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EP0012279B1 - Push-button switch, particularly for keyboards of typewriters and similar devices - Google Patents

Push-button switch, particularly for keyboards of typewriters and similar devices Download PDF

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Publication number
EP0012279B1
EP0012279B1 EP19790104773 EP79104773A EP0012279B1 EP 0012279 B1 EP0012279 B1 EP 0012279B1 EP 19790104773 EP19790104773 EP 19790104773 EP 79104773 A EP79104773 A EP 79104773A EP 0012279 B1 EP0012279 B1 EP 0012279B1
Authority
EP
European Patent Office
Prior art keywords
key
contact
spring
key switch
spring section
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19790104773
Other languages
German (de)
French (fr)
Other versions
EP0012279A1 (en
Inventor
Horst Stahl
Walter Wachs
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE2854096A external-priority patent/DE2854096C2/en
Priority claimed from DE19797914017U external-priority patent/DE7914017U1/en
Application filed by Siemens AG filed Critical Siemens AG
Publication of EP0012279A1 publication Critical patent/EP0012279A1/en
Application granted granted Critical
Publication of EP0012279B1 publication Critical patent/EP0012279B1/en
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J5/00—Devices or arrangements for controlling character selection
    • B41J5/08—Character or syllable selected by means of keys or keyboards of the typewriter type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/50—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a single operating member
    • H01H13/52—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a single operating member the contact returning to its original state immediately upon removal of operating force, e.g. bell-push switch

Definitions

  • the invention relates to a key switch, in particular for keyboards in typewriters and similar devices, for example teleprinters and data stations, with a key tappet which, when the key is pressed against the spring force, a helical spring attached between the key housing and a contact surface of the key tappet from the rest position into the working position is movable, the spring forming the movable contact piece, which is brought into contact with a stationary counter-contact when making contact, and whose key plunger can be moved even further by the contact.
  • the object of the invention is to identify and provide a key switch which is ergonomically particularly favorable for the operator, consists of a few individual parts and can be produced with little production outlay.
  • the solution to the problem is that the helical spring has two spring sections, of which the first spring section is designed in a known manner as a compression spring for returning the key tappet from the working position to the rest position and the second spring section on the side facing away from the first spring section the contact surface of the key tappet rests with a certain pretension, and that the counter-contact is arranged in the range of motion of the helical second spring section of the spring, which is extended over the contact surface of the key tappet.
  • the dimensions of the new key switch are particularly small, with the key height being particularly small.
  • the low height of the key is particularly important for ergonomic reasons, because it results in a posture that is less stressful for the operator when the key is pressed. This is particularly noticeable when the operator presses input keyboards that are located on operating surfaces of different heights.
  • the new key enables the height to be reduced to over half of the keys previously used in practical operation.
  • the key switch is reliable and inexpensive to manufacture.
  • the key switch consists of a few individual parts that can be assembled in a simple manner. The manufacture and assembly in a manufacturing machine is possible.
  • the mechanical contact is particularly safe and there is a low contact resistance between the closed contact elements. By using the helical return spring, a uniform pressure behavior is achieved when the button is pressed.
  • An advantageous embodiment of the new push button is that the two spring sections of the helical spring have different winding diameters. This has the advantage that the spring characteristics for the two spring sections can be selected differently.
  • a further advantageous embodiment of the new push button is that the first spring section has a smaller and the second spring section of the spring has a larger winding diameter. This has the advantage that a particularly soft response of the contact is achieved by the spring section with the larger diameter, although the required minimum contact pressure is given when contacting.
  • the spring section with the larger diameter can also be used to dampen the kickback for the key tappet when returning from the working position to the rest position.
  • a protective collar is arranged around the point to be protected on the key, which is open in the direction of the solder bath and via the Protected area protrudes.
  • the new key switch consists of egg Nem tappet 1, which is movable in a button housing 6 in a guide 7 when the button is pressed.
  • a collar 2 is firmly attached, which limits the movement of the key tappet 1 in the rest position of the key.
  • the contact surface 2a of the collar 2 is used to support a spring 4 for resetting.
  • the helical spring 4 consists of two spring sections 4a and 4b, which have different winding diameters. The first spring section 4a with the smaller winding diameter is used as a compression spring, while the second spring section 4b with the larger winding diameter is used for making contact.
  • the second spring section 4b which consists of at least one turn, rests with a pretension on a driving lug 5, which is firmly connected to the collar 2 of the key tappet.
  • the preload is selected so that the required contact pressure occurs when the contact is made.
  • the characteristic of the spring can be adjusted with the help of the winding diameter. A soft spring action is achieved due to the larger winding diameter selected compared to the spring section 4a, so that the operator does not have a hard pressure point when making contact.
  • the spring 4 is used as a movable contact element, the end being designed as a contact connection 9.
  • the mating contact 3 with its contact connection 8 is arranged in the key housing 6 in a stationary manner as a rigid contact element in the range of motion of the second spring section 4b.
  • the counter contact 3 is advantageously designed as a simple sheet metal plate.
  • the key housing 6 and the key tappet 1 with the firmly attached collar 2 and the support surface 2a and the driving nose 5 can be produced in a simple manner as plastic parts.
  • the contact surfaces of the mating contact 3 and the winding part 10 of the second spring section 4b, which lie one on top of the other when the key switch is contacted, are coated with a layer which increases the conductivity, for example gold or palladium, for better contact.
  • the key switch In the state shown in Fig. 1, the key switch is in the rest position, i.e. before pressing the button.
  • the key plunger 1 When the key is pressed, the key plunger 1 is moved in the direction of the arrow A by the operator's finger pressure by means of the attached key button.
