EP3520128B1 - Foot pedal for controlling a medical device - Google Patents

Description

The present invention relates to a foot pedal for controlling a medical device, in particular a dental device.

Such foot pedals are from the prior art, for example from the US 7 439 463 B2 , well known and are intended to guarantee a treating physician a scope of action during the treatment that allows him to continue the treatment without interrupting it for manual modifications to the medical device. Instead of interrupting treatment, he makes modifications to the medical device using the foot pedal. Essential components of the foot pedal are a housing with a housing base and a cover element which is mounted so that it can be moved in height along an actuating device and usually also tilted or tilted relative to the housing base. Typically, the cover element rests on an actuating device arranged centrally below the cover element and displaceable along the actuation direction, so that the cover element can also be tilted to each side (cf. DE 20 2006 015 718 U1 ). Here, the actuating device serves as a lever point or lever surface.

Furthermore, from the DE 6 603 334 U a foot pedal according to the preamble of claim 1 is known, in which a rocker-mounted rocker element is provided. By pressing one end of the rocker element, it can be moved as far as a stop in order to initiate a first functionality of a dictation machine. By further pressure on the other end of the rocker link, the require second functionality. the U.S. 3,663,772 A shows a similar foot pedal in terms of functionality.

From the DE 28 14 869 A1 Furthermore, an actuating arrangement for a foot pedal is known, in which two spring elements arranged one above the other and having different hardnesses are used.

In order to induce different functionalities on the medical device with the foot, it is desirable that an occurrence on the edge area of the cover element of a first functionality on the medical device and an occurrence on a central area of the cover element of a second functionality different from the first functionality on medical device is assigned. In order to be able to differentiate between these two types of actuation, the actuation device is mounted so that it can be shifted in height, with a height offset of the actuation device taking place both when stepping onto the edge area and when stepping onto the central area. The height offset of the actuating device when stepping on the edge area is supported by the fact that, when tilting, the movement of the cover element upwards on the side opposite the actuated edge area, ie. H. in a direction opposite to the direction of actuation, is limited.

With the same force magnitude, however, a force acting on the edge area leads to a smaller height offset of the actuating device than a central force acting on the cover element, in particular directly above the actuating device usually located in the central area. Correspondingly, a differentiation can be determined on the basis of the respective size of the height offset. Therefore, the U.S. 7,439,462 a first switch to initiate a first functionality on the medical device and a second switch to initiate a second functionality on the Medical device designed in such a way that the first switch in a first height offset section and the second switch in a second height offset section adjoining the first height offset section can be actuated one after the other by the actuating device moving in the actuating direction.

However, this cannot prevent a user of the foot pedal from exerting so much force when actuating the cover element at the edge area that the actuating device imperceptibly enters the second height offset area and thus the second functionality is accidentally triggered.

It is therefore an object of the present invention to provide a foot pedal for controlling a medical device, in which the probability of accidentally initiating the second functionality can be reduced compared to the prior art.

• -- ein Gehäuse mit einem Gehäuseboden,
• -- ein Deckelelement, das gegenüber dem Gehäuseboden entlang einer Betätigungsrichtung höhenverschiebbar und gegenüber dem Gehäuseboden neigbar gelagert ist,
• -- einen ersten Schalter zur Veranlassung einer ersten Funktionalität am medizinischen Gerät und einen zweiten Schalter zur Veranlassung einer zweiten Funktionalität am medizinischen Gerät und
• -- eine entlang der Betätigungsrichtung höhenverschiebbare Betätigungseinrichtung, die bei einer Bewegung in Betätigungsrichtung innerhalb eines ersten Höhenversatzabschnitts den ersten Schalter betätigt und innerhalb eines zweiten Höhenversatzabschnitts den zweiten Schalter betätigt, wobei die Betätigungseinrichtung derart ausgestaltet ist, dass sie sich im ersten Höhenversatzabschnitt in einem ersten Zustand, z. B. einem auseinandergeschobenen Zustand, befindet und im zweiten Höhenversatzabschnitt in einem zweiten Zustand, z. B. einem zusammengeschobenen Zustand, befindet, wobei das Fußpedal derart ausgestaltet ist, dass bei einem vorbestimmbaren Neigungswinkel des Deckelelements die Betätigungseinrichtung stets innerhalb des ersten Zustands befindet, d.h. innerhalb des ersten Höhenversatzabschnitts angeordnet ist.

