Abstract
The invention relates to a multipole (32) with a holding device (10) for holding the multipole (32), for example a quadrupole in a mass spectrometer or on a mounting unit (40), wherein the holding device (10) is arranged on the multipole (32). For attaching the multipole (32) to a receiving device (36, 36a) for receiving the holding device (10), the holding device (10) has one or more planar supporting surfaces (13, 15). The holding device (10) is attached to surfaces (30) of the multipole (32) that are manufactured together with electrodes (26A, 26B) of the multipole (32) in one work step. Furthermore, the invention relates to a holding device (10) of such a multipole (32), a mass spectrometer with such a multipole (32), a mounting unit (40) with a receiving device (36, 36a) for positioning a holding device (10) relative to such a multipole (32) and a method for positioning a holding device (10) relative to the multipole (32).
Claims
1. An assembly comprising: (a) a multipole comprising multipole surfaces, two electrode half-shells and electrodes arranged on the electrode half-shells; and (b) a holding device attached to the multipole; wherein the holding device has at least one planar supporting surface for fastening the multipole to a receiving device for receiving the holding device; wherein the multipole surfaces and the electrodes are manufactured together in one work step by grinding with the same grindstone so that the multipole surfaces thus have a clear and exact geometric reference to the thus formed ground surfaces of the electrodes; and wherein the holding device is attached to the multipole surfaces.
2. The assembly according to claim 1, wherein the holding device is arranged laterally of the multipole in the region of a cylindrical surface surrounding the multipole.
3. The assembly according to claim 2, wherein the holding device is arranged in a central section of the surrounding cylindrical surface, this central section being symmetrical to the central transverse axis of the multipole and corresponding to a maximum of 90% of the cylindrical surface.
4. The assembly according to claim 1, wherein the holding device has at least one positioning means for aligning the holding device on the receiving device.
5. The assembly according to claim 4, wherein the at least one positioning means of the holding device is formed by a hole and/or a bore in the holding device; wherein the at least one positioning means is configured to receive a fastener designed to fit the hole and/or the bore, in the radial direction of the fastener for positively connecting the holding device to the receiving device; and wherein the at least one positioning means in the holding device is arranged to correspond with an arrangement of at least one receiving element in the receiving device.
6. The assembly according to claim 5, wherein the holding device comprises at least one slotted hole having a width equal to the diameter of a correspondingly arranged receiving hole in the receiving device and at least one bore having a diameter equal to the width of the at least one slotted hole.
7. The assembly according to claim 1, wherein the holding device is connectable via roof edge and prismatic connections with the multipole; wherein the multipole can be dismantled along its central longitudinal axis into at least two electrode shells joinable together via the roof edge and prismatic connections; wherein each roof edge and prismatic connection has a roof edge structure and either a prism structure on the electrode shells corresponding to the roof edge structure or a roof edge element on the holding device and a corresponding prismatic structure formed by the roof edge structure; or wherein the roof edge element is roof-shaped and the prism structure is channel-shaped; wherein the roof edge structures or roof edge elements are aligned with each other and the prism structures are aligned with each other parallel to the central longitudinal axis of the multipole and each roof edge structure or roof edge element is interlockable with a prismatic structure.
8. The assembly according to claim 1, wherein the holding device comprises through and/or tapped holes arranged to correspond to receiving tapped holes of the receiving device.
9. The assembly according to claim 1, wherein the holding device is configured to be arranged on a receiving device of a mass spectrometer, a mounting unit and/or a unit serving for maintenance of the multipole; and wherein the holding device has at least one roof edge structure and/or at least one prism structure for attachment to the multipole.
10. A mass spectrometer comprising: (a) the assembly according to claim 1; and (b) a receiving device for receiving the holding device; wherein said multipole is arranged in an exact geometric position relative to all axial directions of the multipole and relative to other components of the mass spectrometer in the mass spectrometer by means of the holding device of said multipole.
11. The assembly according to claim 1, further comprising a mounting unit with a receiving device for positioning the holding device relative to the multipole arranged on the receiving device, wherein the mounting unit has a bottom plate which is aligned such that the center longitudinal axis of the multipole and the effective direction of gravity are aligned perpendicular to the bottom plate.
12. The assembly according to claim 11, wherein the mounting unit has a rear wall which has recesses through which connecting elements of the holding device for connecting the holding device with the multipole are visible and accessible with a tool.
