Position Indicator as Well as a Rotary Actuator Equipped Therewith and a Process Valve

Abstract

A position indicator for a rotary drive of a process valve is proposed, which can be mounted on a rotatable indicator shaft of the rotary drive and which has a base indicator element and an additional indicator element, wherein the additional indicator element can be positioned and fixed about a vertical axis in different angular positions. On the base indicator element a plurality of base indicator markings are arranged, while the additional indicator element has an additional indicator markings. In order to indicator various visually perceptible valve-type symbols, the additional indicator element can be positioned, inter alia, in at least one cover angle position, in which it covers at least one base indicator marking, but leaves at least one further base indicator marking uncovered, which together with the always visible additional indicator marking represents the valve-type symbol.

Claims

1. A position indicator for a rotary drive of a process valve, which is designed for the torque-proof mounting on a rotatable indicator shaft of the rotary drive and has a vertical axis which in the mounted position of use of the position indicator coincides with the axis of rotation of the indicator shaft, the position indicator comprising a base indicator element having at least one base indicator marking and an additional indicator element having an additional indicator marking, wherein the additional indicator element can be positioned and fixed around the vertical axis as centre in different rotational angular positions with respect to the base indicator element, wherein the base indicator element has a plurality of base indicator markings arranged distributed around the vertical axis, wherein the additional indicator element can be positioned and fixed in at least one cover angle position with respect to the base indicator element, in which it covers at least one of the base indicator markings and in which at least one of the base indicator markings is uncovered, so that different visually perceptible valve-type symbols can be represented depending on the angular position adopted by the additional indicator, which in each case are composed of the additional indicator marking and the at least one uncovered base indicator marking.

2. A position indicator according to claim 1, wherein the base indicator element has two base indicator markings angularly offset by 90 degrees with respect to one another, wherein, depending on the angular position adopted by the additional indicator element, only one or neither of the two base indicator markings is covered.

3. A position indicator according to claim 1, wherein the additional indicator element can be positioned and fixed in three angular positions with respect to the base indicator element, in which the additional indicator marking together with at least one non-covered base indicator marking represents an I-shaped or L-shaped or T-shaped valve-type symbol.

4. A position indicator according to claim 1, wherein each indicator marking is formed strip-shaped in radial alignment with respect to the vertical axis.

5. A position indicator according to claim 1, wherein the base indicator element on a lower side has a mounting interface coaxial with the vertical axis for the torque-proof plug-in connection with an end section of the indicator shaft of the rotary drive.

6. A position indicator according to claim 5, further comprising a fastening screw, which in the mounted position of use of the position indicator passes through the two indicator elements under axial clamping in the axial direction of the vertical axis and is screwed to the indicator shaft.

7. A position indicator according to claim 1, wherein the base indicator element is disc-shaped with a circular outer contour, wherein it has an upper end surface which in the mounted position of use of the position indicator faces away from the associated rotary drive, and has a radially outwardly facing outer circumferential surface, wherein the additional indicator element is L-shaped and is attached to the base indicator element in such a way that it extends with a first leg section comprising at last partially the additional indicator marking in a radial direction with respect to the vertical axis along the upper end surface and with a second leg section angled downwardly with respect to the first leg section in the axial direction along the outer circumferential surface of the base indicator element.

8. A position indicator according to claim 7, wherein, the base indicator element is dish-shaped and is arranged with the open side facing downwards towards the rotary drive.

9. A position indicator according to claim 7, wherein the outer circumferential surface of the base indicator element tapers axially in the direction of the upper end face, wherein the second leg section of the additional indicator element is inclined correspondingly.

10. A position indicator according to claim 7, wherein the first leg section of the additional indicator element is formed in the shape of a circular sector.

11. A position indicator according to claim 10, wherein the first leg section of the additional indicator element is formed in the shape of a circular sector with a central angle of 90 degrees.

12. A position indicator according to claim 10, wherein the second leg section is formed shell-shaped with a curvature adapted to the outer circumferential surface of the base indicator element.

13. A position indicator according to claim 7, wherein the additional indicator marking is arranged in the region of one of the two side edges of the first leg section oriented in the circumferential direction of the vertical axis.

14. A position indicator according to claim 13, wherein the additional indicator marking is arranged on the outer surface of the first leg section facing away from the base indicator element.

15. A position indicator according to claim 7, wherein the first leg section on its free end region facing away from the second leg section is penetrated by a fastening hole provided for the passage of a fastening screw, which is aligned flush with a further fastening hole passing axially centrally through the base indicator element.

