the locked position, one or more springs provide additional force in the direction of pulling the door open, for example, if a slot is provided as described above, such one or more springs can provide a force to pull the door back if the door is not pushed past the edge point into the locked position.

[0031] The present invention further provides an ICP torch cabinet having a sliding door assembly as described herein.

[0032] Another aspect of the present invention provides an inductively coupled plasma optical emission spectrometer comprising an ICP torch box having at least one sliding door assembly as described herein.

[0033] Yet another aspect of the invention provides for use of an ICP torch box having at least one sliding door assembly as described herein. Such use may include opening and / or closing the torch box by movement generally parallel to a front surface of the torch box. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Those skilled in the art will appreciate that the drawings described below are for illustration purposes only and are not intended to limit the scope of the present teachings in any way.

[0035] Figure 1 An exploded view of a door assembly according to the present invention is shown.

[0036] Figure 2A side view of a door assembly according to the present invention is shown.

[0037] Figure 3 A perspective view of the door assembly is shown in a closed position.

[0038] Figure 4 A perspective view of the door assembly is shown in an open position with the outer door panel removed from the figure.

[0039] Figure 5 The door assembly is shown in a second closed position (without the outer door panel).

[0040] Figure 6 A close up view of the slot in the guide of the second slide mechanism of the guide arrangement is shown.

[0041] Figure 7 A door frame of a door assembly according to the present invention is shown.

[0042] Figure 8 An alternative embodiment of a door assembly according to the present invention is presented.

[0043] Fig. 9A and 9B A schematic diagram of an ICP torch box with a sliding door assembly according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0044] Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings. These examples are provided to provide a further understanding of the present invention, but not to limit its scope.

[0045] In the following description, a series of steps are described. Those skilled in the art will appreciate that the order of the steps is not critical to the resulting configuration and its effects unless the context requires. Further, it will be apparent to those skilled in the art that regardless of the order of the steps, the presence or absence of time delays between steps may exist between some or all steps.

[0046] The sliding door according to the present invention can be arranged on an ICP torch box, such as an ICP torch box for an ICP emission spectrometer. The sliding door allows easy and safe access to the interior of the torch box and can have a two-stage mechanism for closing the door, thereby providing a safe closing and sealing mechanism for the interior of the torch box from its surroundings.

[0047] Thus, the sliding door may be adapted to move along an opening of the ICP torch box, which opening may be provided in a wall of the torch box. When the door moves from an open position to a closed position, the door moves in two directions; a first direction along the opening of the ICP torch box, and a second direction approximately perpendicular to the first direction towards the opening and therefore towards the ICP torch box. When the door moves in the second direction, the door is sealed in a locked position, thereby isolating the interior of the box. Movement in the second direction preferably follows movement in the first direction, i.e., first moving in the first direction to close the ICP torch box, followed by moving in the second direction to lock the door in the closed position, while providing a seal between the door and the torch box.

[0048] The sliding door can be configured as an assembly comprising two door panels, an inner door panel and an outer door panel. During a first movement of the door assembly, the inner door panel and the outer door panel move in a consistent manner; movement in the second direction is preferably achieved only by the inner door panel. Thus, the inner door panel provides a seal between the door assembly and the torch box.

[0049] exist Figure 1 An exploded view of the main parts of a door assembly according to an embodiment together with a guide device of such a door assembly is shown in FIG. Figure 1 It is shown how the guide block 7 is fastened to the outer door panel 3 using screws 8. Adhesive fasteners 30 are fastened to the outer door panel to hold an optional outer front cover 5 (not shown).

[0050] A window frame 22 is arranged on the outer door panel 3 to expose a window on the inner door panel 2, said window comprising a window 32 (preferably made of heat-welded glass to block UV light) and a grille 33 formed by a drilling pattern in the inner door panel 2 (this makes it possible to observe the plasma without generating an opening for electromagnetic radiation). The glass 32 can be held by, for example, two or four clamps. The handle 4 is fastened to the outer door panel with a screw 31. The second guide 9 is fastened to the outer door panel with a screw 11. The second guide has a groove 10 that interacts with a bearing 12 held by a support member 13. The support member 13 is fastened to the inner door panel 2 with a screw 29. A seal 28 is adhered to the inner side of the inner door panel. The guide block 7 can slide along the track 6. When the door moves toward the fully open position, the outer door stop 15 stops the sliding movement of the door.