13. A method, comprising the following steps: (a) providing the assembly according to claim 1; (b) form-fitting connecting the holding device with an associated receiving device; (c) moving the multipole relative to the holding device in the longitudinal direction of the multipole until a predetermined relative position of the multipole to the holding device is achieved; and (d) fixing this relative position.
14. The method according to claim 13, wherein the positive connection of the holding device with the receiving device is effected by means of at least two positioning means.
Description
(1) Further embodiments of the invention will become apparent from the claims and from the embodiments explained in more detail with reference to the drawing. In the drawing
(2) FIGS. 1a-d show a holding device of a multipole according to the invention from different perspectives,
(3) FIGS. 2a-c show an electrode half shell of a quadrupole together with a holding device from different perspectives,
(4) FIG. 3a shows a multipole comprising two electrode half-shells together with a holding device in a perspective view,
(5) FIG. 3b shows a multipole comprising two electrode half-shells together with a holding device in a side view along the central longitudinal axis of the multipole,
(6) FIG. 4 shows a side view of a multipole comprising two electrode half-shells together with a holding device on a receiving device,
(7) FIG. 5 shows a frontal view of an empty mounting unit without multipole and holding device,
(8) FIG. 6a, b show a side view and a frontal view of the mounting unit with multipole and holding device,
(9) FIGS. 7a-d show several embodiments of a holding device,
(10) FIGS. 8a-d show several embodiments of introduced into the fixture holes and holes,
(11) FIG. 9 shows the multipole according to FIG. 4 without the receiving device with exaggeratedly represented inaccurately worked outer contours of the electrode half-shells, and
(12) FIG. 10 shows the multipole according to FIG. 9 without the inventive holding device depicted in FIG. 9, however, with a conventional annular holding device for illustrating an undesirable offset of the common centre of the electrodes of the multipole with respect to the centre of the outer contour of the electrode half-shells.
(13) Like reference numerals in the figures indicate like parts. Further letters behind a reference numeral designate further exemplary embodiments of the corresponding part.
(14) FIGS. 1a-d show a possible embodiment of a holding device 10 of a multipole according to the invention, as shown for example in FIG. 3a by the reference numeral 32. In FIGS. 1a-d, however, only one part 10a of the two-part holding device 10 is shown.
(15) FIG. 1a shows a particularly preferred embodiment of the holding device 10a in a perspective view. It describes a U-shape, wherein two supports 12 form the mutually parallel sides of the U-shape and a support connection 14 forms the lower part of the U-shape, which connects the parallel sides of the U-shape and thus the supports 12. The supports 12 each comprise as positioning means a bore 16 and a hole 18 and two through and/or tapped holes 20.
(16) The surfaces of the supports 12 have a first support surface 13 and a second support surface 15, which are formed as a high-precision machined, planar surface plane-parallel to each other. These supporting surfaces 13, 15 are preferably manufactured with respect to their nominal dimensions according to ISO basic tolerances IT5 to IT11. Furthermore, these supporting surfaces 13, 15 also have high-precision positional tolerances with respect to the parallelism of the two supporting surfaces 13 and 15 with respect to one another and with respect to the perpendicularity between the supporting surfaces 13, 15 and the positioning means.
(17) The bore 16 is formed in this embodiment as a bore which serves a later accurate positioning of the holding device 10a. The bore 16 preferably has a corresponding counterpart located in a further component, on which the holding device 10a is to be aligned and positioned, so that a pin form-fitting in the radial direction of the bore 16 matching in the bore 16 can be inserted through the bore 16 and the corresponding counterpart.
(18) The hole 18 is formed in this preferred embodiment as a slotted hole having the same width as the diameter of the bore 16. The through and/or tapped holes 20 are used to attach the holding device 10a to another component.
(19) The preferred holding device 10a also has roof edge elements 22 with roof edge tapped holes 24. Each roof edge element 22 has two mutually angled surfaces, a narrow roof edge 21 and a broad roof edge 23, each with the same pitch. These roof edge flanks 21 and 23 are highly precisely manufactured, preferably by grinding. Via a preferably angularly arranged side surface 19, the surface of the angularly arranged roof edge 23, which is wider than the narrower edge of the roof edge 21, comprises a connection with the first supporting surface 13 of the holding device 10a.
