WO1985002487A1

WO1985002487A1 - Key with non linear travel-force characteristic

Info

Publication number: WO1985002487A1
Application number: PCT/HU1984/000057
Authority: WO
Inventors: Miklós HOMOK; Péter Pál KÖVES; Endre Nagy
Original assignee: Számitástechnikai Koordinációs Intézet
Priority date: 1983-11-30
Filing date: 1984-11-30
Publication date: 1985-06-06
Also published as: RO93602B; HU194440B; BG46757A3; EP0164388A1; SU1466666A3; AU3749885A; RO93602A; HUT37290A; EP0164388B1; DE3471399D1

Abstract

Key with non linear travel-force characteristic provided with a motionless part (3), a movable part (1) moving relatively with respect to the motionless part (3) when the key is depressed, as well as switching, respectively detection elements using the relative displacement. The aim of the present invention is to form between the motionless part (3) and the moving part (1) a magnetic circuit which sets, at least in part, the travel-force characteristic and of which the ferromagnetic elements are coupled on one hand with the motionless part (3) and on the other hand with the moving part (1), at least one ferromagnetic element being comprised of a permanent magnet.

Description

PUSH BUTTON WITH NON-LINEAR WAY FORCE CHARACTERISTICS

The invention relates to a push button which realizes an ergonomically advantageous section of the displacement-force characteristic with a negative inclination angle and which can advantageously be combined with various sensor elements, in particular with elements whose function is based on the change in the magnetic field strength or the change in the electrical one Capacity based.

The push button according to the invention can advantageously be used in computing technology or in the formation of keyboards for manual control and actuation of a wide variety of devices.

The various keyboards are particularly important elements in the human-machine relationship, and their ergonomic distribution is to be carried out with great care, since this can significantly influence the effectiveness of the work of the operating personnel.

These existing problems are particularly noticeable in the practice of computing technology; in this context, one of the best summaries of the various points of view can be found in the textbook A. Chakir "Visual Display Terminals" / John Wiley and Sons, Chichester, New York-Brisbane, Toronto, 1980 /. The path-force characteristic, which is advantageous in terms of ergonomics, includes a section in which an increase in the path is associated with a clear drop in the pressure force, which gives the operator the feeling of "tipping over" / snap action / the push button evokes. This feeling is used for touch-based feedback / tactile feedback / pressing the push button. The realization of the section of the displacement-force characteristic characterized with a negative inclination angle is generally ensured in the known solutions by parts which are exposed to a great deal of wear, or by the use of spring elements, the non-linearity of which is determined by a corresponding construction.

One of the simplest of the universally usable, known solutions can be found in the FUJITSU FEES-833 pushbuttons. In this solution, an attachment part is formed on a movable part that is moved against a spring by pressing the pushbutton. This attachment part strikes and moves an attachment which is formed on the stationary part and which adjoins it elastically and moves it. The desired characteristic section results from the cancellation of the additional compressive force after passing through the elastic attachment. A disadvantage of this solution is that the attachment parts are subject to relatively heavy wear.

With regard to the construction, the fact that the force resulting from the friction of the attachment parts is subtracted from the returning spring force has a restrictive effect.

The company KEYTRONIC CORP. The solution used does not include any parts exposed to wear in the above sense, but uses the deflection of coil springs in such a way that a switch or sensor element is actuated by rotating a preferably mounted plate to an extent corresponding to the angle of the deflection. The one with a negative inclination angle! characterized characteristic results from the difference in the forces required to compress the spring along its longitudinal axis and in the extended state. With the usual dimensional limits, this difference in force is relatively small. This solution cannot be used in constructions in which the distance covered by the push button or the height of the push button is small.

A section of the displacement-force characteristic provided with a negative inclination angle is also realized with pushbuttons formed with membranes. These are ergonomically less demanding and cheap devices / z. B. in calculators / used. In addition to the usual size limitations - apart from the above solutions with rubber bell - the diaphragm springs only allow a short switching travel. The spring elements made of rubber and similar material, due to the internal friction resulting from the properties of the material, ensure only a realistically low activation frequency and give the operator a less certain feeling of "tipping over".

