Abstract:
There is provided a switch having a flexible upper member, that is substantially electrically non-conductive, having an inner surface with an upper contact area that is electrically conductive and connected to a circuit, and a lower member that is substantially electrically non-conductive, having an inner surface with a lower contact area that is electrically conductive and connected to the circuit, wherein the upper member and the lower member are sealingly connected to form a chamber therebetween, the upper contact area and the lower contact area are separated by at least a portion of the chamber and a force applied to the upper member causes the upper contact area and the lower contact area to make contact and close the switch of the circuit.

Description:
ELECTRICAL SWITCH 
     1. Field of the Invention 
     The present invention relates to electrical switches. More particularly, the present invention relates to a flexible, air-cushioned electrical switch. 
     2. Description of the Prior Art 
     The use of electrical switches for completing a circuit is known. Such switches include substantially rigid mechanical devices that selectively connect electrically conductive areas to complete the circuit. Also, conductive fibers in various sewn or woven fabrics used as conductive traces, bio-sensors, electrodes, and other wearable electronic devices is known. These wearable electronic devices typically require switches to operate. A drawback of contemporary switches is the rigidity of the device that is connected to the flexible wearable electronic device. This rigidity limits comfort for the wearer of the wearable electronic device and further increases the likelihood of damage to the device as a result of being worn. Thus, there is a need for a flexible electric switch without the above noted drawbacks. The preferred embodiments of the present invention fulfill this need. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an improved electrical switch. 
     It is another object of the present invention to provide such a switch with flexibility. 
     It is yet another object of the present invention to provide such a switch adapted for use with various wearable electronic devices and/or sensors. 
     It is a further object of the present invention to provide such a switch that enhances comfort. 
     It is still a further object of the present invention to provide such a switch that reduces the likelihood of damage. 
     These and other objects and advantages of the present invention are achieved by a switch comprising a flexible upper member, that is substantially electrically non-conductive, having an inner surface with an upper contact area that is electrically conductive and connected to a circuit, and a lower member that is substantially electrically non-conductive, having an inner surface with a lower contact area that is electrically conductive and connected to a circuit. The upper member and the lower member are sealingly connected to form a chamber therebetween, the upper contact area and the lower contact area are separated by at least a portion of the chamber and a force applied to the upper member causes the upper contact area and the lower contact area to make contact and close the switch of the circuit. The chamber of the switch can contain a fluid to separate the upper member and the lower member and the fluid can be air. Preferably, the lower member is flexible and the upper member has a dome-like shape. The upper contact area and the lower contact area can be aligned across the chamber. Preferably, the upper contact area is generally centrally located along the inner surface of the upper member and the lower contact area is generally centrally located along the inner surface of the lower member. The upper contact area can be partially embedded in the inner surface of the upper member and the lower contact area can be partially embedded in the inner surface of the lower member. The upper member and the lower member can be integrally formed. The upper contact area can be a plurality of upper contact areas, the lower contact area can be a plurality of lower contact areas and each of the plurality of upper contact areas can be aligned with one of the plurality of lower contact areas. 
     The present invention can also be an array of electrical switches comprising a flexible upper member that is substantially electrically non-conductive, separated into two or more portions, that each have an inner surface with an upper contact area that is electrically conductive and connected to a circuit and a lower member that is substantially electrically non-conductive, having an inner surface with a corresponding lower contact area for each of the upper contact areas, and is electrically conductive and connected to the circuit. Each of the two or more portions and the lower member are sealingly connected to form chambers therebetween. Each of the chambers is in fluid communication with at least one of the other of the chambers and each of the chambers contains a fluid that separates the two or more portions from the lower member. The upper contact areas and the lower contact areas are separated by at least a portion of the chambers and a force applied to one of the chambers causes the fluid to flow from the one of the chambers to at least one of the other of the chambers allowing the upper contact area of the one of the chambers and the corresponding lower contact area to make contact and close the switch of the circuit. Each of the chambers can be in fluid communication with at least one of the other of the chambers by a channel. Preferably, the fluid is air. More preferably, the lower member is flexible. Each of the two or more portions can have a dome-like shape. Preferably, the upper contact areas and the corresponding lower contact areas are aligned across the chambers. More preferably, the upper contact areas are centrally located along the inner surface of the two or more portions and the corresponding lower contact areas are centrally located along the inner surface of the lower member. Each of the upper contact areas can be partially embedded in the inner surface of the two or more portions and the lower contact areas can be partially embedded in the inner surface of the lower member. The two or more portions and the lower member can be integrally formed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is more fully understood by reference to the following detailed description of a preferred embodiment in combination with the drawings identified below. 
