Patent Publication Number: US-8109775-B2

Title: Juvenile product assembly with intrinsic electrical connection

Description:
BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The present disclosure is generally directed to child devices or juvenile products, and more particularly to electrically powered child devices and juvenile products. 
     2. Description of Related Art 
     Child swings and other juvenile products commonly include electrically powered components. The types of components vary widely, ranging from electric motors to speakers and lights of an audio-visual entertainment system, to name but a few. Most products utilize a battery power source to support these loads. As the electrical loads have increased with more complex product features and component functionality, some juvenile products have been plugged into a standard wall outlet to rely on AC line power. 
     Juvenile products have been constructed to deliver power from the AC line in different ways. For example, a child pendulum swing has been connected to AC line power by way of wires running along a frame leg to reach the elevated housing in which the electronics and drive mechanism are located. Assembly of the swing then requires a caregiver to connect the wires and the housing using a connector at the end of the wires. Unfortunately, both the wires and the connector are often considered unsightly. 
     Some juvenile products have wires running inside a frame leg. While these wires are thus hidden from view, a caregiver is forced to make electrical connections during product assembly. That is, the electrical connections must be made before access to the interior of the frame leg is foreclosed as a result of the product being assembled. The steps taken to establish these electrical connections resulted in added complexity in the assembly process. The complexity can lead to errors, thereby requiring assembly steps to be reversed, which may be impracticable or impossible. 
     Child swings have been equipped with a switch to select between battery-powered and AC line-powered operation. U.S. Patent Publication No. 2007/0207870 describes one example of a child swing with a switch to support these two modes of operation. A caregiver generally must choose between the two power sources, make any necessary connections, and position the switch accordingly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Objects, features, and advantages of the present invention will become apparent upon reading the following description in conjunction with the drawing figures, in which like reference numerals identify like elements in the figures, and in which: 
         FIG. 1  is a front, perspective view of one example of a child swing constructed in accordance with several aspects of the disclosure. 
         FIG. 2  is an exploded, perspective view of a structural assembly of the child swing of  FIG. 1  in which a device housing and two frame legs have a structural connection with an intrinsic electrical connection in accordance with an exemplary embodiment. 
         FIG. 3  is a perspective view of an exemplary frame leg of the structural assembly of  FIG. 2  with an end plug constructed in accordance with several aspects of the disclosure to establish the intrinsic electrical connection. 
         FIG. 4  is an exploded, perspective view of the frame leg and the end plug of  FIG. 3  to show the end plug in greater detail. 
         FIG. 5  is a side, elevational view of the end plug of  FIG. 3 . 
         FIG. 6  is a side, elevational view of the structural assembly of  FIG. 2  with the device housing fragmented to depict a housing shell constructed in accordance with several aspects of the disclosure to establish the intrinsic electrical connection. 
         FIG. 7  is a partial, perspective view of the device housing shell of  FIG. 6  to show the intrinsic electrical connection in greater detail. 
         FIG. 8  is an exploded, perspective view of the device housing shell of  FIG. 6  to show an exemplary contact assembly in accordance with several aspects of the disclosure. 
         FIG. 9A  is a rear, perspective view of the contact assembly of  FIG. 8 . 
         FIG. 9B  is a side, elevational view of the contact assembly of  FIG. 8 . 
         FIG. 9C  is a rear, elevational view of the contact assembly of  FIG. 8 . 
         FIG. 10  is a partial, perspective view of an exemplary frame leg having an electrical connector constructed in accordance with an alternative embodiment. 
         FIG. 11  is a schematic diagram of an exemplary power source control circuit configured in accordance with several aspects of the disclosure and for coupling to the intrinsic electrical connection(s) of the disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     The disclosure is generally directed to juvenile products or child devices having a structural assembly that intrinsically includes or establishes an electrical connection. As described below, the structural assembly includes one or more structural connections with a built-in electrical connection, thereby facilitating the delivery power from a power source, such as an AC line source. Product assembly is not complicated by the built-in electrical connection, inasmuch as the electrical connection is a direct consequence of the structural connection of a number of structural components of the assembly. In other words, the products and devices described below minimize, if not eliminate, the need for wire routing or electrical connections on the product beyond the intrinsic connection(s) formed during structural assembly. 
