1. Field of the Invention
The present invention relates to an elastic sheet and a switch using the elastic sheet, and particularly to an elastic sheet and a switch using the elastic sheet applied in consumer electronic applications.
2. Description of the Prior Art
A conventional elastic sheet and a switch using the sheet are disclosed in
A switch using the elastic sheet 5′ comprise the elastic sheet 5′ and a circuit board 6′. In assembling, the separator sheet 40′ is peeled from the bottom surface of the second sheet 30′. The elastic sheet 5′ is attached to the circuit board 6′ by an adhesive on the bottom surface of the second sheet 30′. The circuit board 6′ defines a plurality of outer fixed contacts 61′ and a central fixed contacts 62′, wherein the outer fixed contacts 61′ are defined on outside of the circuit and the central fixed contacts are defined on inside of the circuit. Each fringe portion of the moveable contact abuts against the first fixed contact and the center portion of the moveable contact is separated with the second fixed contact. Referring to
However, the drawback of said elastic sheet 5′ lies in: when the first sheet 10′ and the second sheet 30′ are bent toward the second sheet 30′, since the first sheet 10′ is disposed on the second sheet 30′ the metal film 11′ plated on the first sheet 10′ generates a deformation, which is prone to be torn apart. If the metal film 11′ is torn apart, the static conducting test can not be attained or the heat produced during the static test makes the metal film 11′ split
Hence, an improved elastic sheet and a switch using the elastic sheet are required to overcome the disadvantages of the prior art.
An object of the present invention is to provide an elastic sheet and a switch using the elastic sheet able to prevent a metal film breaking, which can ensure the sheet to pass the better static conducting test.
An elastic sheet in according with the present invention comprises a first sheet defining a metal film on an upper surface, an adhesive on a lower surface thereof, a plurality of moveable contacts attached on the lower surface of the first sheet, a second sheet mounted on the lower surface of the first sheet and defining a plurality of holes for receiving the corresponding moveable contacts, and a separator sheet attached on a lower surface of the second sheet, wherein the first sheet, the second sheet and the separator sheet each define respectively a extending portion from lateral side thereof. The extending portion of the second sheet defines a recess and the second sheet defines a plurality of channels to connecting the adjacent holes and an adhesive on each the lower and upper surface thereof.
The switch using the sheet comprises the aforementioned sheet and a circuit board with the a plurality of fixed contacts. In assembly, the separator sheet is peeled off from the lower surface of the second sheet. When the moveable contacts engage with the fixed contacts, the elastic sheet is affixed on the circuit board by the adhesive of on the lower surface of the second sheet and the first sheet and the second sheet are bent along the A-A line, thereby the metal film of the upper surface of the first sheet abuts against the ground portion of the circuit board, which can conduct the static electricity thereof.
Relative to the present technology, the sheet and the switch using the sheet define a recess in the second sheet thereof. When the first sheet and the second sheet are bent, only the first sheet is bent along the recess direction, hence, the stretch degree of the metal sheet of the upper surface of the sheet can be decreased, which can prevent the metal film from breaking and ensure the elastic sheet to pass though the static electricity test.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of a preferred embodiment when taken in conjunction with the accompanying drawings.
Referring to
The first sheet 10 is made of insulative material and defines a metal film 11 on an upper surface thereof. The first sheet 10 defines a first extending portion 12 from a side thereof. Throughout the upper surface of the first extending portion 12 is applied an adhesive, however, other place of the upper surface of the first sheet 10 is applied a reticulation metal film and defines an adhesive 13 on a lower surface thereof.
The moveable contact 20 defines a central portion 21. The central portion 21 is affixed on the upper surface of the first sheet 10′ by the adhesive.
The second sheet 30 is also made of the insulative material and defines a plurality of receptacle holes 31 corresponding of the moveable contacts 20, a number of connecting slots 32 for connecting the adjacent receptacle holes 20, and a second extending portion 33 extending from a lateral side thereof and disposing a rectangular recess 34. The second sheet 30 is applied adhesive on upper and lower surfaces thereof.
The separator sheet 40 defines a third extending portion 41 from a lateral side thereof and is applied an adhesive 42 on an upper surface thereof. The separator sheet 40 can prevent dust or the like from dropping into by the adhesive 42 affixed to a lower surface of the second sheet 40 and a lower surface of the moveable contact 20.
The first sheet 10, the second sheet 30 and the separator sheet cling with each other, and the first sheet 10 and the second sheet 30 can bend towards the second sheet 30.
Referring to the
The operation of the sheet switch thus constructed will now be described. When an operating force is applied on the central portion 21 of the moveable contact 20, the associated movable contact 20 is depressed through the first sheet 10 and is inverted thereby, with the result that its central portion 21 comes into abutment against the associated central fixed contact 62, whereby the central fixed contact 62 is electrically connected with the associated outer fixed contact 61. In this position, air contained in the moveable contact 20 can circulate in the connecting slot 32 arranged on two sides of the receptacle holes 31. Upon release of the depressing force imposed on the push-button, the central portion 21 of the movable contact 20 is disconnected from the central fixed contact 62 with an elastic restoring force of the movable contact 20.
It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not be limited to the details given herein.
Number | Date | Country | Kind |
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95102309 A | Jan 2006 | TW | national |
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Number | Date | Country | |
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20070170645 A1 | Jul 2007 | US |