ELECTRONIC NOVELTY ASSEMBLY INCLUDING A PIN SWITCH AND EMBEDDED PRINTED CIRCUIT COMPONENT
Field of the Invention
This invention relates to electrical novelty devices, and more particularly, relates to a low profile electronic novelty button assembly.
Background of the invention
Electronic novelty devices have been available for a number of years to suit many applications such as decorations, advertising signs and other attention- getting devices. Some of such electronic novelty devices have used both digital and analog oscillating circuitry coupled to a light emitting element to produce a blinking effect. Such novelty items, however, have been made with little regard to the profile height of the device.
Some novelty devices, such as those disclosed in U.S. Patent No. 5,143,439, use a pin to attach a novelty button to a garment, and also use the pin as a switch to activate and deactivate the electronic circuity used in the novelty button. Such novelty devices, however, do not include any mechanism to prevent the inadvertent activation of the novelty button.
Summary of the Invention
The invention is directed to a novelty device having an electrical circuit, including a printed circuit board having a void formed therein, wherein an electrical component is attached to the printed circuit board such that a portion of a body of the electrical component is positioned in the void below a surface of the printed circuit board, thereby providing a low profile novelty device. The dimensions of the void adjacent the surface of the printed circuit board are slightly larger than a set
of cross-sectional dimensions of the body of the electrical component.
In preferred embodiments, the novelty device further includes a battery coupled to the electrical circuit and a pin-switch coupled between the battery and the electrical circuit. The pin-switch includes an electrically conductive pin portion and an electrically conductive hook portion which are separable such that the electrical circuit is deactivated when the pin portion does not engage the hook portion, and wherein the electrical circuit is activated when the pin portion engages the hook portion. A cover assembly is attached to the printed circuit board. The cover assembly includes a base having a non-conductive hook portion coupled thereto. The non-conductive hook portion permits engagement thereof with the conductive pin portion to prevent the conductive pin portion from accidentally contacting the conductive hook portion after the electrical circuit is deactivated.
In preferred embodiments, the base has a recessed region formed therein, and the cover assembly further includes a device for retracting the non-conductive hook portion into the recessed region. The device for retracting includes a member integral with the non- conductive hook portion and an axle-like support extending from opposing sides of the member to a region of the base adjacent the recessed region. In some embodiments, the base includes a receiving space for receiving a magnet, wherein the magnet is mounted in the receiving space such that a substantial portion of the magnet is contained below a surface of the base.
A preferred method of manufacturing an electrical novelty device of the invention includes the steps of providing a printed circuit board; forming conductive circuit paths on a surface of the printed circuit board; providing an electrical component having a body and a plurality of leads; forming at least one void in the printed circuit board for receiving the body of the electrical component; positioning the body of the component in the void such that the body is supported by the plurality of leads contacting the conductive circuit paths; and soldering the plurality of leads to the printed circuit board to form an electrical circuit.
Preferred methods further include the step of coupling a pin-switch between a battery and the electrical circuit, wherein the pin-switch includes an electrically conductive pin portion and an electrically conductive hook portion which are separable such that the electrical circuit is deactivated when the pin portion does not engage the hook portion, and wherein the electrical circuit is activated when the pin portion engages the hook portion.
Preferred methods of manufacturing the invention, further include the steps of providing a cover assembly; forming a first recessed portion in a base of the cover assembly; and mounting an assembly including a non-conductive hook portion to the base such that the non-conductive hook portion is retractable to position the non-conductive hook portion in the recessed region for storage, and is extendable to protrude above a surface of the base to permit engagement of the retractable non-conductive hook portion with the conductive pin portion to prevent the conductive pin portion from accidentally
contacting the conductive hook portion after the electrical circuit is deenergized.
The methods of the invention may further include the steps of forming a second recessed region and mounting a magnet in the second recessed region.
Other features and advantages of the invention may be determined from the drawings and the detailed description of preferred embodiments of the invention that follows.
Brief Description of the Drawings
Fig. 1 is a perspective view of the face plate of a novelty button assembly of the invention.
Fig. 2 is a rear perspective view of a novelty button assembly of the invention having the face plate removed from an electronic assembly.