(20) FIG. 1b shows a side view of the same preferred embodiment of the holding device 10a as in FIG. 1a. This illustration highlights the formation of the bore 16, formed as a slotted hole 18, the through and/or tapped holes 20 and the roof edge tapped holes 24. The mutually angled roof edge flanks 21 and 23 form the roof edge element 22. The roof edge element 22 has a roof edge tapped hole 24, by means of which the holding device 10a can be fastened to a corresponding further device by means of screws.
(21) FIG. 1c shows a side view of the longitudinal side of the same holding device 10a as in FIGS. 1a, b. This illustration shows that the height or thickness of the supports 12 is a multiple of the height or thickness of the support connection 14. The height or thickness of a support 12 is defined by the distance of the first support surface 13 to the second support surface 15 of the holding device 10a.
(22) The different thickness of the support connection 14 compared to the supports 12 is used advantageously for material savings. Furthermore, the small thickness of the overlay connection 14 advantageously allows, to some extent, the absorption of torsional movements. The support connection 14 serves to hold the supports 12 at a predetermined distance and a predetermined position to each other. The support surfaces 13 and 15 of the supports 12 are formed exactly parallel to one another, so that these surfaces must be precisely machined. The production of these surfaces is preferably carried out by means of milling and/or grinding.
(23) FIG. 1d shows a side view transverse to the longitudinal direction of the same preferred holding device 10a as in FIGS. 1a-c. Here it can be seen that the supports 12 are formed thicker than the height of the roof edge element 22, wherein the height of the roof edge element 22 is determined by the distance of the support surface 15 to the vertex 25 of the roof-shaped side of the roof edge 22. The mutually angled roof edge shoulders 21 and 23 have a predetermined angle and an axis of symmetry, wherein the axis of symmetry extends through the vertex 25 of the roof edge shape. This angle between the symmetry axis of each one of the roof edge flanks 21 and 23 of the roof wall element 22 is preferably 120, in particular 110, in particular 130.
(24) The holding device according to the invention according to FIGS. 1a-d is preferably made of one work-piece. This manufacture is preferably carried out by means of milling. Surfaces which require a precise machining with high accuracy and/or a low roughness of the surface are further processed by grinding.
(25) FIG. 2a shows a perspective view of a support element or an electrode half-shell 26 of a multipole with two electrodes arranged on the electrode half-shell 26. The blackened surfaces represent essentially hyperbolically shaped surfaces of these electrodes, which surfaces determine the field profile within the quadrupole.
(26) Furthermore, FIG. 2a shows a holding device 10a, which is arranged on a support element or an electrode half-shell 26 of a multipole. As in FIGS. 1a-d, FIG. 2a shows a preferred embodiment of the holding device 10. Other embodiments of the holding device 10 are also applicable to the following explanations.
(27) The half-shell electrode 26 has connecting elements, which are formed as a roof edge structure 28 and prism structure 30. The roof edge structures 28 and prismatic structures 30, as well as the roof edge element 22 of the holding device 10a in FIGS. 1a-d, have two surfaces arranged at an angle to one another, each with the same pitch. On one side of the electrode half shell 26 only roof edge structures 28 are arranged and on the other, opposite side of the electrode half-shell 26 only prism structures 30 are arranged. The roof edge structures 28 and prism structures 30 are formed corresponding to one another in such a way that in each case a roof edge structure 28 and a prism structure 30 can be joined to one another to form a roof edge and prismatic connections 31. The prismatic structures 30 have a channel-shaped or convex shape. The number of prism structures 30 is the sum of the number of fabricated roof edge structures 28 and the number of roof edge elements 22 of a holding device 10a to be fastened to the electrode half-shell 26. The roof edge and prismatic connections 31 thus serve on the one hand the joining of two electrode half-shells 26 to a multipole and on the other hand the fastening of a holding device 10a to an electrode half shell 26, wherein each roof edge element 22 of the holding device 10a is interlocked to a prism structure 30. The attachment of the holding device 10a to the electrode half-shell 26 via a roof edge and prism connections 31 advantageously allows a m accurate positioning of the holding device 10a to the center of the multipole, or to the central longitudinal axis of the multipole and thus a precise positioning of the multipole within a mass spectrometer.
