Classifications

• • 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
  • H01H13/02—Details
  • H01H13/10—Bases; Stationary contacts mounted thereon
• • 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
  • H01H13/70—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard
  • H01H13/81—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard characterised by electrical connections to external devices
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H2207/00—Connections
  • H01H2207/032—Surface mounted component
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H2219/00—Legends
  • H01H2219/054—Optical elements
  • H01H2219/062—Light conductor

Definitions

• the present invention relates to an electrical switching element of the SMD type according to the preamble of claim 1, in particular an electric illuminated pushbutton of the SMD type.
• the SMD manufacturing process which stands for Surface Mounted Device, is a circuit board assembly process that has several advantages. If there is computerized equipment, the electrical elements to be equipped can be soldered directly to the surface of a printed circuit board. Since no parts of the electrical components through the circuit board punched through, it is advantageous that both sides of the circuit board can be equipped with circuits.
• an optical touch switch is known, which is arranged as an SMD component on a carrier having SMS contacts, which can then be contacted electrically with the conductor track of a printed circuit board.
• the four lateral SMD contacts allow a contacting of the plate-shaped optical switching element on a printed circuit board.
• the switch is protected by a cover against direct contact and works as an optical touch switch.
• An SMD-type electrical switching element has a body comprising the switching element, at least two contact surfaces provided on the underside of the body for SMD mounting, and an actuator provided on the opposite side of the underside corresponding to the body for a movement amount the longitudinal axis of the switching element is movably connected.
• an electrically conductive connection between the contacts is now made via a switching contact which can be closed to the switching contact with the relative movement of the actuating element, in particular a relative movement along the longitudinal axis of the switching element, ie the central axis perpendicular to the printed circuit board.
• the body now has a lower part, which has the two contact surfaces and the switching contact, and an upper part, which comprises the actuating element.
• Lower part and upper part are to be connected via complementary locking elements.
• the lower part can be made of a heat resistant to the heat of an SMD solder resisting plastic, while the upper part, made of conventional materials, after soldering is first placed on the base and completes the switch or push button.
• Such a switching element has an actuating element with an actuating nose, with which by the said relative movement of the actuating element to the switching contact Contacts are closed.
• the switching contact is a resilient tongue, which is fixedly connected to a contact, for example, soldered, and has a projecting into the range of movement of the actuating nose area, which can therefore be pushed away.
• the switching contact is an elongated spring, which is divided by at least one longitudinal slot in at least two parallel resilient blades. In the case of two or more longitudinal slots, these slots are at least partially different in length from each other, all slots penetrating at least the contact area between the tongue and the mating contact, at least one projecting into the end area of the resilient lamellae.
• FIG. 1 shows a partially sectioned cross-sectional view of two pushbuttons arranged side by side on a printed circuit board according to an embodiment of the invention
• FIG. 2 is a perspective view of a pressure switch of FIG. 1,
• FIG. 3 is an exploded view of the switch according to FIG. 2,
• Fig. 4 is a partially sectioned perspective view of the lower part of
• FIG. 5 is a partially sectioned plan view of the lower part of FIG. 4, and FIG. 6 is a partially sectioned cross-sectional view of the on a
• Fig. 1 shows a partially sectioned cross-sectional view of two side by side arranged on a printed circuit board push-buttons 1, which are mounted on a printed circuit board 2, wherein the actuating hood 3 of the push-button 1 protrude through a front panel 4.
• the SMD type electrical switching element according to the invention is an electrically illuminated pushbutton or pushbutton.
• the illustration is schematic with respect to the printed circuit board 2.
• a printed circuit board 2 is equipped with a corresponding circuit in a control panel, which are switchable via various actuators, in particular the push-button 1.
• the printed circuit board 2 is arranged in a frame below the front panel 4 of a control panel, wherein the operating covers 3 of the controls protrude to the front panel 4.
• the push-button 1 is not actuated, so the Rontakt not closed, while in the pressed push-button 1 on the right side of the representation of the contact is closed.
• the structure of the pushbutton 1 will now be described in more detail in connection with the perspective view of FIG. 2 and the exploded view of FIG. 3.
• a pushbutton 1 which latches on the releasable locking lugs 15 and 16 and thus defines an ON and an OFF position
