Operating element for a laboratory device

Abstract

The invention relates to an operating element (11) having a support part (13) which can be mounted on a device housing, in particular on a housing of a laboratory device, for example a laboratory stirrer, and having a rotary knob (15) which is held on the support part, is rotatable about an axis of rotation, is provided with a permanent magnet (17) and is additionally adjustable relative to the support part in the axial direction between a released position and a depressed position, wherein, as a result of a magnetic force acting between the support part and the rotary knob, the rotary knob can be reset from the depressed position into the released position.

Claims

1. A control element comprising: a carrier part attachable to a device housing, and a rotary knob, the rotary knob being held at the carrier part, the rotary knob being rotatable about an axis of rotation, the rotary knob being provided with a permanent magnet, the carrier part provided with a holding pin extending through a center of the permanent magnet, and the rotary knob additionally being adjustable in an axial direction relative to the carrier part between a non-pressed position and a pressed position, wherein the rotary knob can be returned from the pressed position into the non-pressed position on the basis of a magnetic force acting between the carrier part and the rotary knob, wherein the permanent magnet is configured as a ring magnet, and the rotary knob comprises a polygon socket, in a view parallel to the axial direction, at a side facing the carrier part in which the ring magnet is received in a force-fitted manner.

2. The control element in accordance with claim 1, wherein the device housing is a housing of a laboratory device.

3. The control element in accordance with claim 1, wherein the rotary knob is fixedly connected to the permanent magnet and the carrier part is provided with an element attracted by the permanent magnet and composed of a magnetic material.

4. The control element in accordance with claim 3, wherein the permanent magnet is insertable into the polygon socket from an axial direction.

5. The control element in accordance with claim 3, wherein the polygon socket is placeable onto the permanent magnet from an axial direction.

6. The control element in accordance with claim 3, wherein the permanent magnet and the magnetic element are arranged with respect to one another such that the spacing between the permanent magnet and the magnetic element increases on the adjustment of the rotary knob into the pressed position.

7. The control element in accordance with claim 3, wherein the magnetic material is a ferritic steel.

8. The control element in accordance with claim 1, wherein the carrier part comprises: a carrier base attachable to the device housing; and the holding pin projects from the carrier base in the direction of the rotary knob and onto which the ring magnet is placed.

9. The control element in accordance with claim 8, wherein a free end of the holding pin is of sleeve shape.

10. The control element in accordance with claim 9, wherein the sleeve-shaped free end of the holding pin comprises flexible snap-in hooks to hold the placed-on ring magnet in a shape matched manner at the carrier part and can be radially compressed to enable a placing on of the ring magnet.

11. The control element in accordance with claim 10, wherein the sleeve-shaped free end of the holding pin is provided with a radially outwardly projecting collar and comprises axially outwardly extending slits to form the flexible snap-in hooks.

12. The control element in accordance with claim 8, wherein a magnetic element or at least a part thereof is arranged at a free end of the holding pin, adjoining the holding pin, in the axial direction, with the ring magnet being arranged between the carrier base of the carrier part and the magnetic element or the part thereof.

13. The control element in accordance with claim 8, wherein a magnetic element comprises a shaft that carries a head, with the shaft being plugged into a sleeve-shaped free end of the holding pin, and with the head being arranged outside the sleeve-shaped free end of the holding pin.

14. A device comprising a housing and a control element arranged outside the housing, the control element comprising: a carrier part attachable to the housing of the device the carrier part including a holding pin extending therefrom; and a rotary knob, the rotary knob being held at the carrier part, the rotary knob being rotatable about an axis of rotation, the rotary knob being provided with a permanent magnet, the holding pin extending through a center of the permanent magnet, and the rotary knob additionally being adjustable in an axial direction relative to the carrier part between a non-pressed position and a pressed position, wherein the rotary knob can be returned from the pressed position into the non-pressed position on the basis of a magnetic force acting between the carrier part and the rotary knob, wherein the permanent magnet is configured as a ring magnet, and the rotary knob comprises a polygon socket, in a view parallel to the axial direction, at a side facing the carrier part in which the ring magnet is received in a force-fitted manner.

15. The device in accordance with claim 14, wherein the control element is attached to the housing in a shape matched or force-fitted manner or with material continuity.

Description

(1) A non-restrictive embodiment of the invention is illustrated in the drawing and will be described in the following. There are shown:

(2) FIG. 1 a control element in accordance with the invention in an exploded view;

(3) FIGS. 2A, 2B the control element of FIG. 1 in a non-pressed position and in a pressed position, each in longitudinal section; and

(4) FIG. 3 a rotary knob of the control element of FIG. 1 in a lower view.