[0051] Figure 2 A side view of the door assembly is shown, showing the outer door panel 3 interconnected with the inner door panel 2. An optional front cover 5 is fixed to the outer door panel 3, and a handle 4 is also fixed to the outer door panel 3 for operating the door. The outer door panel 3 is connected to the parallel guide rails 6. A support member 13 is fixed to the inner door panel 2; a bearing (not shown in this figure) is attached to the support member, the bearing cooperating with a groove in a second guide member 9 forming part of the second guide means. The second guide member 9 is fixed to the outer door panel 3. The sliding of the inner door panel 2 stops when the inner door stop 14 has reached the desired closed position.

[0052] The door assembly is assembled so that the inner door panel and the outer door panel can move in unison when the door slides along the guide rails 6. Stops 14, 15 limit the movement of the inner door panel 2 along the side of the torch box (i.e., parallel to the torch box opening), while the inner guide 9, specifically the slot 10 and bearing 12 in the inner guide 9, provide a mechanism to urge the inner door panel 2 inward when the door is closed.

[0053] During use, the door assembly moves along the guide rail 6 in a first direction along the opening in the side wall of the torch box. As the door moves toward the closed position (in Figure 1 4 (from right to left in the torch box), the inner door panel 2 will reach the inner door stop 14. As a result, the inner door panel 2 can no longer move in the first direction, i.e., in front of the opening of the torch box, substantially perpendicular to the direction of access to the opening. Continuing to apply force to the door assembly, such as by applying force to the handle 4 toward the closed position, will apply force to the outer door panel 3 and the groove 10 attached in the guide member 9. At the same time, the bearing 12 fixed to the inner door panel will be forced to move along the groove 10. As a result, the outer door panel 3 will continue to move along the torch box opening (in the first direction), while the inner door panel 2 will be forced to be in a second direction perpendicular to the first direction. When the outer door panel 3 has moved so that the bearing 12 has reached the end of the groove 10, further movement of the outer door panel and the inner door panel is prevented, and the door has reached the closed and locked position.

[0054] Figure 3 A perspective view of a door assembly is shown having a front cover 5 secured to an outer door panel 3 and a handle 4. A window frame 22 is disposed in the outer door panel 3 (and the front cover 5) to expose a window 23 disposed in the inner door panel 2 through which the plasma can be observed.

[0055] Figure 4 The details of the door assembly are shown by removing the outer door panel 3 from the figure. Here, the door assembly is in the fully opened position. The first direction of movement (opening / closing direction) is indicated by arrow X, and the second direction, i.e. the lateral direction, is indicated by arrow Z. A first sliding mechanism is shown, which includes a guide rail 6 and a guide block 7 that can slide along the guide rail 6. The guide block 7 is fastened to the outer door panel 3 with screws 8 (for clarity in FIG. 1 ). Figure 4). The track and guide block fit together so that the guide block can only move forward and backward along the track, but cannot move upward from the guide track transversely to the sliding direction. The guide rail 6 is fastened to the front surface of the ICP torch box (the surface with the opening of the torch box, which the door assembly will close and open), or to a door frame 25, which is fastened to the front surface of the torch box. A pair of parallel second guide members 9 are shown, which are fixed to the outer door panel 3 with screws 11 (not shown in this figure). The support member 13 is fixed to the inner door panel 2. A bearing 12 that cooperates with the guide groove 10 of the second guide member 9 is attached at the end of the support member 13. When the door moves toward the closed position, by pushing the handle 4 in the first direction, the outer door panel 3 moves with the handle (because these are connected), and as the groove 10 pulls the bearing 12 fixedly arranged to the inner door panel 2 via the support member 13, the inner door panel 2 moves forward. The inner door panel 2 will eventually meet the inner door stopper 14 (which may also be referred to as the inner stopper) and cannot move further. If the handle is pushed further, the outer door panel 3 will move further together with the second guide member 9 to which it is fixed, so the slot 10 also moves in the longitudinal direction, and due to the shape of the slot 10, the bearings 12 are forced inwardly (toward the torch box opening) until they reach the end of the slot 10. The inner door panel 2 moves together with the bearings 12 and is therefore pressed inwardly toward the door frame 25 of the torch box.