16. A position indicator according to claim 1, wherein a toothed device is associated jointly with the two indicator elements, by means of which the additional indicator element in the respective adjusted angular position is locked in a non-rotatable manner by positive engagement to the base indicator element.

17. A position indicator according to claim 16, wherein the additional indicator element can be lifted axially from the base indicator element in order to change its adopted angular position with respect to the base indicator element by cancelling the positive connection of the toothed device, can then be rotated with respect to the base indicator element, and after this, with renewed formation of the positive engagement of the toothed device, can be replaced on the base indicator element.

18. A position indicator according to claim 16, wherein the base indicator element is disc-shaped with a circular outer contour, wherein it has an upper end surface which in the mounted position of use of the position indicator faces away from the associated rotary drive, and has a radially outwardly facing outer circumferential surface, wherein the additional indicator element is L-shaped and is attached to the base indicator element in such a way that it extends with a first leg section comprising at last partially the additional indicator marking in a radial direction with respect to the vertical axis along the upper end surface and with a second leg section angled downwardly with respect to the first leg section in the axial direction along the outer circumferential surface of the base indicator element, and wherein the toothed device comprises a ring gear formed in the region of the outer circumferential surface on the base indicator element, coaxial to the vertical axis, and a counter-toothing formed on the second leg section, complementary to the ring gear.

19. A position indicator according to claim 18, wherein the counter-toothing is formed on the free end portion of the second leg section.

20. A position indicator according to claim 1, wherein the base indicator element is equipped with at least one actuating element, which is part of a position detection device for detecting multiple rotational positions of the position indicator.

21. A position indicator according to claim 20, wherein the at least one actuating element has permanent magnetic properties.

22. A position indicator according to claim 20, wherein the at least one actuating element is inserted from the underneath side into the base indicator element.

23. A position indicator according to claim 20, wherein the position detection device includes multiple actuating elements distributed around the vertical axis and arranged on the position indicator.

24. A rotary drive of a process valve, with a drive housing, in which drive means for generating a rotary drive movement of a drive shaft that can be coupled or is coupled to the rotatable valve member of a valve fitting are arranged, and on the outside of which the end section of a rotatable indicator shaft rotating together with the drive shaft is provided, on which is mounted in a torque-proof manner a position indicator participating in the rotational movement of the indicator shaft and having a vertical axis which coincides with the axis of rotation of the indicator shaft, wherein the position indicator further comprises a base indicator element having at least one base indicator marking and an additional indicator element having an additional indicator marking, wherein the additional indicator element can be positioned and fixed around the vertical axis as centre in different rotational angular positions with respect to the base indicator element, wherein the base indicator element has a plurality of base indicator markings arranged distributed around the vertical axis, wherein the additional indicator element can be positioned and fixed in at least one cover angle position with respect to the base indicator element, in which it covers at least one of the base indicator markings and in which at least one of the base indicator markings is uncovered, so that different visually perceptible valve-type symbols can be represented depending on the angular position adopted by the additional indicator, which in each case are composed of the additional indicator marking and the at least one uncovered base indicator marking.

25. A process valve, with a valve fitting and a rotary drive fixed to the valve fitting for rotationally driving a valve member of the valve fitting, wherein the rotary actuator has a rotatable indicator shaft on which a position indicator is mounted, wherein the position indicator has a vertical axis which coincides with the axis of rotation of the indicator shaft, the position indicator further comprising a base indicator element having at least one base indicator marking and an additional indicator element having an additional indicator marking, wherein the additional indicator element can be positioned and fixed around the vertical axis as centre in different rotational angular positions with respect to the base indicator element, wherein the base indicator element has a plurality of base indicator markings arranged distributed around the vertical axis, wherein the additional indicator element can be positioned and fixed in at least one cover angle position with respect to the base indicator element, in which it covers at least one of the base indicator markings and in which at least one of the base indicator markings is uncovered, so that different visually perceptible valve-type symbols can be represented depending on the angular position adopted by the additional indicator, which in each case are composed of the additional indicator marking and the at least one uncovered base indicator marking.