  • the key tappet slides along the guide 7 in the key housing 6.
  • the spring section 4a is compressed.
  • the push button plunger 1 With the push button plunger 1, the collar 2 with the firmly attached driving lug 5 moves in the direction of the mating contact 3.
  • the driving lug 5 is turned on. the contact surface of the mating contact moves past and the winding part 10 of the spring section 4b comes into contact with the contact surface of the mating contact 3.
  • the contact is closed and there is an electrically conductive connection via the contact connection 9, the spring sections 4a and 4b, the mating contact 3 and the contact connection 8. Due to the prestressing of the spring section 4b, the winding part 10 rests on the counter contact when the contact is made with the required contact pressure. This closes the contact of the key switch without bouncing.
  • the key tappet 1 is moved further, so that the driver nose 5 comes to rest below the contact surface of the counter contact 3.
  • the winding part 10 lies freely on the contact surface of the mating contact 3. This prevents malfunctions during operation due to uneven presses, a decrease in finger pressure or tremors when the button is pressed.
  • the key tappet has then reached its end position, the working position, the movement being limited either by the bottom surface of the guide 7 or by the spring section 4a which can no longer be compressed.
  • the button plunger 1 When the operator releases the button, the button plunger 1 returns from the working position to the rest position.
  • the compressed spring section 4a which is delimited on the one hand by the button housing 6 and on the other hand by the contact surface 2a on the collar 2, presses the key tappet over the collar 2 in the direction of the arrow R.
  • the contacting is reliably interrupted when the driver nose 5 on the contact surface of the mating contact 3 moves past.
  • the spring section 4b then rests on the driving lug 5 with the predetermined pretension.
  • the return movement of the key tappet is limited either by the spring travel of the spring section 4a or by the housing on which the collar 2 abuts.
  • the impact of the key tappet 1 on the housing cover during the return movement is advantageously dampened by the spring section 4b.
  • FIGS. 2 and 3 show an advantageous exemplary embodiment of a key switch as a changeover contact which can be switched over between a normally closed contact and a normally open contact.
  • Fig. 2 shows a side view of the key switch in section.
  • Fig. 3 shows the arrangement of FIG. 2 in section in the view from above.
  • the push button consists of a button 11 which is attached to the push button 1.
  • the key stroke 1 is moved in the key housing 6.
  • the components required for the switching function of the changeover contact are contained in the key housing 6, which is closed off by a key cover (14) is engaged in a recess of a carrier plate 13 via latching springs 19 and 20, which absorbs the assembly and keying-in forces
  • Most housing 6 and the key cover 14 formed chamber protects the contacts and the related moving parts from external influences such as dust or vapors, which arise for example during the automatic soldering process of the circuit boards.
  • the key tappet 1 is guided in the guide 7 in the housing and a guide 15 in the key cover 14 when actuated.
  • a collar 2 is fixedly attached to the key tappet 1.
  • the first spring section 4a is supported on the support surface 2a on the underside of the collar 2.
  • the second spring section 4b of the helical spring 4 has a larger diameter than the spring section 4a and extends beyond the contact surface 2a.
  • the other end of the first spring section 4a is supported on the bottom surface of the key housing 6.
  • the driver lugs 5 and 17 are attached to the collar 2.
  • the counter contacts 3 and 16 are arranged in a fixed manner, the contact connections of which are connected to the printed circuit board 12.
  • the normally closed contact is closed, so that via the contact connection 9 and the spring sections 4a and 4b, there is an electrically conductive connection to the mating contact 16 and its contact connection (not shown) on the printed circuit board 12.
  • the uppermost turn 18 of the second spring section 4b rests on the contact surface of the mating contact 16 with the required contact pressure.
  • the contact surface of the counter-contact 16 comes to lie below the underside of the driving lug 17 and the spring tension is selected such that the uppermost turn rests on the contact surface with the contact pressure required for correct contacting.
  • the lowermost turn 10 of the second spring section 4b rests on the upper side of the driving lug 5 under prestress. The preload is selected so that it corresponds to the required contact pressure when making contact in the working state.
  • the key tappet 1 When the key is pressed in the direction of arrow A, the key tappet 1 is moved downward, and the first spring section 4a is thereby compressed. During the downward movement of the key tappet, the second spring section 4b is also moved. The driver nose 17 lifts the uppermost turn 18 of the second spring section 4b from the contact surface of the mating contact 16. From this point in time, the uppermost turn 18 rests on the underside of the driving lug 17 with a prestress corresponding to the contact pressure when the contact is made.
  • the push button returns to the rest position by the spring force of the first spring section 4a.
  • the driver nose 5 lifts the lowermost turn 10 of the spring section 4b from the contact surface of the mating contact 3.
  • the lowermost turn 10 of the spring section 4b then lies on the driving lug 5 with a prestress corresponding to the contact pressure when the contact is made.
  • the uppermost turn 18 of the second spring section 4b comes to lie on the contact surface of the mating contact 16 with the required contact pressure, which corresponds to the pretension on the driving lug 17. This is achieved in that the underside of the driver lug 17 comes to lie above the contact surface of the mating contact 16.
  • the upward movement is limited by the top of the collar 2, which abuts the key cover 14. In the idle state, there is the conductive connection via the mating contact 16, the spring sections 4b, 4a and the contact connection 9.
  • Fig. 4 shows a sectional view of the key switch with a protective collar against the effects of the solder bath.
  • a protective collar 19 which is open to the solder bath is formed on the key housing 6 made of plastic.
  • this protective device designed as a protective collar 19 the guide 7 is prevented from being deformed when the button with the circuit board 12 is immersed in a trailing or immersion solder bath under the action of heat from the solder, and the guide function is thus impaired.
  • a warping or damage to the protective collar 19 is of no importance since it has no influence on the function of the button. It is also think bar to remove the protective collar 19 after the soldering process. To facilitate removal, the protective collar 19 can be detachably connected to the button, for example.
  • the protective collar 19 is arranged in a ring around the point to be protected, namely the guide 7. It is also conceivable for it to have the shape of other geometric figures. It is expediently formed from the same material as the underside of the key switch.

