IE63468B1 - Switch keypad for the control panel of an electrical appliance - Google Patents
Switch keypad for the control panel of an electrical applianceInfo
- Publication number
- IE63468B1 IE63468B1 IE182390A IE182390A IE63468B1 IE 63468 B1 IE63468 B1 IE 63468B1 IE 182390 A IE182390 A IE 182390A IE 182390 A IE182390 A IE 182390A IE 63468 B1 IE63468 B1 IE 63468B1
- Authority
- IE
- Ireland
- Prior art keywords
- key
- switch keypad
- keypad according
- front wall
- membrane
- Prior art date
Links
- 239000012528 membrane Substances 0.000 claims abstract description 13
- 239000004033 plastic Substances 0.000 claims abstract description 7
- 229920003023 plastic Polymers 0.000 claims abstract description 7
- 229920001296 polysiloxane Polymers 0.000 claims abstract description 5
- 239000011810 insulating material Substances 0.000 claims description 3
- 229920000515 polycarbonate Polymers 0.000 claims description 3
- 239000004417 polycarbonate Substances 0.000 claims description 3
- 229920000728 polyester Polymers 0.000 claims description 3
- 238000004026 adhesive bonding Methods 0.000 claims description 2
- 239000000463 material Substances 0.000 abstract description 2
- 238000000465 moulding Methods 0.000 abstract 1
- 238000007789 sealing Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000005489 elastic deformation Effects 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
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
- H01H13/70—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
- H01H13/702—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 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H2209/00—Layers
- H01H2209/002—Materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H2215/00—Tactile feedback
- H01H2215/004—Collapsible dome or bubble
- H01H2215/006—Only mechanical function
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H2215/00—Tactile feedback
- H01H2215/034—Separate snap action
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H2223/00—Casings
- H01H2223/002—Casings sealed
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H2223/00—Casings
- H01H2223/044—Protecting cover
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H2227/00—Dimensions; Characteristics
- H01H2227/002—Layer thickness
- H01H2227/004—Membrane
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H2227/00—Dimensions; Characteristics
- H01H2227/028—Key stroke
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H2229/00—Manufacturing
- H01H2229/024—Packing between substrate and membrane
- H01H2229/026—Riveting
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H2231/00—Applications
- H01H2231/012—Household appliance
Landscapes
- Push-Button Switches (AREA)
- Input From Keyboards Or The Like (AREA)
- Keying Circuit Devices (AREA)
Abstract
A keyboard comprises keys (1), projecting from respective housings (2) formed in the front wall (3) of a control panel 1 of an electrical appliance. The keys are made by moulding in a silicone sheet (4) and each has one end (5) bearing a conducting zone (6) arranged to face two electric contacts (7) on a printed circuit plate (8), the key being mounted to be movable over a predetermined extent of travel (d). The external surface (17) of the front wall (3) is covered by a membrane (18) made of semi-rigid plastics material and comprising, facing each housing (2), a blister (19) having the shape of a spherical cap the height (h) of which is equal to or slightly greater than the predetermined extent of travel (d) of the key.
Description
Switch keypad for the control panel of an electrical appliance The invention relates to switch keypads for the control panel of an electrical appliance, comprising a plurality of keys which project slightly from respective receptacles made in the front wall of the said panel and which are moulded integrally from a sheet of elastic insulating material, such as a silicone, and each having one end carrying a conductive zone located opposite two studs carried by a board comprising a printed circuit, and one end forming a bearing zone, the said key being mounted movably in an orthogonal direction relative to the said board and according to a specific stroke by means of a frustoconical skirt, the small base of which is connected to the central region of the key and the large base of which is attached to the insulating sheet.
The object of the invention is to improve not only the sealing of these keypads, but also their electrical functioning, whilst at the same time giving the user the feeling by touch that the switch key has been actuated correctly, this being especially useful when the keypad is intended for controlling the various functions of a microwave oven for domestic use.
According to the invention, the outer face of the front wall of the panel is covered with a membrane made of a semi-rigid plastic and opposite each receptacle of a key possesses a blister having the form of a spherical dome, the convexity of which faces outwards and the height of which is equal to or slightly greater than the specific stroke of the key.
This provision of the membrane affords not only a sealing protection of the electrical parts of the control panel, but also a key actuation flexibility which is very attractive to the user and which, by means of the blisters, makes it possible to obtain a typical quickacting effect in terms of electrical contact.
According to another characteristic of the invention, the semi-rigid plastic of the membrane is a polycarbonate and polyester copolymer.
This type of material provides blisters, the elastic characteristics of which remain reliable in the long term, and direct screen printing of an indelible nature can also be carried out on the said blisters.