This object is achieved by a foot pedal according to claim 1. Further advantages and features of the invention emerge from the subclaims as well as the description and the attached figures. According to the invention, a foot pedal for controlling a medical device, in particular a dental device, is provided, comprising

• - a case with a case back,
• - A cover element which is vertically displaceable with respect to the housing base along an actuating direction and is mounted so as to be inclinable with respect to the housing base,
• a first switch to initiate a first functionality on the medical device and a second switch to initiate a second functionality on the medical device and
• - an actuating device that can be moved in height along the actuating direction, which actuates the first switch when moving in the actuating direction within a first height offset section and actuates the second switch within a second height offset section. B. a pushed apart state, and in the second height offset section in a second state, z. B. a collapsed state, the foot pedal is designed such that at a predeterminable angle of inclination of the cover element, the actuating device is always within the first state, ie is arranged within the first height offset section.

According to the invention, the predeterminable angle of inclination is the maximum possible angle of inclination of the cover element, which is achieved on the one hand by at least some sections of the cover element resting on the housing base and on the opposite side by the cover element resting against at least one radial projection of the housing, which protrudes radially outward and a Preventing the cover element from lifting upwards is defined. However, the predeterminable angle of inclination is generally an angle range which lies between a first angle and the maximum possible angle, e.g. between 5 ° and 15 °, preferably between 6 ° and approximately 10 °.

Compared to the prior art, the invention provides that the actuation of the second switch is made more difficult because on the one hand the actuating device must be transferred to the second state before it can reach the second height offset section, and on the other hand the foot pedal in this way is designed or dimensioned in such a way that the actuating device remains exclusively within the first height offset section, when the cover element has assumed a maximum possible angle of inclination. The latter robs the actuating device of the possibility of actually causing a transition to the second state in order to get into the second height offset section when the cover element has assumed a maximum possible angle of inclination. This advantageously reduces the likelihood of inadvertent triggering of the second functionality, in particular if a user acts with his foot on the edge region of the cover element.

For this purpose, the foot pedal is designed, in particular, in such a way that the cover element cannot be displaced further along the actuation direction when the maximum possible angle of inclination determined by the design of the foot pedal is assumed. In order to make the transition from the first height offset section to the second height offset section more difficult, the actuating device is designed according to the invention in such a way that an additional force is required for a transition from the first state to the second state. For example, a restoring force of a spring is to be overcompensated for this, the restoring force of which does not counteract a movement of the actuating device in the first height offset section. In principle, the cover element rests on the actuating device in the central area of the cover element, so that the cover element can be tilted to either side. Furthermore, it is conceivable that the cover element and / or the housing is completely rotationally symmetrical with respect to an axis of symmetry running parallel to the actuating device.

According to a further embodiment of the present invention, it is provided that the cover element rests in sections on the housing base when the maximum possible angle of inclination is taken. In this way, it is advantageously possible to prevent the maximum inclined cover element from being able to be lowered further, and at the same time the actuating device so that the actuating device is transferred to the second height offset section. It is preferably provided that the foot pedal can assume precisely one position in every possible tilting direction, in which the angle of inclination is maximum. Furthermore, it is conceivable that the housing base has a circumferential shoulder facing the cover element, on which the inclined cover element strikes when the predeterminable, for example the maximum angle of inclination is assumed.

It is preferably provided that the cover element has a limited offset height in the edge region or on the outer circumference, which determines the predeterminable, for example the maximum angle of inclination. In addition, the maximum angle of inclination is determined by the diameter of the foot pedal. The foot pedal or the cover element preferably has a diameter between 13 cm and 25 cm. The offset height in the axial direction is limited, for example, in that a circumferential collar which is directed radially inward on the underside of the cover element engages in a receiving area of the housing that is open radially outward. This receiving area is preferably delimited in a direction running parallel to the actuation direction on one side by projections protruding radially from a housing wall and on the other side by the housing base, in particular the circumferential shoulder of the housing base. The maximum inclined cover element then rests on one side on at least one of the projections and on the other side in sections on the housing base.

In an advantageous embodiment of the present invention it is provided that a height offset of the actuating device caused by the assumption of the predeterminable, for example the maximum inclination position, is smaller than an extension of the first height offset section. This makes it possible to ensure that the actuating device remains within the first height offset section when the cover element is at its predeterminable, for example the maximum Assumes the angle of inclination and thereby carries the actuating device. Here, the first height offset section is dimensioned starting from an initial position which the cover element assumes when no external force acts on the cover element.