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  • Push-Button Switches (AREA)

Description

Gegenstand der Erfindung ist ein Tastenschalter, insbesondere für Tastaturen in Schreibmaschinen und ähnlichen Einrichtungen, beispielsweise Fernschreibmaschinen und Datenstationen, mit einem Tastenstössel, der bei der Tastenbetätigung gegen die Federkraft einer zwischen dem Tastengehäuse und einer Auflagefläche des Tastenstössels angebrachten schraubenförmigen Feder aus der Ruhestellung in die Arbeitsstellung bewegbar ist, wobei die Feder das bewegliche Kontaktstück bildet, das bei der Kontaktgabe mit einem ortsfesten Gegenkontakt in Verbindung gebracht wird, und dessen Tastenstössel von der Kontaktgabe noch weiter bewegbar ist.The invention relates to a key switch, in particular for keyboards in typewriters and similar devices, for example teleprinters and data stations, with a key tappet which, when the key is pressed against the spring force, a helical spring attached between the key housing and a contact surface of the key tappet from the rest position into the working position is movable, the spring forming the movable contact piece, which is brought into contact with a stationary counter-contact when making contact, and whose key plunger can be moved even further by the contact.

Es ist bereits ein Drucktastenschalter mit einem in einem Schaltkörper angebrachten Druckknopf bekannt, der zwischen einer Ruhestellung und einer Arbeitsstellung betätigbar angeordnet ist, sowie mit einer Druckfeder, durch welche der Druckknopf von der Arbeitsstellung in die Ruhestellung zurückgestellt wird (DE-A1- Nr. 2657783). Bei diesem bekannten Drucktastenschalter ist die Druckfeder mit einem langgestreckten Fortsatz versehen, der bei der Betätigung mit einem Gegenkontaktstück zur Zusammenwirkung gebracht wird. Der bekannte Drucktastenschalter hat den Nachteil, dass bei der Kontaktgabe der langgestreckte Fortsatz starr auf den Gegenkontakt auftrifft, wodurch Kontaktprellungen entstehen können. Der Gegenkontakt muss daher federnd ausgebildet sein. Der Drucktastenschalter ist in der Höhe durch den langgestreckten Forstsatz begrenzt, so dass keine besonders niedrige Taste realisierbar ist. Es ist eine grössere Anzahl von Bauteilen erforderlich, so dass der Aufbau und der Zusammenbau schwierig ist.There is already known a push button switch with a push button mounted in a switch body, which can be actuated between a rest position and a working position, and with a pressure spring, by means of which the push button is reset from the working position to the rest position (DE-A1 No. 2657783 ). In this known push button switch, the compression spring is provided with an elongated extension which is brought into interaction with a counter-contact piece when actuated. The known push-button switch has the disadvantage that when the contact is made, the elongated extension strikes the mating contact rigidly, which can cause contact bruises. The counter contact must therefore be resilient. The height of the push button switch is limited by the elongated forest set, so that no particularly low button can be realized. A large number of components are required, so assembly and assembly are difficult.

Aufgabe der Erfindung ist es, einen Tastenschalter aufzuzeigen und bereitzustellen, der für die Bedienungsperson ergonomisch besonders günstig ist, aus wenigen Einzelteilen besteht und mit geringem Fertigungsaufwand herstellbar ist. Die Lösung der Aufgabe besteht darin, dass die schraubenförmige Feder zwei Federgabschnitte aufweist, von denen der erste Federabschnitt in sich bekannter Weise als Druckfeder für die Rückführung des Tastenstössels aus der Arbeitsstellung in die Ruhestellung ausgebildet ist und der zweite Federabschnitt auf der vom ersten Federabschnitt abgewandten Seite der Auflagefläche des Tastenstössels mit einer bestimmten Vorspannung aufliegt, und dass der Gegenkontakt im Bewegungsbereich des über die Auflagefläche des Tastenstössels weitergeführten schraubenförmigen zweiten Federabschnittes der Feder angeordnet ist.The object of the invention is to identify and provide a key switch which is ergonomically particularly favorable for the operator, consists of a few individual parts and can be produced with little production outlay. The solution to the problem is that the helical spring has two spring sections, of which the first spring section is designed in a known manner as a compression spring for returning the key tappet from the working position to the rest position and the second spring section on the side facing away from the first spring section the contact surface of the key tappet rests with a certain pretension, and that the counter-contact is arranged in the range of motion of the helical second spring section of the spring, which is extended over the contact surface of the key tappet.

Der neue Tastenschalter ist in seinen räumlichen Abmessungen besonders klein, wobei insbesondere die Tastenhöhe klein ist. Die geringe Höhe der Taste ist aus ergonomischen Gründen besonders wichtig, weil dadurch bei der Tastenbetätigung eine die Bedienungsperson geringer belastende Körperhaltung erreicht wird. Dies macht sich besonders stark bemerkbar, wenn von der Bedienungsperson Eingabetastaturen, die auf unterschiedlich hohen Bedienungsflächen angebracht sind, betätigt werden.'Die neue Taste ermöglicht eine Reduzierung der Höhe auf über die Hälfte der bisher im praktischen Betrieb benutzten Tasten. Trotz der geringen Höhe ist der Tastenschalter funktionssicher und kostengünstig herstellbar. Der Tastenschalter besteht aus wenigen Einzelteilen, die auf einfache Weise zusammengefügt werden. Die Herstellung und der Zusammenbau in einem Fertigungsautomaten ist möglich. Die mechanische Kontaktgabe ist besonders sicher und es besteht ein geringer Übergangswiderstand zwischen den geschlossenen Kontaktelementen. Durch die Verwendung der schraubenförmigen Rückführfeder, wird ein gleichmässiges Druckverhalten bei der Betätigung der Taste erzielt.The dimensions of the new key switch are particularly small, with the key height being particularly small. The low height of the key is particularly important for ergonomic reasons, because it results in a posture that is less stressful for the operator when the key is pressed. This is particularly noticeable when the operator presses input keyboards that are located on operating surfaces of different heights. The new key enables the height to be reduced to over half of the keys previously used in practical operation. Despite the low height, the key switch is reliable and inexpensive to manufacture. The key switch consists of a few individual parts that can be assembled in a simple manner. The manufacture and assembly in a manufacturing machine is possible. The mechanical contact is particularly safe and there is a low contact resistance between the closed contact elements. By using the helical return spring, a uniform pressure behavior is achieved when the button is pressed.

Eine vorteilhafte Ausgestaltung der neuen Drucktaste besteht darin, dass die beiden Federabschnitte der schraubenförmigen Feder unterschiedliche Windungsdurchmesser aufweisen. Dies hat den Vorteil, dass die Federkennlinien für die beiden Federabschnitte unterschiedlich gewählt werden können.An advantageous embodiment of the new push button is that the two spring sections of the helical spring have different winding diameters. This has the advantage that the spring characteristics for the two spring sections can be selected differently.

Eine weitere vorteilhafte Ausgestaltung der neuen Drucktaste besteht darin, dass der erste Federabschnitteinen kleineren und der zweite Federnabschnitt der Feder einen grösseren Windungsdurchmesser aufweist. Dies hat den Vorteil, dass durch den Federabschnitt mit dem grösseren Durchmesser ein besonders weiches Ansprechen des Kontaktes erreicht wird, obwohl bei der Kontaktgabe der erforderliche Mindestkontaktdruck gegeben ist. Der Federabschnitt mit dem grösseren Durchmesser ist auch zur Dämpfung des Rückschlages für den Tastenstössel bei der Rückkehr aus der Arbeitsstellung in die Ruhestellung verwendbar.A further advantageous embodiment of the new push button is that the first spring section has a smaller and the second spring section of the spring has a larger winding diameter. This has the advantage that a particularly soft response of the contact is achieved by the spring section with the larger diameter, although the required minimum contact pressure is given when contacting. The spring section with the larger diameter can also be used to dampen the kickback for the key tappet when returning from the working position to the rest position.