     Several aspects of the disclosure are directed to simplifying assembly, while ensuring a consistent and robust electrical connection to a power source, such as an AC line source. One way in which assembly is simplified involves not requiring a user to make electrical connections on or in the product, or within structural components thereof. In this way, these aspects achieve an aesthetically pleasing product design (e.g., the absence of external wire connections) without complicating assembly. These aspects also generally address the challenges of delivering power from an AC outlet to a load device (or devices) spaced from the floor and, for that matter, the outlet. These aspects still further address the challenge of establishing an electrical connection to load device(s) located within a housing or other enclosure. To that end, in some cases, the electrical connection is established within the device housing. In these and other cases, the electrical connection is established using a frame leg or other frame component that is axially connected to another structural component. In those cases, the electrical contacts may be configured and aligned so that an electrical connection is made even when the frame leg moves axially. A number of other challenges are also addressed, including establishing an electrical connection in a safe and effective manner, and the protection of contacts or other components of the electrical connection during shipping and before assembly. 
     These and other aspects of the disclosure are compatible with products that are both battery-powered and powered via an intrinsic electrical connection to the AC line. In some examples, these power sources are coupled to the electrical load(s) via a circuit having one or more isolation diodes. The circuit generally allows the product to automatically switch between the AC line power and the battery power in a safe and convenient manner. In this way, a caregiver may safely elect to use the product with both batteries and a wall plug connection to the AC line present. In one example, the isolation diode(s) of the circuit prevents conflicts between the two power sources from arising, thereby avoiding, for instance, two sources competing to establish a voltage level, or a reverse current flow through the batteries. In this way, the circuit described below helps maintain a stable and safe supply voltage for the electrical load(s). 
     Although described below in connection with a child pendulum swing, these and other aspects of the disclosure arc well-suited for any juvenile product or child device, including, for instance, bouncers, rockers, cribs, and playards. Thus, the examples described below are set forth with the understanding that the disclosure is not limited to child pendulum or other swings, or the other products identified above. Moreover, the nature of the electrical load need not involve a drive mechanism or, for that matter, any motion whatsoever. 
     Turning now to the drawing figures,  FIG. 1  depicts an exemplary child swing  20  with a structural assembly  21  having a number of structural components arranged in an A-frame configuration to suspend an occupant seat assembly  22  above a floor surface. The structural assembly  21  of the swing  20  generally includes a structural frame  24  and a pair of pivot joints  26 ,  28 . The frame  24  includes pairs of front legs  30  and rear legs  32  that extend upward from the floor surface and either rearward or forward to meet at one of the pivot joints  26 ,  28 . Located at the pivot joints  26 ,  28  are housings  34 ,  36  in which top ends of the legs  30 ,  32  are received. The pivot joints  26 ,  28  also include respective hubs  38  to support the reciprocal motion of the swing  20 . To that end, hanger arms  40  extend from the pivot axis defined by the hubs  38  to support the seat assembly  22 . In this example, the hanger arms  40  are bent rearward from the pivot axis before turning downward for coupling to the seat assembly  22 . 
     The frame  24  may also include a number of other structural components to provide support for the swing  20 . In this example, feet  42  are disposed at lower ends of each leg  30 ,  32  to provide a stable foundation for the assembly  21  when resting on the floor surface. A cross bar  44  couples the feet  42  of the front legs  30 , while a cross bar  46  couples the feet of the rear legs  32 . Together, the front legs  30 , the rear legs  32 , the crossbars  44 ,  46 , and the feet  42  form a support base or stand for the swing  20  and any one or more operational components or devices thereof. Above the support base, the frame  24  may include a seat frame  48  and one or more entertainment bars  50 . In this example, the entertainment bar  50  extends upward from and between the hanger arms  40  such that one or more entertainment items  52  may be suspended above the seating area defined by the seat assembly  22 . 
     Generally speaking, the swing  20  includes a number of components or devices configured for electrically powered operation. In many cases, these components or devices are directed to entertaining or soothing the child occupant. Operation of the components or devices may involve movement, sound, lighting and other visual stimuli, or any combination of these and other actions or activities. The swing  20  generally includes a drive mechanism (not shown) enclosed in the housing  34  and/or the housing  36  for imparting movement to the hanger arms  40  and thereby giving rise to the reciprocating motion of the seat  22 . As described further below, the drive mechanism may include a DC electric motor. The swing  20  also includes a control panel  54  disposed on the housing  34  and configured to control the operation of the drive mechanism and other devices and components. For instance, the control panel  54  may have a number of buttons or switches to select music or sounds for playback to soothe the child occupant. The control panel  54  may include a number of electrically powered lights or other visual elements to indicate an operational status or provide other information to the caregiver. In this example, the entertainment items  52  may also be electrically powered to include, for instance, lights or motion. 