26. A process valve, with a valve fitting and a rotary drive fixed to the valve fitting for rotationally driving a rotatable valve member of the valve fitting, wherein the rotary actuator has a rotatable indicator shaft on which a position indicator is mounted, wherein the rotary drive further has a drive housing, in which drive means are arranged for generating a rotary drive movement of a drive shaft that is coupled to the rotatable valve member, and on the outside of which the end section of a rotatable indicator shaft rotating together with the drive shaft is provided, on which is mounted in a torque-proof manner a position indicator participating in the rotational movement of the indicator shaft and having a vertical axis which coincides with the axis of rotation of the indicator shaft, wherein the position indicator further comprises a base indicator element having at least one base indicator marking and an additional indicator element having an additional indicator marking, wherein the additional indicator element can be positioned and fixed around the vertical axis as centre in different rotational angular positions with respect to the base indicator element, wherein the base indicator element has a plurality of base indicator markings arranged distributed around the vertical axis, wherein the additional indicator element can be positioned and fixed in at least one cover angle position with respect to the base indicator element, in which it covers at least one of the base indicator markings and in which at least one of the base indicator markings is uncovered, so that different visually perceptible valve-type symbols can be represented depending on the angular position adopted by the additional indicator, which in each case are composed of the additional indicator marking and the at least one uncovered base indicator marking.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Aspects of the invention will be explained in more detail with the aid of the accompanying drawings, in which:

[0034] FIG. 1 is a perspective representation of a preferred embodiment of the process valve according to the invention, which is arranged with a preferred embodiment of the rotary drive according to the invention and which furthermore has an advantageous embodiment of the position indicator according to the invention,

[0035] FIG. 2 shows the rotary drive apparent in FIG. 1, equipped with a position indicator, in an exploded perspective individual representation,

[0036] FIG. 3 is an individual representation in an exploded perspective representation of the position indicator contained in the arrangement of FIGS. 1 and 2, in the state of the additional indicator element when lifted from the base indicator element,

[0037] FIG. 4 shows a bottom view of the position indicator from FIG. 3 looking in the direction of the arrow IV from FIG. 3,

[0038] FIG. 5 is a perspective bottom view of the position indicator, in which actuating elements used for a position detection are shown prior to the insertion into the base indicator element,

[0039] FIG. 6 is a perspective view of the position indicator, in which the additional indicator is positioned angularly to illustrate an I-valve-type symbol,

[0040] FIG. 7 shows the position indicator from FIG. 6 in a plan view, in which the illustrated valve-type symbol is additionally shown as a thickened line symbol for clarity,

[0041] FIG. 8 is a perspective view of the position indicator, in which the additional indicator is positioned angularly to illustrate an L-valve-type symbol,

[0042] FIG. 9 shows the position indicator from FIG. 8 in a plan view, in which the illustrated valve-type symbol is additionally shown as a thickened line symbol for clarity,

[0043] FIG. 10 is a perspective view of the position indicator, in which the additional indicator is positioned angularly to illustrate a T-valve-type symbol,

[0044] FIG. 11 shows the position indicator of FIG. 10 in a plan view, in which the illustrated valve-type symbol is additionally shown as a thickened line symbol for clarity.

DETAILED DESCRIPTION

[0045] FIG. 1 illustrates a process valve 1, in which advantageous embodiments of the measures according to the invention are realized.

[0046] The process valve 1 contains a valve fitting 2 with a valve housing 3, which has a plurality of externally accessible valve connections 4, to which in each case an extension pipeline can be connected. A fluid channel structure 5 formed in the interior of the valve housing body 3 communicates with all valve connections 4 and allows the passage of a fluid process medium through the valve housing 3.

[0047] A valve member 6, indicated only schematically, is located in the interior of the valve housing 3, which can be positioned in various operating positions by rotation about a valve member rotation axis 7, in order to free or shut off the fluid connection between the individual valve connections 4 according to a valve-type-specific pattern within the fluid channel structure 5.

[0048] In the illustrated embodiment, the fluid channel structure 5 has a fluid channel passing substantially rectilinearly through the valve housing 3, which terminates in two oppositely facing valve connections 4. The valve member 6 can be positioned by turning it in two operating positions, in which it frees or shuts off the fluid connection between the two valve connections 4. On account of the rectilinear flow behaviour the process valve 1 represents an I-valve-type.

[0049] Depending on the number and distribution of the valve connections 4, the valve fitting 2 can also have a different functionality, which then results in other types of process valves. Thus, an L-valve-type can have more than two valve connections 4 arranged angularly with respect to one another, so that the fluid passage through the valve fitting 2 follows an L-shaped course, which means that one can speak of an L-valve-type. In a likewise advantageously possible T-valve-type of the process valve 1, the fluid channel structure 5 is designed so that the associated valve connections 4, in particular four pieces, are in case each connected together in a T-shaped flow pattern depending on the adjusted operating position of the valve member 6.