(5) FIG. 1 shows a control element 11 for a laboratory device. The control element 11 comprises a carrier part 13 via which the control element 11 is attachable, in particular adhesively bondable, to a housing of a laboratory device and a rotary knob 15 that is held at the carrier part 12, that is manually actuable, and that is rotated about an axis of rotation. A permanent magnet is furthermore provided in the form of a diametrically magnetized ring magnet 17 that is fixedly connected to the rotary knob 15 and whose axial direction coincides with the axis of rotation of the rotary knob 15. The rotational position of the ring magnet 17 that can be recognized by a sensor arrangement arranged within the device housing corresponds to a corresponding rotational position of the rotary knob 15 so that operating parameters of the laboratory device can be set by rotating the rotary knob 15.

(6) The fixed connection between the rotary knob 15 and the ring magnet 17 is achieved in accordance with FIG. 3 in that the rotary knob 15 has a hexagon socket 19 at its inner side facing the carrier part 13 and the ring magnet 17 is received therein with an interference fit and thus in a force-fitted manner. A rotation of the rotary knob 15 therefore has the result of a corresponding rotation of the ring magnet 17.

(7) To hold the rotary knob 15 at the carrier part 13, the carrier part 13 has a holding pin 23 that projects in the axial direction of the rotary knob 15 from a disk-shaped carrier base 21 of the carrier part 13 and onto which the ring magnet 17, that is fixedly connected to the rotary knob 15, is placed in a latching manner. The free end of the holding pin 23 is configured in sleeve shape for this purpose and has a peripheral, radially outwardly projecting collar 25 as well as two axially outwardly extending slits 27. The free end of the holding pin 23 is hereby configured as two respectively radially inwardly bendable flexible snap-in hooks 29 that, on the one hand, permit a placing on of the ring magnet 17 and, on the other hand, latch the placed-on ring magnet and hold it at the carrier part 13 with shape matching.

(8) The rotary knob 15 is furthermore additionally also pressable, i.e. is adjustable in the axial direction relative to the carrier part 13 between a non-pressed position such as is shown in FIG. 2A and a pressed position such as is shown in FIG. 2B. Since the ring magnet 17 is fixedly connected to the rotary knob 15, the ring magnet 17 also adopts a non-pressed or pressed position corresponding to the rotary knob 15. This axial position of the ring magnet 17 can likewise be recognized by the aforesaid sensor arrangement. Once an operating parameter of the laboratory device has been set by rotating the rotary knob 15, the setting of the operating parameter can be confirmed by a subsequent pressing of the rotary knob 15.

(9) To return the rotary knob 15 from its pressed position back into the non-pressed position, an element 31 composed of a magnetic material is provided in the form of a punch. The magnetic element 31 has a shaft 33 and a head 35, with the shaft 33 being plugged into the sleeve-shaped free end of the holding pin 23 and with the head 35 being arranged outside the holding pin 23 adjoining it in the axial direction. The ring magnet 17 is thus arranged between the carrier part 13 and the head 35 of the magnetic element 31 so that the spacing between the ring magnet 17 and the magnetic element 31 increases when the rotary knob 15 is pressed. The diameter of the shaft 33 of the magnetic element 31 is selected such that the free end of the sleeve-shaped holding pin 23 cannot be compressed at least so much that the ring magnet 17 can be pulled off the holding pin 23 when the shaft 33 of the magnetic element 31 is plugged into the holding pin 23.

(10) The magnetic material is a ferromagnetic and soft magnetic material, preferably a ferritic steel, that is magnetized and thereby attracted by the magnetic field of the ring magnet 17. The actuated rotary knob 15 is automatically returned into the unactuated position after the removal of the pressure actuation by the magnetic force that hereby acts between the ring magnet 17 and the magnetic element 31 and thus between the rotary knob 15 and the carrier part 13.

(11) To assemble and attach the above-explained control element 11 to a laboratory device, the carrier part 13 is first adhesively bonded to the housing of the laboratory device, and indeed at the point at which the aforesaid sensor arrangement is located at the inner housing side. The ring magnet 17 is then placed onto the holding pin 23 of the carrier part 13 in a latching manner. The magnetic element 31 is subsequently plugged into the holding pin 23, with the plug-in connection being able to be subject to clearance since the magnetic element 31 is attracted by the ring magnet 17 and is thus already magnetically held at the holding pin 23. Finally, the rotary knob 15 is placed onto the ring magnet 17 from the axial direction. The placing on takes place with force-fit here, with the rotary knob 15 also being able to be pulled off the ring magnet again by a corresponding force.

(12) The control element in accordance with the invention is simple and is made up of few elements and does not require any mechanical spring to return the control button to its starting position after a pressing actuation.

REFERENCE NUMERAL LIST

(13) 11 control element 13 carrier part 15 rotary knob 17 ring magnet 19 hexagon socket 21 carrier base 23 holding pin 25 collar 27 slit 29 bending snap-in hook 31 magnetic component 33 shaft 35 head