Moreover, the characteristics and advantages of the invention will emerge from the following description given by way of example, with reference to the accompanying drawing in which: Figure 1 is a partial view, in vertical section and on a large scale, of a switch keypad for a control panel, more particularly illustrating a switch-forming key according to the invention. This switch keypad for a control panel is intended for equipping an electrical appliance, such as, for example, a microwave oven, and for this purpose comprises a plurality of identical keys 1 which project slightly from respective receptacles 2 made in the front wall 3 of the control panel and which are moulded integrally from a sheet 4 of elastic insulating material, such as, for example, silicone.
As shown in Figure 1, each key 1 has one end 5 carrying a conductive zone 6 made of conductive material, for example a carbon-reinforced silicone, and located opposite two studs 7 carried by a board 8 comprising a printed circuit 9, and one end 10 forming a bearing zone, the said key 1 being mounted movably in an orthogonal direction relative to the said board 8 and according to a specific stroke d by means of a frustoconical skirt 11, the small base 12 of which is connected to the central region of the key 1 and the large base 13 of which is attached to the insulating sheet 4.
The board 8 and the sheet 4 are joined to the front wall 3 by means of rivets 14 which are integral with the said front wall 3 and which pass through the said sheet and the said board and are intended for gripping the board 8 and the sheet 4 between the end of ribs 15, likewise integral with the front wall 3, and the heads 16 of the rivets 14.
According to the invention, the outer face 17 of the front wall 3 is covered with a membrane 18 made of a semi-rigid plastic consisting of a polycarbonate and polyester copolymer and known by the trade name of Bayfol (registered trademark of Messrs. BAYER AG), the said membrane possessing, opposite each receptacle 2 of k a key 1, a blister 19 having the form of a spherical dome, the convexity of which faces outwards and of which the height h, taken on the vertical straight line A-A passing through its vertex region, is equal to or slightly greater than the specific stroke d of the key 1.
In the preferred embodiment, the ideal stroke is equal to 0.7 mm and the plastic, designated by BAYER as BAYFOL K L 3-1010, has a thickness of approximately 175 μ and on its outer face and even on the blisters receives a screen print illustrating the various functions of the keys 1.
Furthermore, to allow the blistering to function perfectly in the long term without permanent deformation, it has been found that the ratio of the height h of the dome to its polar base circle base p must be between 0.06 and 0.07. This ratio must be considered important because the Bayfol membrane has virtually no extensibility and the stroke of the key has to be relatively large to prevent inopportune contacts under slight touch pressure on this membrane.
To guarantee the sealing of the control panel and the strict retention of the membrane in place on the front wall 3, whilst at the same time improving the flexibility of the blistering, this membrane is glued to the outer face 17 of the front wall 3 by means of a layer of glue 20 of a thickness of, for example, 250 μ, the gluing zone stopping round each blister 19 at a specific distance x from the corresponding polar base circle p. This distance x is virtually equal to or smaller than one eighth of the diameter of the said polar base circle p.
Moreover, to ensure the linear guidance of the vertex region of the dome under touch pressure along the axis A-A. the receptacle 2 of each key has an orifice with a widened edge 21. To avoid permanent blistering, this widened edge 21 must have a slope a less than 9‘ and preferably equal to 8’ (eight degrees).
On the other hand, to assist the onset of the 5 blistering and the depression of the key 1, the bearing zone 10 of each key 1 has the form of an arch, so as to be in point contact with the concave region of the vertex 19' of the spherical dome.
The switch keypad functions as follows: when touch pressure is exerted on the vertex 19' of a blister 19, this gives rise firstly to a slight depression of the edge 22 located opposite the non-glued zone and then to the depression of the said vertex 19' which bears at a point on the vertex of the arch 10 of the key 1 and which transmits the touch pressure to the said key virtually linearly, and secondly to the sudden blistering of the blister 19, until the concave face buts against the widened edge 21 of the orifice 19.
This abrupt movement amplifies the touch pressure and, in a way known per se, causes the elastic deformation of the skirt 11 and the abrupt depression of the key 1, thereby ensuring the instantaneous abrupt closing of the contact by the laying of the conductive zone 6 onto the two studs 7, and thus preventing an electric arc from being generated.
When the touch pressure on the blister 19 is released, because of the widened edge 21 of the orifice 19 limited to 8 degrees, the blistering is not permanent and the blister resumes its initial convex form, thereby freeing the key 1 which, under the effect of the opposite deformation of the skirt 11, returns to its opening position illustrated in Figure 1.