Fig. 3 is a sectional view of a circuit board of the invention taken along line 3-3 of Fig. 2.
Fig. 4 is a top view of a portion of a printed circuit board of the invention showing an electrical component in cross-section.
Fig. 5 is a circuit diagram of an electronic circuit suitable for use with the invention.
Fig. 6 is a rear view of another embodiment of the invention.
Fig. 7 is a sectional view of the embodiment depicted in Fig. 6 taken along line 7-7.
Fig. 8 is a sectional view of still another embodiment of the invention.
Detailed Description of Preferred Embodiments
Fig. 1 shows a front view of a novelty button 10 including a front plate 11 and an electronic assembly 12. Front plate 11 is adapted to bear indicia on its face. Front plate 11 is also adapted to provide an
opening 13 to receive a light emitting element, such as a light emitting diode, electrically controlled by an electronic assembly 14. Although Fig. 1 shows the front plate having a simplified indicia depicting a winter scene with an opening positioned to simulate a blinking star, front plate 11 may be provided with any indicia, slogan, trademark or advertising, and opening 13 may be located at any location on front plate 11.
Fig. 2 is an exploded perspective drawing showing a back side of novelty button 10 in which electronic assembly 14 is depicted in more detail. Electronic assembly 14 includes a printed circuit board 16, which may be circular as shown in Fig. 2, or may be rectangular, or any other convenient shape. Electronic assembly 14 is adapted to be removably fastened to the front plate 11.
Printed circuit board 16 includes an electronic circuit 17, such as flasher circuit, which includes one or more discrete components 18 identified as components I8a-18d in Fig. 2 and which may, for example, correspond to some of the electrical and electronic components 41-47 shown in the circuit diagram of Fig. 5. As shown in Fig. 2, a light emitting diode 19 is connected to electronic circuit 17 on printed circuit board 16 by flexible conducting leads 20. Flexible conducting leads 20 have sufficient length to allow light emitting diode 19 to be located at any location in the surface of front plate 11. Accordingly, light emitting diode 19 may be placed in opening 13 and will be held within opening 13 when printed circuit board 16 is fastened to front plate 11. Printed circuit board 16 is preferably fastened to front plate 11 by an adhesive material, or glue, but may be fastened by any convenient means.
Electronic assembly 14 further includes one or more batteries 22 to power electronic circuit 17 and light emitting diode 19. Printed circuit board 16 carries a pin-switch 24 to fasten novelty button 10 to a person's clothing and to activate and deactivate electronic circuit 17. Pin 24 includes a pin portion 26 and a hook portion 27. Portions 26 and 27 are fastened to circuit board 16, wherein pin portion 26 is coupled directly to battery 22 and hook portion 27 is coupled directly to electronic circuit 17, as shown for example, in Fig. 5. Those skilled in the art will recognize that, alternatively, pin portion 26 may be connected to electronic circuit 17 and hook portion 27 may be connected with battery 22. As shown in Fig. 2, an opening 25, such as a hole or notch, is formed in circuit board 16 to electrically separate a mounting portion of pin 24 into pin portion 26 and hook portion 27, thereby allowing pin 24 to operate as a switch. Preferably, opening 25 is formed by punching or drilling circuit board 16 after pin 24 is attached to circuit board 16.
Pin portion 26 and a hook portion 27 are structurally fastened to the printed circuit board 16, for example, by soldering and are connected to electronic circuit 17, as shown for example, in Fig. 5.
Electronic circuits used in novelty devices typically include one or more discrete components, such as resistors, capacitors, inductors, transistors, etc., soldered to a printed circuit board. In prior electronic devices, such discrete components rest on the surface of the circuit board prior to being soldered to circuit traces on the circuit board. As shown in Fig. 2, however, electronic circuit 17 includes discrete components 18a-18d which are at
least partially recessed below a surface 16a of circuit board 16 in corresponding voids 28a-28d, thereby allowing for a low profile novelty button. Such voids 28a-28d extend at least partially below surface 16a of circuit board 16, and in preferred embodiments, form openings through circuit board 16.