(28) FIG. 2b shows a side view of the electrode half-shell 26 with the preferred holding device 10a. The roof edge element 22 of the holding device 10a can be inserted into the prism structure 30 of the electrode half-shell 26 due to its shape corresponding to the prism structure 30. According to the invention, the wide roof edge 23 of the roof edge element 22 is oriented in the direction of the support surface 13 and is designed wider than the narrow roof edge 21 of the roof edge element 22. This results in the roof edge 23 protruding beyond the outside of the electrode half-shell 26 after the roof edge element 22 of the holding device 10a is fitted into the prism structures 30 of the electrode half shell 26. This has the advantage that tilting of the roof edge element 22 on the prism structure 30 and thus of the holding device 10a on the electrode half-shell 26 is prevented.
(29) FIG. 2c shows a plan view of an electrode half-shell 26 with the electrodes attached to the electrode half-shell 26 and a holding device 10a in the same embodiment as in FIGS. 2a and 2b. Again, as shown in FIG. 2a, the substantially hyperbolic surfaces of the electrodes are shown in black.
(30) The supports 12 of the holding device 10a cover in this plan view the two further prismatic structures 30, which serve to secure the holding device 10a. Thus, in each case the same number of roof edge structures 28 and prismatic structures 30 is visible. The holding device 10a can be fastened by means of screws through connecting bores 29 in the prismatic structures 30 by means of the roof-edge tapped holes 24 in the holding device 10a on the electrode half-shell 26. The roof edge structures 28 of the electrode half-shell 26 have connecting tapped holes 27 which are preferably of the same design as the roof-edge tapped holes 24 of the holding device 10a.
(31) FIG. 3a shows two electrode half-shells 26, which are joined together to form a multipole 32, each electrode half-shell 26 having a holding device 10a according to the embodiment of FIGS. 2a-c. Such a multipole 32 is preferably designed as a quadrupole. FIG. 3a shows such a preferred quadrupole, which comprises two of the half-shells 26, attached to a two-part holding device 10a. Each part of the holding device 10a is arranged and fastened to prism structures 30 laterally to an electrode half-shell 26 via the roof edge elements 22. The electrode half-shells 26 are connected to each other via the roof edge structures 28 and the prism structures 30, wherein each roof edge structure 28 is joined into a prism structure 30. Attached to each other, a roof edge structure 28 with a prismatic structure 30 forms a roof edge and prismatic connection 31. The roof edge and prismatic connections 31 can be fixed by means of screws 33. Compared to the narrow roof edges 21, the wider constitution of the roof edge 23 serves advantageously to ensure a defined distance of the supporting surfaces 13 of the supports 12 to the roof edge and prismatic connections 31.
(32) FIG. 3b shows a side view along the central longitudinal axis of the electrode half-shells 26 assembled to form a multipole 32, each having a holding device 10a, as in FIG. 3a. The side view shows the joints formed as roof edge and prismatic connection 31 of the mounted electrode half-shells 26. Thus, in this view, only one of the two fasteners 10a fixed visible. The second holding device 10a is located just behind the holding device 10a visible in FIG. 3b. Each of the connections of a roof edge structure 28 and a prism structure 30, which are joined together to form a roof edge and prism connection 31, is fixed with one screw 33 each. For this purpose, a connecting bore 29 is made into each prism structure 30 and a connecting tapped hole 27 is made into each roof edge structure 28. These connecting tapped holes 27 of the electrode half-shell 26 are preferably designed in the same way as the roof edge tapped holes 24 of the holding device 10a. Thus, in an advantageous manner, the holding device 10a can be fixed by means of the same screws 33 via the prismatic structures 30 to the electrode half-shells 26 as the electrode half-shells 26 with one another.
(33) The holding device 10a fastened to the electrode half-shell 26 has a mounting spacing 34 relative to the respective other electrode half-shell. As a result, the holding device 10a can also be connected to the prism structures 30 after the electrode half-shells 26 have been joined together, the holding device 10a being inserted into the prism structures 30 by means of lateral insertion along the alignment of the roof edge elements 22, which are aligned parallel to the longitudinal direction of the multipole 32.
(34) Preferably, the holding device 10a has at least one roof edge structure 28, which can be connected to a correspondingly formed prism structure 30 of the electrode half-shell 26. Thus, the reception of a holding device 10 can be produced advantageously by means of already known and existing tools for the manufacture and processing of the electrode half-shells 26.
