WO2014165947A2

WO2014165947A2 - Switching device

Info

Publication number: WO2014165947A2
Application number: PCT/BE2014/000017
Authority: WO
Inventors: Wim HELLEBAUT
Original assignee: Miles, Vennootschap Onder Firma
Priority date: 2013-04-10
Filing date: 2014-04-09
Publication date: 2014-10-16
Also published as: WO2014165947A3; EP3005038A2

Abstract

Switching device (1) for executing electronic signals characterised in that it takes on the form of a key (3) that is mechanically movable axially over a number of discrete switch positions that each execute a different electronic signal by the vertical axial mechanical movement of the pressed key (3) being mechanically converted into a horizontal rotation of contact surfaces (12a, 12b, 12c), which depending on the switch position make contact with different contact points (13a, 13b, 13c) on an underlying printed circuit, such that for each switch position a different electronic signal is generated in the printed circuit, and whereby each switch position is felt by the tactile feedback on the finger pressing on the key (3).

Description

Switching device.

The present invention relates to a switching device with a number of positions.

More specifically the invention is intended to provide a key that can be moved mechanically over a number of discrete switch positions whereby each switch position generates a different electronic signal that can be guided to an instrument connected to the switching device where the electronic signal is processed or interpreted.

It is known that switches generally have only two positions: on or off and consist of a pushbutton that can be placed in just two positions. A simple example is a light switch that switches the light on in one position and switches the light off in the other position.

Another simple switch is a key on a keyboard, which when pressed generates a certain sound in a piano or displays a certain letter on a computer screen if it is a keyboard of a computer .

Traditionally a computer keyboard comprises a separate key for each letter or symbol, such that a keyboard of more than 36 keys is quickly required. Two hands are required to operate such a keyboard, at least if this keyboard is to be operated using the touch-typing method. On certain mobile telephones there is insufficient space to employ such a complete keyboard, and there has to be a limited number of keys that frequently have to be operated with one single finger, but which can nevertheless represent the entire alphabet in order to write e-mails or text messages.

This problem was solved by a key representing a different letter depending on whether the key is pressed once, twice, three times or sometimes four times in quick succession.

A disadvantage of such a keyboard is that the time needed to write a message is hereby lengthened as every key frequently has to be pressed a number of times.

US 4.816.671 describes a switch with three pressed positions whereby each position generates an accompanying signal with tactile feedback by means of a small spring- loaded ball that generates a perceptible click by sliding over a notch in a guide. The accompanying signal is generated by the selective mechanical interruption of the light flux between three light sources and three corresponding photo sensors .

A disadvantage of this type of switch is that it takes up a relatively large amount of space and is difficult to integrate into an electronic printed circuit of an application, such as in a mobile telephone, because three light sources must be provided for each switch, and the necessary mechanical means to selectively interrupt these three light rays and the optical signals have to be converted into electronic signals.

US 6.164.853 describes a keyboard to be operated by one hand for generating electronic signals whereby each finger of the hand can press one of three different keys, so that a large number of combinations can be formed with an accompanying meaning. In principle a keyboard can be formed in this way to enter a text in a mobile telephone. However, the problem is that one side of the keyboard is occupied by keys, while the other side is covered by the palm of the same hand, and there is no further room to place the screen for the text formed in a compact way, and an extra device is needed for the display.

Another disadvantage of this keyboard to be operated with one hand is that for each of the three states that must be indicated by one finger, the finger must move to another key, which is slower than with the current mobile telephones because these three states are only separated from one another by the number of presses on the same key, and hereby three or four different letters can be generated with the same key.

The purpose of the present invention is to provide a solution to the aforementioned and other disadvantages by providing a switching device for executing electronic signals whereby it takes on the form of a key that is mechanically movable axially over a number of discrete switch positions that each execute a different electronic signal by the vertical axial mechanical movement of the pressed key being mechanically converted into a horizontal rotation of contact surfaces, which depending on the switch position make contact with different contact points on an underlying printed circuit, such that for each switch position a different electronic signal is generated in the printed circuit, and whereby each switch position is felt by the tactile feedback on the finger pressing on the key.

An advantage of such a switching device with rotating contact surfaces is that it lends itself better to a compact construction than sliding contacts because they take up less space and the rotating system can be made of injection moulded parts, and also because the contact formation is simpler on a flat printed circuit which leads to better stability and conduction.

