Step-down switch unit for sequential switching of currents

Abstract

Step-button unit (2) for sequentially switching currents, comprising at least one first switching contact (3) and one second switching contact (3) and comprising a switching unit (4) with actuators (5) arranged on the switching unit (4) above the switching contacts (3) at different distances from them, wherein the switching contacts (3) and the switching unit (4) are arranged relative to each other such that when pressure is applied to the switching unit (4) in the direction of the switching contacts (3), the actuators (5) are pressed onto it and different actuators (5) contact the switching contacts (3) at different pressure forces, wherein the switching unit (4) extends at least partially over the switching contacts (3) and has a planar return area (R) made of an elastic plastic material which exerts a force on the actuators (5) directed away from the switching contacts (3).wherein the switching unit (4) includes a recess for receiving a pressure element (6), wherein both the pressure element (6) and the recess for the pressure element (6) are inclined such that in a first part they are closer to the first switching contact (3) than in a second part to the second switching contact (3).

Description

[0001] The invention relates to a step switch unit for sequentially switching currents, an operating device for operating a device and a medical device.

[0002] For the manual operation of medical devices, switches or pushbuttons are used to turn an electrical current on and off. Switches are generally designed to maintain a constant current over a long period, while pushbuttons are often used when a short switching signal is required, such as triggering an X-ray.

[0003] Besides simple pushbuttons, there are also two-stage switching mechanisms that have different switching states depending on the pressure applied (different pressures or presses in different directions). For example, there are operating devices for X-ray imaging (e.g., "OPTIGRIP") that have a large number of pushbuttons to control a wide variety of functions. With such an operating device, for example, precise patient positioning is possible using multiple pushbuttons, as well as image capture and storage of the acquired image.

[0004] A conventional two-stage push button consists of a relatively large number of individual parts. It is operated by a plastic push button that must be pressed. This button is connected to a rocker switch. The rocker switch, in turn, presses on silicone actuators, which then contact metal snap discs (switching contacts) on a circuit board. In a two-stage push button, there are two metal snap discs on the circuit board. The push button is designed so that when the button is pressed, one switching contact is contacted first, and with further depressing, the second switching contact is contacted. The mechanical principle is based on applying a tilting moment to the silicone actuators. This tilting moment is created by the asymmetrical mounting of the plastic push button to the rocker switch.

[0005] Such switches have mechanical disadvantages: For example, the rocker switches are sometimes prone to installation errors, as they must be aligned very precisely and a different rocker switch must be used for each button. In particular, the layered construction (switching contact - silicone actuator - rocker switch - plastic button) results in a complex mechanical design that increases both the component costs and the required installation space.

[0006] It is an object of the present invention to provide a step-button unit for sequential switching of currents, an operating device for operating a device and a medical device, with which the disadvantages described above are avoided.

[0007] This problem is solved by a step-button unit according to claim 1, an operating device according to claim 8 and a medical device according to claim 12.

[0008] A step-switch unit according to the invention serves for the sequential switching of currents. It comprises at least two switching contacts and a switching unit with actuators arranged on the switching unit above the switching contacts at different distances from them. The switching contacts and the switching unit are arranged relative to each other such that when pressure is applied to the switching unit in the direction of the switching contacts, the actuators are pressed onto it, and different actuators make contact with the switching contacts under different pressure forces. The switching unit extends at least partially over the switching contacts and has a planar return area made of an elastic plastic material, which exerts a force on the actuators directed away from the switching contacts.

[0009] As mentioned, the step switch unit is used for the sequential switching of currents. Sequential in this context means that the switching of currents occurs one after the other at different pressures. For this purpose, the step switch unit comprises at least two switching contacts and a switching unit with actuators, which are arranged above the switching contacts at varying distances from them on the switching unit.

[0010] Switching contacts are well known in the art and are often formed from metal snap discs arranged on a circuit board. Other commonly used switching contacts are formed by a pattern of conductive traces (often meandering) over which a metal contact is held at a distance by a spring element.

[0011] The actuators are, for example, silicone or plastic elements that are cylindrical, cuboid, or conical. The key requirement is that they are capable of triggering the switching contacts to establish an electrical connection. Such actuators are known in the prior art. The actuators are arranged at varying distances from the switching contacts, meaning that in the button's rest position, the actuators are not at the same distance from the switching contacts. This allows switching to occur sequentially, i.e., one after the other with a time delay, rather than simultaneously.

