This U.S. utility patent application claims the benefit of DE patent application no. 202021103152.2, filed Jun. 10, 2021, the entire contents of which are incorporated herein by reference.
The invention elates to a sealed thumbwheel, in particular as operating element on an operating panel or a multi-function operating handle.
Operating elements, which can be operated by means of slight finger movements, in the form of thumbwheels, are often used as control elements on or in operating panels, in particular in agricultural vehicles or machines or in the field of manufacturing technology. The combination of several operating elements on an operating panel or on a multi-function handle, such as a joystick, provides for the control of a large number of working procedures, devices, or machine functions via a single compact operating system.
With regard to their tightness against the ingress of dirt and water, the used control elements have to satisfy high requirements in particular in the field of agricultural machines and vehicles because the cleaning mostly takes place with high pressure and steam jet, and an ingress into the control electronics and mechanism must be prevented.
Known thumbwheels do not have a sufficient tightness, in particular when providing a sufficiently large maximum deflection angle.
Even though it is known, for example, from EP 3 174 081 B1 to further develop thumbwheels in the form of a joystick, a sufficient tightness cannot be attained by means of the disclosed system comprising several housing parts, which have a plurality of connecting edges with contact to the external environment as well as to the interior space, which is to be protected.
It is thus the object of the invention to propose an operating element for the finger operation, which has an improved tightness against the ingress of dust and water, in particular in the case of high pressure cleaning with simultaneously increased degree of freedom of movement.
This object is solved by means of an operating element having a thumbwheel, wherein the thumbwheel has an operating lever, which can be rotated about at least one first axis of rotation, a mounting box, wherein a point of intersection of the first axis of rotation with the thumbwheel is formed within the mounting box, as well as an integral sealing system having at least one seal, wherein sealing system and mounting box are produced so as to be connected to one another by means of a substance-to-substance bond by means of a two-component injection molding, and wherein the mounting box has injection channels for injecting a material of the sealing system, in which corresponding injection channel connections of the sealing system are formed, wherein the seals are connected to one another via the injection channel connections, and wherein a seal is formed in the form of a bellows, which partially surrounds the operating lever along its longitudinal axis on contact surfaces.
By means of its integral nature as well as the substance-to-substance bond with the mounting box, the sealing system has a minimized number of connecting edges, which can be accessed from the outside and which are sources for the ingress of dirt and moisture. A tightness for the interior of the mounting box, in particular of the protection type IP 6K9K, is attained in an advantageous manner in this way. An efficient production of the sealing system in one piece is furthermore provided therewith via the known two-component injection molding process, which simplifies the further mounting. A connection of the sealing system to the mounting box has also already been created in the production of the sealing system, whereby connecting edges are avoided, in turn, as sources for the ingress of dirt and water. A loosening of the seals as a result of corrosion or wear is furthermore prevented. The service life of the sealing system is thus several millions of movement cycles. Within the injection channels of the mounting box, injection channel connections are made of a material of the sealing system, which simultaneously connect the individual seals to one another, during the two-component injection molding. The production process for the operating element according to the invention additionally provides for a respective optimized material selection for a stable mounting box and a flexible, durable sealing system.
The bellows provides for a sealed connection of the operating lever and thus of the entire thumbwheel to the mounting box, wherein a rotatory movability of the operating level remains to a large extent. A deflection of the operating lever by up to 30° relative to a zero position is possible thereby.
On its upper end, the connecting surface created along the longitudinal axis of the bellows thus has the single connecting edge of the operating lever to the external environment. This position of the connecting edge provides for a simple, additional seal by means of covering or sheathing.
Further static seals of the sealing system at points of intersection to other components or elements, for example to light guides or the mounting frame, which surrounds the operating element in an operating panel, are likewise provided.
In further development of the invention, it is provided that the bellows has exactly one fold. This provides for a sufficient movability and extendibility of the bellows with simultaneously material-compatible deformation and minimized cost of materials.