Um bei der Verlötung der Taste mittels eines Lötbades die Taste selbst vor Einwirkungen durch das Lötbad zu schützen, ist bei einer weiteren vorteilhaften Ausführungsform der Erfindung um die zu schützende Stelle an der Taste ein Schutzkragen angeordnet, der in Richtung zum Lötbad offen ist und über die zu schützende Stelle hinausragt.In order to protect the key itself from the effects of the solder bath when the key is soldered by means of a solder bath, in a further advantageous embodiment of the invention a protective collar is arranged around the point to be protected on the key, which is open in the direction of the solder bath and via the Protected area protrudes.

Einzelheiten der Erfindung werden anhand von in den Figuren dargestellten vorteilhaften Ausführungsbeispielen erläutert.Details of the invention are explained on the basis of advantageous exemplary embodiments shown in the figures.

Es zeigt:

  • Fig. 1 einer Prinzipdarstellung den grundsätzlichen Aufbau und die Wirkungsweise des neuen Tastenschalters anhand eines vorteilhaften Ausführungsbeispiels,
  • Fig. 2 und Fig. 3 ein vorteilhaftes Ausführungsbeispiel des neuen Tastenschalters, und
  • Fig. 4 ein Ausführungsbeispiel des Tastenschalters mit einem Schutzkragen gegen Einwirkungen des Lötbades bei der Herstellung.
It shows:
  • 1 is a schematic representation of the basic structure and operation of the new button switch based on an advantageous embodiment,
  • Fig. 2 and Fig. 3 shows an advantageous embodiment of the new key switch, and
  • Fig. 4 shows an embodiment of the key switch with a protective collar against the effects of the solder bath during manufacture.

Anhand der Fig. 1 wird das neue Tastenprinzip erläutert. Der neue Tastenschalter besteht aus einem Tastenstössel 1, der in einem Tastengehäuse 6 in einer Führung 7 bei der Betätigung der Taste bewegbar ist. Im oberen Bereich des Tastenstössels 1 ist ein Bund 2 fest angebracht, der in der Ruhestellung der Taste die Bewegung des Tastenstössels 1 nach oben begrenzt. Gleichzeitig wird die Auflagefläche 2a des Bundes 2 zum Abstützen einer Feder 4 zur Rückstellung verwendet. Die schraubenförmige Feder 4 besteht aus zwei Federabschnitten 4a und 4b, die unterschiedliche Windungsdurchmesser aufweisen. Der erste Federabschnitt 4a mit dem kleineren Windungsdurchmesser wird als Druckfeder verwendet, während der zweite Federabschnitt 4b mit dem grösseren Windungsdurchmesser zur Kontaktgabe verwendet wird. Der zweite Federabschnitt 4b, der aus mindestens einer Windung besteht, liegt mit einer Vorspannung an einer Mitnehmernase 5 auf, die fest mit dem Bund 2 des Tastenstössels verbunden ist. Die Vorspannnung wird so gewählt, dass der erforderliche Kontaktdruck bei der Kontaktgabe auftritt. Mit Hilfe des Windungsdurchmessers kann die Charakteristik der Feder eingestellt werden. Durch den gegenüber dem Federabschnitt 4a gewählten grösseren Windungsdurchmesser wird eine weiche Federwirkung erreicht, so dass für die Bedienungsperson kein harter Druckpunkt bei der Kontaktgabe entsteht. Die Feder 4 wird als bewegliches Kontaktelement verwendet, wobei das Ende als Kontaktanschluss 9 ausgebildet ist. Der Gegenkontakt 3 mit seinem Kontaktanschluss 8 ist im Tastengehäuse 6 ortsfest als starres Kontaktelement im Bewegungsbereich des zweiten Federabschnittes 4b angeordnet. Der Gegenkontakt 3 ist vorteilhaft als einfaches Blechplättchen ausgeführt. Das Tastengehäuse 6 und der Tastenstössel 1 mit dem fest angebrachten Bund 2 und der Auflagefläche 2a sowie der Mitnehmernase 5 sind auf einfache Weise als Kunststoffteile herstellbar.The new key principle is explained with reference to FIG. 1. The new key switch consists of egg Nem tappet 1, which is movable in a button housing 6 in a guide 7 when the button is pressed. In the upper area of the key tappet 1, a collar 2 is firmly attached, which limits the movement of the key tappet 1 in the rest position of the key. At the same time, the contact surface 2a of the collar 2 is used to support a spring 4 for resetting. The helical spring 4 consists of two spring sections 4a and 4b, which have different winding diameters. The first spring section 4a with the smaller winding diameter is used as a compression spring, while the second spring section 4b with the larger winding diameter is used for making contact. The second spring section 4b, which consists of at least one turn, rests with a pretension on a driving lug 5, which is firmly connected to the collar 2 of the key tappet. The preload is selected so that the required contact pressure occurs when the contact is made. The characteristic of the spring can be adjusted with the help of the winding diameter. A soft spring action is achieved due to the larger winding diameter selected compared to the spring section 4a, so that the operator does not have a hard pressure point when making contact. The spring 4 is used as a movable contact element, the end being designed as a contact connection 9. The mating contact 3 with its contact connection 8 is arranged in the key housing 6 in a stationary manner as a rigid contact element in the range of motion of the second spring section 4b. The counter contact 3 is advantageously designed as a simple sheet metal plate. The key housing 6 and the key tappet 1 with the firmly attached collar 2 and the support surface 2a and the driving nose 5 can be produced in a simple manner as plastic parts.

Die bei der Kontaktgabe des Tastenschalters aufeinanderliegenden Kontaktflächen des Gegenkontaktes 3 und des Windungsteiles 10 des zweiten Federabschnittes 4b, werden zur besseren Kontaktgabe mit einer die Leitfähigkeit erhöhenden Schicht, beispielsweise Gold oder Palladium überzogen.The contact surfaces of the mating contact 3 and the winding part 10 of the second spring section 4b, which lie one on top of the other when the key switch is contacted, are coated with a layer which increases the conductivity, for example gold or palladium, for better contact.