An advantage of such a switching device is that a very compact construction is possible for entering electronic signals in an apparatus such as a mobile telephone, whereby each finger of one hand can control a key with three switch positions at the edge of the device and space is left for a display screen on one side of the device.

Preferably the underside of the key is provided with a widening with three concentric teeth and one ridge, which when the key is pressed slides through a helical groove that slopes obliquely downwards through a rotatable shell such that the shell rotates with respect to the central key axis and is mechanically movable over a number of discrete switch positions that each give tactile feedback to the pressing finger, and whereby in each switch position a contact ring with three contact surfaces is rotated such that either no, three, two or one electrode is connected to a power source, which corresponds to either no electronic signal, or one of three electronic signals depending on the switch position, that are then processed by a processing unit that interprets the signals.

An advantage of such a switching device is that one switch or key is able to generate a number of electronic signals whereby the switch or the key only has to be pressed once, but over different depths, which as a result of the ridge is simultaneously converted into different rotation angles in the radial direction of the rotatable shell.

Another advantage of such a switching device is that the user has tactile feedback in each switch position such that he can feel the required pressure for each switch position

Preferably the mechanical tactile feedback, that enables the pressing finger to feel the position in which the key is pressed at that time, consists of a small ball that is pushed by a small spring and that, when the shell rotates, moves partly into one of the four openings provided in the shell to this end, which causes a mechanical click that is felt in the pressing finger synchronously with, but without making use of, the mechanical contact of the contact surfaces with the contact strips on the printed circuit.

An advantage of such tactile feedback is that the mechanical feedback is synchronous with, but independent of, the actual contact formation with the underlying circuit, so that the contact strips are not damaged or worn by the mechanical pressure of the key, and so that this mechanical feedback is completely absorbed in the housing of the key and does not take up any space in the underlying apparatus .

Another advantage of such a switching device is that a limited number of switching devices can yield a large number of combinations of electronic signals whereby these combinations can be recognised as a large number of different symbols or instructions.

Indeed, if each switching device has three different discrete positions and can thus generate electronic signals, then with four pushbuttons 81 combinations are possible, and with five pushbuttons 243 combinations.

The number of combinations with four switching devices is more than sufficient for representing the alphabet and each figure, for example, so that it is possible to define each of these symbols by pressing four switching devices in the required switch position.

Preferably for each switch position of the switching device, a different combination of electrodes are connected together when the contact surfaces of the rotatable shell slide over the contact points of the printed circuit, with the formation of an electronic signal that is sent to a processing unit, such that the processing unit recognises the switch position of one switching device and allocates a different electronic signal to each switch position. Preferably the processing unit deduces from the combination of the electronic signals from a number of switching devices what letter, figure, other symbol or instruction is meant by the combination of electronic signals.

An advantage of the combination is that it provides the possibility to build an entry device that can be operated with one hand with four or five switching devices in the form of mechanical keys that can be operated by four or five fingers of the same hand.

A return spring on the base of the housing ensures that the rotatable shell and the key, when no longer pressed, return by themselves to their original non-pressed position, and this without remaining in an intermediate position when returning.

It goes without saying that this return spring can also be replaced by a spiral spring around the central rotation axis, or by another mechanism that ensures that the key returns by itself to its starting position.

A preferred embodiment can be a mobile telephone that is equipped with five switching devices and can be operated by the fingers of one hand, whereby each letter or symbol to be formed can be determined by entering the suitable combination of switch positions of the pushbuttons.

With the intention of better showing the characteristics of the invention, a preferred embodiment of a switching device according to the invention is described hereinafter by way of an example_/ without any limiting nature, with reference to the accompanying drawings, wherein:

Figure 1 schematically shows a perspective view of a switching device or key according to the invention; figure 2 gives an exploded view of figure 1;

figure 3 schematically shows figure 1 in the non- pressed position, and this as a cross-section at the level of the ridge, and in the position of the rotatable contact surfaces over the contact strips of the printed circuit, and in the position of the small spring-loaded ball in one of the perforations of the rotatable shell;

figure 4 shows figure 3 but now in the first pressed switch position;

figure 5 shows figure 3 but now in the second pressed switch position;

figure 6 shows figure 3 but now in the third and fully pressed switch position;

figure 7 shows a cut-away side view of a switching device according to the invention, from left to right in the non-pressed position and the three successive pressed switch positions;

figure 8 shows an application with five switching devices in a mobile telephone;

figure 9 shows an application with eight switching devices in one keypad that can be operated in a left- handed or right-handed way; figure 10 shows in tabular form how the combination of five switching devices with 3 positions can represent the entire alphabet and the ten figures.