[0012] The switching contacts and the switching unit are arranged in such a way that when pressure is applied to the switching unit in the direction of the switching contacts, the actuators are pressed against them, and different actuators make contact with the switching contacts at different pressure forces. This pressure force can also be described as the actuator's stroke. A short stroke corresponds to a shorter pressure force, a longer stroke to a longer pressure force.

[0013] The switching unit serves to receive external pressure from an operator and extends at least partially over the switching contacts. It has a flat return area made of an elastic plastic material (silicone is a particularly common plastic material). The switching unit preferably covers the switching contacts completely. The return area exerts a force on the actuators. This force is a restoring force and is therefore directed away from the switching contacts. Its purpose is to prevent pressure from being exerted on the switching contacts, thus disengaging them from contact when no external pressure is applied to the switching unit.

[0014] The return area is planar, meaning that the return area made of elastic plastic material covers a certain area, extending in at least two directions, and possibly three. The actuators are thus kept away from the switching contacts by the return area made of elastic plastic material when no external pressure is applied to the switching unit.

[0015] An operating device according to the invention serves to operate a device. It comprises a number of step-button units according to the invention. This means that it comprises at least one step-button unit according to the invention.

[0016] A medical device according to the invention comprises an operating device according to the invention.

[0017] Further, particularly advantageous embodiments and developments of the invention result from the dependent claims and the following description, wherein the claims of one claim category may also be further developed analogously to the claims and description parts of another claim category and, in particular, individual features of different embodiments or variants may be combined to form new embodiments or variants.

[0018] A preferred stepped push-button unit is characterized by a switching unit comprising a single-piece, flat element made of an elastic plastic material. This element includes the return path and a designated pressure area and / or a retaining element for attaching a pressure element. The pressure area can also be elastic, for example. Alternatively, it can be rigid. The retaining element for attaching a pressure element is, for example, a snap-in mechanism. The switching unit can therefore be simply molded from silicone (e.g., as a single-piece molded part) and have a pressure area that an operator simply presses. Alternatively, the switching unit can also be provided with an additional plastic part that serves as the pressure area.

[0019] It is preferred that the pressure area comprises a less elastic, i.e., more plastic or inelastic, material than the return area, which in particular surrounds the pressure area, and that the switching unit is preferably manufactured in one piece by co-extrusion. As is generally known, co-extrusion consists of the continuous pressing of several identical or dissimilar plastic melts through a die; thus, several plastics or polymers are joined together by chemical bonding as they exit the die. Such a part can be manufactured simply and inexpensively.

[0020] A preferred step switch unit is characterized by the fact that the switching unit comprises a one-piece, flat element made of an elastic plastic material, in which the actuators are formed. These are therefore actuators that are integrated into the flat element.

[0021] A preferred step probe unit is characterized by the fact that at least part of the actuators are elastic, preferably with a Shore A hardness of less than 100, preferably less than 70. The Shore hardness is directly related to the penetration depth and is therefore a measure of the material hardness.

[0022] A preferred step-button unit is characterized in that at least the reset area, and preferably also the actuators and preferably also the pressure area, are made of silicone, particularly preferably by injection molding. Silicone has the advantage of being a very durable, elastic material that can be easily cleaned and disinfected.

[0023] A preferred step-button unit is characterized by the fact that the actuators have a larger spring constant for a force in the direction of the switching contacts upon contact than the return range, so that after an actuator contacts a switching contact, a tilting moment is exerted on the switching element by the respective actuator as the force on the switching element increases. Tilting moment here refers to the torque sufficient to tilt the switching element.

[0024] A preferred step switch unit comprises housing elements arranged to keep the switching unit at a distance from the switching contacts, so that switching requires a force to be applied to the contacts. The reset area is preferably shaped such that the actuators of the switching unit no longer press against the switching contacts in the unloaded state and preferably maintain a distance from them. Only when a force is applied does the switching unit, with its actuators, move towards the switching contacts until they make contact after a certain distance.