In dem in Fig. 1 gezeichneten Zustand befindet sich der Tastenschalter in der Ruhestellung, d.h. vor der Betätigung der Taste. Bei der Tastenbetätigung wird der Tastenstössel 1 mittels des angebrachten Tastenknopfes durch einen Fingerdruck der Bedienungsperson in die Pfeilrichtung A bewegt. Der Tastenstössel gleitet in der Führung 7 im Tastengehäuse 6 entlang. Dabei wird der Federabschnitt 4a zusammengedrückt. Mit dem Tastenstössel 1 bewegt sich der Bund 2 mit der fest angebrachten Mitnehmernase 5 in Richtung zum Gegenkontakt 3. Die Mitnehmernase 5 wird an. der Kontaktfläche des Gegenkontaktes vorbeibewegt und der Windungsteil 10 des Federabschnittes 4b kommt mit der Kontaktfläche des Gegenkontaktes 3 in Berührung. In diesem Zeitpunkt ist der Kontakt geschlossen und es besteht über den Kontaktanschluss 9, die Federabschnitte 4a und 4b, den Gegenkontakt 3 und den Kontaktanschluss 8 eine elektrisch leitende Verbindung. Aufgrund der Vorspannung des Federabschnittes 4b, liegt der Windungsteil 10 bei der Kontaktgabe mit dem erforderlichen Kontaktdruck auf dem Gegenkontakt auf. Dadurch wird prellfrei der Kontakt des Tastenschalters geschlossen. Der Tastenstössel 1 wird noch weiter bewegt, so dass die Mitnehmernase 5 unterhalb der Kontaktfläche des Gegenkontaktes 3 zu liegen kommt. Dadurch liegt der Windungsteil 10 frei auf der Kontaktfläche des Gegenkontaktes 3 auf. Dadurch werden Störungen bei der Bedienung durch ungleichmässiges Drücken, ein Nachlassen des Fingerdruckes oder ein Zittern beim Betätigen der Taste vermieden. Der Tastenstössel hat dann seine Endstellung, die Arbeitsstellung erreicht, wobei die Bewegung entweder durch die Bodenfläche der Führung 7 oder durch den nicht mehr weiter zusammendrückbaren Federabschnitt 4a begrenzt wird.In the state shown in Fig. 1, the key switch is in the rest position, i.e. before pressing the button. When the key is pressed, the key plunger 1 is moved in the direction of the arrow A by the operator's finger pressure by means of the attached key button. The key tappet slides along the guide 7 in the key housing 6. The spring section 4a is compressed. With the push button plunger 1, the collar 2 with the firmly attached driving lug 5 moves in the direction of the mating contact 3. The driving lug 5 is turned on. the contact surface of the mating contact moves past and the winding part 10 of the spring section 4b comes into contact with the contact surface of the mating contact 3. At this time, the contact is closed and there is an electrically conductive connection via the contact connection 9, the spring sections 4a and 4b, the mating contact 3 and the contact connection 8. Due to the prestressing of the spring section 4b, the winding part 10 rests on the counter contact when the contact is made with the required contact pressure. This closes the contact of the key switch without bouncing. The key tappet 1 is moved further, so that the driver nose 5 comes to rest below the contact surface of the counter contact 3. As a result, the winding part 10 lies freely on the contact surface of the mating contact 3. This prevents malfunctions during operation due to uneven presses, a decrease in finger pressure or tremors when the button is pressed. The key tappet has then reached its end position, the working position, the movement being limited either by the bottom surface of the guide 7 or by the spring section 4a which can no longer be compressed.

Beim Loslassen des Tastenknopfes durch die Bedienungsperson, kehrt der Tastenstössel 1 aus der Arbeitsstellung in die Ruhestellung zurück. Der zusammengedrückte Federabschnitt 4a, der einerseits durch das Tastengehäuse 6 und andererseits durch die Auflagefläche 2a am Bund 2 begrenzt wird, drückt den Tastenstössel über den Bund 2 in die Pfeilrichtung R. Die Kontaktgabe wird sicher unterbrochen, wenn die Mitnehmernase 5 an der Kontaktfläche des Gegenkontaktes 3 sich vorbeibewegt. Der Federabschnitt 4b liegt dann wieder mit der festgelegten Vorspannung an der Mitnehmernase 5 auf. Die Rückkehrbewegung des Tastenstössels wird entweder durch den Federweg des Federabschnittes 4a oder durch das Gehäuse, an dem der Bund 2 anstösst, begrenzt. Der Aufprall des Tastenstössels 1 am Gehäusedekkel bei der Rückkehrbewegung wird vorteilhaft durch den Federabschnitt 4b gedämpft.When the operator releases the button, the button plunger 1 returns from the working position to the rest position. The compressed spring section 4a, which is delimited on the one hand by the button housing 6 and on the other hand by the contact surface 2a on the collar 2, presses the key tappet over the collar 2 in the direction of the arrow R. The contacting is reliably interrupted when the driver nose 5 on the contact surface of the mating contact 3 moves past. The spring section 4b then rests on the driving lug 5 with the predetermined pretension. The return movement of the key tappet is limited either by the spring travel of the spring section 4a or by the housing on which the collar 2 abuts. The impact of the key tappet 1 on the housing cover during the return movement is advantageously dampened by the spring section 4b.

Während in Fig. 1 der Aufbau und die Wirkungsweise des Tastenschalters für einen Arbeitskontakt dargestellt ist, zeigen die Fig. 2 und 3 ein vorteilhaftes Ausführungsbeispiel eines Tastenschalters als Umschaltkontakt, der zwischen einem Ruhekontakt und einem Arbeitskontakt umschaltbar ist.1 shows the structure and mode of operation of the key switch for a normally open contact, FIGS. 2 and 3 show an advantageous exemplary embodiment of a key switch as a changeover contact which can be switched over between a normally closed contact and a normally open contact.

Die Fig. 2 zeigt eine Seitenansicht des Tastenschalters im Schnitt. Die Fig. 3 zeigt die Anordnung nach Fig. 2 im Schnitt in der Ansicht von oben.Fig. 2 shows a side view of the key switch in section. Fig. 3 shows the arrangement of FIG. 2 in section in the view from above.

Die Drucktaste besteht aus einem Tastenknopf 11, der am Tastenstössei 1 befestigt ist. Der Tastenstössei 1 wird im Tastengehäuse 6 bewegt. Die für die Schaltfunktion des Umschaltkontaktes erforderlichen Bauteile sind im Tastengehäuse 6 enthalten, das durch einen Tastendecke( 14 abgeschlossen ist. Der Tastendeckel 14 wird beim Aufsetzen auf das Tastengehäuse 6 über die am Gehäuse angebrachten Rastnasen 14a und 14b durch Einrasten formschlüssig verbunden. Das Tastengehäuse 6 ist in einer Ausnehmung einer Trägerplatte 13 über Rastfedern 19 und 20 eingerastet, die die Montage- und Eintastkräfte aufnimmt. An der Unterseite des Tastengehäuse 6 ist eine Leiterplatte 12 angeordnet, an der die Kontaktanschlüsse 8 und 9 verlötet sind. Die durch das Tastengehäuse 6 und den Tastendeckel 14 gebildete Kammer schützt die Kontakte und die damit in Verbindung stehenden beweglichen Teile vor Fremdeinwirkungen wie Staub oder Dämpfen, die beispielsweise beim automatischen Lötvorgang der Leiterplatten entstehen.The push button consists of a button 11 which is attached to the push button 1. The key stroke 1 is moved in the key housing 6. The components required for the switching function of the changeover contact are contained in the key housing 6, which is closed off by a key cover (14) is engaged in a recess of a carrier plate 13 via latching springs 19 and 20, which absorbs the assembly and keying-in forces Most housing 6 and the key cover 14 formed chamber protects the contacts and the related moving parts from external influences such as dust or vapors, which arise for example during the automatic soldering process of the circuit boards.