[0050] It is understood that, depending on the valve-type of the process valve 1, the associated valve member 6 is designed so that the described connection and isolation pattern between the various valve connections 4 can be predetermined.

[0051] The possible rotational movement of the valve member 6 about the valve member rotational axis 7 in order to specify the individual operating positions is referred to as adjusting movement 12 and is indicated in the drawing by a double arrow.

[0052] The process valve 1 furthermore has a rotary drive 8 serving to produce the adjusting movement 12 of the valve member 6. The rotary drive 8 is attached to the valve fitting 2. In particular the rotary drive 8 has a drive housing 13, which is fastened to the valve housing 3 via a suitable fastening interface 14.

[0053] The rotary drive 8 has drive means 15 arranged in the interior of the drive housing 13, by means of which a drive shaft 17 rotatably mounted in the drive housing 13 can be driven in a reciprocating drive movement in a direction indicated by a double arrow. The axis of rotation of the drive movement 16 coincides with the longitudinal axis 18 of the drive shaft 17.

[0054] The drive shaft 17 is accessible from outside the valve housing 3 at a lower side of the rotary drive 8 facing the valve fitting 2. The drive shaft 17 has there a coupling end portion 22, with which it is connected in a torque-proof manner to the valve member 6, so that the drive movement 16 of the drive shaft 17 directly results in the adjusting movement 12 of the valve member 6. The longitudinal axis 18 of the drive shaft 17 is aligned coaxially with the valve member rotation axis 7.

[0055] The rotary drive 8 of the embodiment is of a fluid-operated design and is actuated in particular with compressed air or another fluid pressure medium. In this connection the drive means 15 include in particular a rack and pinion arrangement 23 linearly reciprocally movable in the interior of the drive housing 13 by fluid force and a sprocket arrangement 24 arranged coaxially and in a torque-free manner on the drive shaft 17, and meshing with the rack and pinion arrangement 23. By means of a valve arrangement, not shown in further detail, the rack and pinion arrangement 23 can be driven to perform a reciprocating linear movement by controllable fluid impact on the rack and pinion arrangement 23, resulting in the rotatory drive movement on account of the existing toothing engagement with the ring gear 24 arrangement.

[0056] According to a non-illustrated embodiment, the rotary drive 8 may also be an electric or electromagnetic rotary drive.

[0057] By appropriate control of the rotary drive 8, the drive shaft 17 can be rotated and in this way the valve member 6 connected thereto in a torque-proof manner can be positioned in the desired operating position. Preferably the operational control of the rotary drive 8 is accomplished by an electronic control device, not illustrated further.

[0058] The rotary drive 8 has an indicator shaft 25 accessible from outside the valve housing 3, and which always rotates together with the drive shaft 17 about an axis of rotation 29 defined by its longitudinal axis. The indicator shaft 25 is preferably formed as a single-piece assembly with the drive shaft 17, but may also be a separate shaft coupled by suitable means on the drive side to the drive shaft 17.

[0059] The indicator shaft 25 is used to indicate the current rotational position of the drive shaft 17 and thus indirectly also the current operating position of the valve member 6 coupled in a torque-free manner to the drive shaft 17. Depending on the operating position of the valve member 6, the indicator shaft 15 adopts different relative rotational positions with respect to the valve housing 3. These are recognisable to a viewer, wherein in order to improve the visual perceptibility of the respective rotational position, the indicator shaft 25 is combined with a position indicator 26 located outside the drive housing 13.

[0060] The position indicator 26 is connected in a torque-free manner in the region of an outer side of the valve housing 3 oriented in the axial direction of the indicator shaft 25 to an end portion 27 of the indicator shaft 25 that is accessible there. The end portion 27 expediently protrudes from the valve housing 3. It is located in particular on an upper side 28 of the rotary drive 8 opposite the valve fitting 2.

[0061] The position indicator 26, also shown again separately in FIGS. 3 to 11, has an imaginary central vertical axis 32 which coincides with the axis of rotation 29 of the indicator shaft 25, formed by way of example by the longitudinal axis 18, when the position indicator 26 is mounted on the end portion 27 of the indicator shaft 25 on adopting its position of use.

[0062] On turning the indicator shaft 25, the position indicator 26 performs a synchronous rotational movement 39 about the vertical axis 32.

