Abstract:
An electric adapter for providing output power to an accessory includes an adapter housing having a projection configured for insertion into a DC power accessory port, the projection carrying an electrical input conductor, a power outlet cord extending from the housing, a manually operable power switch mounted on the housing, the switch operable to electrically connect the electrical input conductor to the power outlet cord, and a timer circuit contained within the housing and configured to electrically disconnect the input conductor from the power outlet cord after a predetermined cycle time period, without removing the projection from the DC power accessory port.

Description:
TECHNICAL FIELD 
     This invention relates to an electrical adapter for powering accessories, and more particularly to adapters for use with the accessory port of an automobile. 
     BACKGROUND 
     Portable electrical devices can be designed for operation with the 12-volt electrical systems commonly present in automobiles. The accessory port of an automobile, originally used for cigarette lighters, can also provide electrical power for portable devices. Accessory adapters are designed for insertion into the accessory port for providing power to the portable devices. 
     SUMMARY 
     An electric adapter for providing output power to an accessory includes an adapter housing having a projection that carries an electrical input conductor and is configured for insertion into a DC power accessory port, a power outlet cord extending from the housing, a manually operable power switch mounted on the housing, and is operable to electrically connect the electrical input conductor to the power outlet cord, and a timer circuit contained within the housing and configured to electrically disconnect the input conductor from the power outlet cord after a predetermined cycle time period, without removing the projection from the DC power accessory port. 
     In some implementations, the cycle timer circuit can be configured to electrically connect the input conductor from the power outlet cord after a predetermined delay time period. The adapter can also include a timer switch connected to the timer circuit to set the predetermined cycle time period. The timer switch can include a first cycle control to set the cycle time period to a first cycle time period and a second cycle control to set the cycle time period to a second cycle time period. In some examples, the timer switch can also include a first delay control to set the delay time period to a first delay time period and a second delay control to set the delay time period to a second delay time period. The adapter can also include a sequence controller that requires the setting of the timer switch before the power switch is operable to electrically connect the electrical input conductor to the power outlet cord. The operable power switch can be adjustable to control the level of power output. 
     In other implementations, the adapter housing includes an integral fuse. The fuse can also be a user-replaceable. The adapter can also include a power indicator lamp configured to light when the adapter is inserted into the power accessory port. 
     In one example, the accessory is a heating unit electrically connected to the adapter by the power outlet cord. The heating unit can be configured for warming the contents of a baby bottle. The heating unit can include a flexible wrap having engagable fasteners at opposing ends and sized for covering a portion of the bottle. The heating unit can also include a temperature sensor, which can be a thermister, for example. 
     The heating unit can also include a temperature controller connected to the temperature sensor and configured to electrically disconnect the heating unit from the power outlet cord when the heating unit exceeds a maximum threshold temperature, and to electrically connect the heating unit from the power outlet cord when heating unit reaches a minimum threshold temperature. 
     The adapter can also include a temperature cut-off control connected to the temperature sensor the control configured to permanently electrically disconnect the heating unit from the power outlet cord when the heating unit exceeds a critical temperature. 
     In another aspect, an electric bottle warmer includes an adapter housing having a projection with an electrical input conductor for insertion into the a DC power accessory port, a power outlet cord extending from the housing, a manually operable power switch mounted on the housing, the switch operable to electrically connect the electrical input conductor to the power outlet cord, and a cycle timer circuit contained within the housing and configured to electrically disconnect the input conductor from the power outlet cord after a predetermined cycle time period, without removing the projection from the DC power accessory port. The bottle warmer also includes a flexible wrap having engagable fasteners at opposing ends and sized for covering a portion of the bottle, a resistance heating element disposed within the wrap and electrically connected to the power output cord of the adapter, a temperature sensor disposed within the wrap for measuring the temperature, and a thermal switch connected to the temperature sensor to control the electrical connection of the power output cord to the heating element. 