The object of the invention is to develop a pushbutton characterized in terms of ergonomic travel-force characteristics, which has a simple structure, is widely used in accordance with the various requirements, produces a safe "switching feeling" and, compared to the usual, a "switching feeling "Non-initiating pushbuttons contain no parts that are subject to increased wear and tear.

The invention is based on the knowledge that a path-force characteristic that is favorable from an ergonomic point of view with a negative inclination angle in the case of push buttons either only by the action of magnetic force or by a combination of the spring force of the Push buttons commonly used celebration elements with linear characteristics and magnetic force can be realized.

As is known, the magnetic force between two bodies with ferromagnetic properties depends on the resistance of the magnetic circuit. If paramagnetic sections are inserted into the magnetic circuit or their dimensions are increased, the measurable force effect can suddenly decrease. Even with relatively small dimensions, the modern soft or hard magnetic materials are capable of exerting the forces usual with pushbuttons, and by means of these materials both electrically insulating / powder metallurgy methods are produced / electrically conductive molded bodies can also be produced in mass production. To solve the problem, a push button was developed in which between an immovable part and a moving part - when pressing the push button - relatively moving and possibly performing a limited movement to realize the desired displacement-force characteristic and / or to guide the Moving part in the base is partially or completely used a magnetic force effect that occurs between the ferromagnetic elements of the immovable part and the moving part or their inserts or parts made of ferromagnetic material, the ferromagnetic material of the immovable part and / or the moving part is a correspondingly magnetized material with permanent magnet properties.

Since the solution according to the invention essentially utilizes the properties of the materials of the construction, a large number of execution forms can be implemented in the design of the shape according to other preferred aspects and the number of possibilities can be further increased by the use of various spring elements which deform elastically when the pushbutton is pressed and of various switching or sensor elements which use the movement directly or indirectly.

The movement characteristic of the magnetic force can be influenced by the change in the magnetic resistance of the magnetic circuit used, depending on the movement. In constructions with a longer actuation path or in those applications in which the non-linear characteristic is to be limited to a section of the actuation path, the solution can be combined with the spring elements generally used for push buttons.

The keyboards provided with an electrical output signal are constructed in such a way that the individual pushbuttons on a common carrier plate, preferably on a printed circuit board, are to be provided with additional stiffening elements to ensure a corresponding strength. The push button designed according to the invention can be designed in a delayed embodiment in such a way that the soft ferromagnetic element of the immovable part is designed as a common element of the entire keyboard and at the same time serves as a support and stiffening element.

The various embodiments of the push button according to the invention can actuate any switching or sensor element which uses the movement of the movable part directly or indirectly to implement any switching effect.

According to the ergonomic requirements, the so-called membrane keyboard can be designed, for example, which is used as a sensor element to which the Mechanical elements of the push button are applied as an adapter, and thus represents an advantageous solution with regard to the displacement-force characteristic and the actuation path / full-travel membrane /. The solution according to the invention can preferably be used in switching and sensor elements, the function of which is based on the change in the magnetic field strength. Such elements are e.g. B. the elements based on the Hall effect, reed relays or induction sensors, etc. In this case, the built-in serve. Permanent magnet and the magnetic circuit formed in its vicinity have a dual purpose and can simultaneously actuate a magnetic switch and a sensor element. The solution according to the invention can also preferably be used in pushbutton constructions which are provided with sensors which work on changing capacitance, the parts consisting of electrically conductive material / ferromagnetic / n / insert / s / or parts of the movable part and / or the immovable part simultaneously can form movable and / or fixed conductor of the capacitor.

