Reverse dome switch

Information

  • Patent Grant
  • 6614380
  • Patent Number
    6,614,380
  • Date Filed
    Thursday, June 1, 2000
    24 years ago
  • Date Issued
    Tuesday, September 2, 2003
    21 years ago
Abstract
A key fob for signaling a receiver includes a housing having at least one depressable dome for initiating transmission of a signal. A circuit board disposed within the housing is printed onto the circuit board for generating the signal. The circuit board includes a switch situated beneath the dome. A bulge molded into the circuit board carries the switch. The bulge is depressable for closing the switch and transmitting the signal.
Description




BACKGROUND OF THE INVENTION




A key fob is a remote control assembly for signaling a receiver located on a vehicle. The key fob includes a housing having at least one flexible dome that is depressable for transmitting a signal. Typically, three or four domes protrude through the housing, each for signaling a different electrical component on the vehicle, such as, for example a door lock, a trunk latch, a panic alert, and the like. Each of the domes is depressable independent of the other domes for initiating transmission of the signal.




A circuit board is disposed within the housing. An electrical circuit is printed on the circuit board for generating the signals. The electrical circuit includes a switch situated beneath each of the domes. Typically, each switch is closed by depressing the adjacent dome. The dome includes conductive material that contacts the switch allowing current to flow through the circuit to a transmitter.




Circuit boards now being used in key fobs are formed from a rigid composite material having a thickness of up to two millimeters. Consumer trends have indicated fob is by reducing the thickness of the circuit board the electrical circuit is printed on. However, to do so, provisions must be made for the switch to meet the operational standards required of the prior art. Thus, a need exists for a thinner circuit board that still provides each of the features available in switches used in today's circuit boards.




SUMMARY OF THE INVENTION AND ADVANTAGES




The present invention discloses a flexible switch disposed upon a flexible circuit board. A key fob assembly for signaling a receiver on a vehicle includes a housing having at least one depressable dome for initiating transmission of a signal. A circuit board is disposed within the housing. An electrical circuit is printed on the circuit board. The electrical circuit includes a switch situated beneath the dome. The circuit board is formed from a flexible composite material having a thickness of less than one millimeter. A bulge is molded into the circuit board having the switch is printed beneath. The bulge is depressable for closing the switch and transmitting the signal. The assembly includes conductive material adjacent the switch for closing the switch when the bulge is depressed by the dome.




Combining the flexible circuit with the depressable bulge for closing the switch provides the ability to reduce the overall thickness of the key fob. First, the flexible circuit board is thinner than the conventional rigid circuit boards therefore requiring less volume displaced within the housing. Further, the flexible circuit board does not require a fixed linear space in the housing as a rigid circuit board does. The flexible circuit board can be manipulated to fit irregular contours in a smaller housing. Still further, the depressable bulge meets operational features available in the prior art switches commonly used in the thicker circuit boards of current key fobs.











BRIEF DESCRIPTION OF THE DRAWINGS




Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:





FIG. 1

is a top view of the remote control assembly of the subject invention;





FIG. 2

is a partial sectional view of the subject invention through line


2





2


of

FIG. 1

;





FIG. 3

is a section view of the circuit board of the subject invention through line


2





2


of

FIG. 1

; and





FIG. 4

is a top view of the circuit board of the subject invention.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring to

FIG. 1

, a key fob assembly for signaling a receiver is generally shown at


10


. The assembly


10


includes a housing


12


having at least one dome


14


protruding therethrough. The dome


14


is depressable for initiating transmission of a signal. In the preferred embodiment, a plurality of domes


14


protrudes through the housing


12


. Each dome


14


transmits a different signal for actuating electrical devices on a vehicle (not shown). The devices include, for example, a door lock, a trunk unlatch, a panic alarm, and the like.




As shown in

FIG. 2

, a circuit board


16


is disposed within the housing


12


. An electrical circuit


18


is printed onto the circuit board


16


(FIG.


4


). The electrical circuit


18


includes at least one switch


20


situated beneath the dome


14


. For a plurality of domes


14


, each dome


14


has a switch


20


situated therebeneath. When one of the switches


20


is closed, the electrical circuit


18


transmits a signal to a transmitter in the key fob, which transmits a signal to a receiver on the vehicle for actuating one of the electrical devices. Each switch


20


transmits a different signal for actuating different electrical devices.




A bulge


22


is molded into the circuit board


16


above each switch


20


. Each bulge


22


is depressable for closing the switch


20


and transmitting the signal. Each of the bulges


22


is biased towards the dome


14


it is situated beneath. As seen in

FIG. 2

, a plunger


24


is disposed beneath each dome


14


whereby depressing the dome


14


drives the plunger


24


into contact with the bulge


22


. Subsequently, the plunger


24


depresses the bulge


22


for closing the switch


20


.




