Abstract:
A motion-activated electrical switch has a pair of spaced electrical circuits, each disposed on a support, and an electrical conductor interposed between spaced from and electrically insulated from the electrical circuits. An electrically conductive movable element is structured to assume a first position in contact with the electrical conductor and one of the electrical circuits and a second position out of contact with the electrical circuit is provided along with a power supply for energizing the switch. In one embodiment, the electrical conductor is a closed shape having an opening defined therethrough. A pair of conductive strips may be connected to the electrical conductor and to one of the electrical circuits such that movement of the electrically conducted movable element may serve to complete the circuit or to break the circuit.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a motion-activated electrical switch and, specifically, one which does not require the use of a flowable, electrically conductive material, such as mercury. 
   2. Description of the Prior Art 
   It has been known for many years to employ various types of electrical switches which are structured to move between an “off” position wherein the electrical circuit is not complete and one or more “on” positions wherein the electrical circuit is complete, thereby permitting electrical energy to energize whatever article or appliance is to receive the electrical energy, when desired. 
   Among the known electrical switches are mechanical switches, which move a conductive element into and out of physical contact with other switch components to achieve switch open and switch closed positions. 
   It has also been known to employ mercury in switches wherein in one position the mercury is located in an “off” position as a result of the lack of continuous electrical contact. In another position generally achieved by tilting the switch so as to cause the mercury to flow to a different position wherein the electrical circuit is complete, the switch is in the “on” position. One of the major problems with mercury is that it has been recognized as a hazardous material. For example, the European Union Directive 2002/95/EC entitled “Restriction of Hazardous Substances (RoHS)” restricts the use of certain hazardous substances in electrical and electronic equipment sold or used in the European Union after Jul. 1, 2006. Mercury is among the materials listed within this category. 
   There remains, therefore, a very real and substantial need for an improved electrical switch which is activated by motion and avoids the use of hazardous materials. 
   SUMMARY OF THE INVENTION 
   The present invention has met the hereinbefore described need. The present invention does provide a motion-activated electrical switch which has a pair of spaced electrical circuits disposed on supports and an electrical conductor interposed between an electrically insulated portion from the spaced electrical circuits. An electrically conductive movable element is structured to assume a first position in contact with said electrical conductor and a said electrical circuit and a second position out of contact with said electrical conductor. An internal power supply may be provided for energizing the switch. Otherwise, power is provided from an external source. 
   Movement of the movable conductor serves to establish a switch open or switch closed position. 
   The electrical conductor has an opening within which the electrically conductive movable element, which may be in the form of a rollable element, is positioned. 
   The switch assembly may be mounted on a base which is securable to an electrical appliance or lamp or other item to be energized. 
   It is an object of the present invention to provide an efficient, economical, motion-activated electrical switch which will function regardless of switch orientation. 
   It is a further object of the present invention to provide such a switch which does not require use of hazardous materials, such as mercury. 
   It is another object of the present invention to provide such a switch which employs printed circuit technology and may be provided as a very thin switch. 
   A further object of the present invention is to provide such a switch which will economically, structurally and functionally be suitable for a wide range of uses. 
   It is yet another object of the present invention to provide such a switch which enables the use of reduced power consumption. 
   These and other objects of the invention will be more fully understood from the following detailed description of the invention on reference to the illustrations appended hereto. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front elevational view of a form of switch of the present invention provided on a suitable base member. 
       FIG. 2  is a rear elevational view of the switch and base of  FIG. 1  with a portion of the adhesive layer and protective barrier broken away. 
       FIG. 3  is an elevational cross-sectional illustration of a switch assembly of the present invention showing an embodiment with an external source of power. 
       FIG. 4  is a cross-sectional illustration of an electrically conductive ring of an embodiment of the present. 
       FIG. 5  is a cross-sectional illustration of a switch and base of the present invention showing the movable conductive element and a printed circuit. 
       FIG. 6  is an enlarged fragmentary illustration of a portion of an electrical circuit employable in the present invention. 
       FIG. 7  is a plan view of a spacer layer employable with the present invention. 
       FIG. 8  shows a modified embodiment of the invention having an internal source of power. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now in greater detail to  FIGS. 1 and 2 , there is shown a base member  2  containing a switch  4  of the present invention secured to the base  2  and having a pair of electrically conductive strips  10 ,  14  extending outwardly therefrom to an object to be energized  12 , which object might, for example, be a light-emitting diode (LED) or piezo electric device or other similar device such that when motion causes the switch to go on or off, responsive visual, audible or other events will occur. In the form shown, the rear surface of the base  2  has a strippable protective film  16  which is shown partially broken away underlying which is a layer of a pressure-sensitive adhesive  18  so as to facilitate securing the switch-supporting base  2  to another article. An alternate means of securing the switch base to a desired article would be facilitated through opening  22  defined within base  2 . This would permit employing a lanyard, mechanical fastener or other mechanical element to secure the base to a person or object. The switch could also incorporate a stitchable material that would allow it to be sewn onto another item. The opening  22  could also function as a window to facilitate passage of light from LED&#39;s therethrough. 