(35) FIG. 4 shows a multipole 32 with a two-part holding device 10a, which is arranged on a receiving device 36. The holding device 10a and thus the multipole 32 is connected by means of fastening elements 38, in particular dowel pins, with the receiving device 36. Such a receiving device 36 is, for example, arranged in a mass spectrometer.
(36) This view, shown in FIG. 4, on the end face of the multipole 32 shows the arrangement according to the invention of the holding device 10a in the receiving device 36, which is characterized by the following features:
(37) The holding device 10a is arranged laterally of the multipole 32 in the area of a cylindrical surface surrounding the multipole 32, wherein the vertical extent or thickness of the supports 12 of the holding device 10a is advantageously dimensioned such that a plane containing a straight line passing through the center of the circular cross section of the multipole 32, is a plane of symmetry of the cylindrical shape of the preferred multipole 32 in FIG. 4, and is dividing the holding device 10a into two parts of the same vertical extent or thickness. Due to the advantageous embodiment and arrangement of the holding device 10a on the multipole 32, in which the planar supporting surfaces 13, 15 of the supports 12 are rotationally asymmetric to the central longitudinal axis of the multipole 32, it is ensured that the multipole 32 is aligned parallel to a plane defined by the supported surfaces of the supports 12 of the holding device 10a. The supports 12 of the holding device 10a may be arranged on or in a corresponding receiving device 36.
(38) FIG. 5 shows a front view of a preferred mounting unit 40. The mounting unit 40 preferably has a bottom plate 42, a rear wall 44 and a receiving device 36a for a holding device 10a. Such a mounting unit 40 is used to mount the holding devices 10a according to FIGS. 1a-d, 2a-c and 3a-b to a multipole 32 and possibly the electrode half-shells 26 to each other.
(39) The receiving device 36a according to the embodiment shown has four receiving holes 46 and four receiving tapped holes 48. The receiving holes 46 and the receiving tapped holes 48 of the receiving device 36a are arranged such that they correspond to the arrangement of the bores 16, holes 18 and through and/or tapped holes 20 of the holding device 10a. In addition, the diameters of the holes 16 in the holding device 10a and the receiving holes 46 in the mounting unit 40 and the diameter of the through and/or tapped holes 20 in the holding device 10a and the receiving tapped holes 48 in the mounting unit 40 are of the same size. The rear wall 44 has advantageously recesses 50, which allow the introduction of a tool, preferably a screwdriver.
(40) FIG. 6a shows a side view of the preferred mounting unit 40 according to FIG. 5 with a multipole 32 and a holding device 10a. The holding device 10a is connected to the receiving device 36a by means of at least two, preferably four, pins 38. This connection of the pins 38 through the bores 16 in the holding device 10a and the receiving holes 46 of the receiving device 36a is formed in a form-fitting or positive manner in the radial direction of the pins 38. Preferably for producing such a positive connection correspondingly formed dowel pins are used, which extend through the holes formed as fitting bore holes 16 in the holding device 10a and the receiving holes 46 in the receiving device 36a.
(41) FIG. 6b shows a frontal view of the same structure as in FIG. 6a, which has a mounting unit 40 with a receiving device 36a, a bottom plate 42, a rear wall 44 with recesses 50 and a multipole 32 with a holding device 10a, which is arranged on the mounting unit 40 by means of suitably designed pins 38. Recesses 50 are not visible due to the arrangement of the multipole 32 in the mounting unit 40 in this view, shown in FIG. 6b. The holes 18 formed in the holding device 10a as slotted holes advantageously enable a locking or arrangement of the holding device 10a on the receiving device 36a, without any tilting. The mounting unit 40 allows the positioning of the holding device 10a relative to the multipole 32. The procedure is as follows:
(42) The electrode half-shells 26 are already loosely connected to one another and to the holding device 10a. By means of at least two pins 38, the holding device 10a is connected to the receiving device 36a by a respective hole 18 and a bore 16. To fix this connection fixing screws 52 can be introduced into the through and/or tapped holes 20 of the holding device 10a and the through and/or receiving tapped holes 48 in the receiving device 36a of the mounting unit 40.
(43) Preferably, this fixing is carried out via a through hole 20 each with a corresponding tapped hole 48 by means of a fixing screw 52. For fixing via a respective tapped hole 20 or a partial tapped hole with a corresponding receiving tapped hole 48, a thin shaft screw is used as a fixing screw 52 with a partial thread, which has a thread only in the area of the receiving tapped hole 48.