Referring to

FIG. 4

, each of the switches


20


includes a first group of first fingers


26


and a second group of second fingers


28


. Each of the first fingers


26


is spaced apart from each of the second fingers


28


in an interleafing pattern. The switch


20


is representative of those commonly used in current vehicle remote controls. To close the switch


20


, a connection must be made between one of the first fingers


26


and one of the second fingers


28


. A signal is transmitted when one of the switches


20


is closed.




As best shown in

FIGS. 2 and 3

, conductive material


30


is located beneath and adjacent the fingers


26


,


28


for connecting the first fingers


26


to the second fingers


28


when the bulge


22


is depressed. The conductive material


30


closes the switch


20


by connecting the first fingers


26


to the second fingers


28


allowing current to flow through the circuit


18


for transmitting the signal. The appropriate electrical circuits and connections are within the skill of a worker in this art. The bulge


22


is biased towards the dome


14


, therefore, the bulge


22


returns to original position when the dome


14


is released opening the switch


20


and terminating the current flow. That is the switch


20


has a relaxed position where it is spaced from the conductive material


30


.




Any of the hardware disposed within the housing


12


can function as the conductive material


30


for closing the switch


20


. In the preferred embodiment, the conductive material


30


comprises a battery


32


. For an additional embodiment, the conductive material


30


comprises a support clip


34


for supporting the circuit board


16


or the battery


32


. The inventors conceive that one item disposed within the housing


12


may function as the conductive material for closing plural switches


20


. For example, two switches


20


may contact the battery


32


upon being depressed, and a third switch may contact the clip


34


upon being depressed.




The circuit board


16


comprises a flexible material. Printing the electrical circuit


18


upon the flexible material facilitates actuating the bulge


22


. Further, the flexible material is thinner than conventional rigid circuit board material allowing for a decrease in volume of the housing


12


. Further, manufacturing the circuit board


16


to have bulges


22


is within the skill of a worker in this art. The flexible material can also be manipulated to fit the contours of the housing


12


further enabling volume reduction within the housing.




The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.




Many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, wherein reference numerals are merely for convenience and are not to be in any way limiting, the invention may be practiced otherwise than as specifically described.



Claims
  • 1. A remote control assembly for signaling a receiver comprises:a housing; at least one dome protruding from said housing and being depressable for initiating transmission of a signal; a circuit board disposed within said housing having an electrical circuit printed thereon, said circuit including a switch situated beneath said dome; and said circuit board including a bulge having said switch printed thereunder, said bulge being depressable for closing the switch and transmitting the signal.
  • 2. An assembly as set forth in claim 1 wherein said circuit board comprises flexible material.
  • 3. An assembly as set forth in claim 2 wherein said bulge is biased towards said dome.
  • 4. An assembly as set forth in claim 1 wherein said switch includes a first group of fingers and a second group of fingers, each of said first fingers being spaced apart from each of said second fingers in an interleafing pattern.
  • 5. An assembly as set forth in claim 4 including conductive material located adjacent said fingers for connecting said first fingers to said second fingers when said bulge is depressed.
  • 6. An assembly as set forth in claim 1 including conductive material spaced from said circuit board and said bulge in a direction away from said dome, with said bulge contacting said conductive material when said bulge is depressed to close said switch.
  • 7. An assembly as set forth in claim 6 wherein said conductive material comprises a battery.
  • 8. An assembly as set forth in claim 6 wherein said conductive material comprises a support clip.
  • 9. A remote control assembly for signaling a receiver comprises:a housing; at least one dome protruding from said housing and being depressable for initiating transmission of a signal; a circuit board comprising flexible material disposed within said housing having an electrical circuit printed thereon, said circuit including a switch situated beneath said dome; and said circuit board including a bulge biased towards said dome and having said switch printed thereunder, said bulge being depressable for contacting conductive material and closing the switch for transmitting the signal.
  • 10. An assembly as set forth in claim 9 including conductive material for contacting said circuit and closing said switch.
  • 11. An assembly as set forth in claim 9 wherein said conductive material comprises a battery.
  • 12. An assembly as set forth in claim 9 wherein said conductive material comprises a support clip.
  • 13. A method for transmitting a signal from a remote control assembly by closing a switch on a circuit board disposed within the assembly comprises:providing a switch including a circuit board having a bulge biased towards a dome switch, said bulge having a switch printed there under, said bulge being depressable for contacting conductive material and closing the switch; depressing the dome for contacting the switch; displacing the switch by flexing the circuit board bulge with the dome; and closing the switch by contacting the conductive material situated adjacent the displaced switch.
Parent Case Info

This application claims priority to provisional patent application No. 60/151,630, which was filed Aug. 31, 1999. The subject invention relates generally to an improved circuit board for a key fob.

US Referenced Citations (5)
Number Name Date Kind
3898421 Suzumura Aug 1975 A
4720610 MacHarrie Jan 1988 A
5819568 Christie et al. Oct 1998 A
6031465 Burgess Feb 2000 A
6208271 Armstrong Mar 2001 B1
Provisional Applications (1)
Number Date Country
60/151630 Aug 1999 US