     FIG. 1 is a top plan view of a switch in accordance with the present invention; 
     FIG. 2 is a cross-sectional plan view of the switch taken along line  2 — 2  of FIG. 1; 
     FIG. 3 is a cross-sectional plan view of the switch being depressed, taken along line  2 — 2  of FIG. 1; 
     FIG. 4 is a top plan view of an alternative embodiment of a switch in accordance with the present invention; 
     FIG. 5 is a cross-sectional plan view of the switch taken along line  5 — 5  of FIG. 4; and 
     FIG. 6 is a cross-sectional plan view of the switch being depressed, taken along line  5 — 5  of FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings and, in particular, FIG. 1, there is shown an improved switch in accordance with the present invention generally represented by reference numeral  10 . Switch  10  is a single switch having a substantially rectangular shape. However, alternative shapes for switch  10  can also be used including circular or square. 
     Referring to FIGS. 1 and 2, switch  10  has an upper layer  100  and a lower layer  200 . Upper and lower layers  100 ,  200  are made of a soft, flexible material such as silicone. The flexibility of layers  100 ,  200  protect against damage when switch  10  is used with wearable electronics. Moreover, the flexibility of layers  100 ,  200  provide comfort to the wearer when switch  10  is used with wearable electronics. Preferably, upper and lower layers  100 ,  200  are made of a material that is air-tight. More preferably, upper and lower layers  100 ,  200  are made of a material with elasticity. Upper and lower layers  100 ,  200  are substantially electrically non-conductive. Preferably, upper layer  100  has a convex, dome-like shape. Upper layer  100  has an outer surface  125  for providing comfort to the wearer when switch  10  is used with wearable electronics and an inner surface  130 . Lower layer  200  has an inner surface  220  and an outer surface  225  for providing comfort to the wearer when switch  10  is used with wearable electronics. 
     Referring to FIG. 2, upper layer  100  is sealingly connected to lower layer  200 . Alternatively, upper layer  100  and lower layer  200  can be integrally formed. Additionally, while this embodiment has two layers  100 ,  200  that are sealingly connected, switch  10  can have more than two layers that are sealingly connected. In this embodiment, upper layer  100  and lower layer  200  are sealingly connected directly to each other, however alternative embodiments can include an indirect sealing engagement such as a material disposed between the layers. 
     The sealing connection of upper layer  100  with lower layer  200  forms first chamber  320 . In this embodiment, chamber  320  is filled with air. The air separates upper and lower layers  100 ,  200  when switch  10  is not being depressed. Alternatively, other non-conductive fluids or combinations of fluids may fill chamber  320 . Chamber  320  has an upper contact  420  connected to upper layer  100  and a lower contact  430  connected to lower layer  200 . Upper contact  420  and lower contact  430  are areas of electrical conductivity which, when in contact with each other, allow the flow of electricity therethrough. Upper contact  420  and lower contact  430  are each connected to, and part of, a circuit (not shown) which requires selective opening and closing of the switch, i.e., the contact areas. Outer surface  225  of lower layer  200  can be secured to wearable electronics by various means including adhesive and being sewn. 