Fig. 3 shows a partial side sectional view of electronic circuit 17 taken along line 3-3 of Fig. 2. As shown in Fig. 3, component 18d, such as a resistor, includes a body 29. A pair of leads 30 axially extend from the ends of component body 29. In order that substantially all of body 29 may lie below surface 16a of printed circuit board 16, each of the leads 30 are bent upwardly to form a lead portion 32 and then outwardly to form a lead portion 34, which together form a somewhat L-shaped support structure for component body 29 and provide electrical conductors for attachment of resistor 18d to circuit traces 36 on printed circuit board 16. Thus, resistor 18d is suspended across opening 28d by its leads 30, and the depth at which resistor 18d is recessed into opening 28d is dependent upon the length of lead portion 32, and the angular relationship between lead portion 32 and body 29, and between lead portion 32 and lead portion 34.
The low profile design described above is advantageously easier to manufacture than circuits using surface mounted components. For example, in conventional circuit construction using surface mounted components, the discrete components must be held or clamped in position while component leads are soldered to the circuit traces. In contrast, the low profile configuration of the invention relies on gravity and the mass of the component to hold the component in position for soldering and hold the
component leads in contact with the circuit traces. Referring to Fig. 3, gravity acting on the mass of body 29 causes lead portions 34 of resistor 18d to be held in contact with circuit traces 36, with the center of gravity of resistor 18d advantageously well below the plane of surface 16a of printed circuit board 16 so as to enhance position stability of resistor 18d.
As shown in Fig. 4, it is preferred that the dimensions v,, v2 of opening 28d adjacent surface 16a be slightly larger than the cross-sectional dimensions d,, d2 of body 29 at a location where the plane of surface 16a intersects body 29, and have a similar shape, so that resistor 18d aligns itself into position as body 29 of resistor 18d is lowered into recess 28d. Accordingly, during circuit fabrication, circuit board 16 can withstand some vibration and movement prior to the soldering of discrete components 18a-18d to circuit traces 36 without the risk of components 18a-18d moving out of position. Thus, circuit board 16 may be transported through a solder bath, or other soldering station, for application of solder 38 to the leads 30 and circuit traces 36 without the necessity of holding or clamping components 18a-d in position.
Fig. 5 represents an exemplary electronic circuit for electronic circuit 17, which may be used in producing the invention. The exemplary electronic circuit 17 is provided merely as an aid in understanding and practicing the invention, and is not intended to limit the scope of the claims. For example, although circuit 17 is shown as a bipolar circuit, electronic circuit 17 may be fashioned by those skilled in the art using metal-oxide semiconductor components, such as a CMOS components.
In addition, the invention is not limited to a flashing electronic circuit; but rather, is applicable to similar novelty items incorporating any type of electronic circuit. As shown in Fig. 5, pin portion 26 of pin-switch
24 is connected with one terminal of battery 22 and hook portion 27 is connected with the remainder of electronic circuit 17. When pin portion 26 is engaged with hook portion 27, for example, when the button is fastened to the clothes of a user, pin-switch 24 is closed, thereby providing electrical power through flasher circuit 17 and light emitting diode 19. When pin-switch 24 is open and pin portion 26 does not engage hook portion 27, then battery 22 cannot supply electrical power through flasher circuit 17 and light emitting diode 19.
Electronic circuit 17 includes a switching transistor 41 having an emitter 41a, a base 41b and a collector 41c. Emitter 41a is coupled to battery 22 via switch 24. Collector 41c is coupled to light emitting diode 19 via a resistor 42. In the circuit of Fig. 5, switching transistor 41 is, for example, a Motorola MMBT 3906T transistor, and the current limiting resistor 42 has a resistance of about 18 ohms. Electronic circuit 17 further includes a control transistor 43, which is a Motorola MMBT 3904T transistor. A base 43a of control transistor 43 is coupled via resistor 44 to emitter 41a of switching transistor 41 and to hook portion 27 of pin-switch 24. Thus, base 43a of control transistor 43 is coupled via resistor 44 to battery 22 when pin-switch 24 is closed. Also, base 43a of control transistor 43 is coupled to a series R-C circuit including a timing capacitor 45 and a resistor 46. Resistor 44, which is, for example, 10 megohms, substantially determines
the rate of charging of timing capacitor 45 by battery 22 through a path including battery 22, pin-switch 24 (when closed), resistor 44, resistor 46, capacitor 45, resistor 42 and light emitting diode 19. The resistances of resistors 42 and 46 are very small compared to the high resistance of resistor 44, and have a negligible effect upon the charging rate of capacitor 45 by battery 22. Resistor 44 also isolates the base 43a of control transistor 43 from battery 22 so that the voltage on capacitor 45 effectively determines the voltage at base 43a of control transistor 43 and, therefore, the flow of current through control transistor 43 and switching transistor 41. Preferably, resistor 46 has 4,700 ohms of resistance and thus provides a very short discharge time for capacitor 45 and short conduction times for transistors 41 and 43, thereby providing a bright emission from light emitting diode 19 with a minimum of conduction time of switching transistor 41 and providing a duty cycle that is effective at conserving battery power.