     In some implementations, the cycle timer circuit can be configured to electrically connect the input conductor from the power outlet cord after a predetermined delay time period. The bottle warmer can include a timer switch connected to the timer circuit to set the predetermined cycle time period. The timer switch can also include a first cycle control to set the cycle time period to a first cycle time period and a second cycle control to set the cycle time period to a second cycle time period. The timer switch can also include a first delay control to set the delay time period to a first delay time period and a second delay control to set the delay time period to a second delay time period. 
     In one implementation, the first cycle control is configured to heat the contents of a bottle having a first volume and the second cycle control is configured to heat the contents of a bottle having a second volume to predetermined temperature. The first and second controls can be located on the adapter housing and be marked with indicia corresponding to a first bottle volume and a second bottle volume, respectively. The bottle warmer can also include a sequence controller that requires the setting of the cycle timer switch before the electrical input conductor can be electrically connected to the power outlet cord. 
     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIGS. 1A and 1B  are plan and side views of an electrical adapter according to one example. 
         FIG. 2  is an exploded perspective view of the adapter of  FIGS. 1A and 1B . 
         FIG. 3  is a schematic view of a system including an electrical adapter connected to a bottle warmer. 
         FIG. 4  is a plan view of a flexible wrap for a bottle warmer. 
         FIG. 5  is a diagrammatic view of the flexible wrap of  FIG. 4 , showing the internal electrical components. 
         FIG. 6  is a detail view of the flexible wrap of  FIG. 4 , showing the multiple layers. 
       Like reference symbols in the various drawings indicate like elements. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1A and 1B , an electrical adapter  10  is configured for engagement with a DC accessory power port, such as a typical 12-volt car receptacle, or a portable power source, such as a portable 12-volt power inverter, for example. The adapter  10  includes a housing  15  having a base region  20  and a port region  25 . A power card  30  extends from a first end of the base region  20  at a molded strain relief  35 . The base region  20  includes a power switch having an on-button  40  and an off-button  45 . A power indicator light  50 , a first timer control switch  55  and a second timer control switch  60  are disposed on a top surface of the housing  15 . The buttons can be configured to illuminate when activated. The adapter  10  can be ergonomically designed for ease of insertion and removal from the accessory port, such as a typical 12-volt car receptacle, for example. The face of the housing  15  is substantially flush to permit ready access to buttons  40 ,  45 , control switches  55 ,  60 , and the indicator light  50 . In one example, the length of the adapter  10  is about 30 millimeters and the width across the widest portion of the base region is about 50 millimeters. 
     The port region  25  is configured for engaging the accessory power port and includes a first electrical contact  65  disposed at an end of a tapered neck  70  and a second electrical contacts  75 ,  77  disposed along a length of both sides of the neck  70 . Prongs  80 ,  85  extend along the length of both sides of the neck disposed between the second electrical contacts  75 ,  77  to secure the adapter  10  in the accessory port. 
     Referring now to  FIG. 2 , the exploded view of adapter  10  shows an upper housing  15   a  and a lower housing  15   b  containing internal components as follows. A control pad  90  includes the on-button  40 , off-button  45 , and timer controls  55 ,  60 . A circuit  100  is connected to the control pad  90  and the power cord  30 . A clip  105  is connected to the circuit  100  and includes protruding surfaces which extend through openings in the housing  15  to form the second electrical contacts  75 ,  77  ( FIGS. 1A and 1B ). A spring  110  biases the first electrical contact  65  outwardly against a cap  115  which secures a retainer ring  120  to the neck  70 , by threaded engagement thereto, for example. 
     Referring now to  FIG. 3 , and in one example, a system  150  for heating a bottle containing a liquid includes the adapter  10  connected to a bottle warmer  155  by the power cord  30 . The cord  30  is of sufficient length to permit convenient access to the bottle warmer  155  while the adapter  10  is inserted into the accessory port. 
     Referring now to  FIGS. 4–6 , the bottle warmer  155  is connected to power cord  30  and includes a flexible wrap  160  having a seem  165  along the top and side edges, and an elastic cord threaded along the bottom edge  170 . The wrap  160  is sized and configured to be wrapped around a bottle (not shown), the drawn edge  170  contours the wrap  160  to securely fit a tapered portion of the bottle. A strap  175  is attached to a middle portion of the wrap  160  and includes a buckle  180  at a first end and a touch fastener  185  at a second end, the touch fastener having a first region  190 , such as hooks for example, and a second region  195 , such as loops for example. 