It is preferably provided that the actuating device is arranged adjacent to the second height offset section when the maximum possible angle of inclination of the cover element is assumed. In particular, the cover element rests in sections on the housing base at a contact point and would have to be pivoted further about this contact point for a further height offset of the actuating device. This is counteracted by the actuating device, for the transfer of which into the second state an additional expenditure of force would be required, whereby an unintentional actuation of the second switch is advantageously made more difficult. In other words: the cover element acts as a lever arm pivotable about the contact point (on the housing base), on the side of which is remote from the contact point or in the center of which the actuating device is arranged, the actuating device continuing the pivoting movement with a force necessary for the transfer of the first is required in the second state counteracts. In order to reduce the effort required to continue the pivoting movement, the user must lengthen the actuation length of the lever arm that can be pivoted around the contact point by moving the foot further in the direction of the center. If he first actuates the cover element at the edge, i.e. at or near the contact point, the lever length is short and the usual effort exerted by means of a foot is not sufficient to overcome the restoring force of the actuating device that would be necessary to move into the to get to the second state. This results in a radial dependency of a force to be applied to actuate the second switch, according to which the force to be applied to actuate the second switch increases at least linearly from the central area to the edge area with increasing distance from the actuating device.

Furthermore, it is preferably provided that the offset height in the edge area and an extension of the first height offset section are designed such that their size ratio limits the arrangement of the actuating device when the maximum possible angle of inclination of the cover element is assumed to the first height offset section. The extension of the first height offset section is preferably designed as a function of the offset height. This makes it possible to prevent the actuating device from reaching the second height offset section when the cover element is inclined to the maximum. For example, the ratio of the offset height to the extent of the first height offset section is between 0.8 and 1, preferably between 0.9 and 1 and particularly preferably between 0.95 and 1.

A projection is provided on the housing bottom to define the extension of the first height section. In particular, the projection is designed in such a way that it comes into contact with an underside of the actuation device in order to transfer the actuation device from the first to the second state. As a result, an extension of the first height offset section can be established in an uncomplicated manner in that the height of the projection is adapted accordingly. The material from which the projection is made preferably differs from the material from which the rest of the housing bottom is made. In particular, the projection is made of a load-bearing material, such as a metal or a fiber-reinforced plastic.

This advantageously takes account of the fact that the projection serving as an abutment is exposed to increased loads when the actuating device resting on the projection is to be transferred into the second state with the application of force.

According to the invention it is provided that the actuating device is connected to the housing bottom via a first spring, wherein the Actuating device comprises a first element and a second element, wherein a second spring is arranged between the first element and the second element, wherein the actuating device is designed such that the first spring is elastically deformed during the movement of the actuating device in the first height offset section and in the second Height offset section, the second spring is elastically deformed. The first spring advantageously ensures that the actuating device and the cover element are returned to an initial position when there is no force acting on the cover element. By means of the second spring, it is possible, in particular, to set a force that has to be applied and which is required for the transition of the actuating device from the first state to the second state. In particular, the first element and the second element are pushed together in the second state or during the transition from the first to the second state. The second element is preferably mounted in the first element in a longitudinally movable manner. For example, the first element and the second element are designed in the form of a sleeve or cup and are placed inside one another.

According to a further embodiment of the present invention it is provided that a spring force of the second spring is more than twice, preferably more than three times and particularly preferably essentially five times as great as the spring force of the first spring. As a result, a corresponding additional force is required if the actuating device is to be transferred to the second state in which the second switch can be actuated. As a result, the likelihood of accidentally operating the second switch is further reduced.

Furthermore, it is preferably provided that the first switch and the second switch are offset in height relative to one another. This will be beneficial dispenses with a complicated actuation mechanism which would otherwise be required if the first switch and the second switch were arranged at the same height in the direction of actuation. The actuating device preferably moves in an interspace between the first switch and the second switch, which are, for example, opposite one another.

It is also provided that the housing is designed as an insert in the form of a housing base body which is connected to the housing base. The housing base is preferably attached to the housing via a magnetic release mechanism. For this purpose, the housing base comprises a magnet which interacts with a magnetic part of the housing or the housing base body. The magnetic release mechanism is preferably arranged below the actuating device. In particular, a projection on which the actuating device comes into contact when moving along the actuating direction forms the magnetic part of the housing, which holds the housing bottom with its magnets in the assembled state.