     Preferably, upper contact  420  is centrally located along upper layer  100  and adjacent to inner surface  130 . Similarly, lower contact  430  is preferably centrally located along lower layer  200  and adjacent to inner surface  220 . Preferably, upper contact  420  and lower contact  430  are aligned on opposing sides of chamber  320 . Upper and lower contacts  420 ,  430  can be secured to upper and lower layers  100 ,  200  by various means including adhesive or partially embedding the contacts in the layers so as to leave an area exposed for flow of electricity therethrough. 
     Referring to FIG. 3, switch  10  is shown after being depressed by finger  50 . The depression of upper layer  100  causes upper contact  420  to be brought into contact with lower contact  430 . The contact of upper contact  420  and lower contact  430  closes switch  10 . The flexibility of upper layer  100  allows the air that was disposed generally in the space or volume between upper and lower contacts  420 ,  430  to move radially outward, outside of that space. Outer and inner surfaces  125 ,  130  of upper layer  100  are stretched outwardly as a result of the displaced air from the space between upper and lower contacts  420 ,  430 . Broken lines  125 ′,  130 ′ show outer and inner surfaces  125 ,  130  when not being outwardly stretched as a result of the displaced air from the space between upper and lower contacts  420 ,  430 . 
     Referring to FIG. 4, there is shown an improved switch in accordance with an alternative embodiment of the present invention, generally represented by reference numeral  20 . Switch  20  is an array of switches, as will be discussed later in detail, that have a substantially rectangular shape. However, alternative shapes for switch  20  can also be used including circular or square. Features common to both the embodiments of switch  10  and switch  20  are denoted with the same reference numbers. 
     Referring to FIGS. 4 and 5, switch  20  has an upper layer  100  and a lower layer  200 . Upper and lower layers  100 ,  200  are made of a soft, flexible material such as silicone. Additionally, upper and lower layers  100 ,  200  are impermeable or air-tight and are substantially electrically non-conductive. Preferably, upper and lower layers  100 ,  200  are made of a material with elasticity. Preferably, upper layer  100  has convex, dome-like portions  120 ,  140 ,  160 . Portions  120 ,  140 ,  160  have outer surfaces  125 ,  145 ,  165  and inner surfaces  130 ,  150 ,  170 , respectively. In this embodiment, three portions  120 ,  140 ,  160  are shown. The number of portions preferably corresponds to the number of switches contained in switch  20 . The dome-like shape of portions  120 ,  140 ,  160  assists a user in distinguishing between the different switches of the array. However, alternative shapes for portions  120 ,  140 ,  160  can also be used including flat or concave shapes. Also, while this embodiment provides for a plurality of portions each with a switch disposed therein, alternatively, switch  20  can have a single portion having a plurality of switches disposed therein, or any combination of portions and switches. 
     Referring to FIG. 5, portions  120 , 140 , 160  of upper layer  100  are sealingly connected to lower layer  200 . Alternatively, upper and lower layers  100 ,  200  can be integrally formed. Additionally, while this embodiment has two layers  100 ,  200  that are sealingly connected, switch  20  can have more than two layers that are sealingly connected and can have an indirect sealing connection of layers  100 ,  200 . 
     The sealing connection of portions  120 ,  140 , 160  of upper layer  100  with lower layer  200  forms first chamber  320 , second chamber  340  and third chamber  360 . In this embodiment, chambers  320 ,  340 ,  360  are filled with air. The air separates upper and lower layers  100 ,  200  when switch  20  is not being depressed. Alternatively, other non-conductive fluids or combination of fluids may be placed in chambers  320 ,  340 ,  360 . The embodiment shown has three chambers  320 ,  340 ,  360  that form a linear array of three switches. However, any number of switches and any number of chambers can be used including a single chamber having a plurality of switches, i.e., electrical contact areas. While switch  20  shows a linear array of switches, chambers  320 ,  340 ,  360  can be positioned in any configuration. Thus, as described above, switch  20  is not limited to any particular shape but, by way of example, is shown in a rectangular shape. Lower layer  200  of chambers  320 ,  340 ,  360  have inner surfaces  220 ,  240 ,  260  and outer layers  225 ,  245 ,  265 , respectively. 