     After the wrap  160  is wrapped around the bottle, the second end of the strap  175  can be inserted into the buckle  180  and pulled back toward the strap to releasably engage the first region  190  with the second region  195  of the touch fastener, thereby securing the wrap  160  around the bottle. A mesh pocket  200  having an opening  205  can be disposed along a portion of the wrap  160  for storing the power cord  30 . An elastic cord is threaded along the top edge  210  of the opening  205  to keep the edge  210  taught and adjacent the wrap  160  while permitting some defamation for opening the pocket  200 . A flap  215  is disposed in a generally vertically orientation and attached to an upper edge of the wrap  160  at a first end  217  and releasably attached to a lower portion of the wrap  160  at a second end  219 . The second end  219  includes a first region  220  of a touch fastener with a second region  225  of the touch fastener is affixed to a lower portion of the wrap  160 . The flap  215  can inserted through a loop of an accessory bag (not shown) for attaching the wrap  160  thereto when the system  150  is not in use. The accessory bag can be insulated and adapted for holding icepacks and for storing the bottles until they are ready to be heated. 
     Referring to  FIG. 5 , the electrical components of the warmer  155  include a heating wire  230  disposed along an inside surface of the wrap  160 . The heating wire  230  is electrically connected to a heat overload fuse  235  and a non-resettable thermal cut-off switch  240 , both of which can include temperature sensors and are disposed along an inside surface of the wrap  160 . The heating wire  230  is connected to a re-setting temperature controller, which can be included in the circuit  100 , contained within the housing of the adapter, for example, having a rating of 95 C +/−5.0 C. In one example, when the re-setting temperature controller senses a temperature exceeding a predetermined critical temperature, electric current is disconnected from the heating wire  230 . When the temperature falls to 65+/−15.0 C, electric current is reconnected to the heating wire. As a failsafe measure, the thermal cut-off switch  240 , disconnects electric current from the heating wire  230  if the measured temperature reaches 113 C, in the event that the temperature controller fails. 
     Referring to  FIG. 6 , the wrap  160  includes multiple layers including an inner layer  250 , a flexible metallic foil  255 , the resistance heating wire  230 , a foil-coated heat conductive/reflective layer  260 , a foam-backed reflective/insulation bonded material  265 , a polyurethane foam layer  270 , and an outer layer  275 . The combination of multiple layers provide the desired thermal and structural properties for the wrap  160 . 
     The inner and outer layers  250 ,  275  are formed from a textured polyvinyl carbonate which are flame-retardant and heat resistant to about 120 C. Each layer has a thickness of about 0.3 mm. The flexible metallic foil  255  includes an adhesive backing that secures the heating wire  230  in place to the foil-coated heat conductive/reflective layer  260  in a coiled or looped configuration to maximize resistance heat dispersion. The heating wire  230  is rated for about 36 W+/−5%, and has a resistance value of about 3.65 ohm/meter. The wire is formed from Fe Cr and has a diameter of about 0.7 0 mm. The wire can be coated with a wire wrap of extruded silicon, having a heat resistance up to about 180 C and include two-rope glass fiber having a heat resistance up to about to 200 C. The foil coated heat conductive/reflective layer  260  is formed from four material bonded compositions including a first layer of metallic foil, a second layer of paper, a third layer of glass fiber and a fourth layer of metallic foil. Layer  260  is the primary heat conduction/reflective medium to direct heat generated from the heating wire  230  toward the radial center of wrap  160  when in a wrapped configuration about the bottle. The glass fibers add strength to the material and the paper adds thermal insulation. The foam-backed reflective/insulation bonded material  265  includes a top layer having a quilted metallic foil for providing an additional heat reflective medium for the heating wire  230 , and a back layer of expanded polyethylene foam (EPE) for insulation, having a thickness of about 3 mm. The polyurethane foam layer  270  adds additional insulation to minimize heat transfer to outside of the wrap  160 . The foam layer  270  is fire-retardant, meets CA116/117 requirements and has a thickness of about 4 mm. 