The magnetic release mechanism allows uncomplicated detachment of the housing bottom from the housing. Furthermore, the magnetic release mechanism, if it is attached centrally to the housing base, as shown in the figures, enables a rotational movement of the housing base body and the cover element connected to it around the housing base, which is usually adhesively connected to the floor. For this purpose, the opposing surfaces of the magnet and the magnetic part of the housing, such as the projection, are mounted in such a way that a rotating movement is made possible. Smooth surfaces that slide on one another are preferred.

The housing is preferably designed on its side facing the housing base in such a way that a compartment for energy storage cells is freely accessible is when the case base is separated from the case. Together with the magnet release mechanism, changing the energy storage cells can be simplified, which is regularly necessary for the supply of the transmitter in the housing.

Further advantages and features emerge from the following description of preferred embodiments of the subject matter according to the invention with reference to the attached figure. Individual features of the individual embodiment can be combined with one another within the scope of the invention.

Fig.1:

eine schematische Explosionsdarstellung eines Fußpedals gemäß einer bevorzugten Ausführungsform der vorliegenden Erfindung, und

Fig. 2a bis 2d:

Schnittansichten des Fußpedals aus Fig.1 in verschieden Betriebszuständen

Show it:

Fig. 1:

a schematic exploded view of a foot pedal according to a preferred embodiment of the present invention, and

Fig. 2a to 2d:

Sectional views of the foot pedal Fig. 1 in different operating states

In Figure 1 is a schematic exploded view of a foot pedal 1 according to a preferred embodiment of the present invention. In particular, the foot pedal 1 is one which is provided for controlling a medical device, preferably a dental device. Settings are to be made on the medical device by means of the foot pedal 1 so that the user does not have to interrupt his work, for example a treatment measure on the patient, in order to operate the medical device manually.

An essential part of the Figure 1 In addition to a housing 20 with a housing base 22, the illustrated embodiment is also a cover element 10, which is opposite to the housing base 22 along a Operating direction B is vertically displaceable and mounted inclinable with respect to the housing base 22. Specifically, the cover element 10 rests centrally on an actuating device 15. Because it rests centrally on the actuation device 15, the cover element 10 can be tilted or inclined on all sides, and the contact between the cover element 10 and the actuation device 15 causes the actuation device 15 to be displaced in the actuation direction B when a force is applied, in particular with the foot , takes place on the cover element 10, in particular essentially vertically. In this case, the actuating device can be offset in height in actuating direction B both when stepping onto the edge area and when stepping onto the central area. The invention understands a height offset to mean a displacement of the actuating device 15 along the actuating direction B, which as a rule is directed essentially vertically from above in the direction of the floor. In order to return the actuating device 15 to its starting position, a first spring 31 is provided, which is connected on the one hand to the housing base 22 and on the other hand to the actuating device 15, in particular to a first element 51 of the actuating device 15.

Depending on the position and size of the force acting on the cover element 10, there is a difference in the height offset of the actuating device 15, which is caused by stepping on the cover element 10 with the foot. If, for example, a force acts on an edge of the cover element 10, the cover element 10 is tilted about a lever point provided by the actuation device 15 or a lever surface provided by the actuation device 15. In addition to the inclination, a height offset of the vertically displaceable actuating device 15 is also caused. The height offset of the actuating device when stepping on the edge area is supported by the fact that, when tilting, the movement of the cover element upwards on the side opposite the actuated edge area, ie into a the direction opposite to the direction of actuation, is limited. That is, when the cover element 10 is tilted, the cover element comes into contact with a radial projection 21 on the opposite side in a direction opposite to the actuation direction, so that the actuation device 15 is carried along by the cover element 10 when the cover element 10 is tilted.

This height offset caused by tilting is, however, smaller than that caused by a force of the same magnitude when the force acts on the cover element 10 above the actuation device 15 and parallel to the actuation direction B, i.e. more in the central middle area of the cover element 10. Correspondingly, the different height offsets can be used for the targeted differentiation between two types of actuation of the foot pedal 1, as a result of which different functionalities can be assigned to the different types of actuation. In particular, a first functionality can be assigned to an occurrence on an edge area and the tilting of the cover element 10 caused thereby, and a second functionality can be assigned to an occurrence on a central area of the cover element.