With various pushbutton designs, there is often the requirement that the movable part should contain a self-adjustable element which, when the pushbutton is pressed, hits a specific element of the immovable part. This is generally solved in such a way that the self-adjustable element is connected to the other elements of the movable part via a spring element for the transmission of tensile and compressive force / elastic plastic foam, plate spring, etc./.

In a further preferred embodiment of the push button according to the invention, the self-adjustable element consists partially or completely ferromagnetic material, on which the respective magnetic force acts directly. in this case it only has to be ensured that the other parts of the movable part hit the self-adjustable element of the desired degree of freedom, which can also be brought into the starting position. This solution enables a simplified construction and facilitates the assembly of the construction. Inelastic electrical contacts or capacitor coatings, for example in the form of a printed circuit on a plate, are preferably usable.

In the aforementioned solutions with a multi-part movable part, such embodiments are also possible in which the path of movement of the self-adjustable base part is designed such that its impact on the stops or surface of the immovable part belonging to the pushbutton is intentionally carried out in several phases. By suitable selection of the point of the magnetic circuit, the mentioned stops of the immovable part, as well as the self-adjustable part and other parts of the movable part, the moment generated by the magnetic force comes to the newspaper in arms of different lengths, in the characteristic of the force perceptible on the push button an easily realizable, ergonomically usable jump can be created.

On the basis of the advantages of the push button according to the invention, it can be seen that it is suitable for solving the task and offers advantageous possibilities for the use of various switching and sensor elements. Another advantage is that after releasing the pushbutton, the return of the moving part to the starting position is more pronounced, since nonlinearly increasing magnetic forces / also / act on it.

The invention is illustrated below with the aid of preferred embodiments with reference to the accompanying drawings, wherein in the drawing

1 to 5 show the construction diagrams illustrating the function of various embodiments of the push button according to the invention.

In the embodiment according to FIG. 1, both the guiding of the movable part into the starting position and the realization of the negative increase in the displacement-force characteristic are based entirely on the use of the magnetic force effect.

A movable part 1, which is preferably limited in its movement, is provided with an insert 2 made of ferromagnetic material, and a fixed immovable part 3 likewise consists of ferromagnetic material, at least one of the ferromagnetic materials having permanent magnet properties. The movement of the movable part 1 is converted into an electrical signal by contacts 4. In the starting position, the distance between the ferromagnetic elements is preferably zero, which the magnetic force cannot change. When the push button is pressed, the movable part 1 remains in the starting position for as long as the pressing force is smaller than the magnetic force belonging to the starting position. With the movement of the movable part 1, the distance between the ferromagnetic elements increases, the magnetic force effect suddenly decreases, as a result of which the operator is given an ergonomically favorable, tilt-like feeling.

During the movement of the movable part 1, this closes the contact 4 starting from an appropriate point on its movement path. When the push button is released, the magnetic force in the end position of the movable part 1 is always high enough the movable part 1 is moved in the direction of the starting layer and is returned to the starting layer with a steeply increasing force as the distance decreases. The embodiment shown in FIG. 2 differs from that shown in FIG. 1 in that the movable part 1 can also be moved out of the idle state with an initial compressive force that is smaller than the magnetic force required to separate the ferromagnetic elements. The immovable part consists of several pieces. A separated part 5 made of ferromagnetic material is connected via a spring element 6 to a fixed part 7 of the immovable part and can move on a preferably limited path. This path is limited at an appropriately chosen point by stops belonging to the fixed part 7. The spring element 6 determines the displacement-force characteristic when the button is pressed for as long as the pressure force is less than the force required to separate the ferromagnetic elements and the separated part 5 has not yet struck. After the pressure force exceeds the force required to separate the ferromagnetic elements, the push button behaves as described in the previous example. The embodiment shown in FIG. 3 gives a displacement-force characteristic similar to that of the previous embodiment, but when the movable part returns to the starting position, a spring element used also cooperates. The movable part is formed with an upper part 8, which preferably moves on a limited path, and a base part 9, which consists of ferromagnetic material / or contains such a part, insert, and is preferably movable to a limited extent. In a suitably selected point on the path of the upper part 8, this strikes the Base part 9 and moves it. A spring element 10 is arranged between the upper part 8 and the immovable part. In the exit position of the movable part, the upper part 8 is held in a position corresponding to the exit position by the spring element 10 and the base part 9 by the magnetic force.