[0056] At the closed end of the groove 10, the bearing 12 can be locked into the groove of the groove 10 ( Figure 8 26), provided that such grooves or other means are provided to define the end position of the bearing 12. Generally speaking, an end position defining surface can be provided, which can be composed of grooves and / or at least one ridge, and which can assist the bearing 12 to reach a stable predetermined end position.

[0057] Springs 16 are arranged between the inner door panel and the outer door panel. These springs 16 exert a force to pull the door back from the approximately closed position (if the bearing 12 has not reached the groove or edge in the slot to enter the defined closed position). The springs 16 thus assist in providing movement of the bearing 12 so that the door will not remain in the approximately but not completely closed position.

[0058] exist Figure 5 1 and 2 (and for clarity, the outer door panel 3 is not shown in this figure). The handle 4 has been moved until first the inner door panel 2 hits the inner stop 14, and then the outer door panel is pulled further with the fixed second guide 9, so that the slot 10 moves into the closing direction and the bearing 12 remains put in this direction (because the inner door panel cannot move further), but as the slot 10 moves, the bearing 12 is forced inwards until the bearing 12 meets the closed end of the slot. At the closed end, the slot 10 may have a tiny groove and / or notch, which is arranged so that the bearing 12 can move slightly outwards to abut against the end position defining surface.

[0059] As the bearing 12 approaches the edge point of the groove 10 during the closing movement ( Figure 6 ), after which the bearing abuts against the end position defining surface which may include a groove or notch, and the seal 28 on the inner door frame is being compressed against the door frame 25. As the bearing falls into the groove, the pressure is relieved slightly because the bearing moves slightly outward (away from the torch box). In order to move the door in the opposite direction to open the door again, the bearing must move back past the higher pressure point ( Figure 6 The edge point P in the groove or notch 26 is located at the edge point P in the groove or notch 26, and this produces a locked position of the door because the bearing 12 is placed in the groove or notch of the slot 10. Figure 6 The P) in is appropriately shaped to be sharp to provide a tactile snap feeling as the door reaches the locked position.

[0060] The groove 10 is shaped to have a main direction that is generally inclined relative to the direction of the opening / closing movement of the door. This forces the bearing 12 (and the inner door panel 2) to be inward when the door moves to the second closed position, and to be outward when the door opens from the second closed position to the first closed position. The angle of the groove 10 can have a gradient, which means that during the closing movement, the angle gradually decreases to compensate for the increased pressure required when the door moves further and the seal is pressed. Therefore, relative to the X direction (the main opening / closing direction of the door, see Figure 4 ) unit distance in the Z direction (lateral direction) is reduced to reduce the force required for closing movement.

[0061] Figure 6 A close-up view of one of the slots 10 is shown. In this embodiment, the inclination of the slot generally changes in steps. On the right hand side is the open end of the slot 10, where the bearing 10 is located when the door is open. When the bearing 12 is positioned in the open end, the spacing between the inner door panel 2 and the outer door panel 3 is minimal, and there is no pressure applied by the seal 28 against the door frame 25 or any other surface (the seal 28 does not touch or rarely touches the door frame 25 when the bearing 12 is in this position). As the bearing 12 moves from the open end toward the relatively closed end, it passes through a point O, at which the seal 28 may touch the door frame 25. Beyond this point O, the inclination of the slope of the slot 10 is less, so that the lateral movement of the inner door panel 2 is less relative to the unit movement of the outer door panel 3. As the outer door panel 3 (and thereby the slot 10) is pushed further to move the bearing relative to the slot from point O toward point P, the seal 28 is more compressed and the force required to move the door gradually increases. Then, as the bearing 12 reaches point P, the sealing pressure is maximum, and as the bearing 12 moves beyond point P, the sealing pressure decreases slightly because beyond point P, the inclination of the slope of the groove 10 is reversed, thereby slightly reducing the spacing between the inner door panel 2 and the outer door panel 3.

[0062] Figure 7 The door frame 25 of the door assembly to which the track 6 (not shown) and the internal stopper 14 will be mounted is shown. The door frame 25 can be provided as a separate component to be attached to the torch box. Alternatively, the door frame can be inside the torch box so that additional door assembly components can be directly attached to the torch box.