Figure 1 shows a perspective view of a switching device 1 according to the invention, consisting of a cylindrical housing 2 through which a key 3 can move and which is fastened at the bottom with electrodes to a printed circuit.

Figure 2 shows an exploded view of the components from which the switching device according to the invention is constructed. The switching device 1 is composed of a cylindrical housing 2 through which a movable key 3 fits that is provided on the underside with a widening 4 with three concentric teeth 4a, 4b, 4c and one ridge 5 that is fastened by means of a screw 6 to a fixed position on the widening 4, and also of a return spring 7a, which is supported on the underside in a cylindrical support column 7b and when the key cap 3 is pressed makes it return to the starting position if no further pressure is exerted on it. The support column 7b is surrounded by a rotatable shell 8 that is provided with four identically shaped perforations 9a, 9b, 9c, 9d in which a small ball 10 partially fits that is pushed by a small spring 11.

The shell 8 is provided with a helical groove 39 that slopes obliquely downwards and which is open at the top of the shell and through which the ridge 5 of the key 3 is guided when the key 3 is pressed. The shell 8 is connected with a close fit to a contact ring 12 provided with three contact surfaces 12a, 12b, 12c that co-rotate with the rotatable shell 8 and which make contact or otherwise with contact strips on an underlying printed circuit 13, that are each connected to a contact electrode 14,15,16 and is held in a fixed position by a pressure ring IT with respect to the underlying base 17 on which the printed circuit 13 is placed, and whereby the underside of the base 17 is bordered by a baseplate 18 that provides support for two small springs 19, 20 that keep a distance between the baseplate 18 and the printed circuit 13, and which itself is fastened to the base 17 by means of a radial spring clip 21 and a central screw 22,

Figure 3 shows the switching device 1 according to the invention in the non-pressed position and this both as a cross-section 23 at the level of the ridge 5, and a top view 24 of the three rotatable contact surfaces 12a, 12, 12c on the rotatable contact ring 12. The return spring 7a is not yet compressed and the three rotatable surfaces make no contact with the three contact strips 13a, 13b, 13c of the printed circuit 13, while the small spring-loaded ball 10 is still partly in the first perforation 9a of the rotatable shell, as shown in the side view 25.

Figure 4 shows the switching device 1 according to the invention in the first pressed switch position and this both as a cross-section 26 at the level of the ridge 5, and a top view 27 of the three rotatable contact surfaces 12a, 12b, 12c on the rotatable contact ring 12 that are rotated by a small angle in the clockwise direction. The return spring 7a is now partly compressed and the three rotatable contact surfaces 12a, 12b, 12c now make contact with the three contact strips 13a, 13b, 13c of the printed circuit 13, while the small spring-loaded ball 10 is now partly in the second perforation 9b of the rotatable shell 8, as shown in the side view 28.

Figure 5 shows the switching device 1 according to the invention in the second pressed switch position and this both as a cross-section 29 at the level of the ridge 5, and as a top view 30 of three rotatable contact surfaces 12a, 12b, 12c on the rotatable contact ring 12 that is rotated by a somewhat larger angle in the clockwise direction. The return spring 7a is now somewhat more compressed and the two rotatable contact surfaces 12b and 12c still make contact with the two contact strips 13b and 13c of the printed circuit 13 but the contact surface 12a no longer makes contact with the contact strip 13a on account of the rotation of the contact surfaces, while the small spring-loaded ball 10 is now partly in the third perforation 9c of the rotatable shell 8, as shown in the side view 31.

Figure 6 shows the switching device 1 according to the invention in the third and deepest pressed switch position, and this both as a cross-section 32 at the level of the ridge 5, and a top view 33 of the three rotatable contact surfaces 12a, 12b, 12c on the rotatable contact ring 12 that is rotated by an even larger angle in the clockwise direction. The return spring 7a is now completely compressed and the two rotatable contact surfaces 12a and 12c no longer make contact with the two contact strips 13a and 13c of the printed circuit 13 but only the contact surface 12b still makes contact with the contact strip 13b as a result of the rotation of the contact surfaces, while the small spring-loaded ball 10 is now partly in the fourth and last perforation 9d of the rotatable shell 8, as shown in the side view 3 .