Der Tastenstössel 1 wird bei der Betätigung in der Führung 7 im Gehäuse und einer Führung 15 im Tastendeckel 14 geführt. Am Tastenstössel 1 ist fest ein Bund 2 angebracht. An der Auflagefläche 2a an der Unterseite des Bundes 2, ist der erste Federabschnitt 4a abgestützt. Der zweite Federabschnitt 4b der schraubenförmigen Feder 4 weist einen grösseren Durchmesser als der Federabschnitt 4a auf und ist über die Auflagefläche 2a hinaus weitergeführt. Das andere Ende des ersten Federabschnittes 4a stützt sich an der Bodenfläche des Tastengehäuses 6 ab. Am Bund 2 sind die Mitnehmernasen 5 und 17 angebracht. Im Tastengehäuse 6 sind ortsfest die Gegenkontakte 3 und 16 angeordnet, deren Kontaktanschlüsse mit der Leiterplatte 12 verbunden sind.The key tappet 1 is guided in the guide 7 in the housing and a guide 15 in the key cover 14 when actuated. A collar 2 is fixedly attached to the key tappet 1. The first spring section 4a is supported on the support surface 2a on the underside of the collar 2. The second spring section 4b of the helical spring 4 has a larger diameter than the spring section 4a and extends beyond the contact surface 2a. The other end of the first spring section 4a is supported on the bottom surface of the key housing 6. The driver lugs 5 and 17 are attached to the collar 2. In the button housing 6, the counter contacts 3 and 16 are arranged in a fixed manner, the contact connections of which are connected to the printed circuit board 12.

Im Ruhezustand ist der Ruhekontakt geschlossen, so dass über den Kontaktanschluss 9 und die Federabschnitte 4a und 4b, eine elektrisch leitende Verbindung mit dem Gegenkontakt 16 und dessen nicht dargestellten Kontaktanschluss an der Leiterplatte 12 besteht. In diesem Zustand liegt die oberste Windung 18 des zweiten Federabschnittes 4b mit dem erforderlichen Kontaktdruck an der Kontaktfläche des Gegenkontaktes 16 auf. Dazu ist es erforderlich, dass die Kontaktfläche des Gegenkontaktes 16 unterhalb der Unterseite der Mitnehmernase 17 zu liegen kommt, und die Federspannung so gewählt ist, dass die oberste Windung mit dem für eine einwandfreie Kontaktgabe erforderlichen Kontaktdruck an der Kontaktfläche aufliegt. Im Ruhezustand des Tastenschalters liegt die unterste Windung 10 des zweiten Federabschnittes 4b an der Oberseite der Mitnehmernase 5 unter Vorspannung auf. Die Vorspannung ist so gewählt, dass sie dem erforderlichen Kontaktdruck bei der Kontaktgabe im Arbeitszustand entspricht.In the idle state, the normally closed contact is closed, so that via the contact connection 9 and the spring sections 4a and 4b, there is an electrically conductive connection to the mating contact 16 and its contact connection (not shown) on the printed circuit board 12. In this state, the uppermost turn 18 of the second spring section 4b rests on the contact surface of the mating contact 16 with the required contact pressure. For this purpose, it is necessary that the contact surface of the counter-contact 16 comes to lie below the underside of the driving lug 17 and the spring tension is selected such that the uppermost turn rests on the contact surface with the contact pressure required for correct contacting. In the idle state of the key switch, the lowermost turn 10 of the second spring section 4b rests on the upper side of the driving lug 5 under prestress. The preload is selected so that it corresponds to the required contact pressure when making contact in the working state.

Bei der Betätigung der Taste in der Pfeilrichtung A, wird der Tastenstössel 1 nach unten bewegt, und dadurch der erste Federabschnitt 4a zusammengedrückt. Bei der Abwärtsbewegung des Tastenstössels, wird der zweite Federabschnitt 4b mitbewegt. Dabei hebt die Mitnehmernase 17 die oberste Windung 18 des zweiten Federabschnittes 4b von der Kontaktfläche des Gegenkontaktes 16 ab. Die oberste Windung 18 liegt ab diesem Zeitpunkt mit einer dem Kontaktdruck bei der Kontaktgabe entsprechenden Vorspannung an der Unterseite der Mitnehmernase 17 an.When the key is pressed in the direction of arrow A, the key tappet 1 is moved downward, and the first spring section 4a is thereby compressed. During the downward movement of the key tappet, the second spring section 4b is also moved. The driver nose 17 lifts the uppermost turn 18 of the second spring section 4b from the contact surface of the mating contact 16. From this point in time, the uppermost turn 18 rests on the underside of the driving lug 17 with a prestress corresponding to the contact pressure when the contact is made.

Beim Erreichen der Arbeitsstellung kommt die unterste Windung 10 des zweiten Federabschnittes 4b auf der Kontaktfläche des Gegenkontaktes 3 zu liegen. Der Kontaktdruck, mit dem die unterste Windung auf der Kontaktfläche aufliegt, entspricht dabei der Vorspannung, mit der die unterste Windung 10 auf der Mitnehmernase 5 aufgelegen hat. Damit dies erreicht wird, ist es jedoch erforderlich, dass die Oberseite der Mitnehmernase 5 in der Arbeitsstellung der Drucktaste unterhalb der Kontaktfläche des Gegenkontaktes 3 zu liegen kommt. In der Arbeitsstellung ergibt sich zwischen den Kontaktanschlüssen 8 und 9 über den ersten Federabschnitt 4a, die unterste Windung 10deszweiten Federabschnittes4b und den Gegenkontakt 3 eine elektrisch leitende Verbindung.When the working position is reached, the lowermost turn 10 of the second spring section 4b comes to rest on the contact surface of the mating contact 3. The contact pressure with which the lowermost turn lies on the contact surface corresponds to the pretension with which the lowermost turn 10 has been placed on the driving lug 5. In order for this to be achieved, however, it is necessary that the upper side of the driving lug 5 comes to lie below the contact surface of the mating contact 3 in the working position of the push button. In the working position, there is an electrically conductive connection between the contact connections 8 and 9 via the first spring section 4a, the lowermost turn 10 of the second spring section 4b and the mating contact 3.