Claims (8)
1. Switch keypad for the control panel of an electrical appliance, comprising a plurality of keys (1) which project slightly from respective receptacles (
2. ) 5 made in the front wall (3) of the said panel and which are moulded integrally from a sheet (4) of elastic insulating material, such as a silicone, and each having one end (5) carrying a conductive zone (6) located opposite two studs (7) carried by a board (8) comprising 10 a printed circuit (9) and one end (10) forming a bearing zone, the said key (1) being mounted movably in an orthogonal direction relative to the said board (8) and according to a specific stroke (d) by means of a frustoconical skirt (11), the small base (12) of which is 15 connected to the central region of the key and the large base (13) of which is attached to the insulating sheet (4), characterized in that the outer face (17) of the front wall (3) of the panel is covered with a membrane (18) 20 made of a semi-rigid plastic and opposite each receptacle (2) of a key (1) possesses a blister (19) having the form of a spherical dome, the convexity of which faces outwards and the height (h) of which is equal to or slightly greater than the specific stroke (d) of the key (1). 25 2. Switch keypad according to Claim 1, characterized in that the semi-rigid plastic of the membrane (18) is a polycarbonate and polyester copolymer of the Bayfol type.
3. Switch keypad according to Claim 1 or 2, characterized in that the ratio of the height (h) of the dome (19) to its polar base circle (p) is between 0.06 and 0.07.
4. . Switch keypad according to any one of the preceding claims, characterized in that the bearing zone (10) of each key (1) has the form of an arch, so as to be in point contact with the concave region of the vertex (19') of the spherical dome (19).
5. Switch keypad according to any one of the preceding claims, characterized in that the membrane (18) is glued to the outer face (17) of the front wall (3) of the panel, the gluing zone (20) stopping round each blister (19) at a specific distance (x) from the corresponding polar base circle (p), this distance (x) being virtually equal to or smaller than one eighth of the length of the diameter of the said polar base circle.
6. Switch keypad according to any one of the preceding claims, characterized in that the receptacle (2) of each key (1) has an orifice with a widened edge (21).
7. Switch keypad according to Claim 6, characterized in that the widened edge (21) has a slope * (a) of less than nine degrees and preferably equal to eight degrees . -9
8. A switch keypad according to any preceding claim substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings .
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8906743A FR2647588B1 (en) | 1989-05-23 | 1989-05-23 | SWITCHING KEYBOARD FOR CONTROL PANEL OF AN ELECTRICAL APPARATUS |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| IE901823L IE901823L (en) | 1990-11-23 |
| IE63468B1 true IE63468B1 (en) | 1995-04-19 |
Family
ID=9381928
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| IE182390A IE63468B1 (en) | 1989-05-23 | 1990-05-21 | Switch keypad for the control panel of an electrical appliance |
Country Status (8)
| Country | Link |
|---|---|
| DE (1) | DE4016122A1 (en) |
| ES (1) | ES2023317A6 (en) |
| FR (1) | FR2647588B1 (en) |
| GB (1) | GB2234115B (en) |
| IE (1) | IE63468B1 (en) |
| IT (1) | IT1248805B (en) |
| NL (1) | NL9001194A (en) |
| SE (1) | SE500280C2 (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2233841B (en) * | 1989-06-28 | 1994-02-02 | Lutron Electronics Co | Touch-operated power control |
| GB9021188D0 (en) * | 1990-09-28 | 1990-11-14 | Telektron Ltd | Membranes keyboard for pressurisation protection systems |
| FR2669462B1 (en) * | 1990-11-16 | 1994-04-01 | Syrelec | SWITCH STRUCTURE FOR USE IN THE PRODUCTION OF KEYBOARDS, AND KEYBOARDS USING SUCH A STRUCTURE. |
| ES2042373B1 (en) * | 1991-06-21 | 1995-01-01 | Toho Polymer Europ S A | ACTUATING ELEMENT OF AN ELECTRICAL CONTACT, IN SPECIAL KEY OR SIMILAR, AND PROCEDURE FOR THE MANUFACTURE OF SUCH ELEMENT. |
| DE9412474U1 (en) * | 1994-08-03 | 1994-12-08 | AutoAir Klimaanlagen GmbH, 47574 Goch | Air conditioning switch unit |