[0063] The position indicator 26 has an upper side 33 oriented in the axial direction of the vertical axis 32 and an underneath side 34 axially opposite thereto. In the mounted position of use its underneath side 34 faces towards the rotary drive 8.

[0064] The position indicator 26 is designed for the releasable torque-proof plug-in connection with the end section 27 of the indicator shaft 25. For this purpose, it has on the underneath 34 a mounting interface 35 coaxial with the vertical axis 32, which can be axially plugged onto the end portion 27 in such a way that in the circumferential direction 36 of the vertical axis 32 indicated by a double arrow a positive type engagement is established, enabling a torque transmission between the position indicator 26 and the indicator shaft 25.

[0065] By way of example, the mounting interface 35 comprises a transverse web 35a extending radially with respect to the vertical axis 32, which engages in a carrier slit 35b having a complementary cross-sectional contour, which is introduced from the free front face into the end section 27 of the indicator shaft 25.

[0066] For the axially immovable fixing on the indicator shaft 25 the position indicator 26 expediently includes a fastening screw 37, which passes centrally axially through the position indicator 26, wherein axially is understood to mean the axial direction of the vertical axis 32. The fastening screw 37 has a screw head 37a, by means of which it is supported on the upper side 33 of the position indicator 26, and also a position indicator 26 passing centrally through the threaded shaft 37b, which is screwed into a threaded bore 38 of the indicator shaft 25, open at the front on the end portion 37. By suitably tightening the fastening screw 37 the position indicator 26 is axially clamped in a releasable manner to the indicator shaft 25.

[0067] By unscrewing the fastening screw 37 from the threaded bore 38 the position indicator 26 can be removed at any time for any reason from the indicator shaft 25 and thus from the rotary drive 8 as a whole.

[0068] Instead of the fastening screw 37, in a non-illustrated embodiment, a fastening clip is provided. The fastening clip expediently has a head supported on the upper side 33 of the position indicator 26 and a shaft passing centrally through the position indicator 26 is provided for locking engagement with the indicator shaft 25. The mounting clip is locked to the indicator shaft 25, in particular in a releasable manner

[0069] The position indicator 26 is formed of several parts, and in particular of two parts. It comprises two indicator elements 42, 43 cooperating in a special way, which for the sake of better differentiation are referred to in one case as base indicator element 42 and in the other case as additional indicator element 43. They are components separated from another that can be assembled or are assembled to form one unit, namely the position indicator 26.

[0070] Each indicator element 42, 43 has at least one visually recognisable marking, which in the case of the base indicator element 42 is referred to as base indicator marking 44 and in the case of the additional indicator element 43 as additional indicator marking 45. The base indicator element 42 has multiple base indicator markings 44 that are distributed about the vertical axis 32 in the circumferential direction 36. Preferably the base indicator element 42 is provided with exactly two base indicator markings 44, which are expediently arranged angularly offset from one another by 90 degrees, which applies to the embodiment. The additional indicator element 43 has at least one additional indicator marking 45, wherein it is expediently provided with only a single additional indicator marking 45, which applies to the embodiment.

[0071] Preferably, each indicator marking 44, 45 is strip-shaped and is radially aligned with respect to the vertical axis 32. As a result the indicator marking 44, 45 is very clearly visible to an observer. Each indicator marking 44, 45 conveniently has a different colour and/or a different surface structure than the remaining component of the associated indicator element 42, 43, so that there is a colour and/or structural contrast, which promotes optical perceptibility.

[0072] Each indicator marking 44, 45 is preferably arranged facing at least partially axially upwards on the associated indicator element 42, 43, so that it is clearly visible when viewed from the upper side 33. Each indicator marking 44, 45 can however extend at least partially also in the outer circumferential region, facing radially outwardly with respect to the vertical axis 32, of the respective indicator element 42, 43. In the illustrated embodiment each indicator marking 44, 45 advantageously extends radially outwards starting from a region close to the centre on the upper side associated with the vertical axis 42, and then along the radially outer circumference of the relevant indicator element 42, 43 downwards in the direction of the underneath side 34. As a result the indicator markings 44, 45 can be recognised particularly well also obliquely from the side.

[0073] In the position of use of the position indicator 26, the additional indicator element 43 is attached externally to the base indicator element 42. The attachment is preferably effected with an attachment movement 46 illustrated by an arrow in the axial direction of the vertical axis 32 in the region of the upper side 33.