[0025] A preferred operating device comprises a plurality of switching contacts and a button made of an elastic material, with actuators arranged over the switching contacts, wherein the switching contacts and the button are arranged relative to each other such that when pressure is applied to the switching unit in the direction of the switching contacts, the actuators are pressed onto the switching contacts, and wherein at least one area of ​​the button over at least two of the switching contacts is designed as a switching unit for a step switch unit, wherein the button is preferably designed in one piece.

[0026] A preferred operating device comprises a handle, a front and a back, wherein both the front and the back have at least one stepped push-button unit according to the invention. It is preferred that the operating device is designed for operating a medical device.

[0027] A preferred operating device comprises a housing made of a plastic body with a Shore A hardness greater than 100, preferably polycarbonate, in conjunction with a number of step-button units according to the invention, the actuators of which are elastically connected to the housing, preferably with a material that also forms or accommodates the pressure area. It is particularly preferred that the housing and the number of step-button units are joined together by means of a co-extrusion process. A co-extruded workpiece has the advantage that it can have elastic and inelastic areas and that there are no crevices between these areas in which dirt or pathogens can become trapped.

[0028] The invention is explained in more detail below with reference to the accompanying figures and exemplary embodiments. The same components are designated with identical reference numerals in the various figures. The figures are generally not to scale. They show: Fig. 1 an operating device, Fig. 2 a state-of-the-art push button, Fig. 3 a step-button unit according to the invention, Fig. 4 the operation of a step switch unit according to the invention, Fig. 5 the operation of a step switch unit according to the invention, Fig. 6 another step-button unit according to the invention, Fig. 7 a backdrop according to the invention for the back of an operating device, Fig. 8 a backdrop according to the invention for the front of an operating device.

[0029] Fig. Figure 1 shows an embodiment of an operating device 1 for operating a device from two different perspectives: a front oblique view looking at the front side V and a rear oblique view looking at the back side W of the operating device. The two perspectives, i.e., front side V (left) and back side W (right), are shown side by side in the same figure. The operating device 1 comprises a number of step-button units 2 for sequentially switching currents. The front side V and the back side W are each formed by a so-called "scene".

[0030] The operating device 1 comprises an ergonomic handle 8 with a substantially round cross-section, adapted to the average hand shape of an operator. Above the handle 8, where the operator's thumb would normally be positioned when gripping or holding the operating device 1, there is a wider button section with buttons for operation with the thumb of the gripping hand. Additionally, on the reverse side of this button section at the upper end of the handle 8, there is an actuable pressure element 6 for the index finger of the gripping hand (see Fig. 3 to 6), which can be pressed into handle 8 with the index finger or, in other words, pulled towards the palm of the hand.

[0031] Above this push-button section, which comprises several step push-button units 2 according to the invention, and the pressure element 6, as well as below the handle 8, each end of a semicircular arc begins, which connects the upper end of the handle 8 (above the push-button section or pressure element 6) with the lower end of the handle 8 in an arc. In the middle of the arc, the handle 8 of the operating device 1 can be attached – if necessary – to a device to be operated or to an arm of a device, as can be seen from the hole on the back of the arc of the operating device 1.

[0032] Fig. Figure 2 shows a state-of-the-art push button. This comprises a specially shaped switching unit 4, which is in contact with a (here upper) switching contact 3, an actuator 5, and a spring F, which is bridge-like between the upper switching contact 3 and another (here lower) switching contact 3. The switching unit 4 is specially shaped so that it butts against the upper of the two switching contacts 3, while maintaining a small gap to the lower switching contact 3. As can be seen here, the switching unit consists of a comparatively large number of different elements, which makes its construction quite complex and expensive, and results in a relatively large volume.

[0033] Fig. Figure 3 shows the internal structure of an example of a step-button unit 2 according to the invention in cross-section. The switching unit 4 can be disassembled – as can be seen from the Fig. 4 and Fig. As can be seen, the actuators press into a housing part 9 that is essentially U-shaped in cross-section, with two lateral legs and a yoke connecting the legs perpendicularly, in order to actuate two switching contacts 3. These switching contacts are actuated by actuators 5, which are arranged at different distances from each other and at varying distances from their respective switching contacts 3. The actuators 5 are located below the pressure area D of the switching unit 4 and protrude at different distances from the rest of the switching unit 4, such as the lateral return areas R, towards the yoke of the housing part of the housing 9. When pressure is applied to the pressure area, the actuators 5 press against two equally spaced, vertically arranged switching contacts 3 on the yoke of the U-shaped housing part of the housing 9.