A reference plane E is defined by the lower edge of the cover element 10 and, in the unloaded state, is essentially parallel to the plane of the floor. The predeterminable angle of inclination α is the angle between this reference plane E and the plane which is defined by the lower edge of the cover element 10 and which occurs when the cover element is tilted (see FIG Figure 2c ).

In the Figures 2a to 2d are sectional views of the foot pedal Fig. 1 shown in different operating states. In Figure 2a the starting position is shown in which the cover element 10 is when no external force acts on the cover element 10. About this difference in height between the different actuations for differentiation To use the actuation with the foot, in particular a first switch 41 and a second switch 42 are provided, which are arranged vertically offset from one another in the housing, the first switch 41 when the actuating device 15 is moved in actuation direction B within a first height offset section and the second switch 42 can be actuated within a second height offset section. In this case, the second height offset section, viewed in the direction of actuation B, directly adjoins the first height offset section. Figures 2b and 2c show the cover element 10 in the first state, once without tilting or inclination ( Figure 2b ) and another time ( Figure 2c ) in the first state, which is typically set when stepping on the edge, namely tilted, with the predeterminable angle of inclination α of the cover element. In both alternatives, the actuating device is always located within the first height offset section.

The actuation of the first switch 41 and the second switch 42 takes place, for example, via pins 33 which are displaceable perpendicular to the actuation direction B and which, by means of spring elements (not shown), against an outside 17 of the actuation device 15, in particular against an outside 17 of a first element 51 of the actuation device 15, are biased. The outside 17 of the actuating device 15 has a stepped outer contour, for example in the form of a projection or a ramp. When the actuating device 15 is moved in the actuating direction B, this outer contour interacts with the displaceable pins 33 in such a way that the pins 33 move away to the side, ie. H. along a direction running perpendicular to the actuation direction B and against a restoring force of the spring elements, are pressed radially outward so that the pins 33 can actuate the first switch 41 or second switch 42.

Since the first switch 41 and the second switch 42 are arranged offset in height from one another, the first switch 41 and the second switch 42 can be moved in the actuating direction B by moving the Actuating device 15 can be switched one after the other, in particular depending on the respective height offset of the actuating device 15. Together with a transmission device 40 and a control device, the current state of the foot pedal 1 can be communicated to the medical device. In this case, the control device is preferably designed in such a way that when the second switch 42 is actuated immediately after the first switch 41 is actuated, the second functionality is not initiated. This can also prevent the second functionality from being triggered in the event of an unintentional occurrence of the central area of the actuating device, although no triggering or only triggering of the first functionality is intended by the user.

Alternatively, this function can also be omitted, ie the second functionality is always activated as soon as the second switch 42 has been activated, regardless of a specific time span between the activation of the first and the second switch 41 or 42 Activation of the two switches 41, 42 triggered immediately one after the other does not cause any functionality at all.

In principle, however, there is the risk that the user will achieve a height offset by stepping on the edge area, with which the actuating device 15 will move into the second height offset section and thereby actuate the second switch 42. In such a situation, the second functionality would accidentally and unintentionally be triggered. In order to counteract an inadvertent initiation of the second functionality, it is provided that the actuating device 15 is designed in such a way that an entry into the second height offset area required for actuating the second switch 42 can only be carried out by the actuating device 15 when the actuating device 15 is operated by a first state in a second state is transferred. It is provided in particular that the transfer of the actuating device 15 from the first state to the second state is linked to an additional force. I. E. In order to transfer the actuating device into the second state, an additional expenditure of force is required, which must first be applied in order to bring about the transition from the first height offset section to the second height offset section.

In the illustrated embodiment, a second spring 32 is arranged between a first element 51 and a second element 52 of the actuating device 15 for this purpose. The first element 51 and the second element 52 of the actuating device 15 are mounted so as to be displaceable with respect to one another, wherein they are kept at a distance from one another in the first state by the relaxed second spring 32. I. E. the actuating device 15 is in the first height offset section in a pushed apart state. To transfer the actuating device 15 to the second state, a force that overcompensates the restoring force of the second spring 23 and pushes the first element 51 and the second element 52 together must be applied. In the Figure 2d the actuating device 15 is shown in the second state. Only by pushing the first element 51 and the second element 52 together can a transition from the first height offset section to the second height offset section be brought about for the actuating device 15.