| US5729221A (en) * | 1996-04-01 | 1998-03-17 | Motorola, Inc. | Keypad configuration |
| DE19653322C2 (en) * | 1996-12-20 | 1999-02-18 | Hahn Schickard Ges | Micromechanical switch |
| AU2001244340A1 (en) * | 2000-03-30 | 2001-10-15 | Electrotextiles Company Limited | Input device |
| DE10225920A1 (en) * | 2002-06-11 | 2003-11-06 | Siemens Ag | Keyboard for equipment, has input keys integrated into a totally enclosing protective foil with each key actuating electrical contacts |
| DE20212254U1 (en) | 2002-08-08 | 2002-12-19 | TRW Automotive Electronics & Components GmbH & Co. KG, 78315 Radolfzell | The multifunctional pushbutton switch |
| DE20212255U1 (en) | 2002-08-08 | 2002-12-19 | TRW Automotive Electronics & Components GmbH & Co. KG, 78315 Radolfzell | The multifunctional pushbutton switch |
| DE10238864B4 (en) * | 2002-08-24 | 2006-10-19 | Tripus Gmbh Kunststoff- Und Elektrotechnik | Device for switching on and off an electrical device |
| GB2396253A (en) * | 2002-12-13 | 2004-06-16 | Itt Mfg Enterprises Inc | Sealed switch |
| DE10306682A1 (en) | 2003-02-13 | 2004-08-26 | C. & E. Fein Gmbh | Electric tool with motor and switch element that is provided within signaling circuit and that is coupled to load circuit via power switch element |
| DE112004000492B4 (en) * | 2003-04-03 | 2008-11-06 | Danfoss Drives A/S | Cover for a key switch |
| CN1326170C (en) * | 2003-04-25 | 2007-07-11 | 乐金电子(天津)电器有限公司 | Button set of controller in microwave oven |
| DE102004034554A1 (en) * | 2004-07-17 | 2006-02-16 | Diehl Ako Stiftung & Co. Kg | Pushbutton switch e.g. for time switch of cooking stove, has push-rod which causes dome surface to makes contact with switch contact, and has film head |
| CN102306577B (en) * | 2011-07-18 | 2015-04-08 | 惠州Tcl移动通信有限公司 | Mobile communication terminal and key panel |
| FR3003080B1 (en) | 2013-03-08 | 2015-03-13 | Seb Sa | CONTROL PANEL OF HOUSEHOLD APPLIANCE AND METHOD FOR MANUFACTURING SUCH CONTROL PANEL |
| US9307816B2 (en) * | 2013-09-04 | 2016-04-12 | Apple Inc. | Accessory covers for mobile phones or other consumer electronic devices |
| CA2960223C (en) | 2014-09-10 | 2023-04-04 | Becton, Dickinson And Company | Activation system and method for on-body medical devices |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3978297A (en) * | 1975-03-31 | 1976-08-31 | Chomerics, Inc. | Keyboard switch assembly with improved pushbutton and associated double snap acting actuator/contactor structure |
| FR2523365B1 (en) * | 1982-03-11 | 1988-05-13 | Mektron France Sa | MONOLITHIC AND FLAT TOUCH KEYBOARD |
| FR2539247B1 (en) * | 1983-01-07 | 1986-11-07 | F M Atelier Meca Precision | ADAPTABLE KEY MARKING KEYBOARD |
| DE3481670D1 (en) * | 1983-04-20 | 1990-04-19 | Bebie & Co | KEYBOARD ARRANGEMENT. |
| DE8406665U1 (en) * | 1984-03-03 | 1986-09-18 | Debeg GmbH, 2000 Hamburg | Device input keyboard with mechanically operable, tactile actuation elements |
| FR2576450A1 (en) * | 1985-01-22 | 1986-07-25 | Hutchinson | Keyboard with integral control elements which are selfcentred with respect to the front face |
-
1989
- 1989-05-23 FR FR8906743A patent/FR2647588B1/en not_active Expired - Fee Related
-
1990
- 1990-05-11 SE SE9001717A patent/SE500280C2/en not_active IP Right Cessation
- 1990-05-16 GB GB9010972A patent/GB2234115B/en not_active Expired - Fee Related
- 1990-05-18 DE DE4016122A patent/DE4016122A1/en not_active Withdrawn
- 1990-05-21 IE IE182390A patent/IE63468B1/en not_active IP Right Cessation
- 1990-05-22 ES ES9001415A patent/ES2023317A6/en not_active Expired - Lifetime
- 1990-05-23 IT IT02040490A patent/IT1248805B/en active IP Right Grant
- 1990-05-23 NL NL9001194A patent/NL9001194A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| GB2234115B (en) | 1993-08-18 |
| IE901823L (en) | 1990-11-23 |
| IT9020404A1 (en) | 1991-11-23 |
| GB9010972D0 (en) | 1990-07-04 |
| GB2234115A (en) | 1991-01-23 |
| ES2023317A6 (en) | 1992-01-01 |
| SE9001717L (en) | 1990-11-24 |
| NL9001194A (en) | 1990-12-17 |
| FR2647588B1 (en) | 1996-07-19 |
| IT9020404A0 (en) | 1990-05-23 |
| FR2647588A1 (en) | 1990-11-30 |
| IT1248805B (en) | 1995-01-30 |
| SE500280C2 (en) | 1994-05-24 |
| SE9001717D0 (en) | 1990-05-11 |
| DE4016122A1 (en) | 1990-11-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MM4A | Patent lapsed |