When the push button is pressed, the upper part 8 is moved by the pressure force exerted thereon and until the upper part 8 strikes the base part 9, the required pressure force depends only on the displacement-force characteristic of the spring element 10. After the stop, the pressure force required to further depress the pushbutton is a sum of the respective spring force and the magnetic force. The further function of the embodiment shown in FIG. 3 corresponds to that shown in FIG. 1.

The embodiment shown in FIG. 4 differs from that shown in FIG. 3 in that a spring element 11 is not supported on the immovable part but on the base part. In this case, when the pushbutton is pressed until the state in which the magnetic force required to bring the ferromagnetic elements apart is greater than the spring force resulting from the deformation of the spring element 11 and the upper part does not yet rest on the base part, Force characteristic determined by the spring element 11. If the pressure force just exceeds the magnetic force required to separate the ferromagnetic elements, the spring force "shoots" the base part over into its other end position. The shift feeling is caused by the drop in spring force. The rapid movement of the base part, with a speed exceeding the speed of the top part, can be achieved with a large number of different switching and sensors elements are an advantage.

The figures belonging to the explained embodiments assume a straight / uniaxial / guidance of the moving parts, but this does not affect the nature of the solutions. The preferably limited movement can also be by means of other constructions / z. B. by rotation around an axis or around several axes / can be ensured. As an exemplary embodiment of more complicated movements, a variant of the solutions described above is explained, in which the basic part has self-adjustability.

In the embodiment according to FIG. 5, a base part 13 can be moved out of its starting position by abutment of the push rod of an upper part 12 and can tip over the attachment point. In its starting position, the base part 13 presses against an upper limiting element 16 of an immovable part 14 and holds the upper part 12 in a position corresponding to the starting position. When the pushbutton is pressed, the abutting base part assumes a position in the end position which the points or surface of a lower delimitation element 15 designed as stops determine.

Should the base part 13 be tilted in the intermediate positions, this is limited depending on the dimensional characteristics by partial striking on the upper or lower surface.

The resulting displacement-force characteristic depends on whether the magnetic force acting on the base part 13 has a torque on the respective attachment point of the base part 13 and the upper part 12.

In the event that the point of attachment of the base part 13 and the upper part 12 coincides with the resultant of the magnetic forces in every point of the movement path, the construction functions like the embodiment according to FIG. 1. In the event that the path of the abovementioned attachment points does not coincide with the resultant of the magnetic forces (for example asymmetrical mechanical design or asymmetrical magnetic field), when the pushbutton is pressed, the base part 13 has a moment which tilts it. The tilting is limited by the upper limiting element 16 or by the ferromagnetic insert of the immovable part.

As long as not until each point of the base part 13 hits the lower limiting element 15 of the immovable part, the force felt on the push button via the arm relating to the upper stop point maintains equilibrium with the torque of the magnetic force calculated on the same point. After any point of the base part 13 hits the lower limiting element 15, it is tilted in the opposite direction until the base part 13 comes into a certain, certain position by being hit in further points. In this section, the force that can be felt on the pushbutton has a value that increases suddenly and that is marked with the moments calculated on the stop point on the lower limiting element 15 and then suddenly decreases due to the simultaneous reduction in the magnetic forces.

Variants of this embodiment are also possible in which the tilting movement, the rotation of the base part 13 is very different in both directions, e.g. B. In extreme cases - within the limits of manufacturing inaccuracies - in one

Direction is zero. In these cases, the surfaces that characterize the end positions of the lower and upper stops are not parallel to one another. The push button according to the invention can also have embodiments that each of the in Fig. 3 and 4th Use the spring elements 10, 11 shown, or use these or each of these together with the immovable part shown in FIG. 2 or with the self-adjustment according to FIG. 5. Furthermore, in the embodiments according to FIGS. 1 and 2 between the movable part and the immovable part and in the embodiments according to FIGS. 3, 4 and 5 between the base part and the immovable part, such a spring element can be inserted, which is used to return the corresponding Moving element contributes to the output.