     In accordance with one aspect of the disclosure, AC line power acts as a power source for the above identified components and devices (and other electrically powered components or devices of the swing  20 ). As described further below, the power derived from the AC line is routed to the swing  20  from an AC wall plug outlet (not shown) via an AC adapter or AC-to-DC converter  56 , a cord  58  extending from the converter  56 , an external or off-board coupling  60 , and a cord  62  coupling the connection to the structural assembly  21  and, in this case, the frame  24 . The AC-to-DC converter  56  is generally configured to down-convert or step down the AC line voltage (e.g., 110 V) to a lower DC voltage level (e.g., 6 V). In this way, the voltage step-down safely occurs at the wall (i.e., remotely from the product) rather than on-product, although in some cases the 110 V supply may be delivered to the product. The DC voltage is then carried via the cord  58  to complementary connector jacks  64  and  66  of the coupling  60 . The jacks  64 ,  66  may be configured to establish the connection in any desired manner (e.g., press-fit, magnetic, etc.), but are generally cooperatively shaped to engage one another for a suitably low resistance connection. In this case, the connector jack  66  is configured as the jack plug of the connection. However, the coupling  60  need not rely on, or be limited to, a typical plug-socket arrangement, as in the example shown. In some cases, the connector jack  66  includes one or more safety features to ensure that the DC voltage level is not easily or readily accessed at the connector jack  66  or, more generally, the connection between the jacks  64 ,  66 . 
     The external routing of the line-derived power is generally configured to provide a safe and convenient delivery of power from the AC wall outlet. To this end, the cord  62  may extend from a port  68  located on one of the rear legs  32  at a relatively low height or position. In that way, the external delivery path can transition to an internal delivery path as soon as possible. The cord  62  may also be relatively short, extending only a short distance from the leg  32  or, more generally, the frame  24 , to minimize the extent to which the cord  62  presents a hazard when not in use. For example, the length of the cord  62  may be short relative to the length of the cord  58 . In some cases, the cord  62  has a length insufficient to reach the floor surface, even though the cord  62  may project from the housing  24  at the low height shown in  FIG. 1 . 
     The coupling  60  may, but need not, be configured with a quick release or disengagement feature to avoid the creation of a trip hazard via the external routing of the line-derived power. In this example, the connector jacks  64  and  66  of the coupling  60  can be readily disengaged. In this way, the extent to which the cords  58  and  62  are disposed remotely from the structural assembly  21  also does not pose a safety problem for the child occupant. The force required to disconnect or disengage the jacks  64  and  66  may thus be relatively low, and may be substantially lower than the force involved in overcoming a retaining grommet  70  disposed in the port  68 . As a result, the jacks  64  and  66  disengage before any permanent damage occurs to the components involved in the internal or on-board routing of the line-derived power. 
     The structural components and characteristics of the assembly  21 , the frame  24 , the housings  34 ,  36 , and any other component of the swing  20  may vary considerably from the example shown. The legs  30 ,  32 , for instance, may be arranged in a variety of configurations to form different support bases or stands for the swing  20  and its operational devices and components. 
     The motion characteristics of the swing  20  may also vary considerably. The arrangement or configuration of structural components may thus vary accordingly. For instance, some alternative swing designs involve a single arm cantilevered from an upstanding post. Several examples of such alternative swings are described in commonly assigned and co-pending U.S. application Ser. No. 11/385,260, entitled “Child Motion Device,” and published under U.S. Patent Publication No. 2007/0111809, the entire disclosure of which is hereby incorporated by reference. 
       FIG. 2  depicts the assembly of several structural components of the exemplary swing  20  in greater detail to show several aspects of the internal or on-board routing of the line-derived power. In this example, the line-derived power is routed through one of the rear legs  32  after entering the frame  24  at the port  68  via the cord  62  and the connector jack  64 . To that end, a cord  72  generally runs the length of the leg  32 , from the port  68 , through an interior of the leg  32 , eventually reaching a top end  74  of the leg  32 . The leg  32  (and other legs of the frame  24 ) may be tube-shaped to provide an open interior. Alternatively or additionally, the leg  32  includes an interior tube or conduit (not shown) through which the cord  72  runs. More generally, the cord  72  may be routed through the interior of the leg  32  in any desired manner, and through any desired conduit. Due to the protection from the leg  32  or any internal conduit, the cord  72  may, but need not, differ from the cords  58  and  62 . As a result, the internal routing of the line-derived power may include or involve any type or form of two-wire pair or other wiring, and a variety of different insulation or protective sleeve arrangements. 