[0074] The position indicator 26 offers the advantageous possibility of positioning the additional indicator element 43 about the vertical axis 32 as centre in different rotational angular positions with respect to the base indicator element 42 and fixing it in a torque-proof manner in any angular position. In FIGS. 6 to 11 three positions of use of the position indicator 26 are shown, in which the additional indicator element 43 is fixed in different angular positions with respect to the base indicator element 42.

[0075] In each angular position of the additional indicator element 43 adjusted on the base indicator element, at least one base indicator marking 44 and the at least one additional indicator marking 45 are visible to the viewer. Due to the angular position in which the additional indicator element 43 is positioned on the base indicator element 42, it is possible to influence which of the base indicator markings 45 arranged on the base indicator element 42 are visible. In this connection there is the advantageous possibility of positioning the additional indicator element 43 in at least one angular position, which is referred to as cover angle position, because at least one base indicator marking 44 is covered by the additional indicator element 43 and at the same time at least one base indicator marking is uncovered and is therefore clearly visible to a viewer.

[0076] The respectively covered base indicator marking 44 is preferably completely invisible to a viewer. The desired effect can of course also be achieved even if the covered base indicator marking 44 is still visible to some extent, but appears visually in the background with respect to the other indicator markings 44, 45, for example if the additional indicator element 43 has a low light transmittance.

[0077] By way of example, the additional indicator element 43 can be positioned, inter alia, in an angular position evident from FIGS. 10 and 11, in which it does not cover any of the base indicator markings 44, so that from the outside each base indicator marking and each additional indicator marking 45 is visible.

[0078] FIGS. 6 and 7 on the one hand and FIGS. 8 and 9 on the other hand show the additional indicator element 43 in two different angle cover positions, which differ from one another in the rotational angle alignment with respect to the base indicator element 42. In a first cover angle position apparent from FIGS. 6 and 7, one of the two base indicator markings 44 is covered by the additional indicator element 43, which for a better differentiation is also termed first base indicator marking 44a. The other, second base indicator marking 44b is at the same time uncovered. In a second cover angle position visible in FIGS. 8 and 9, again only one of the existing base indicator markings 44 is covered by the additional indicator element 43, but in contrast to the first cover angle position the covered base indicator marking 44 is the second base indicator marking 44b, whereas the first base indicator marking 44a is uncovered.

[0079] Each multiple arrangement of indicator markings 44, 45 visible to the viewer represents a valve-type symbol 47 visually perceptible to a viewer, which is also additionally emphasised in the drawing as a line structure 48, because in practice colour and/or structure contrasts that are normally present in the drawings are not shown in the graphical depictions.

[0080] The valve-type symbols 47 that are for example adjusted are, according to FIGS. 6 and 7, an I-valve-type symbol 47a, in which an additional indicator marking 45 and a single, uncovered base indicator marking 44, 44b are linearly aligned. In an L-valve-type symbol adjusted according to FIGS. 8 and 9, the additional indicator marking 45 and two uncovered base indicator marking 44, 44a are arranged in an L-shape. In a T-valve-type symbol 47c adjusted in FIGS. 10 and 11 the additional indicator marking 45 and two uncovered base indicator markings 44, 44a, 44b are arranged in a T-shape.

[0081] During a rotational movement 39 of the position indicator 26 as a result of a rotary actuation of the indicator shaft 25 carrying it, the respectively associated valve-type symbol 47 is co-rotated, so that in each case it is directly recognisable what type of valve the associated process valve 1 is, and which operating position the valve member 6 of the relevant process valve adopts.

[0082] The mounting interface 35 already discussed further above is expediently formed on the underneath side 34 of the base indicator element 42. As an example, the transverse web 35a is interrupted, so that access to the threaded shaft 37b is possible.

[0083] The base indicator element 42 is expediently disc-shaped and has a circular outer contour when viewed in the axial direction of the main axis 32.

[0084] The base indicator 42 has a front surface 52 associated with the upper side 33 and an outer circumferential surface 53 facing radially outwards with respect to the main axis 32. While the outer circumferential surface 53 in the embodiment tapers slightly axially in the direction of the upper surface 52, it is formed circular cylindrically in an embodiment that is not illustrated.

[0085] The additional indicator element 43 is L-shaped and has two mutually angularly aligned first and second leg sections 54, 55. The angle enclosed by the two leg sections 54, 55 corresponds to the angle between the upper end face 52 and the outer circumferential surface 53, so that by way of example, on account of the tapering shape of the outer circumferential surface 53, it is a slightly obtuse angle.