Claims

1. Pushbutton with non-linear displacement-force characteristic, which is provided with an immovable part, a part that moves relatively when the pushbutton is pressed in relation to the immovable part, and any switching element or sensor element that uses the relative movement, that between the immovable part / 3 / and the movable part / 1 / a magnetic circuit which at least partially determines the displacement-force characteristic is formed, the ferromagnetic elements of which are on the one hand connected with the immovable part / 3 / and on the other hand with the movable part / 1 / are coupled, wherein at least one ferromagnetic element is formed by a permanent magnet.

2. Push button according to claim 1, d a d u r c h g e k e n n z e i c h n e t that a magnetic circuit completely determining the displacement-force characteristic is provided.

3. Push button according to claim 1, characterized in that the immovable part with a fixed part / 7 /, a separate, limited movable, a ferromagnetic element containing separated part / 5 / and a movement of the separated part / 5 / counteracting spring element / 6 / is provided, which is inserted directly or via a transmission element between the fastened part / 7 / and the separated part / 5 /, furthermore the movement path of the separated part / 5 / abuts the fastened part / 7 /.

4. Push button according to claim 2, characterized in that the movable part of an upper movable on a limited path Part / 8 / and a base part / 9 / which is separated from it and contains a ferromagnetic element and is likewise movable on a limited path, the movement path of the upper part / 8 / abutting the base part / 9 /.

5. Push button according to claim 1, characterized in that the movable part is formed with a movable upper part on a limited path / 8 / and a spaced apart, containing a ferromagnetic element and also movable on a limited path base part / 9 / and a spring element / 10 / is provided which counteracts the movement of the upper part / 8 / from the starting position and is inserted directly or by means of a transmission element between the upper part / 8 / and the immovable part, with a section of the movement path of the upper part / 8 / through the Distance between the upper part / 8 / and the base part / 9 / is limited. Pushbutton according to claim 1, characterized in that the movable part is formed with an upper part which can be moved on a limited path and a base part which is separate from it and also contains a ferromagnetic element and is also movable on a limited path, and a spring element which counteracts the movement of the upper part from the starting position / 11 / is provided, which is coupled directly or via a transmission element between the upper part and the base part, the path of movement of the upper part being initiated with the base part.

7. Pushbutton according to one of claims 3 to 6, characterized in that the base part / 13 / around the point of impact of the upper part / 12 / on the base part / 13 / is arranged tiltable, wherein the tilting movement is limited by stop points or surfaces formed on the immovable part / 14 / and / or on the end positions of the push button associated with the limiting elements / 15 / of the push button. 8. Pushbutton according to one of claims 1 to 7, characterized in that between the movable part and / or the base part and the immovable part is arranged in a spring element opposing to the direction of movement exciting.

9. Pushbutton according to one of claims 1 to 8, d a d u r c h g e k e n n e e c h n e t that a formed for several push buttons as a common part, belonging to the immovable part is provided.

10. Pushbutton according to one of claims 1 to 9, characterized in that the switching or sensor elements form the magnetic field strength or its change using elements, the magnetic circuit of which is connected to the magnetic circuit of the ferromagnetic elements of the movable part and the immovable part .

11. Push button according to one of claims 1 to 9, d a d u r c h g e k e n n z e i c h n e t that an electrical as a switching or sensor element

Capacitance is formed, wherein one of the coatings is formed by the electrically conductive ferromagnetic element of the movable part and / or the immovable part. 12. Push button according to one of claims 1 to 9, characterized in that an electrical short circuit and / or an interruption contact is provided as the switching or sensor element, and the ferromagnetic element of the immovable part and / or movable part consists of electrically conductive material and at the same time form parts of the contacts.