[0063] Figure 8 An alternative embodiment of a door assembly is shown (shown with the outer door panel removed) having a differently shaped slot 10 and a stop plate 35 acting as a stop for the movement of the door along the torch box opening. Two second guide members 9 (one shown as transparent for clarity) are fastened to the outer door panel (not shown) and have guide slots 10. Support members 13 are mounted on the inner door panel 2, these support members 13 having bearings 12 that interact with the slots 10. The slots 10 have grooves 26 into which the bearings 12 lock in the second closed position of the door. In this embodiment, the inner door panel 2 has a recess 34 for receiving a portion of the second guide member 9 when the door panels are close together (in the open position). Two grooves 36, 37 surround the opening of the door frame 25. These grooves 36, 37 are designed to receive a seal (not shown) that forms a seal between the door frame 25 and the door.

[0064] Thus, this embodiment also provides a two-step closing mechanism for the torch box door assembly by moving in a first direction along the torch box opening and by moving in a second direction to force the inner door panel toward the torch box, thereby providing a seal between the closed door and the torch box.

[0065] exist Fig. 9A and 9B In FIG. 1 , a schematic diagram of a torch box with a sliding door according to the present invention is shown. The axial and radial viewers 41, 42 of the ICP emission spectrometer are shown in dotted lines, indicating that the torch box can be configured as a single or dual view instrument. It should be understood that the torch can be mounted horizontally or vertically in the torch box.

[0066] exist Fig. 9A 4 shows a torch box 40 and a sliding door assembly 50, wherein the door is in an open position, showing the access opening 45 of the torch box 40. Only the front cover 5, handle 4, window frame 22 and window 23 of the door assembly 50 and portions of the guide rail 6 and inner door stop 14 can be seen in this view.

[0067] exist Fig. 9B , the door assembly 50 is shown in a closed position, exposing portions of the guide rails 6 and the outer door stop 15. During use, the plasma torch can be viewed through the window 23, allowing the plasma torch to be inspected without opening the torch box.

[0068] like Fig. 9A and 9BAs schematically shown in FIG. 1 , the door assembly 50 allows complete or nearly complete access to the opening 45 in the torch box, as also shown in FIG. Figure 4 and 8 45. That is, the door assembly 50 allows access to nearly 100%, preferably at least 75%, and more preferably at least 90% of the opening 45. The entire opening 45 is preferably closed using a single door, however, the use of two doors is also contemplated. Conversely, a single door can be used to close two (or more) openings. If the torch box 40 includes two or more openings that need to be temporarily closed, a separate sliding door for each opening is preferred.

[0069] As used herein, including in the claims, terms in the singular should be understood to include the plural, and vice versa, unless the context clearly dictates otherwise. Therefore, it should be noted that, as used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0070] Throughout the specification and claims, the terms “comprises,” “including,” “has,” and “contains” and variations thereof should be understood to mean “including (but not limited to),” and are not intended to exclude other components.

[0071] The present invention also covers exact terms, features, values ​​and ranges, etc. if these terms, features, values ​​and ranges, etc. are used in conjunction with terms such as about, around, usually, substantially, essentially at least, etc. (i.e., "about 3" should also cover exactly 3 or "substantially constant" should also cover exactly constant).

[0072] The term "at least one" should be understood to mean "one or more", and therefore includes both embodiments including one or more components. In addition, when features are referred to as "said" and "at least one", dependent claims referring to the independent claim describing the "at least one" feature have the same meaning.

[0073] It should be understood that the foregoing embodiments of the present invention may be modified while still falling within the scope of the present invention. Unless otherwise specified, features disclosed in the specification may be replaced by alternative features for the same, equivalent or similar purposes. Therefore, unless otherwise specified, each feature disclosed represents an example of a general series of equivalent or similar features.

[0074] The use of exemplary language, such as "for instance", "such as", "for example", etc., is only to better illustrate the present invention and does not limit the scope of the present invention unless so stated. Any steps described in the specification can be performed in any order or simultaneously unless the context clearly indicates otherwise.

[0075] All features and / or steps disclosed in the specification may be combined in any combination, except combinations in which at least some features and / or steps are mutually exclusive. In particular, the preferred features of the present invention are applicable to all aspects of the present invention and may be used in any combination.