[0086] The additional indicator element 43 is attached to the base indicator element 42 in such a way that it extends with the first leg section 54 along the upper end surface 52 in a radial direction with respect to the vertical axis 32 and with the second leg section 55 angled with respect thereto along the outer circumferential surface 53 in the axial direction towards the lower side 34. The second leg section 55 is suitably inclined corresponding to the tapering of the outer circumferential surface 43.

[0087] The additional indicator element 43 attached to the base indicator element 42 thus covers with its first leg section 54 a part of the upper end surface 52 and with its second leg section 55 a part of the circumferential extension of the outer circumferential surface 53.

[0088] The angular extension of the additional indicator element 43 in the circumferential direction 36 is selected depending on the valve-type symbols 47 to be visualised. It is particularly advantageous if the angular extent is 90 degrees, which is applicable to the embodiment.

[0089] According to the example, the first leg section 54 is formed in the shape of a circle sector with a central angle of at least substantially 90 degrees. The second leg section 55 adjoins the first leg section 54 in the region of the greatest circumferential extension and is expediently designed shell-shaped, in which connection it has at least substantially the same curvature in the circumferential direction 36 as the outer circumferential surface 53.

[0090] At the free end region opposite the second leg section 55 the first leg section 54 is penetrated by a fastening hole 56, whose centre also lies on the vertical axis 32, like the centre of another fastening hole 57, which is axially and centrally penetrated by the base indicator 42.

[0091] The two fastening holes 56, 57 are provided for the passage of the fastening screw 37, which is inserted through the two fastening holes 56, 57 when mounting the position indicator 26 on the indicator shaft 25 from the upper side 33. On tightening the fastening screw 37 the screw head 37a presses from above onto the first leg section 54 of the additional indicator element 43, which as a result is braced together with the base indicator element 42 incorporated axially therebetween with the end portion 27 of the indicator shaft 25.

[0092] The edge of the fastening hole 56 formed in the first leg section 54 is expediently shaped widening conically upwards, the screw head 37a tapering conically on the outer circumference, so that the additional indicator element 43 is centred with respect to this when it is fixed to the base indicator element 42.

[0093] The base indicator element 42 is preferably dish-shaped and has an interior 58 open towards the underneath side 34. The mounting interface 35 is expediently located in this interior. In the assembled position of use the indicator shaft 25 protrudes with its end portion 27 from below into the interior 58 of the base indicator element 42.

[0094] The preferably single additional indicator marking 45 of the additional indicator element 43 is expediently located in the region of one of the two side edges 54a, 54b of the sector-shaped first leg section 54 oriented in the circumferential direction 36 of the vertical axis 32. Preferably the additional indicator marking 45 is arranged on the outer surface 62 of the additional indicator element 43 facing away from the base indicator element 42.

[0095] In the illustrated embodiment each base indicator marking 45 extends radially outwards from the centre region of the upper end surface 52 with a first length along the upper end surface 52 and then with a second length along the outer circumferential surface 53 as far as the lower edge region 63 associated with the lower side 43. In a similar way the additional indicator markings 45 extends from a region adjacent to the vertical axis 32 on the outer surface 62 first of all radially outwards along the first leg section 54 and then along the second leg section 55 downwards to the lower edge region 64 of the second leg section 55. In the first cover angle position visible in FIGS. 6 and 7, the additional indicator marking 45 extends in the axial extension to the uncovered second base indicator marking 44b, which applies correspondingly to the associated first side edge 54a. The opposite second side edge 54b of the additional indicator element 43 in the circumferential direction 32 extends beyond the first base indicator marking 44a, so that this too is covered so as to be invisible from the outside.

[0096] In the second cover angle position visible in FIGS. 8 and 9, the additional indicator element 43 is attached to the base indicator element 42 in a torque-proof manner in such a way that the first side edge 54a comprising the additional indicator marking 45 covers the second base indicator marking 44b, whereas the first base indicator 44a is uncovered.

[0097] In the two cover angle positions one of the two base indicator markings 44a, 44b is therefore covered in each case by the additional indicator element 43, while the respective other base indicator marking 44b, 44a remains uncovered. The covering function is performed in the first cover angle position by the second side edge 54b free of markings, and in the second cover angle position by the first side edge 54a provided with the additional indicator marking 45.