Beim Loslassen des Tastenknopfes 11, kehrt die Drucktaste durch die Federkraft des ersten Federabschnittes 4a in die Ruhestellung zurück. Bei der Bewegung des Tastenstössels in Pfeilrichtung R hebt die Mitnehmernase 5 die unterste Windung 10 des Federabschnittes 4b von der Kontaktfläche des Gegenkontaktes 3 ab. Die unterste Windung 10 des Federabschnittes 4b liegt dann mit einer dem Kontaktdruck bei der Kontaktgabe entsprechenden Vorspannung auf der Mitnehmernase 5 auf. Beim Erreichen der Ruhestellung kommt die oberste Windung 18 des zweiten Federabschnittes 4b mit dem erforderlichen Kontaktdruck, der der Vorspannung an der Mitnehmernase 17 entspricht, auf die Kontaktfläche des Gegenkontaktes 16 zu liegen. Dies wird dadurch erreicht, dass die Unterseite der Mitnehmernase 17 oberhalb der Kontaktfläche des Gegenkontaktes 16 zu liegen kommt. Die Bewegung nach oben wird durch die Oberseite des Bundes 2, die am Tastendeckel 14 anstösst, begrenzt. Im Ruhezustand besteht die leitende Verbindung über den Gegenkontakt 16, die Federabschnitte 4b, 4a und den Kontaktanschluss 9.When the button 11 is released, the push button returns to the rest position by the spring force of the first spring section 4a. When the key tappet moves in the direction of the arrow R, the driver nose 5 lifts the lowermost turn 10 of the spring section 4b from the contact surface of the mating contact 3. The lowermost turn 10 of the spring section 4b then lies on the driving lug 5 with a prestress corresponding to the contact pressure when the contact is made. When the rest position is reached, the uppermost turn 18 of the second spring section 4b comes to lie on the contact surface of the mating contact 16 with the required contact pressure, which corresponds to the pretension on the driving lug 17. This is achieved in that the underside of the driver lug 17 comes to lie above the contact surface of the mating contact 16. The upward movement is limited by the top of the collar 2, which abuts the key cover 14. In the idle state, there is the conductive connection via the mating contact 16, the spring sections 4b, 4a and the contact connection 9.

Die Fig. 4 zeigt ein Schnittbild des Tastenschalters mit einem Schutzkragen gegen Einwirkungen des Lötbades.Fig. 4 shows a sectional view of the key switch with a protective collar against the effects of the solder bath.

Um die Führung 7 des Stössels ist am Tastengehäuse 6 aus Kunststoff ein zum Lötbad offener Schutzkragen 19 angeformt. Mit Hilfe dieser als Schutzkragen 19 ausgebildeten Schutzeinrichtung, wird verhindert, dass die Führung 7 beim Eintauchen der Taste mit der Leiterplatte 12 in ein Schlepp- oder Tauchlötbad unter der Hitzeeinwirkung des Lots verformt wird, und damit die Führungsfunktion beeinträchtigt wird.Around the guide 7 of the plunger, a protective collar 19 which is open to the solder bath is formed on the key housing 6 made of plastic. With the help of this protective device designed as a protective collar 19, the guide 7 is prevented from being deformed when the button with the circuit board 12 is immersed in a trailing or immersion solder bath under the action of heat from the solder, and the guide function is thus impaired.

Beim Eintauchen der Taste mit der Leiterplatte 12 in das Lötbad, wird in dem Hohlraum zwischen der Führung 7 und dem Schutzkragen 19 ein Luftpolster gebildet, das das Eindringen des Lots in den durch den Schutzkragen 19 gebildeten Hohlraum verhindert und als Wärmeisolator wirkt, der Hitzeschäden an der Führung 7 verhindert. Um zu verhindern, dass das Lot bis zur Führung 7 vordringt, ist es dabei notwendig, dass der Schutzkragen 19 über die Führung 7 hinausragt. Beim Löten in einem Tauchlötbad muss der Schutzkragen 19 nur geringfügig über die zu schützende Stelle, nämlich die Führung 7 hinausragen. Beim Löten in einem Schleppiötbad, beispielsweise einem Schwallötbad, ist es dagegen erforderlich, dass der Schutzkragen 19 so weit über die Führung 7 hinausragt, dass die Ausbildung eines Luftpolsters sichergestellt ist. Ein Verziehen oder eine Beschädigung des Schutzkragens 19 sind ohne Bedeutung, da er auf die Funktion der Taste keinen Einfluss hat. Es ist auch denkbar, den Schutzkragen 19 nach dem Lötvorgang zu entfernen. Zum Erleichtern des Entfernens kann der Schutzkragen 19 beispielsweise lösbar mit der Taste verbunden sein.When the button with the printed circuit board 12 is immersed in the solder bath, an air cushion is formed in the cavity between the guide 7 and the protective collar 19, which prevents the solder from penetrating into the cavity formed by the protective collar 19 and acts as a heat insulator to the heat damage the guide 7 prevented. In order to prevent the solder from reaching the guide 7, it is necessary for the protective collar 19 to protrude beyond the guide 7. When soldering in an immersion solder bath, the protective collar 19 only has to protrude slightly beyond the point to be protected, namely the guide 7. In contrast, when soldering in a trailing solder bath, for example a wave solder bath, it is necessary for the protective collar 19 to protrude so far beyond the guide 7 that the formation of an air cushion is ensured. A warping or damage to the protective collar 19 is of no importance since it has no influence on the function of the button. It is also think bar to remove the protective collar 19 after the soldering process. To facilitate removal, the protective collar 19 can be detachably connected to the button, for example.

Der Schutzkragen 19 ist im einfachsten Fall ringförmig um die zu schützende Stelle, nämlich die Führung 7 angeordnet. Es ist auch denkbar, dass er die Form von anderen geometrischen Figuren aufweist. Zweckmässigerweise wird er aus demselben Material gebildet, wie die Unterseite des Tastenschalters.In the simplest case, the protective collar 19 is arranged in a ring around the point to be protected, namely the guide 7. It is also conceivable for it to have the shape of other geometric figures. It is expediently formed from the same material as the underside of the key switch.