With the second spring 32, an additional expenditure of force for actuating the second switch 42 can be provided as a condition for a transition from the first height offset section to the second height offset section. However, this cannot exclude the possibility that a user, when stepping on the edge area, for example, applies so much force that this condition is nevertheless met and the actuating device 15 is inadvertently transferred to the second state. To this problem To counteract this, it is provided that the foot pedal 1 is designed in such a way that the actuating device 15 is always arranged within the first height offset section when the cover element 10 assumes the maximum possible angle of inclination α in a tilted state. I. E. the actuating device 15 is deprived of the possibility of being transferred from the first state to the second state when the predeterminable, for example the maximum angle of inclination α of the cover element is assumed. Here, the maximum possible angle of inclination α is determined by a limited offset height V in the edge region of the cover element 10.

1. a. nach oben durch vom Gehäuse radial nach außen gerichtete radiale Vorsprünge 21 und
2. b. nach unten durch den Gehäuseboden 22, insbesondere durch einen umlaufenen Absatz am Gehäuseboden 22,

in seiner Bewegung in einer parallel zur Betätigungsrichtung B verlaufenden Richtung beschränkt ist. Um den vorbestimmbaren Neigungswinkel a einzunehmen, liegt der Kragen dabei an einer Seite auf, z.B. am Gehäuseboden 22, und auf einer gegenüberliegenden Seite an einem der radialen Vorsprünge 21 an.In the specific exemplary embodiment, this offset height V is limited by the fact that a collar, which is directed radially inward on the underside of the cover element 10, is provided on the cover element 10

1. a. upward through radial projections 21 and 21 directed radially outward from the housing
2. b. down through the housing base 22, in particular through a circumferential shoulder on the housing base 22,

is limited in its movement in a parallel to the direction of actuation B direction. In order to assume the predeterminable angle of inclination α, the collar rests on one side, for example on the housing base 22, and on an opposite side on one of the radial projections 21.

In order to prevent the second state from being reached when the predeterminable, for example the maximum angle of inclination α is assumed, the actuating device 15 is designed in such a way that the height offset is not sufficient to assume a position in which an additional force acts on the edge area of the cover element 10 a transition to the second state is possible. It is provided in particular that the actuating device 15 is designed in such a way that a height offset is associated with the alignment of the cover element 10 in the position associated with the predeterminable, for example the maximum angle of inclination, is smaller than or equal to the first height offset section. For this purpose, it is provided in particular that the extent of the first height offset section is dimensioned accordingly by a distance, measured in actuation direction B, between the second element 52 and a projection 16 of the housing base 22 arranged below the second element 52. The projection 16 serves in particular to support the second element 52 when the first element 51 and the second element 52 are pushed together, ie when the actuating device 15 is transferred from the first state to the second state. In other words: without coming into contact with the projection 16, the actuating device 15 cannot be transferred to the second state and the actuating device 15 remains within the first height offset section and thus cannot actuate the second switch 42.

The projection 16, in particular the distance to be determined in an initial position between the projection 16 and the second element 52, thus defines the extent of the first height offset section. In particular, no further lowering of the actuating device 15 in the actuating direction B while maintaining the angle of inclination is conceivable if the cover element 10 rests on the housing base 22 when the predeterminable, for example the maximum angle of inclination a is assumed. The actuating device preferably rests with the second element 52 on the projection 16 when the cover element 10 is inclined to the maximum. Together with the spring system, which comprises the first spring 31 and the second spring 32, with such a dimensioning of the first height offset section and the offset height V, with increasing distance from the actuating device 15 in the radial direction, a force is required to transfer the actuating device 15 in the second state increases until finally, when the outer edge area is actuated, a transition to the second state with normal foot force is shot out. In order to get into the second state, the user must accordingly direct his force application specifically to the central area of the cover element 10, whereby the probability of accidentally actuating the second switch 42 when a force is applied to the edge area can be reduced or even excluded.

Furthermore, it is preferably provided that the housing 20 is designed as an insert in the form of a housing base body which is connected to the housing base 22 and which has the radial projections 21. The housing base 22 is preferably released via a magnetic release mechanism 50 ( Fig. 2a ) bound to the housing 20. For this purpose, the housing base 22 comprises a magnet which interacts with a magnetic part of the housing 20 or the housing base body. The magnetic release mechanism 50 is preferably arranged below the actuating device 15. In particular, the projection 16, on which the actuating device 15 comes into contact when moving along the actuating direction B, forms the magnetic part of the housing 20, which holds the housing bottom 22 with its magnets in the assembled state.