Claims

1. A sliding door assembly (50) for use with an inductively coupled plasma torch box (40), the door assembly comprising a door, a guide mechanism, the door including an inner door panel and an outer door panel, the guide mechanism for allowing the door to move along an opening (45) of the torch box in a first direction (X) to allow the torch box to be opened and closed, and in a second direction (Z) substantially perpendicular to the first direction to move the door or at least a portion thereof toward the opening when closing the torch box, the outer door panel is engaged with a first sliding mechanism to allow the door to move in the first direction, and wherein the inner door panel and the outer door panel are connected to each other via a second sliding mechanism to allow the inner door panel to move in both the first direction and the second direction, The second sliding mechanism is provided by at least one pair of parallel inner guide members and at least two pairs of bearings interconnected with the inner guide members, the inner guide members being arranged substantially between the inner door panel and the outer door panel in the first direction, And the sliding door assembly further includes a locking mechanism for locking the door in a closed position. 2 . The sliding door assembly of claim 1 , wherein the door assembly further comprises a sealing mechanism for sealing the door to the torch box.

3. The sliding door assembly of claim 2, wherein the sealing mechanism comprises at least one resilient sealing element for providing a seal between the door and the torch box or a door frame thereof. 4 . The sliding door assembly of claim 1 , wherein the guide mechanism is arranged to provide generally linear movement in both the first direction and the second direction.

5. The sliding door assembly of claim 1, wherein the inner door panel and the outer door panel are connected to each other such that the inner door panel is moved by the outer door panel.

6. The sliding door assembly of claim 1, wherein the guide mechanism is arranged to allow the inner door panel to move in both the first direction and the second direction while allowing the outer door panel to move only in the first direction.

7. A sliding door assembly according to claim 1, wherein the inner door panel is configured so that the door assembly has a first closed position, the first closed position is achieved by the door moving along the first sliding mechanism in the first direction toward the inner door stop, and wherein the door assembly is further configured so as to have a second closed position, the second closed position is achieved by the inner door panel moving relative to the outer door panel in the door assembly along the second sliding mechanism in the first direction and the second direction at the same time.

8. The sliding door assembly of claim 7, wherein the inner door stopper is disposed on the torch box or a door frame thereof on which the door assembly is to be mounted. 9 . The sliding door assembly of claim 8 , wherein the second sliding mechanism is actuated by applying a force to the outer door panel in the first direction after the inner door panel meets the inner door stop.

10. A sliding door assembly according to claim 1, wherein the inner guide component is fixed to the outer door panel, and the bearing is fixed on the inner door panel, so that when a force is applied to the outer door panel in the first direction after the door assembly has reached the first closed position, the bearing is pressed along the inner guide component, thereby applying a lateral force on the inner door, thereby moving the inner door in an inward direction.

11. A sliding door assembly according to claim 10, wherein the inner guide component is provided with a groove, the bearing cooperates with the groove and is capable of moving along the groove from its open end to the closed end, and wherein the groove is formed so that when the door assembly moves toward the closed position, the bearing moves relative to the groove in the first direction and the second direction.

12. The sliding door assembly of claim 11, wherein the slot has a gradient geometry such that relative inward movement of the inner door panel is reduced in magnitude relative to unit movement in the first direction as the door moves toward a closed position.

13. The sliding door assembly of claim 1, wherein the door comprises an inner door panel and an outer door panel, and wherein the inner door panel is provided with a sealing mechanism for securely sealing the inner door to the torch box or a door frame thereof.

14. A sliding door assembly according to claim 13, wherein the sealing mechanism is provided by a heat-resistant elastomeric seal extending around or near the outer periphery of the inner door panel, so that when in a closed position, the elastomeric seal meets the outer surface of the torch box or its door frame to create a seal therebetween.

15. The sliding door assembly of claim 14, wherein the resilient seal is compressed by inward movement of the inner door panel during the movement of the inner door panel along the second sliding mechanism.

16. The sliding door assembly of claim 7, further comprising a locking mechanism for locking the door assembly in the second closed position.

17. A sliding door assembly according to claim 16, wherein the locking mechanism is provided by a groove in the inner guide groove near the closed end of the groove, so that when the door moves toward its second closed position, the bearing is pushed toward the closed end of the groove and into the groove, thereby locking the door in the second closed position.

18. An inductively coupled plasma torch box having the sliding door assembly according to any one of claims 1-17.

19. An inductively coupled plasma optical emission spectrometer comprising the inductively coupled plasma torch box according to claim 18.

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