     During assembly of the swing  20 , the front and rear legs  30  and  32  are secured within respective slots  76 ,  78  in the housing  34  in position for the A-frame configuration. In this example, both of the slots  76 ,  78  are formed in a downward facing surface  80  of a lower or bottom side  82  of the housing  34 . As a result, the legs  30 ,  32  are inserted in a generally upward direction into the housing  34  via the slots  76 ,  78 , respectively. The front leg  30  pivots within the slots  76  to move from a position in which the frame  24  is oriented in a folded configuration to the position shown in  FIG. 2  in which the frame is oriented in the A-frame, in-use configuration. To that end, the slot  76  is elongated or widened to allow the pivoting motion. In contrast, the slots  78  presents a generally circular opening through which the leg  32  is inserted, although a variety of other shapes may be used to correspond with differently shaped tubes or legs. The leg  32  is inserted into the slot  78  and, thus, the housing  34 , until a snap button  84  engages a snap connector disposed within the housing  34 . Further details regarding the connection are provided below in connection with multiple exemplary snap connections. In general, however, the engagement of the snap button  84  and the housing  34  establishes a structural connection between the leg  32  and the housing  34 , thereby securing the leg  32  in position within the housing  34 . That said, the structural connection need not involve a snap connector or connection, but rather include or involve any type of fastener or fastening arrangement. 
     In accordance with one aspect of the disclosure, the structural connection of the leg  32  and the housing  34  forms an intrinsic electrical connection for delivering the line-derived power. As described below, the leg  32  and the housing  34  are generally configured to include respective contacts or contact assemblies that are positioned for establishing a power delivery path with a built-in electrical connection resulting from the structural assembly process. In this example, the contacts or contact assemblies are disposed internally, i.e., within both of the respective structural components. In this way, the contacts or contact assemblies are generally protected from damage during shipment and otherwise before assembly, as well as protected from damage during use (i.e., after assembly). Nonetheless, the internal disposition of the elements establishing the electrical connection is not necessary, as the structural connection may be, for instance, partially or wholly exposed or otherwise accessible from the exterior of the housing  32 . Moreover, one of the elements establishing the electrical connection may be external to the structural component, as shown in the example of  FIG. 10 . More generally, the cord  72  or other line carrying the power derived from AC line is coupled to the contacts or contact assembly within the leg  32 . In this example, contacts are carried within an end plug  86  inserted into the upper end  74  of the leg  32 . The end plug  86  and the leg  32  have a generally similarly shaped cross-section so that the end-plug  86  can lead the insertion of the leg  32  into the slot  78  during assembly. 
     The housing  34  includes a battery compartment  88  configured to contain a battery back or set of individual battery cells so that the electrical components and devices of the swing  20  can also be operated under battery power. The battery compartment  88  is accessed via a removable panel or door  90  disposed in a lateral side  92  of the housing  34 . The lateral side  92  faces inward, or toward the seat ( FIG. 1 ). A hub  94  of the pivot joint  38  is positioned on the lateral side  92  of the housing  34  so that one of the hanger arms  40  ( FIG. 1 ) can extend inward, or toward the seat  22 . The lateral side  92  also includes a speaker  96  for directing music or other sounds toward the child occupying the seat. These and other aspects of the housing  24  may vary considerably from the example shown. For example, the battery compartment  88 , the hub  94 , and the speaker  96  need not be located on the lateral side  92 , and may be re-positioned or otherwise re-configured as desired. Nonetheless, in some cases, the positioning of the battery compartment  88 , the hub  94 , and the speaker  96  shown in  FIG. 2  may be useful for providing room for the leg  30  to pivot within the housing  34 , and room for the intrinsic electrical connection with the end plug  86  inside the housing  34 . For instance, the battery compartment  88  is centrally located within the housing  34  so that each of the legs  30 ,  32  can be received within the housing  34  closer to forward and rearward sides  98 ,  100  of the housing  34 , respectively. 