Light emitting diode 19 is coupled in series with a current limiting resistor 42, and is coupled between the collector 41c of transistor 41 and ground 48. Emitter 41a of transistor 41 is connected to pin- switch 24. Base 41b of transistor 41 is coupled to the collector 43b of the transistor 43. A current limiting resistor 47 is connected between base 41b and voltage source 22. A regenerative feedback loop including resistor 46 and capacitor 45 is interconnected between the collector 41c of switching transistor 41 and the base of control transistor 43. The collector 43b of control transistor 43 is connected to the voltage source 22 through current limiting resistor 47 and pin-switch 24.
With switch 24 initially open, switching transistor 41 and control transistor 43 are biased off and light emitting diode 19 is not energized. When switch 24 is closed, current begins to flow through high resistance 44 to the base 43a of the control transistor 43, resistor 46 and charging capacitor 45. Capacitor 45 slowly charges through resistors 42, 44 and 46 and light emitting diode 19. The charging time of capacitor 45, is determined substantially by the values of capacitor 45 and resistance 44. The accumulated voltage of capacitor 45 drives control transistor 43 in to conduction. The saturation current of control transistor 43 through the emitter- to-base junction of switching transistor 41 drives switching transistor 41 into conduction. With the switching transistor 41 in the saturated state, current flows from capacitor 45 through resistor 42 and 46 and through light emitting diode 19. The current flowing through switching transistor 41 energizes the light emitting diode 19.
Timing capacitor 45 is discharged at a rate determined by resistor 46, which is very short (e.g., about 0.15 millisecond) compared with the charging time of capacitor 45 (e.g., about 0.33 seconds). When timing capacitor 45 is completely discharged, control transistor 43 no longer has an appropriate voltage potential at its base 43a and the collector current is cut off. As the collector current of control transistor 43 is cut off, the current supplied to the base of the switching transistor 41 is reduced sufficiently so that it will no longer be in saturation. At this time, the voltage to the light emitting diode 19 quickly drops, turning the light off, and the control capacitor 45 is then able to begin charging again and the cycle is repeated. This
charging process is comparatively long due to the high resistance of resistor 44 in the charging current path.
Although the circuit shown in Fig. 5 utilizes a PNP transistor for the switching transistor 41, and a NPN transistor for control transistor 43, it is understood that these transistors could be reversed with a corresponding reversal of the voltage source, as it is known in the art. As one skilled in the art will note, the circuit of Fig. 5 does not require a large electrolytic capacitor, but permits smaller, less expensive and more reliable capacitors to be used.
Figs. 6 and 7 show an electrical novelty device 50 embodying the invention, wherein Fig. 7 is a sectional view of novelty device 50 along line 7-7 of Fig. 6. Novelty device 50 of Figs. 6 and 7 include the circuit board 16 described above with respect to Figs. 1 and 2. Therefore, for the sake of brevity, the detailed features of circuit board 16 will not be repeated here.
As shown in Fig. 6, novelty device 50 includes a garment pin 24, including pin portion 26 and hook portion 27, coupled to electronic circuit 17 (not shown) . Pin portion 26 and hook portion 27 are electrically conductive and are separable such that electronic circuit 17 is activated when pin portion 26 engages hook portion 27, and electrical circuit 17 is deactivated when pin portion 26 does not engage hook portion 27.