It is furthermore provided that the operating lever can be moved in a translatory manner along an axis of its zero position. The use of the bellows provides for a required compression and extension of the corresponding seal in a material-friendly manner. A further control variable can be linked to the operating lever in a highly advantageous manner by means of the translatory movability.
In embodiment of the invention, it is provided that the operating lever can be rotated about a second axis of rotation, which is formed perpendicular to the first axis of rotation. Compared to known thumbwheels, an additional degree of freedom of rotation is thus attained, which provides for a two-dimensional movement control or which provides for the control of a further component, respectively. In combination with the translatory movability, in particular a three-dimensional control is made possible.
In an embodiment of the invention, it is provided that the operating lever can be operated by means of a thumb of a user when firmly placing the hand on the mounting box, in the alternative also by means of an index finger. This provides in particular for the integration of the operating element into an operating panel, in the case of which further control systems of the vehicle or of the machine can be controlled by means of movement of the entire hand.
It is additionally also provided that an operating head of the operating lever partially surrounds the bellows in the form of a projection along the axial position of the contact surfaces. The end of the bellows is efficiently closed against a direct ingress of dirt or water in this way.
In further development of the invention, it is provided that the operating lever is arranged on a sliding system, wherein the sliding system has at least a first sliding part and restoring means, which act on the at least one sliding part and transfer the latter to a zero position, and wherein the operating lever is guided in the sliding system, wherein the first sliding part is movably mounted in such a way that a positional change of the operating lever with respect to the sliding system results in a movement of the at least one sliding part in the direction of the restoring means acting on the at least one sliding part.
An operating element comprising sliding system is thus proposed, which provides for the use of a rigid operating lever without separate restoring means. Sliding system and operating lever thereby act as thumbwheel. The at least one sliding part forms a slide for the operating lever guided therein, wherein the slide exerts a restoring force, which is changed depending on the position of the operating lever, on the latter. For the generation of the restoring force, the invention has restoring means, which act on the at least one sliding part, which has a correspondingly formed sliding track, so that the operating lever can be a simple, inherently rigid lever. A zero position of the operating lever, into which the operating lever is returned in the absence of a deflection, is defined by means of the restoring forces. According to the invention, this deflection is a pushing movement in a direction radially to the pivoting movement of the operating lever, as well as the pivoting movement thereof about at least one pivot axis. In the alternative or in addition, it also comprises a displacement of the lever similarly as in the case of a commercially available manual vehicle control, or a pulling movement in the direction radially to the pivoting movement of the operating lever.
The operating element according to the invention is a sealed operating element produced by means of an injection molding process, comprising a thumbwheel, the sealing of which of the inner elements against external influences is improved due to a minimized number of connecting surfaces of mounting box, sealing system, and operating element in such a way that a tightness of the protection class IP 6K9K is attained. The materials used for the two components are adapted to the function of the respective injected element, whereby a stable material can be used for the injection molding of the mounting box, and a more flexible material can simultaneously be used for the injection molding of the sealing system, which provides in particular for the use of a bellows as part of the sealing system for sealing and connecting to operable parts of the operating element.
The invention will be described in more detail below with reference to two figures, in which:
Number | Date | Country | Kind |
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202021103152.2 | Jun 2021 | DE | national |
Number | Name | Date | Kind |
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2929258 | Mackway | Mar 1960 | A |
3772484 | Roeser | Nov 1973 | A |
6549113 | Woodard | Apr 2003 | B1 |
10032572 | Chen | Jul 2018 | B2 |
Number | Date | Country |
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19757907 | Jul 1999 | DE |
10013630 | Oct 2002 | DE |
102015102317 | Aug 2016 | DE |
0122465 | Oct 1984 | EP |
3174081 | Apr 2018 | EP |
3285275 | Jan 2019 | EP |
Number | Date | Country | |
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20220397929 A1 | Dec 2022 | US |