     With reference now to  FIG. 3 , the end plug  86  includes a contact assembly  102  configured to establish the intrinsic electrical connection when the leg  32  is inserted into the housing  34 . To this end, and as described below, the end plug  86  presents one or more structural features that help align the contact assembly  102  with a corresponding contact assembly within the housing  34 . The contact assembly  102  is disposed within an open-ended, cylindrically shaped front (or leading) section  104  of the end plug  86 . The contact assembly  102  includes a pair of contacts  106  mounted on a platform  108  that may extend diametrically across the section  104 . However, the platform  108  need not be oriented within the cylindrically shaped section  104  as shown. For example, in some embodiments, the platform  108  may extend along a non-diametrically oriented segment. The platform  108  may be secured to an inner wall  110  of the section  108  at lateral ends  111  thereof and via one or more radially extending support walls  112 . This example includes a single wall  112  extending orthogonally from a central line of the platform  108 . As a result, the wall  112  divides the platform  108  into two distinct regions isolated or separated from one another to prevent or help avoid electrical shorts. The platform  108  may be shaped as a plank or slab with generally flat, opposite surfaces  114  and  116 . The plank terminates at a front or leading edge  118 . Together, these and other aspects of the end plug  86  may serve as alignment aids in establishing the structural and electrical connections. 
     The contact assembly  102  includes a pair of contacts  120  that engage the surfaces  114  and  116 , and wrap around the front edge  118  as clips. In this example, the clip-shaped contacts  120  are U- or V-shaped to create a pressure fit on the platform  108 . In other cases, the contacts  120  may be secured to one or both surfaces  114 ,  116  of the platform  108  via any number or type of fasteners. 
     When the contacts  120  are shaped as clips as shown, the contacts  120  may have a two-sided configuration well-suited for establishing the intrinsic electrical connection. Each contact  120  has a connection side or interface  122  disposed on one side of the platform  108  and configured to engage a corresponding contact disposed within the housing  34 . Each contact  120  also has a connection side or interface  124  disposed on the other side of the platform having a surface area sufficient for connection with wiring  126  at a solder bump  128 . In this way, the connection interfaces  122 ,  124  are spaced from one another and disposed on opposite or different surfaces. As a result, the solder bumps  128  do not impede or obstruct the electrical connection as the leg  32  slides into position within the housing  34 . More generally, this configuration of the contacts  120  (e.g., the spacing and positioning of the connection sides  122 ,  124 ) allows the electrical connection to be established via sliding movement in a single direction along the principal axis of the leg  32 . Nonetheless, in other cases, the connection may involve additional or alternative movement to the axial sliding described above, including, for instance, a twisting motion or other rotational movement that locks the leg  32  in position and/or establishes the electrical connection. 
     In this example, the connection interface  122  of each contact  120  includes a flat strip that lies flat against the surface  116  of the platform  108 . When the leg  32  is inserted into the housing  34 , the strip is engaged by a corresponding contact within the housing  34 , as described in the examples below. In other cases, the connection interface  122  may be wholly or partially spaced from the platform  108  to act as a spring. When the contact  120  includes a strip similar to the one shown in  FIG. 3 , the spring may be configured as a flat spring that compresses toward the platform  108  as the leg  32  is inserted into the housing  34 . In some cases, the contact  120  is oriented and positioned such that the motion of the spring is in a direction normal or orthogonal to the movement establishing the structural connection (e.g., the axial movement of the leg  32 ). In this way, the contact is aligned and positioned to establish an electrical connection even when the leg  32  moves axially. In some cases, the electrical contact in the other structural component (e.g., the leg  32 ) may be configured with a spring arranged in this manner. More generally, each contact  120  may be configured as any type of spring for elastic compression when the leg  32  slides into position within the housing  34 . For example, each contact  120  may be bent to slope and extend away from the platform  108  as, for instance, a cantilever spring. In these cases, the connection interface  122  is spaced from the platform  108  to a variable extent depending on the engagement of the contact within the housing  34 . 
       FIGS. 4 and 5  depict the end plug  86  in greater detail, including the manner in which the end plug  86  engages the leg  32 . The front or leading section  104  of the end plug  86  is supported by a rear insert or coupling section  126  configured to link to the end plug  86  to the leg  32 . The insert section  126 , in turn, includes a connector segment  128  and an infrastructure or base segment  130  from which the connector segment  128  and the front or leading section  104  extend in opposite, axial directions. The base segment  130  is generally cylindrically (or half-cylindrically) shaped to snugly fit within the end opening of the leg  32 . In this case, the base segment  130  includes a half-cylinder plug or insert  132  that forms a floor or base surface  134  from which the platform  108  extends as a shelf at the outer end of the insert  132 . In some cases, the platform  108  is an integral extension of the insert  132 . More generally, any group of the non-electrical components of the end plug  86  or the insert section  126  may be integrally formed as a single molded component. At the other end of the insert  132 , a disc-shaped wall  136  acts as a foundation for the connector segment  128  and a support wall  138 , which may be integrally formed or connected with the support wall  112  ( FIG. 3 ). The disc-shaped wall  136 , the support wall  138 , and the half-cylinder insert  132  may have a radial extent or size that corresponds with the inner wall of the leg  32 . In this way, the end plug  86  fits snugly within the leg  32  to prevent any relative radial displacement after assembly. 