   Referring to  FIG. 3 , there is an enlarged partially schematic cross-sectional illustration of one embodiment of a switch of the present invention. A switch  30  in the form shown has an outer layer  32  which may contain any desired graphic material and is secured by an interposed adhesive layer  34  to a first support  40  which has electrically conductive portions defining a circuit applied thereto (not shown in this view) such as screen printed conductive traces or copper circuits. The electrically conductive portions would be secured to the first support  40  on the lower surface  42 . Underlying the first support  40  is an electrical conductor  44  which preferably will be a closed continuous conductor such as having a circular, oval or other closed geometric shape and defining a recess  50 . 
   As shown in  FIG. 4 , the inner surface  52  of the electrical conductor  44  preferably has a convexly configured recess-defining inner surface. This shape facilitates free movement of the electrically conductive movable element  90  within recess  50 . An upper annular spacer  60  defines a recess  62  and a lower annular spacer  64  defines a recess  65 . Underlying the lower spacer  64  is a second support member  66  which has on its upper surface  68  electrically conductive circuit components which may be provided as a printed circuit, if desired. Annular spacers  60 ,  64  are electrically insulative and insulate electrical conductor  44  from the electrical circuits on supports  40 ,  66 . Spacers may be made from, for example, a resinous plastic foam. Underlying the second support  66  is an adhesive layer  76  which secures second support  66  to an underlying layer  78  which has a lower surface on which a pressure-sensitive adhesive has been applied. An internal or external power source  80 , which provides electrical energy at a desired level and may be a battery, is connected to the upper electrical circuit by lead  82  and is connected to the lower electrical surface by lead  84 . If desired, a timer  81  may be provided to control the period of operation of the switch  30 . Items such as photo diodes could be incorporated as required to affect the functionality of the switch. 
   A movable electrically conductive element  90  in a preferred form will be of generally spherical shape, but other shapes permitting free movement may be employed. When the element  90  is in contact with both the electrical conductor  44  and, in the form shown, the electrical circuit on second support  66 , this will complete the circuit, thereby permitting energy to flow therethrough to the two conductors  10  and  12  (not shown in this view) to the lamp or other element  12  ( FIGS. 1 and 2 ). It will be appreciated that movement of the switch  30  will result in the electrically conductive movable element  90  engaging both the electrical conductor  44  and the circuit on second support  66  or if the switch is inverted, will result in similar contact between the electrical circuit on upper support  60  and the electrically conductive portion  44 . The convex shape serves to facilitate free movement of the electrically conductive movable element  90 . It will be appreciated that when the electrically conductive movable element  90  is not in contact with the electrical conductor  44 , the switch will be in the “off” position and no electricity will flow therethrough, even though the electrically conductive movable element  90  may be in contact with the electrical circuit on either the upper support  60  or the lower support  66 . In this manner, it will be appreciated that movement of the switch will result in the illumination or activation of a light-emitting diode or a piezo electric device, if that is what is electrically attached to the switch, or other electrically energized article. For example, an individual wearing the device when the individual moves would be subjected to the switch opening and closing, thereby creating on and off cycles of the electrically energized device. Additional circuitry, such as resistors, capacitors, field effect transmitter (FET) or other components, may be added to define other responsive actions prompted by the opening and/or closing of the switch as defined herein. 
   Referring to  FIG. 5 , there is shown a cross-sectional view of the switch showing in plan the electrically conductive movable element  90 , a circular electrical conductor  44 , a support base  2  and a lower electrical conductor  14 . 
   Referring in greater detail to the electrically conductive circuit elements as shown in  FIGS. 5 and 6 , the center portion  94  is electrically insulative and in the form shown is generally circular. A plurality of radially projecting, circumferentially spaced electrically conductive elements, such as  100 ,  102 ,  104 ,  111  are such that when the electrically conductive movable element  90  engages one of them and the electrical conductor  44 , the circuit will be complete and when the electrically conductive movable element engages interposed dielectric portions  110 ,  112 , the switch will be in the “off position”. The electrically conductive movable element  90  preferably has a diameter more than double the spacing between the inner diameter of electrical conductor  44  and the outer diameter of the radially projecting portions, such as  104 – 111  of the electrical circuit, for example. Conductors  10  and  14  may be continuous screen-printed conductive traces which form areas  100 ,  102 ,  104  and the like. Dielectric material may be deposited over the conductive traces  10  and  14  to create non-conductive areas alternating with conductive areas  100 ,  102 ,  104  and the like. This conductive/non-conductive pattern is designed to increase the frequency and probability of the circuit fluctuating between closed and open states. 