     Chambers  320 ,  340 ,  360  have upper contacts  420 ,  440 ,  460  connected to upper layer  100  and lower contacts  430 ,  450 ,  470  connected to lower layer  200 . Upper contacts  420 ,  440 ,  460  and lower contacts  430 ,  450 ,  470  are areas of electrical conductivity which, when in contact, allow the flow of electricity therethrough. Upper contacts  420 ,  440 ,  460  and lower contacts  430 ,  450 ,  470  are each connected to, and part of, a circuit (not shown) which requires selective opening and closing of the respective switches, i.e., contact areas. 
     Preferably, upper contacts  420 ,  440 ,  460  are centrally located along inner surfaces  130 ,  150 ,  170 , respectively. Similarly, lower contacts  430 ,  450 ,  470  are preferably centrally located along inner surfaces  220 ,  240 ,  260 , respectively. Preferably, upper contacts  420 ,  440 ,  460  and lower contacts  430 ,  450 ,  470  are aligned on opposing sides of chambers  320 ,  340 ,  360 , respectively. Upper contacts  420 ,  440 ,  460  and lower contacts  430 ,  450 ,  470  can be secured to layers  100 ,  200  by various means including adhesive or partially embedding the contacts in the layers so as to leave an area exposed for flow of electricity therethrough. 
     Switch  20  further comprises channels  500 ,  550 . Channel  500  is formed in upper layer  100  and provides for fluid communication between chamber  320  and chamber  340 . Preferably, channel  500  is formed adjacent to lower layer  200 . More preferably, channel  500  is centrally located adjacent to lower layer  200  between chamber  320  and chamber  340 . Channel  550  is formed in upper layer  100  and provides for fluid communication between chamber  340  and chamber  360 . Preferably, channel  550  is formed adjacent to lower layer  200 . More preferably, channel  550  is centrally located adjacent to lower layer  200  between chamber  340  and chamber  360 . In this embodiment, individual channels  500 ,  550  provide fluid communication between chambers  320 ,  340  and chambers  340 ,  360 , respectively. Alternatively, a plurality of channels can be formed between chambers  320 ,  340  and chambers  340 ,  360  for fluid communication therebetween. Also, while fluid communication between portions  120 ,  140 ,  160  is provided by channels  500 ,  550  in this embodiment, the switches can have alternative means for fluid communication such as a single portion with a plurality of switches disposed therein. Additionally, while channels  500 ,  550  are centrally located adjacent to lower layer  200 , the channels can also be located remote from the lower layer and do not require placement in a central position. 
     Referring to FIG. 6, switch  20  is shown after being depressed by finger  50 . The depression of upper layer  100  causes upper contact  420  to be brought into contact with lower contact  430 . The contact of upper contact  420  and lower contact  430  closes switch  20 . The air that was disposed within first chamber  320  generally in the space between upper contact  420  and lower contact  430  moves through channels  500 ,  550  into second chamber  340  and third chamber  360 . The displaced air that moves into second chamber  340  and third chamber  360  causes the chambers to expand. Upper layer  100  of portions  140 ,  160  is stretched upwardly as a result of the displaced air from first chamber  320 . Broken lines  150 ′,  170 ′ show inner surfaces  150 ,  170  of upper layer  100  when not being upwardly stretched as a result of the displaced air from first chamber  320 . Due to the air-tight seal and the elasticity of upper layer  100 , after finger  50  is released from portion  120 , the displaced air flows back into first chamber  320 , and outer and inner surfaces  125 ,  130  return to their unbiased positions represented by broken lines  125 ″,  130 ″, respectively. This causes upper contact  420  and lower contact  430  to separate and switch  20  is opened. 
     The present invention having been thus described with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the present invention as defined in the appended claims.