The magnetic release mechanism 50 allows an uncomplicated release of the housing bottom 22 from the housing 20. Furthermore, the magnetic release mechanism 50, if it is, as in FIG Figure 2a shown, is attached centrally to the housing base 22, a rotational movement of the housing base body and the cover element 10 connected to it around the housing base 22, which is usually adhesively connected to the floor. For this purpose, the opposing surfaces of the magnet and of the magnetic part of the housing 20, such as, for example, the projection 16, are mounted in such a way that a rotating movement is made possible. Preferred are smooth surfaces that slide on each other.

The housing is preferably designed on its side facing the housing base in such a way that a compartment for energy storage cells is freely accessible when the housing base 22 is separated from the housing 20. Together with the magnet release mechanism 50, it is possible to simplify the change of the energy storage cells, which is regularly required, for example, for the supply of a transmission device in the housing. The second state cannot be reached when the cover element 10 has assumed the predetermined, in particular a maximum possible angle of inclination α. Once this state has been reached and the cover element 10 is pressed with a force acting vertically away from the edge, the latter will incline, ie the inclination angle a will decrease again until it, with the stop on the housing base 22 as the fulcrum, finally reaches stage two triggers.

In other words, the inventive tilting option with a stop, ie with the maximum possible angle of inclination, ensures that when a force is applied to the edge (this is always the case when the user's foot is placed on the side because this edge protrudes) only switch 41 is activated. If the cover element 10 has reached the edge at one point, other basic conditions apply to the leverage forces. The pivot point moves (jumps) from the opposite point of the cover element 10, i.e. from the radial projections 21 to the stop, i.e. to where the cover element 10 rests on the housing base 22. The cover element 10 can now only be pressed further down, i.e. the angle of inclination a is reduced when the force acts behind the pivot point, i.e. between the stop and the opposite side. Since the upper edge of the cover element 10 lies above or even behind, i.e. on the side facing away from the center of the new pivot point, the cover element 10 cannot be moved any further.

A preferred embodiment is explained below:
Central release: The central restoring forces are taken over by the two springs 31, 32. Spring 31 has a spring constant of approximately 1 N / mm and a preload of 20 N. With a central force of 22.5 N, for example, the cover element 10 is pressed down 2.5 mm and triggers the first switch 41. If the cover element 10 is further loaded, the second spring 32 is also pressed in parallel at 3 mm and 23 N. This spring has a spring constant of 5 N / mm and is preloaded with 25 N. In order to now press in the cover element 10 3.1 mm, a force of 48.6 N (23.1 N + 25.5 N) must therefore be applied. The second switch 42 is activated at 5.3 mm. This requires a force of 61.8 N (25.3 N + 36.5 N). The total compressible distance, ie the sum of the first and second height offset section, is limited to approx. 5.5 mm. Then the cover element 10 is placed on the outside of the housing base 22. This force diagram applies when the foot pedal is pressed centrally.

Decentralized release: When the cover element 10 is loaded on the outer lateral edge (pressure point), the forces opposing the foot force are significantly lower. With a fixed diameter of the cover element 10, the restoring forces can be calculated according to the law of levers, the pivot point being assumed to be exactly opposite the pressure point, i.e. at the contact point of the collar of the cover element 10 on one of the projections 21 and the spring force in the middle of the lever, that is, in the area of the actuating device 15, acts. This halves the necessary forces from the above calculation, whereby the distance covered (on the outer edge) is then also twice as far. If the foot pedal is now operated to such an extent that the cover element 10 strikes the housing bottom 22 on the loaded side, a distance of 5.5 mm is covered, the force required for this is approximately 11.4 N and the first switch 41 is triggered. According to the invention, the second spring 32 is not yet loaded. The lower element 52 then lies precisely on the projection 16 on. By pressing the outer lateral edge further, the second switch 42 cannot be triggered for geometric reasons, as explained above.