Figure 7 shows the side view of the four switch positions of the switching device according to the invention, from left to right starting from the non-pressed position 35 to the next three more deeply pressed positions 36, 37 and 38, whereby the side view is cut away each time at the level of the ridge 5 that slides through the helical groove 39 that slopes obliquely downwards through the rotatable shell 8.

Figure 8 shows an application 40 of five switching devices 1 according to the invention in one mobile telephone 41, whereby by pressing the five keys 1 in the required position, a letter, figure or symbol according to choice can be displayed on the screen 42.

Figure 9 shows another application 43 whereby eight switching devices 1 according to the invention are applied in a keypad 44, in two groups of four switching devices 1, whereby one group is operated by four different fingers of one hand and the other group only by the thumb of the same hand. The keypad 44 recognises the group of switching devices that is operated by one thumb and the group that is operated by four fingers, whereby the two groups are interchangeable so that a right-handed (R) and left-handed (L) person can operate the keyboard. This recognition can be automatic by the keyboard itself, or can be set by a switch for right-handed or left handed use.

An advantage of such a keypad 44, as applied in a mobile telephone for example, is that the keyboard can be operated by both a right-handed (R) and left-handed (L) person. As a result even more combinations are possible as the thumb can now operate one of the four keys and the possible combinations with the opposite four finger keys is hereby simplified.

Figure 10 shows a table 45 that indicates what combinations of five switching devices 1 in a first, second or third switch position can represent the letters of the alphabet or the 10 figures or other symbols. The five switching devices are named according to the finger with which they are operated (T = thumb, I = index finger, M = middle finger, R - ring finger, L = little finger) , while the switch position is shown by the figure 1, 2 or 3.

It goes without saying that the switching device according to the invention can be used in many applications, especially if the key must be small and compact, and must be easy to construct on a printed circuit.

It goes without saying that the invention is not limited to a switch or key with three switch positions, but that other numbers of switch positions can be implemented that can be addressed by the same mechanism by the user. The operation of the switching device 1 for the signal execution of electronic signals according to the invention is simple and as follows.

The switching device 1 is provided with a mechanical key 3, that in the non-pressed position makes any contact between the contact surfaces 12a, 12b, 12c and the contact strips 13a, 13b, 13c on a printed circuit 13 that is at the bottom of the switching device impossible, because the small springs 19,20 ensure that the contact ring 12 with the contact surfaces 12a, 12b, 12c and the underlying contact strips 13a, 13b, 13c are kept apart from one another. In this position the switching device does not generate any electronic signal.

When the key 3 is pressed the user does not yet experience any tactile feedback in the finger for as long as the shell 8 has not rotated but is moved linearly until it comes against an end stop. The small ball remains in the first perforation 9a. It is only when the shell 8 comes up against the end stop and the key is further pressed that a first tactile feedback is caused by the small spring-loaded ball 10 springing into the second perforation 9b of the rotatable shell 8, that the user feels that a first switch position has been reached. The ridge 5, that is connected to the key 3 at a fixed position, is guided by a helical groove 39, that is cut into the rotatable shell 8, so that the shell 8 makes a rotary movement in the clockwise direction while the ridge 5 moves in the axial direction downwards up to this first switch position. In this first switch position contact is made between the three contact surfaces 12a, 12b, 12c of the contact ring 12 and three contact strips 13a, 13b/ 13c respectively on the printed circuit that are each connected to an electrode. The three electrodes now give an electronic signal from which the processing unit connected to these electrodes can deduce that an electronic signal connected to the first switch position has been executed by the switching device.

When the key 3 is further pressed the user experiences a second tactile feedback in the finger caused by the small spring-loaded ball 10 springing into the third perforation 9c of the rotatable shell 8, so that the user feels that a second switch position has been reached. The ridge 5, connected to the key 3 is pushed further downwards in an axial direction by the helical groove 39 in the rotatable shell 8, such that it makes a further rotary movement in the clockwise direction until the second switch position is reached.

In this second switch position contact remains between the two rotatable contact surfaces 12b and 12c with the two contact strips 13b and 13c of the printed circuit 13, but the contact surface 12a no longer makes contact with the contact strip 13a, and only the electrodes connected to 13b and 13c give an electronic signal from which the processing unit connected to the electrodes can deduce that an electronic signal connected to the second switch position has been executed by the switch. When the key 3 is further pressed the user experiences a third tactile feedback in the finger caused by the small spring-loaded ball 10 springing into the fourth perforation 9d of the rotatable shell 8 so that the user feels that a third switch position has been reached. The ridge 5, connected to the key 3 is pushed further downwards in the axial direction by the helical groove 39 in the rotatable shell 8 such that this shell rotates further in the clockwise direction until the third switch position is reached.