• the Lighting should be designed differently due to the greater distance from the light guide 13 to the diffuser 5.
• the push-button 1 consists of several elements of the operation, which are prefabricated as a unit and include as a protruding element, the pressure hood 3.
• the pressure hood 3 is already in several parts and consists of a transparent pressure hood 3 per se, under which a likewise transparent diffuser cap 5 is arranged.
• This advantageous double arrangement allows the insertion of labeling films between the pressure hood 3 and the diffuser 5 or for example a direct laser marking of the surface of the diffuser 5, which is then protected against abrasion during use by the pressure hood 3.
• the print 3 is clipped onto a guide frame 6.
• This embodiment of the connection of pressure hood 3 and diffuser 5 is basically known and could also be produced by gluing or welding.
• the guide frame 6 has a plurality of downwardly from the pressure hood 3 removing guide profiles, one of which is provided with the reference numeral 7. A corresponding profile 8 of the guide frame 6 has been designated by the reference numeral 8.
• the guide frames 7 forming a closed frame comprise an actuating wall 9 with which the contact tongue 10 of the pushbutton 1 can be switched.
• This actuating part of the switch 1 moves in particular along its main axis 43 relative to the upper part 11 of the switch and the lower part 12 of the switch.
• These actuators 3, 6, 9 are advantageously clipped into the upper part 11 of the switch, so that the said longitudinal movement between the upper part 11 and the actuators 3 and 6 of the pushbutton is possible, but these elements before assembly and after assembly in the Do not fall apart.
• the light guide 13 which is centrally inserted in the upper part 11 and the guide frame 6.
• the guide frame 6 can be hooked in via the nose 16 located in a recess in and under corresponding lugs 15 of the upper part 11.
• the light guide 13 engages with lateral grooves 14 in corresponding connection tabs of the upper part 11 a.
• corresponding recesses 28 are provided in the guide frame 6, so that the guide frame 6 via the light guide 13 and between its connection to the upper part 11 longitudinal, ie along the main axis 43 of the probe, is movable.
• the lower part 12 of the push-button 1 has four locking lugs 18.
• the locking lugs 18 are provided in the side surfaces of the lower part 12 respectively on opposite sides. In each case two are arranged near the corners.
• the locking lugs 18 extend upwards in the direction from which the upper part 11 can be placed and they can be inserted into corresponding Aufhahmeöffhungen 19 of the upper part 11 and then latched.
• the lower part 12 and the upper part 11 with inserted and independently latched operating part 3, 6, 13 are connected in a functional unit.
• the lower part 12 has an extending into the upper part 11 contact carrier 20, which may for example be integrally formed and made of the same material with this.
• the contact 23 terminates in a longitudinal edge of the extending contact strip, on which a free end of the contact tongue 10 is arranged fixed, in particular soldered.
• the other end of the contact tongue 10 with the reference numeral 40 extends on the side facing the housing outside of the contact carrier 20. It is arranged at a lateral distance from a mating contact 22 which extends in the contact carrier 20 substantially in the main plane and thus with its broad Surface of the contact tongue 10 and a spring portion 35 is arranged opposite.
• the mating contact 22 then has on the outside of the lower part 12 via a surface which is provided for contacting with the printed circuit board 2.
• the contact 23 can be connected to the printed circuit board 2 via a connection in the interior of the housing via the contact plate 24.
• the contact plate is placed behind a shoulder down and is like the corresponding contact plate 22 on the bottom 42 of the base 12, for example in a corresponding recess. In particular, these contact surfaces with the bottom 42 of the base 12 close flush.
• the illustrated course of the arrangement of the contacts is advantageous. However, it is essential at first only the integration of the SMD-capable contacts 22 and 24 on the lower part 12, wherein a part of the contact chain 24-23-20-35-22, namely the contact 35 by the operating lug 39 of the upper part 11 can be triggered.
• Figs. 2 and 4 are also positioning feet 25 shown, of which in particular the number of two can be provided at diametrically opposite corners of the bottom 42 of the base 12. These protrude then, as shown in FIG. 6, preferably in provided by component side of the pushbutton 1 blind holes 26 in the circuit board 2.
• This positioning aid is particularly useful in a manual assembly of the circuit board 2 with the bases 12, while in an automated SMD Placement these leading positioning feet 25 are not necessary and therefore can be omitted. They thus increase the applicability of the push-button 1 in several embodiments for different needs of customers.
• An illuminated SMD button 1 has the advantage that an internal cavity or opening 29 is present through the frame-shaped shape of the lower part 12, in which one, two or three LEDs 30 on the circuit board 2, in particular LED SMDs equipped can be.
• the light guide 13 is positioned with respect to the upper part 11, and thus determined via the direct connection to the lower part 12 also with respect to the printed circuit board 2 in the position that the underside 31 of the light guide 13, preferably a smooth rectangular surface 31st is arranged in the smallest possible distance of 2 to 3 mm above the upper edge of the SMD-connected LEDs 30 is arranged.