(44) After reaching a predetermined relative position of the holding device 10a to the multipole 32, it is fixed accordingly. This fixation takes place in this preferred embodiment by means of screws 33. For this purpose, the screws 33 are inserted through the connecting bores 29 of the electrode half shells 26 into the connection tapped holes 27 of the electrode half-shells 26 for fixing the electrode half shells 26 to one another.
(45) To fix the holding device 10a on the half-shell electrode 26, the screws 33 are inserted through the connecting holes 29 of the electrode half-shells 26 in the roof edge tapped holes 24 of the holding device 10a. After carrying out the fixation, the desired positioning of the holding device 10a with respect to the multipole 32 is completed. Thus, the multipole 32 is aligned by means of the holding device 10a according to the invention in a predetermined position in the mass spectrometer and quickly and easily installed in the mass spectrometer.
(46) FIGS. 7a-d show various embodiments of a holding device 10 according to the invention on a multipole 32, the list of embodiments not being conclusive:
(47) FIG. 7a shows a multipole 32 with a two-part holding device 10a of the preferred embodiment, as shown in the previous FIGS. 1a-d, 2a-c, 3a-b, 4 and 6a-b. Each of the two parts of the holding device 10a is preferably made of one respective work-piece, in particular milled. The holding device 10a describes a U-shape, wherein the mutually parallel portions of the U-shape form the supports 12, which are connected to each other by means of a support connection 14 and in a fixed relative position.
(48) The supports 12 are thicker than the support connections 14. The supports 12 are made such that they provide high-precision, planar supporting surfaces 13 and 15. This requires a precise production of the surfaces of the supporting surfaces 13 and 15 of the supports 12 with respect to the form tolerances and/or position tolerances, in particular with an ISO basic tolerance of IT5 to IT11.
(49) In a preferred embodiment, the surfaces of the supporting surfaces 13 and 15 are machined by means of machining processes, for example sawing and milling. In order to meet the requirement of high precision in production, machining by means of milling is preferably selected for the supporting surfaces 13 and 15. The processing of the support connections 14 requires compared to the support surfaces 13 and 15 a lower precision, since these serve primarily to ensure and define a fixed axial distance and a desired position of the supports 12 to each other.
(50) FIG. 7b shows a holding device 10b for holding a multipole 32 with a total of four, preferably identical, parts. Such a holding device 10b has no support connection 14 compared to a holding device 10a. The holding device 10b comprises four supports 12 without a support connection 14. This embodiment has the advantage that at least four of the parts of the holding devices 10b can be produced from a material piece of the same size as the material piece from which two of the parts of the holding devices 10a were manufactured. This leads to an advantageous material saving of 50-70% and thus also to a reduction of the work effort.
(51) FIG. 7c shows another embodiment of a holding device 10 according to the invention for holding a multipole 32. In this case, the multipole 32 is connected to three parts of the holding device 10b, whereby further material savings with a guarantee of a stable position of the multipole 32 is achieved. However, this material saving has the consequence that the arrangement of the supports is not symmetrical with respect to an axis of symmetry which runs parallel to the central longitudinal axis of the multipole 32. Thus, the electrode half shells 26 of the multipole 32 would each have a different number of roof edge and prism connections 31.
(52) FIG. 7d shows a further embodiment of the holding device 10 according to the invention. In this case, the multipole 32 has two identically formed parts of a holding device 10c, which does not comprise any support connections 14. The parts of the holding device 10c are aligned centrally along the central longitudinal axis of the multipole 32 and fixed to the electrode half-shells 26. The width or size of the supports 12 of the holding device 10c is designed such that in each case for a stable position a sufficient supporting surface 13 and 15 is ensured. However, this embodiment of the holding device 10c requires a very high precision in the manufacture of the supporting surfaces 13 and 15, which results in higher production costs.
(53) As an alternative to the embodiments according to FIGS. 7a-d, a one-part use of a holding device 10 according to one of the embodiments 10a-c is also possible. When mounted with only a one-piece holding device 10, this holding device 10a-c is preferably arranged in the installed position of the multipole 32 in a mass spectrometer vertically below the multipole 32 in the direction of the central longitudinal axis of the multipole 32, in order to transfer as little vibrations or oscillations as possible on the multipole 32.
