Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H3/00—Mechanisms for operating contacts
  • H01H3/02—Operating parts, i.e. for operating driving mechanism by a mechanical force external to the switch
  • H01H3/14—Operating parts, i.e. for operating driving mechanism by a mechanical force external to the switch adapted for operation by a part of the human body other than the hand, e.g. by foot
  • H01H3/141—Cushion or mat switches

Definitions

• the invention relates to a pressure-sensitive switch, comprising: an edge structure extending in a substantially closed contour; a first carrier which is connected on its edges to the edge structure and which is electrically conductive on its side connected to the edge structure; a second carrier which is connected on its edges to the edge structure and which extends substantially parallel to the first carrier and is electrically conductive on its side connected to the structure; and connecting means for connecting the external connections to the first and the second carrier.
• the carriers are formed by relatively thick plates which are provided in their centre with an inward directed dimple. When pressure is exerted on the plates they will bend and move towards each other in the centre so that the dimples can make mutual electrical contact. It is possible to adjust the sensitivity of the switch by modifying the form and depth of the dimples .
• the object of the present invention is to provide such a device which is suitable for miniaturization and which responds when a force is exerted at any random location on its surface. This objective is achieved in that the distance between the carriers in their neutral position is substantially the same over the whole surface.
• the switch Owing to this uniform spacing between the carriers the switch is identical over its whole active surface, so that no local aberrations such as dimples have to be made.
• the switch can hereby be miniaturized more easily. This uniformity also ensures that the sensitivity of the switch is the same over its whole surface.
• the carriers are preferably manufactured from foil, and spacers are placed between the carriers inside the edge structure, which spacers are fixed to each of the carriers .
• the use of spacers makes the use of a flexible carrier possible.
• the switch can hereby also be made sensitive for a locally applied pressure.
• the spacers are evenly distributed over the surface inside the structure.
• the spacers are distributed in a pattern with varying density over the surface inside the structure.
• the sensitivity can hereby be made location-dependent .
• figure 1 shows a cross-sectional view of a first embodiment of the invention
• figure 2 is a partly broken-away view of the embodiment shown in figure 1
• figure 3 shows a cross-sectional view of a second embodiment of the invention.
• Figure 1 shows a cross-section of a switch according to the invention designated in its entirety with 1.
• the switch comprises an edge structure 2 which extends all-around and which is provided on both sides with an adhesive layer 3.
• Edge structure 2 is formed by cutting out from a plastic foil.
• edge structure 2 Adhered to edge structure 2 is a foil 4 which is formed by a layer of plastic 5 and a layer of metal 12, for instance aluminium. Metal layer 12 is herein directed toward the interior of switch 1. Such a foil 4 is also adhered to the other side of edge structure or peripheral structure 2, wherein metal layer 12 faces toward the interior of switch 1.
• spacers 6 are placed on the innermost foil 4. These spacers are preferably formed by plastic s globules applied to foil 4 by means of screen-printing. Owing to the screen-printing process they take the form of a bell in cross-section.
• the dimensions of the switch can vary very widely; the switch is intended in o the first instance for small design. Envisaged here are dimensions of the foils of several square centimetres and a thickness of less than 1 millimetre. In this anticipated configuration the distance between the foils is 0.08 mm. The mutual distance between the spacers s amounts to 2.3 mm. The spacers are herein ordered in a square grid. Such a switch is suitable for switching at a pressure force of 0.75 N.
• a switch according to the invention with other dimensions .
• the o distance between the foils can be reduced to 0.05 or even to 0.03 mm. It is advisable here to adapt the other dimensions of the switches accordingly, and thus apply for instance a proportionally thinner foil .
• the flexibility o foils 4 and of edge structure 2 makes it possible to bend switch 1 without exerting a significant influence on the sensitivity thereof. It is s important herein that spacers 6 are fixed to only one of the two foils 4.
• the adhesion between foils 4 and edge structure 2 is also important here. This is because adhesive layer 3 must allow a displacement between the foils during bending.
• the two foils 4 are provided with an extension 8 which is suitable for connection to a wire or conductive track on a printed circuit board by means of a connector or a soldered joint.
• the edge structure 2 is also provided with an extension 9 which extends between the extensions of the foils.
• the extensions preferably have an unequal length so as to prevent coincidence of the thickened portions caused by a connector or soldered joint.
• the operation of the switch is such that the foils 4 are normally separated from each other by edge structure 2, spacers 6 and the layer of air between foils 4.
• edge structure 2 spacers 6
• FIG. 2 shows the same embodiment, wherein the structure is shown more clearly.
• figure 3 shows a cross-sectional view of such a switch wherein use is made of a different type of spacer. Use is made in this embodiment of a single spacer 10 which is provided with holes 11 distributed uniformly over the surface.
• foils 4 When a force is exerted on foils 4, the foils will be moved toward each other and make mutual contact so that the switch is closed.
• the flexibility of the foil In this configuration the resilience of the spacer will be necessary to enable the foils to move toward each other, unless the holes 11 are relatively large.

Landscapes

• Push-Button Switches (AREA)
• Switches Operated By Changes In Physical Conditions (AREA)
• Measuring Fluid Pressure (AREA)
• Secondary Cells (AREA)
• Electrophonic Musical Instruments (AREA)
• Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19771635

Family Applications (1)

Country Status (11)

Cited By (2)

Families Citing this family (10)

Citations (5)

Family Cites Families (6)

• 2001
  • 2001-07-02 EP EP01950096A patent/EP1295305B1/en not_active Expired - Lifetime
  • 2001-07-02 DK DK01950096T patent/DK1295305T3/da active
  • 2001-07-02 CN CN01812165.9A patent/CN1258788C/zh not_active Expired - Fee Related
  • 2001-07-02 AT AT01950096T patent/ATE283544T1/de not_active IP Right Cessation
  • 2001-07-02 US US10/312,735 patent/US6774331B1/en not_active Expired - Fee Related
  • 2001-07-02 JP JP2002505638A patent/JP2004502273A/ja active Pending
  • 2001-07-02 WO PCT/NL2001/000497 patent/WO2002001586A1/en not_active Ceased
  • 2001-07-02 AU AU2001271127A patent/AU2001271127A1/en not_active Abandoned
  • 2001-07-02 DE DE60107427T patent/DE60107427T2/de not_active Expired - Fee Related
  • 2001-07-02 ES ES01950096T patent/ES2232641T3/es not_active Expired - Lifetime
  • 2001-07-02 PT PT01950096T patent/PT1295305E/pt unknown

Patent Citations (5)

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