[0098] For the torque-proof fixing of the additional indicator element 43 in the respectively adjusted angular position, in a non-illustrated embodiment exclusively the clamping force is used, with which the two indicator elements 42, 43 are clamped together by the fastening screw 37. In the advantageous illustrated embodiments the adjusted angular position is additionally fixed with a positive engagement effective in the circumferential direction 36.

[0099] A toothed device 65 is associated jointly with the two indicator elements 42, 43, by means of which the additional indicator element 43 is locked in a non-rotatable manner on the base indicator element 42 in the respectively adjusted angular position. By way of example the toothed device 65 contains a ring-shaped self-contained ring gear 66 formed on the base indicator element 42 coaxially to the vertical axis 32. The ring gear 66 is preferably located at the lower edge portion 63 on the radially outer side of the base indicator element 42. Conveniently the ring gear 66 delimits axially downwards the outer circumferential surface 53.

[0100] The toothed device 65 also includes a counter-toothing 67 complementary to the ring gear 66, which expediently has an arcuate longitudinal extension and expediently extends over the whole circumferential length of the second leg section 55. It is formed there in particular on the lower edge region 64, and in fact on the inside of the second leg section 55 facing the base indicator element 42.

[0101] During the axial attachment of the additional indicator element 43 to the base indicator element 42 according to the arrow 46, the counter-toothing 67 engages in the currently predetermined rotation angle position in the ring gear 66, so that the two indicator elements 42, 43 are supported in a non-rotatable manner on one another in the circumferential direction.

[0102] According to a non-illustrated embodiment, the counter-toothing 67 consists only of a single tooth projection, which engages in different recesses of the ring gear 66 depending on the rotational position of the additional indicator element 43.

[0103] While the inter-engaging components of the toothed device 65 are formed by way of example in the manner of the toothing of a toothed wheel and have a zigzag-shaped configuration, alternatively also other configurations may be provided that enable a positive engagement in the circumferential direction 36, for example on the one hand a plurality of successive holes spaced from one another and on the other hand at least one pin- or knob-shaped projection.

[0104] The ring gear 66 is expediently formed as a one-piece integral part of the base indicator element 42, which also applies accordingly to the counter-toothing 67 as regards the additional indicator element 43. Both indicator elements 42, 43 are preferably made of a plastic material.

[0105] If the angular position of the additional indicator element 43 is altered in order to change the illustrated valve-type symbol 47, this is done in such a way that first the fastening screw 37 is unscrewed and then the additional indicator element 43 is lifted from the base indicator element 42 by releasing the positive connection of the toothed device 65 against the arrow 46. In this lifted position the additional indicator element 43 is turned to the desired angular position and then, under renewed formation of the positive connection of the toothed device 65 again according to the arrow 46, is replaced on the base indicator element 42. Finally the fastening screw 37 is tightened again.

[0106] It is advantageous if the rotary drive 8 is additionally equipped with a position detection device 68, by means of which multiple rotational positions of the position indicator 26 can be detected in an electrically processable manner

[0107] The rotary drive 8 of the exemplary embodiment is equipped with such a position detection device 68, which has a sensor device 72 arranged on or in the drive housing 13 and a plurality of actuating elements 73 arranged on the position indicator 26 and suitable for activating the sensor device 72.

[0108] The actuating elements 73, which are preferably permanent magnets, are fixed to a plurality distributed around the vertical axis 32 on the base indicator element 42. For example, they are inserted into and in particular clipped onto receiving pockets 74 of the indicator element 42 open towards the underneath side 34. If only two rotational positions are to be detected, two actuating elements 73 are sufficient, wherein it is advantageous if the base indicating element 42 offers the possibility of installing more than two actuating elements 73.

[0109] With a corresponding configuration of the sensor device 72, a single actuating element 73 is already sufficient to detect a plurality of rotational positions of the position indicator 26. This is realised in a non-illustrated embodiment.

[0110] As an example, a total of four receiving pockets 74 are present, which are arranged at angular intervals of 90 degrees and which can be selectively equipped with an actuating element 73.

[0111] In the rotational movement of the position indicator 26 effected by the indicator shaft 25, the actuators 73 move along a circular path, in the region of which sensor means 75 of the sensor device are arranged on the drive housing 13, so that a contactless operation is possible when moving past the actuators 73, resulting in an electrical position signal that can be processed further. The sensor signals can be transmitted via an electromechanical interface 76 of the sensor device 72 to the already mentioned electronic control device.