[0034] When the pressure element 6 is actuated as intended, the following occurs first: Fig. The upper of the two switching contacts 3 is actuated because the upper actuator 5 contacts the switching contact 3 earlier. Since the actuators 5 have a larger spring constant F than the return range R for a force in the direction of the switching contacts 3 when they contact the switching contacts 3, a tilting moment is exerted on the switching unit 4 by the respective actuator 5 after contact with a switching contact 3, as the force on the switching unit 4 increases.

[0035] This is further supported by the shape of the pressure element 6 and the corresponding shape of the recess on the side of the switching unit 4 facing away from the actuators. Both the pressure element 6 and the recess for the pressure element 6 slope upwards, thus aligning with the Fig. 3 upper part closer to the upper switching contact than with the one in Fig. 3 lower part at the lower switching contact. The inclined pressure surface for the pressure element 6 automatically ensures that the elastic material of the switching unit 4 is slightly twisted upwards during the printing process. In other words, the elastic material of the switching unit 4 is stretched more in the lower part than in the upper part, so that the second switching contact is also actuated with a time delay after the first switching contact, i.e., stepwise or sequentially by the second actuator 5, which protrudes less far but is then in contact with the lower switching contact. The elastic material of the pressure area D of the switching unit 4 at the actuators 5, as well as the elastic material at the two lateral return areas R of the switching unit 4, which already partially protrude beyond or abut the U-shaped leg sections of the housing 9, is stretched in the process, as can be seen from Fig. 5 is recognizable. The pressure area D comprises a less elastic material than the recovery area R, which surrounds the pressure area D in particular.

[0036] Fig. Figure 6 shows another example of a step-button unit 2 according to the invention. Compared to the previously described embodiment, the switching unit 4 is meander-shaped and has a meandering profile, featuring a flat reset area R on either side of the actuators 5 integrated into the meandering. The reset area R exerts a force on the actuators 5, directed away from the switching contacts 3. Furthermore, it differs from the embodiment above in that a holder 10 is interposed between the pressure element 6 and the switching unit 4, which is attached laterally to the housing 9. The holder 10 is hooked onto the pressure element 6 via an interlocking snap-fit ​​connection. Additionally, the holder 10 is attached to the inside of the housing 9 at one end, which is closer to the more protruding actuator 5.Here too, the switching process is carried out in stages, because first the (here in . Fig. 6 left) further protruding actuator 5 the associated switching contact 3 is actuated, then with a time delay with the (here in Fig. The other switching contact is triggered or pressed by the actuator 5 (which protrudes less far) on the right side. In this embodiment as well, the switching unit 4 is slightly twisted or rotated during the pressing process due to its one-sided attachment to the inside of the housing 9.

[0037] Fig. Figure 7 shows an example of a backdrop according to the invention for the rear side W. The figure shows a first housing half of the handle 8 of the operating device 1. In this case, the silicone backdrop or the switching unit 4 is manufactured as a single molded part in the injection molding tool and, in the assembly of the entire assembly, i.e. the operating device 1, is inserted into a suitable groove of a second plastic body of a second housing half of the operating device 1 and secured around its circumference.

[0038] The component according to Fig. Figure 8 shows the second housing half of the handle 8 of the operating device 1. Fig. Figure 8 shows the housing half from the front, or looking at the inner front. This housing half is a polycarbonate (PC+PBT) plastic body. Its function is, firstly, to provide screw bosses for the first housing half (see Fig. 7) to provide and, secondly, to offer a stable base for the silicone mold. For this purpose, the plastic body is placed in an injection mold whose contours represent the cavities of the silicone mold. These cavities are then filled with silicone, thus creating the combined silicone-plastic actuator. The switching unit 4 in Fig. 8 comes into contact with the switching contacts during switching and is otherwise an integral part of the rest of the cam, i.e. it is manufactured “as one piece” with the rest of the handle 8 of the operating device 1.