• This can be ensured with the advantageously curved, here plano-convex upper mold 32, which cooperates with the plano-concave diffuser hood 5, a good light output can be ensured.
• Manufacturing technology is important the division of the housing of the push-button 1 in a SMD-mountable lower part 12 and a the operating part 5, 6, 8 and the light guide 13 comprehensive upper part 11th
• a high-temperature plastic for the lower part 12 is suitable to withstand the temperatures occurring during an SMD soldering over the Lötvonsdauer and remain dimensionally stable. Depending on the method and soldering oven used, temperatures of 180 to 280 degrees Celsius in particular may occur over a period of 1 to 2 minutes. Heat stable means that the lower part does not change or changes only insignificantly compared to its original shape prior to soldering, ie has the same physical shape physically physically the same and advantageously also has no chemically altered properties.
• Fig. 5 shows in the partially sectioned plan view well some elements of the drawings described above, in particular the placement of the springs 17 on corresponding cylinder 33 and the three guide profiles, the laterally projecting profiles 7 and the profile groove 8, in which a nose 34 of the upper part 12 protrudes.
• the profile 7 is opposite to a complementary recess 41 in the wall of the upper part 11, which dilutes the wall thickness. It should be noted that if the upper part 11 becomes warm with respect to the guide frame 6, ie would have a significant temperature difference, this would impair the guiding properties between the sliding surfaces 7-41 and 8-34. Through the elements 7 and 8 results in a Dreitician Mountainang against the inner wall of the upper housing part 11 with a low-noise feel after assembly.
• the base of the light guide 13 occupies the essential part of the interior of the upper part 11 and thus with its opposite the lower surface 31 tapered shape covers the entire cavity 29 of the lower part 12 and thus with respect to the exact positioning of a , two or three LEDs 30 between the SMD attachment points for the push-button 1 with respect to the light pipe is insensitive.
• the cylinder 33 with a counter surface in the region of the example presenting as a collar bottom 27 between guide frame 6 and diffuser 5, as counter-pressure surfaces for compression springs 17 also tension springs can be used, which are then hooked to corresponding stops on top 12 and frame 6.
• Such a switch can be used in particular for example for a video desk use and the circuit board 2 is then back equipped without restriction with other components.
• the lower part 12 of the push-button 1 is fixed for example by means of a reflow soldering process on the circuit board 2.
• the light sources 30 are advantageously SMD LEDs 30, which are fastened centrally between the contacts 22, 24 of the push button 1.
• the lower part or contact carrier 12 is on the circuit board 2 by hand (if the lugs 25 are provided) or automatically positioned and then soldered by means of a soldering process in the heating furnace to the circuit board 2. Subsequently, after cooling, the key top 11 can be placed on the key base or contact carrier 12 and latched by means of the lugs 18 in the recesses 19.
• Another object of the present invention is to ensure the operability of the switching system over a very large number of several hundred thousand switching operations.
• the illustrated pushbutton is not a fully enclosed system, so over time contaminants may enter the housing via the top 11 and base 12 and interfere with the operation of the switching system.
• the contact spring 10 is switched by the operating wall 9 of the frame 6 and there in particular by the recognizable in Fig. 3 contact lug 39 against the mating contact 22 in a traditional manner.
• This contact tongue 10 has for a projecting in the direction of the mating contact 22 spring portion 35, while for the ⁇ Kontaktmaschine with the contact nose 39 an opposite projection 36 is provided.
• the contact tongue 10 is now executed slotted in the illustrated embodiment on the elements 35 and 36 away.
• Fig. 4 also shows that the length of the slots 37 is different.
• the slots 37 have a different length, so that only one slot 37 ends in the end region 40 of the contact tongue 10 and the other slots 37 are set back and thus form a larger solid material of the resilient contact tongue 10 at the reed tip 40.
• the number of actuation cycles can be increased by a factor of 5 to 10 before material fatigue occurs with respect to the case when all slat slots 37 are of equal length.
• the louver slots 37 extend beyond the spring-tab-forming portion 35 opposite the contact 22, but do not all pass beyond the counter-elevation 36 for operation by the tab 39.

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• Push-Button Switches (AREA)

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• 2011
  • 2011-12-02 EP EP11791283.2A patent/EP2647023A1/de not_active Withdrawn
  • 2011-12-02 US US13/990,500 patent/US20130248340A1/en not_active Abandoned
  • 2011-12-02 WO PCT/EP2011/071663 patent/WO2012072809A1/de active Application Filing
  • 2011-12-02 CN CN2011800582308A patent/CN103403828A/zh active Pending

Non-Patent Citations (1)

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