For the triggering of the second switch 42, a pressure point is required on the cover element 10, i.e. at a distance from the edge of the cover element 10, and not on its edge. The trigger values for the second switch 42 can be calculated as a function of the diameter of the cover element 10 and the position of the pressure point. Due to the lever, the values of 61.8 N are lowest with central actuation (see calculations above) and increase significantly with the distance of the pressure point from the center of the cover element. At the edge of the cover element 10, viewed mathematically, these go to infinity, since the force acts vertically on the pivot point. In an embodiment according to the preceding example and a diameter of the cover element 10 of 15 cm, the triggering force for the second switch 42 at a pressure point at a distance of, for example, 2 cm from its edge is at least 232 N. At such a high value, an unintentional triggering is almost impossible. The user is therefore forced to press the foot pedal as centrally as possible in order to activate the second function. In contrast, the first function can be triggered with low forces of 11.4 to 22.8 N (depending on the pressure position) at any point on the cover element 10.

A typical foot pedal according to the invention has a diameter of 13-25 cm and a top height of about 4 cm.

List of reference symbols

1

Foot pedal

10

Cover element

15th

Actuator

16

head Start

17th

Outside

20th

casing

21

radial projection

22nd

Case back

31

first spring

32

second spring

33

Pen

40

Sending facility

41

first switch

42

second switch

50

Magnetic release mechanism

51

first element

52

second element

V.

Offset height

B.

Actuator

E.

Reference plane

α

Tilt angle

Claims (8)

1. A foot pedal (1) for controlling a medical device, especially a dental device, comprising

   - a housing (20) including a housing bottom (22),

   - a cover element (10) which is mounted so as to be vertically displaceable in relation to the housing base (22) along an actuating direction (B) and tiltable in relation to the housing base (22), and

   - a first switch (41) for causing a first operability on the medical device and a second switch (42) for causing a second operability on the medical device and

   - an actuating device (15) which is vertically displaceable along the actuating direction (B) and, upon movement in the actuating direction (B), actuates the first switch (41) within a first vertical offset section and actuates the second switch (42) within a second vertical offset section,

   wherein the actuating device (15) is configured such that it is located in a first state in the first height offset section and is located in a second state in the second height offset section, wherein the foot pedal (1) is configured such that the actuating device (15) is always arranged within the first height offset section when the angle of inclination (α) of the cover element (10) can be predetermined,
   wherein, for making the transition from the first height offset section to the second height offset section more difficult, the actuating device (15) is designed such that additional application of force is required for a transition between the first state and the second state,
   wherein the predeterminable angle of inclination (α) is the maximum possible angle of inclination of the cover element (10), which is defined by the housing base (22) at least partially abutting the cover element (10) on the one side and at least one radial projection (21) of the housing (20) abutting the cover element (10) on the opposite side, and the actuating device (15) is connected to the housing base (22) via a first spring (31), wherein the actuating device (15) comprises a first element (51) and a second element (52), characterized in that a second spring (32) is arranged between the first element (51) and the second element (52), wherein the actuating device (15) is configured such that, when moving the actuating device (15), the first spring (51) is elastically deformed in the first height offset section and the second spring (52) is elastically deformed in the second height offset section, wherein the second spring (32) is not yet loaded in the first height offset section.
2. The foot pedal (1) according to claim 1, wherein the cover element (10) has a limited offset height (V) in the edge region, which determines the predeterminable angle of inclination, for example the maximum angle of inclination.
3. The foot pedal (1) according to one of the preceding claims, wherein the actuating device (15) is arranged adjacent to the second height offset section when the cover element (10) assumes the maximum possible angle of inclination.
4. The foot pedal (1) according to claim 2, wherein the offset height (V) in the edge region and an extension of the first height offset section are designed such that the size ratio thereof restricts arrangement of the actuating device (15) to the first height offset section when taking the maximum possible angle of inclination of the cover element (10).
5. The foot pedal (1) according to claim 4, wherein the ratio of the offset height (V) in the edge region to the extension of the first height offset section is between 0.8 and 1, preferably between 0.9 and 1 and particularly preferably between 0.95 and 1.
6. The foot pedal (1) according to one of the preceding claims, wherein the housing base (22) comprises a projection (16) below the actuating device (15), wherein the projection (16) determines the extension of the first height offset section.
7. The foot pedal (1) according to one of the preceding claims, wherein a spring force of the second spring (32) is more than twice, preferably more than three times and particularly preferably substantially five times as large as the spring force of the first spring (31).
8. The foot pedal (1) according to one of the preceding claims, wherein the first switch (41) and the second switch (42) are offset in height in relation to each other.

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