   It will be appreciated that the printed circuit shown in  FIG. 5  may be duplicated on both first support  40  ( FIG. 3 ) and second support  66 . This redundancy permits the switch to function regardless of switch orientation. It will also be appreciated that other conductive patterns which provide the desired functionality may be employed in lieu of the pattern shown in  FIG. 5 . 
   Referring to  FIG. 7 , there is shown a spacer element, such as  60  or  64 , which has a central recess  114  for receipt of the switch. 
   Referring to  FIG. 8 , another embodiment of the invention will be considered. Shown in  FIG. 8  is the switch assembly without the supporting base and emerging electrical conductors. The switch  120  in this embodiment has an upper graphic layer  122  secured by adhesive layer  124  to upper support  128  which contains on its lower surface  130  a first electrical circuit which may be of the type shown in  FIG. 5  or any other desired type which will function in the manner described herein. An annular electrical conductor  144  is supported by electrically insulative upper spacer member  160  and electrically insulative lower spacer member  164 . A second electrical circuit is also present on the upper surface  168  of the lower support  166  which makes contact with the annular electrical conductor  144 . An electrically conductive movable element  190  is positioned within recess  150  and recesses  162 ,  163  which exist, respectively, in both the top and bottom regions as created by spacers  160  and  164 . When the electrically conductive movable element  190  contacts the electrical conductor  144  and one of the electrical circuits, the switch is in the “on” position and when the electrically conductive movable  190  is not in contact with the electrical conductor  144 , the switch is in the open or “off” position. Underlying the lower support  166  is a lower protective layer  178  which is secured to the support  166  by an adhesive layer  176 . If desired, a further pressure-sensitive adhesive layer  180  may be employed with an appropriate strippable shielding layer (not shown) positioned thereunder. In the alternative, the switch may be secured to another object by using an applied stitchable material or mechanical assembly provided by holes passing through the entire assembly of the perimeter of the switch outside of any and all conductive areas. 
   In this embodiment of the invention, a power source, which in the form shown is a battery  196 , is positioned within the assembly and is in electrical contact with both the electrical circuits positioned respectively on upper support  128  and lower support  166 . The battery may be a 3-volt Lithium Polyer or 3-volt lithium battery, for example. As an alternate power source, if desired, a solar collector may be employed to energize the system. In a preferred embodiment of the invention, the height H ( FIGS. 3 and 8 ) between the lower surface  42  of the upper support  40  and the upper surface  68  of the lower support  66  will preferably be about 0.007 to 0.120 inch and the electrically conductive movable element will have a maximum dimension of about 0.062 to 0.097 inch. While the invention is not limited to specific dimensions, it does provide a movable switch which may be made in small size, while preserving functionality. The overall height of the switch base as shown in  FIG. 1  may be about 1.00 to 3.00 inches and the width might be about 1.00 to 3.00 inches, for example. 
   The annular electrical conductor  44 ,  144  may be composed of any suitable material, such as copper, aluminum or a conductive carbon pill, for example. Also, the electrically conductive trace in the circuits may be composed of silver, copper with gold flash, tin silver flash, tin nickel flash, carbon or aluminum, for example. The annular electrical conductor  44 ,  144  may be of unitary construction or, if desired, could be an assembly of a plurality of annular electrically conductive vertically stacked washer-like elements secured together by an electrically conductive adhesive, such as electrically conductive epoxy, for example. Such an adhesive may also be employed to enhance securement and electrical conductivity between annular electrical conductor  44 ,  144  and the adjacent electrically conductive portions of surfaces  42 ,  68 ,  130 ,  168 , respectively. 
   It will be appreciated that the present invention provides for a movable switch assembly which does require the use of mercury or other hazardous materials. It contemplates a movable electrically conductive element being in contact with one of two electrical circuits with the switch being placed in the “on” position when the movable element also contacts an electrical conductor such as a conductive ring. The invention also provides for movement of the switch to result in cyclic on and off changes in the switch resulting in on and off actuation of a source of illumination such as an LED or lamp, sound such as a buzzer or operation of another electrically energized device. The invention also provides for movement of the switch to result in the responsive stimulation of subsequent events that are desired to occur upon detection of movement. These subsequent events may be determined based on the nature and function of the specific devices. 
   The invention may be employed in a wide variety of uses where its small size, lower power consumption and low cost of manufacture would be beneficial. For example, it may be worn on clothing, employed in toys and used in safety devices. In addition to uses on clothing for safety or other purposes, it will be appreciated that the switch may be employed to illuminate LED&#39;s or other lamps or energize other alarm-type systems, the switch being secured to physical articles such as backpacks, briefcases, luggage, bicycles and other articles where for safety or other reasons, the small, thin, low-energy switch of the present invention could be advantageously employed. 
   Whereas particular embodiments of the invention have been described herein for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details may be made without departing from the invention as set forth in the appended claims.