(54) FIGS. 8a-d show several embodiments of the bores 16, holes 18 and through holes and/or tapped holes 20, which are introduced into the preferred embodiment of the holding device 10a of FIGS. 1a-d. The corresponding variants of the embodiments are identified by the addition of dashes to the reference numeral 10a: for example for the first alternative variant, for the second alternative variant, etc.
(55) FIG. 8a shows the two parts of the holding device 10a, each with a slot 18 formed as a hole, a bore 16 and two through and/or tapped holes 20. The through and/or tapped holes 20 serve to fix the holding device 10a in the receiving device 36.
(56) FIG. 8b shows the same geometric arrangement of the holes 18 and bores 16 as in FIG. 8a. However, in this first alternative variant of the embodiment, the through and/or tapped holes 20 are missing. According to this embodiment, the fixing of the holding device 10a to a receiving device 36 is thus realized, for example, by means of a clamping closure. Such a clamping closure has the advantage that the multipole 32 attached to the holding device 10a, which is arranged, for example, in a mass spectrometer, can be exchanged easily and quickly.
(57) FIG. 8c shows a variant of the introduction of the holes 18 and bores 16 in the holding device 10a and 10a. In the holding device 10a a hole 18, preferably a slotted hole, and a bore 16, as shown in FIG. 8b, are introduced. The holding device 10a in turn has neither a hole nor a bore. Thus, the multipole 32 is locked and centered only by one of the two holding devices 10a and 10a.
(58) FIG. 8d shows a further variant, wherein the holding device 10a has a hole 18 which is preferably designed as a slotted hole and the second holding device 10a has a bore 16. The hole 18 and the bore 16 are arranged to each other such that they are on a diagonal with respect to the central longitudinal axis of the multipole 32.
(59) The fixing of the holding device 10a to 10a on the receiving device 36 is carried out according to FIGS. 8c and 8d analogous to FIG. 8b by means of a clamping closure. In the event, however, that a fixation via at least one fixing screw 52 is provided, additionally through and/or tapped holes 20 in the holding devices 10a to 10a are provided, which, however, are not shown in FIGS. 8c and 8d.
(60) In the embodiments of the bores 16, holes 18 and through and/or tapped holes 20, as shown in FIGS. 8a-d, these can also be combined for the use of a single fastening element 38, whereby the use of a dowel pin screw as a fastening element 38 is possible.
(61) The above-described embodiments 10a to 10a of the bores 16, holes 18 and through holes and/or tapped holes 20 can be applied analogously to the various embodiments 10a-c of the holding device 10 according to FIGS. 7a-d.
(62) FIG. 9 shows the multipole 32 according to FIG. 4 without the receiving device 36 shown in FIG. 4. The outer contours of the electrode half-shells 26 are shown exaggeratedly inaccurate. The two parts 10a of the holding device 10 are attached to surfaces of the prismatic structures 30, which are machined together in one working step with the electrodes 26A, 26B of an electrode half-shell 26. For this purpose, these electrodes 26A, 26B are first fixed, e.g. glued, via insulators 54 with half-shell elements 56. This processing is done, for example, with a single grindstone. Thus, a precise position of the machined surfaces of the electrodes 26A, 26B and the surfaces of the prismatic structures 30 to each other is ensured.
(63) As a result of this precise arrangement of the surfaces of the prismatic structures 30, the parts 10a of the holding device 10 can also be aligned very precisely with the processed electrode surfaces. This allows an exact spacing of the dowel holes 16 to the center M of the processed electrode surfaces. The multipole can thus easily be installed and aligned in a high-precision manner in the mass spectrometer.
(64) FIG. 10 shows the multipole according to FIG. 9 without the holding device according to the invention shown in FIG. 9, but with a conventional ring-shaped holding device 58 for illustrating an undesired offset X in the x-direction and Y in the y-direction of the common center point M of the processed electrode surfaces of the multipole 32 with respect to the center N of the outer contour of the electrode half-shells 26 and thus the annular contoured holding device 58 conventionally attached to this outer contour. Such an offset can be avoided due to the invention. The invention therefore contributes to significantly increase the measurement accuracy of mass spectrometers.
(65) All of the features mentioned in the foregoing description and in the claims can be combined individually or in any combination with the features of the independent claims. The disclosure of the invention is therefore not limited to the described or claimed feature combinations. Rather, all meaningful combinations of features in the context of the invention are to be regarded as disclosed.