In this third switch position the two rotatable contact surfaces 12a and 12c no longer make contact with the contact strips 13a and 13c of the printed circuit 13, but only the contact surface 12b still makes contact with contact strip 13b as a result of the rotation of the contact surfaces, and only the electrode connected to 13b gives an electronic signal from which the processing unit connected to the electrodes can deduce that an electronic signal connected to the third switch position has been executed by the switch.

When the key 3 is released it immediately returns to its starting position by the return spring 7a, and this without staying in the intermediate switch positions.

It goes without saying that the electronic detection of the switch position of the key as a result of the conversion of a vertical to a horizontal rotation movement can be determined by means other than the described contact surfaces 12a, 12b, 12c that slide over contact strips of a printed circuit.

For example it is also possible for the ridge 5 of the switching device 1 to move axially but hereby drives a radial movement of a switch arm by means of a transmission, perpendicular to the axial direction of the key, that can reach discrete radial contact points on a printed circuit such that for each discrete switch position a different electronic signal is generated in the printed circuit.

It goes without saying that the switching devices on a mobile telephone can also take on the form of the already known keys on a mobile telephone, but whereby each key must be pressed up to the desired position instead of having to be pressed repeatedly in order to select the desired symbol for this key.

It also goes without saying that the position of the keys for a keypad or a mobile telephone can be adapted according to whether the user is right-handed or left-handed.

The present invention is by no means limited to the embodiment described as an example and shown in the drawings, but a switching device according to the invention can be realised in all kinds of forms and dimensions, without departing from the scope of the invention.

Claims

Claims .

1.- Switching device (1) for executing electronic signals characterised in that it takes on the form of a key (3) that is mechanically movable axially over a number of discrete switch positions that each execute a different electronic signal by the vertical axial mechanical movement of the pressed key (3) being mechanically converted into a horizontal rotation of contact surfaces (12a, 12b, 12c) , which depending on the switch position make contact with different contact points (13a, 13b, 13c) on an underlying printed circuit, such that for each switch position a different electronic signal is generated in the printed circuit, and whereby each switch position is felt by the tactile feedback on the finger pressing on the key (3) .

2.- Switching device according to claim 1, characterised in that the key 3 is provided with one ridge (5) which when the key is pressed slides through a helical groove (39) that slopes obliquely downwards through a rotatable shell (8) such that the shell (8) rotates with respect to the central key axis and is mechanically movable over a number of discrete switch positions and whereby in each switch position either no, three, two, or one electrode is connected to a power source by the three contact surfaces 12a, 12b, 12c of a contact ring 12 so that a processing unit connected to the electrodes can deduce from this whether no electronic signal, or one of three electronic signals has been executed by the key depending on the switch position, after which the processing unit interprets the electronic signals .

3. - Switching device according to claim 1, characterised in that the processing device (8) deduces from the combination of a number of electronic signals from a number of switching devices (1) which letter_/ which figure, other symbol or instruction is meant by the combination.

4. - Switching device according to claim 1, characterised in that the mechanical tactile feedback, that enables the pressing finger to feel in what position the key (3) is pressed at that time, consists of a small ball (10) that is pushed by a small spring (11) and that when the shell (8) rotates it moves partly into one of the four perforations (9a, 9b, 9c, 9d) provided to this end, which causes a mechanical click that is felt in the pressing finger synchronously with, but without making use of, the mechanical contact of the contact surfaces 12a, 12b, 12c with the contact strips 13a, 13b, 13c on the printed circuit 13.

5. - Apparatus (41,43), characterised in that it is provided with at least four switching devices (1) as described in claim 1, whereby the apparatus (41,43) can be operated with one hand, whether the left or right hand.

6. Apparatus according to claim 5, characterised in that the apparatus (41) is equipped with a display screen (42) , that can be read while the apparatus is operated with its pushbuttons, and is held in one hand.

7.- Use of an apparatus (41_/43) according to claim 5, characterised in that the apparatus is used as a compact control keyboard for a tool or instrument that can be controlled with one hand by means of instructions, wirelessly or otherwise.