CHANGED REQUIREMENTS

[Received at the International Bureau on April 19, 1985 (April 19, 1985); original claims 1-12 replaced by new claims 1-9 (3seiten)]

1. Pushbutton with non-linear displacement-force characteristic, which is provided with an immovable part, a part that is relatively movable by pressing the pushbutton relative to the immovable part, and a sensor element that uses the relative movement, thereby ge knn zeic hn et that the movable part is designed with an upper part (12) which can be moved on a limited path and a separate part which is separated therefrom in a base part (13) which is freely movable by the walls of a nest formed in the immovable part (14) in such a way that the movement track of the upper part (12) abuts against the base part (13) and the base part (13) is arranged to be tiltable during its movement around the stop point of the upper part and the base part, the tilting movement being formed by an upper and lower limiting element formed in the nest of the immovable part ( 16, 15) is limited, further between the immovable part (14) and the base part (13) e in the force-generating magnetic circuit required for returning and holding the movable part consisting of the upper part (12) and the base part (13) in the starting position is designed such that the immovable part (14) is further provided with a ferromagnetic element and the Base part (13) is made of a ferromagnetic material or contains such an element, of which at least one of the ferromagnetic elements is formed by a permanent magnet, the ferromagnetic element of the base part (13) being electrically conductive and at the same time being the movable part of the movement-detecting part Sensor element forms.

2. Push button according to claim 1, characterized g ek e nn z e i c h n t that a formed for several push buttons as a common part, belonging to the immovable part is provided.

3. Push button according to claim 1 or 2, characterized in that the movement of the reason Part delimiting, belonging to the immovable part of the lower limiting element (15) is designed as a common part for several pushbuttons and at the same time carries the resting coverings of the sensor elements.

4. Push button according to one of claims 1 to 3, characterized ge indicates that the contact surface of the upper part (12) and the base part (13) is designed such that the resultant of the magnetic forces acting on the base part (13) and by the upper part (12) forces exerted on the base part (13) on the base part (13) do not generate any torque and this can be moved parallel to its rest position when the pushbutton is pressed.

5. Push button according to one of claims 1 to 3, characterized in that the stop surface of the upper part (12) and the base part (13) is designed such that the forces acting on the base part (13) and through the top part ( on the base part (13) generate forces exerted on the Anschalgsflache to the bottom part (13) 12) a certain torque and said at D _r of the push button from its rest position ücken twisted, whereby the respective rotation by belonging to the end positions of the base part limiting elements (15, 16) of the immovable part is limited.

6. Pushbutton according to one of claims 1 to 5, characterized geke nn that in the interior of a neck part provided with an outer guide of the upper part (12), a cavity is formed in which a spring element is arranged, between which when the button is pressed only after compression of the spring element on the base part (13) and this after the stop moving out of the rest position upper part (12) and the base part (13) is coupled.

7. Push button according to one of claims 1 to 5, characterized in that a cavity is formed in the interior of the neck part of the upper part (12) provided with an outer guide, in which a cavity when the push button is pressed, the upper part (12 ) before opening the upper part (12) on the base part (13) from the rest position moving spring element is arranged, which between the in the fully pressed state of the push button on the immovable part (14) hitting the upper part (12) and the with by the spring element certain force on the lower limiting element impacting base part (13) is coupled.

3. Pushbutton according to one of claims 1 to 7, characterized in that a changing electrical capacitance is provided as the sensing element, the limiting element (15) closing the nest of the immovable part from below forming / carrying the stationary coatings of the capacitances and the basic part is the movable covers of the capacities.

9. Pushbutton according to one of claims 1 to 7, characterized in that ne electrical contacts are provided as the sensor element, the limiting element (15) closing the nest of the immovable part from below forming / carrying the resting contact surfaces of the sensor element and the Basic part forms the movable contact.