     In operation, in one example, a user begins the using the system by inserting the starts the system  150  by inserting the port region  25  of the adapter into the accessory port. Once the adapter is plugged into a 12V receptacle (typical automobile “accessory” receptacle), the indicator light  50  illuminates, such as a red LED light, for example, to signal that power is available to the adapter  10 , yet, no heat is applied to the wrap  160 . 
     The user then places a bottle in the wrap  160  and secures it tightly around the bottle by inserting the second end of the strap  175  into the buckle  180  and pulling it back toward the strap  175  to join the first and second regions  190 ,  195  of the touch fastener  185 . The drawn edge  170  retains the wrap  160  against the tapered end of the bottle. 
     Next, the user first sets the heating cycle duration corresponding to the amount of liquid to be heated, such as standard baby bottle sizes, 5 and 8 ounces, for example, by pressing one of the timer controls  55 ,  60  on the adapter. Each of the controls  55 ,  60  will illuminate when pressed, and shut off if pressed a second time. After the heating cycle duration is set, the user presses the on-button  40 , which illuminates to indicate that power is flowing to the wrap  160 . The control circuit  100  sends power to the heating wire  230  for the set heating cycle duration. In one example, the operation sequence requires the user to press the one of the timer controls  55 ,  60  button first, before pressing the on-button  40  to prevent an accidental one button starting of the system  150  by a child, for example. 
     In one example, if a user accidentally starts the system  150  without a bottle placed inside the wrap  160 , the resetting temperature controller will control the dissipation of excess heat by automatically cycling the heating wire  230  off and on to minimize excess temperatures in the wrap  160  until the adapter off-button  45  is pressed, or the adapter  10  is removed from the accessory port. The resetting temperature controller will also cycle the heating wire  230  off and on while heating a bottle if localized regions of high temperature are detected. This can prevent accidental overheating localized area of the wrap  160  when all normal heat activation controls are properly finctioning. If the re-setting temperature controller fails, the fuse  235  will sense excessive temperature, and disconnect power from the heating wire  230 , permanently. Alternatively, the heat overload fuse  235  can be user-replaceable. The control circuit  100  will also disconnect power from the heating wire  230  if an amperage input overload or an amperage draw overload, from an adapter circuitry fault, for example, is detected. 
     The control circuit  100  will continue to send power from the adapter  10  to the wire  230  to heat the wrap  160  for the duration of the heating cycle and then automatically disconnect power to the wire  230  and switch all button lights off, at the completion of the heating cycle. In one example, control circuit  100  will send power from the adapter  10  to the wire  230  for the time required to raise the temperature of liquid inside the bottle from 10 C (50 F) to 37 C (98 F). If the first timer control  55 , corresponding to about 5 ounces, is pressed, the control circuit  100  will heat the warmer for about 15 minutes. If the second timer control  60 , corresponding to about 8 ounces, is pressed, the control circuit will heat the warmer for about 22 minutes. During this time, the wire  230  heats the liquid inside the bottle to a suitable consumption temperature, for example, about 37 C. At any time, the user may stop the heating cycle before auto-shut off by pressing the off-button  45 . This manual shut-off allows the user to interrupt the heating cycle, if for example, a 5 ounce bottle is placed in the wrap  160  and the second timer control  60  is set (for bottle having a volume of 8 ounces). This also allows a measure of control if the user does not wish to heat the liquid inside the bottle to the consumption temperature, or if the user is heating a bottle containing an already warm liquid. In one example, the power switch is adjustable to control the power level to the wire  230  and the heat generated in the wrap  160 . 
     A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, in place of the bottle warmer  155 , an electric warming blanket, a baby wipes warmer, a cell phone charger, a seat warmer, or an auxiliary light could be connected to the adapter  10 . Accordingly, other embodiments are within the scope of the following claims.