[0039] Finally, it should be noted once again that the invention described in detail above merely represents exemplary embodiments, which can be modified in various ways by a person skilled in the art without departing from the scope of the invention. Furthermore, the use of the indefinite articles "a" or "an" does not preclude the possibility that the features in question may be present multiple times. Likewise, terms such as "unit" do not preclude the possibility that the components in question consist of several interacting sub-components, which may also be spatially distributed. The term "a number" should be read as "at least one." Regardless of the grammatical gender of a particular term, persons of male, female, or other gender identities are included.

Claims

[1] Step-switch unit (2) for sequential switching of currents, comprising at least two switching contacts (3) and a switching unit (4) with actuators (5) arranged on the switching unit (4) above the switching contacts (3) at different distances from them, wherein the switching contacts (3) and the switching unit (4) are arranged relative to each other such that when pressure is applied to the switching unit (4) in the direction of the switching contacts (3), the actuators (5) are pressed onto it and different actuators (5) touch the switching contacts (3) at different pressure forces, wherein the switching unit (4) extends at least partially over the switching contacts (3) and has a planar reset area (R) made of an elastic plastic material which exerts a force on the actuators (5) directed away from the switching contacts (3). [2] Step switch unit according to claim 1, wherein the switching unit (4) comprises a one-piece, planar element made of an elastic plastic material, which has the reset area (R) and a designated pressure area (D) and / or a retaining element for attaching a pressure element (6), preferably wherein the pressure area (D) comprises a less elastic material than the reset area (R), which in particular surrounds the pressure area (D), and the switching unit (4) is preferably manufactured in one piece by co-extrusion. [3] Step switch unit according to one of the preceding claims, wherein the switching unit (4) comprises a one-piece, planar element made of an elastic plastic material in which the actuators (5) are formed. [4] Step sensor unit according to one of the preceding claims, wherein at least part of the actuators (5) is elastic, preferably with a Shore A hardness of less than 100, preferably less than 70. [5] Step-touch unit according to one of the preceding claims, wherein at least the reset area (R) and preferably also the actuators (5) and preferably also the pressure area (D) are made of silicone, particularly preferably in an injection molding process. [6] Step switch unit according to one of the preceding claims, wherein the actuators (5) have a larger spring constant (F) than the return range (R) for a force in the direction of the switching contacts (3) when the switching contacts (3) are touched, so that after contact of an actuator (5) with a switching contact (3) a tilting moment is exerted on the switching element by the actuator (5) in question when the force on the switching element increases. [7] Stepped switch unit according to one of the preceding claims, comprising housing elements (9) arranged such that they keep the switching unit (4) at a distance from the switching contacts (3), so that the latter must be pressed by a force acting on the switching contacts (3) to switch. [8] Operating device (1) for operating a device comprising a number of step switch units (2) according to one of the preceding claims. [9] Operating device according to claim 8, comprising a plurality of switching contacts (3) and a button (7) made of an elastic material, with actuators (5) arranged over the switching contacts (3), wherein the switching contacts (3) and the button (7) are arranged relative to each other such that when pressure is applied to the switching unit (4) in the direction of the switching contacts (3), the actuators (5) are pressed onto the switching contacts (3), and wherein at least one area of ​​the button (7) over at least two of the switching contacts (3) is designed as a switching unit (4) for a step switch unit (2), wherein the button (7) is preferably designed in one piece. [10] Operating device according to claim 8 or 9, comprising a handle (8), a front (V) and a back (W), wherein both the front (V) and the back (W) have at least one step switch unit (2) according to one of claims 1 to 7, preferably wherein the operating device (1) is designed for operating a medical device. [11] Operating device according to one of claims 8 to 10, comprising a housing (9) made of a plastic body of a material with a Shore A hardness greater than 100, preferably made of polycarbonate, in conjunction with a number of step sensor units (2) according to one of claims 1 to 7, the actuators (5) of which are elastically connected to the housing (9), preferably with a material which also forms the printing area (D) or which is intended to accommodate it, particularly preferably wherein the housing (9) and the number of step sensor units (2) have been joined together by means of a co-extrusion process. [12] Medical device comprising an operating device (1) according to any one of claims 8 to 11.

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