Novelty device 50 includes a cover assembly 52 which may be fabricated, for example, as a molded or machined plastic cover plate which is adhesively attached to circuit board 16, or may be a curable resin which is applied directly to surface 16a of
circuit board 16 and molded or machined to the desired shape. Cover assembly 52 provides an insulating barrier over the conductive region of circuit board 16, (i.e., over circuit traces 36 and solder 38). Cover assembly 52 includes a base 54 having a lower section 56 and a plateau section 58. As shown in Fig. 7, pin portion 26 and hook portion 27 protrude through the lower section 56 of base 54 and extend upwardly above lower section 56 to an elevation substantially equal to the height of plateau 58.
Cover assembly 50 further includes a non- conductive hook portion 60 for engaging conductive pin portion 26 to prevent conductive pin portion 26 from accidently contacting conductive hook portion 27 after electrical circuit 17 is deactivated by electrically separating pin portion 26 from hook portion 27. As shown in Fig. 7, lower section 56 of base 54 includes a recessed region 62 which allows hook portion 60 to be mounted in a fashion in which non-conductive hook portion 60 may be retracted into the recessed region 62 during times in which electronic circuit 17 is activated.
As shown in Fig. 7, a retracting mechanism 64 is provided to retract non-conductive hook portion 60 into recessed region 62. Retracting mechanism 64 includes an member 66 integral with non-conductive hook portion 60. An axle-like support 68 extends from opposing sides of member 66 to a region of the base adjacent to recessed region 62. Axle-like support 68 may be simply a portion of base 54 made to be integral with retracting mechanism 64, or may be one or more pins which extend from retracting mechanism 64 and engaging a region of base 54 adjacent to recessed region 62. Accordingly, with reference to Fig. 7, when downward pressure is applied to member 66 at a
location to the right of axle-like support 68, non- conductive hook portion 60 rises above the upper surface 56a of lower section 56 to a height sufficient to receive conductive pin portion 26 to store conductive pin portion 26 out of contact from conductive hook portion 27. Non-conductive hook portion 60 may be stored in recessed region 62 by applying downward force to hook portion 60. Thus, as shown in Fig. 7, non-conductive hook portion 60 is extendable to protrude above surface 56a of lower portion 56 of base 54 to permit an engagement of retractable non-conductive hook portion 60 with the conductive pin portion 26 to prevent the conductive pin portion 26 from accidently contacting conductive hook portion 27 after electronic circuit 17 is deenergized.
Although non-conductive hook portion 60 is shown in Figs. 6 and 7 as being retractable by actuation of elongated member 66, it is contemplated that in some applications it may be sufficient to have non- conductive hook portion 60 permanently mounted above lower region 56, as shown in Fig. 8, (i.e., not retractable) at a height sufficient to receive conductive pin portion 26. This can be accomplished, for example, by attaching a non-conductive hook portion 60 to surface 56a of base 54, or by machining base 54 to establish a non-conductive hook portion 60, or by molding hook portion 60 integral with base 54.
Fig. 8 shows a sectional view of a novelty device 70 representing another embodiment of the invention. Novelty device 70 includes a cover assembly 72 which incorporates all of the features of cover assembly 52 depicted in Figs. 6 and 7. Cover assembly 72, however, differs from cover assembly 52 of Figs. 6 and 7 in that cover assembly 72 includes a recessed region
78 formed in elevated region 76 of base 74. Recessed region 78 is conveniently sized to receive a magnet 80. Magnet 80 may be inserted into recessed region 78 to form a press fit between its outer surface and the region of base 74 adjacent recessed region 78, or may be adhesively affixed to base 74. Preferably, magnet 80 is mounted in recessed region 78 so that a majority of magnet 80 lies below surface 76a of base 74. Thus, novelty device 70 may be affixed to a garment or other cloth material using pin-switch 24, or may be magnetically attached to a metallic structure, such as a refrigerator door using magnet 80.
Although the invention has been described with reference to preferred embodiments, those skilled in the art may make changes in form and detail with departing from the spirit and scope of the following claims.