Claims (17)

1. A key switch, in particular for the keyboards of typewriters and similar devices, for example, teleprinters and data stations, having a key tappet (1) which on operation of the key can be moved from the rest position into the operating position against the spring force of a helical spring (4) which is fixed between the key housing (6) and a contact surface (2a) on the key tappet (1), wherein the spring (4) forms the moving contact piece which is brought into contact with a stationary counter-contact (3) during contacting, and the key tappet (1) of which can be further moved after contacting, characterised in that the helical spring (4) has two spring sections (4a, 4b) the first (4a) of which is designed in known manner as a compression spring for the return movement of the key tappet (1 ) from the operating position to the rest position, and the second (4b) of which rests against the side of the contact surface (2a) of the key tappet (1) which faces away from the first spring section (4a), with a given initial tension, and that the counter-contact (3) is arranged in the range of travel of the second spiral spring section (4b) of the spring (4) which is extended above the contact surface (2a) of the key tappet (1).
2. A key switch as claimed in Claim 1, characterised in that the two spring sections (4a, 4b) of the helical spring (4) have different winding diameters.
3. A key switch as claimed in Claim 2, characterised in that the first spring section (4a) has a smaller winding diameter and the second spring section (4b) has a larger winding diameter.
4. A key switch as claimed in Claim 1, characterised in that the second spring section (4a) has at least one turn.
5. A key switch as claimed in Claim 1, characterised in that the lowermost turn (10) of the second spring section (4b) rests under initial tension against a supporting projection (5) which is fixed to the key tappet (1).
6. A key switch as claimed in Claim 5, characterised in that the supporting projection (5) releases the second spring section (4b) during contacting.
7. A key switch as claimed in Claim 5, characterised in that the key tappet (1) is provided with first and second supporting projections (5, 17) between which the second spring section (4b) is arranged, that in the rest state, the lowermost turn (10) of the second spring section (4b) rests against the first supporting projection (5) under initial tension, that the uppermost turn (18) of the second spring section (4b) rests against a first counter-contact (16) under initial tension, and that, in the operating position, the uppermost turn (18) of the second spring section (4b) rests against the second supporting projection (17) under initial tension and the lowermost turn (10) of the second spring section (4b) rests on the second counter-contact (3) under initial tension.
8. A key switch as claimed in Claim 1, characterised in that the contact surface of the spring section (4b) and the contact surface of the counter-contact (3) are coated with a layer which increases the conductivity of the contact areas.
9. A key switch as claimed in Claim 6, characterised in that the key tappet (1) slows down after contacting.
10. A key switch as claimed in Claim 1, characterised in that the end of the second spring section (4b) which faces away from the contact surface (2a) damps the impact of the key tappet on a key cover (14) during the return movement from the operating position to the rest position.
11. A key switch as claimed in Claim 1, characterised in that the initial tension corresponds to the required contact pressure during contacting.
12. A key switch as claimed in Claim 1, characterised in that the two spring sections (4a, 4b), the counter-contact (3) and the part of the key tappet (1) which carries the contact surface (2a) are arranged in a chamber (6,14) which is closed on all sides.
13. A key switch as claimed in Claim 12, characterised in that the chamber is closed by a snap-on key cover (14).
14. A key switch as claimed in one of Claims 1 to 13, having protection means for protecting the part of the guide (7) of the key tappet (1), which projects through a printed circuit board (12), against the effect of a soldering bath, characterised in that around the place to be protected on the key switch, there is arranged a protective collar (19) which is open towards the soldering bath and projects beyond the place to be protected.
15. A key switch as claimed in Claim 14, characterised in that the protective collar (19) is arranged in the form of a ring around the place to be protected.
16. A key switch as claimed in Claim 14 or Claim 15, characterised in that the protective collar (19) consists of synthetic resin and is moulded onto the housing (6) of the key switch.
EP19790104773 1978-12-14 1979-11-29 Push-button switch, particularly for keyboards of typewriters and similar devices Expired EP0012279B1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE2854096A DE2854096C2 (en) 1978-12-14 1978-12-14 Key switches, in particular for keyboards in typewriters and similar devices
DE2854096 1978-12-14
DE19797914017U DE7914017U1 (en) 1979-05-15 1979-05-15 PROTECTIVE DEVICE FOR A COMPONENT THAT CAN BE SOLVED IN A CIRCUIT BOARD WITH A LOET BATH
DE7914017U 1979-05-15

Publications (2)

Publication Number Publication Date
EP0012279A1 EP0012279A1 (en) 1980-06-25
EP0012279B1 true EP0012279B1 (en) 1982-07-07

Family

ID=25776861

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19790104773 Expired EP0012279B1 (en) 1978-12-14 1979-11-29 Push-button switch, particularly for keyboards of typewriters and similar devices

Country Status (3)

Country Link
EP (1) EP0012279B1 (en)
CS (1) CS216691B2 (en)
MX (1) MX147268A (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH072995Y2 (en) * 1987-07-21 1995-01-30 三菱電機株式会社 Idle position detection switch of engine
GB2209434B (en) * 1987-08-19 1991-11-27 Crabtree Electrical Ind Ltd Switches
GB2371021B (en) * 2000-12-29 2005-07-27 Nokia Mobile Phones Ltd A portable communication device
GB2371022B (en) * 2000-12-29 2005-01-12 Nokia Mobile Phones Ltd A portable communication device
US6965789B2 (en) 2000-12-29 2005-11-15 Vertu Limited Portable communication device
DE102011013286A1 (en) * 2010-03-12 2011-09-15 Marquardt Mechatronik Gmbh Electric switch
CN109192579A (en) * 2018-10-31 2019-01-11 歌尔科技有限公司 Wrist wears class equipment and its key

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1761252U (en) * 1956-10-04 1958-02-13 Lorenz C Ag COMPONENT FOR SOLID-MOUNTED OR PRINTED CIRCUITS.
GB1411761A (en) * 1972-01-19 1975-10-29 Plessey Co Ltd Electric switches
GB1460021A (en) * 1973-01-24 1976-12-31 Gen Electric Co Ltd Electric switches
DE2460457A1 (en) * 1974-12-20 1976-06-24 Gerhard Dekorsy Push-button switch for electronic circuits - has a hollow key which can carry out a limited vertical movement
SE398572B (en) * 1975-12-22 1977-12-27 Raeder Eskil PUSH BUTTON
DE2743156A1 (en) * 1977-09-24 1979-04-05 Baer Elektrowerke Kg Pushbutton switch system with two=part case - has stepped spring with soft and hard part, with bridge contact held between them

Also Published As

Publication number Publication date
CS216691B2 (en) 1982-11-26
EP0012279A1 (en) 1980-06-25
MX147268A (en) 1982-11-01

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