     The connector segment  128  in this example includes a snap connector  140  configured to engage the leg  32  to secure the end plug  86  in position. The snap connector  140  may be arranged to engage the leg  32  via a wide variety of snap-fit configurations. For example, any one of a number of different cantilever-based structures may extend axially into the leg  32  from the base segment  130  of the end plug  86  to engage a corresponding recess or other structure therein configured to receive a projection of the cantilever. In this example, the structure includes a serpentine extension  142  mounted to, and extending axially away from, the disc-shaped wall  136  that doubles over to form a V-shaped spring  144  having a button-shaped projection  146  at a terminal end  148 . The button  146  is shaped to engage a hole  150  formed in the leg  32 . In this example, both the button  146  and the hole  150  have corresponding round shapes, although a variety of other shapes may alternatively be used for the projection and recess of the snap connection. More generally, the exemplary snap connection shown is configured for convenient disassembly, as the snap button  146  may be accessed from the outside of the leg  32 . As described below, the extent to which the snap button  146  extends through the hole  150  may also be useful for securing the leg  32  to the housing  32  ( FIGS. 2 and 3 ). 
     The insert section  126  is generally configured to allow wiring carrying the line-derived power to pass through the end of the leg  32  to reach the contact assembly  102  ( FIG. 3 ). To that end, the disc-shaped wall  136  includes a pair of notches  152  shaped to allow lines or wires  154 ,  156  to pass through the insert section  136  of the end plug  86 . In this way, the wires  154 ,  156  do not interfere with the tight fit of insert section  126  and the leg  32  described above. 
     In an alternative embodiment, the connector segment  128  may be structurally separated from those components directed to supporting the electrical connection. For example, the snap connector  140  and the button  146  may be contained within the leg  32  as a component distinct from the conducting components of the front section and any supporting components of the base segment  130 . Thus, the end plug need not be formed from a single integral mold, and the contact-related components may be secured in place within the leg  32  via a different fastener than the one involved in securing the leg  32  to the housing  34 . 
     With reference now to  FIG. 6 , further details regarding the other part of the intrinsic electrical connection are now provided in connection with an exemplary shell  160  of the housing  34 . The shell  160  has a two-piece, molded construction in this example, one of which is shown in fragmented view to reveal an interior space for devices and structures enclosed within the housing  34 . The structural aspects of the housing  34  generally involve the engagement of the legs  30 ,  32  within the interior space, as well as the pivotal coupling with one of the hanger arms  40  ( FIG. 1 ). Many of these structural components and aspects are not shown in  FIG. 6 , or shown in simplified form, in favor of, and for ease in, illustrating the components and aspects of the housing  34  involved in forming the structural connection with the leg  32  and the intrinsic electrical connection thereof Nonetheless, the housing  34  is described below with the understanding that the two-piece shell defines or forms a number of other devices, components, and other elements. For instance, the shell  160  includes an inward facing half-shell  162  that defines a hub section  164  with a pivot shaft aperture  166  for the hanger arm  40 , a box-shaped recession  168  for the battery compartment  88  ( FIG. 2 ), an electronics platform  170  to support and position a circuit board  172  below the user interface panel  54  ( FIG. 1 ) to receive input signals from the switches and buttons thereof, and a speaker chamber  174  in which a speaker basket  176  is seated. An outward facing half-shell  178  may define a number of additional structural components or features, as well as elements directed to connecting the two half-shells  162 ,  178  together. For example, the outward facing half-shell  178  may include a number of fastener holes (not shown) positioned to align with corresponding fastener-receiving posts  180 ,  182  or other structures. 
     The elements and features of the housing  34  involved with the intrinsic electrical connection are now described. Like the end plug  86  described above, the housing  34  has one or more structural features configured to act as an alignment aid in helping direct the structural components to establish the electrical connection. The inward facing half-shell  162  has a number of components positioned relative to the hole  78  for engagement with the leg  32 . During assembly, the leg  32  is inserted through the hole  78  in the axial direction A to an extent that the contact assembly  102  within the end plug  86  of the leg  32  reaches and touches a contact assembly  184  disposed within the housing  34 . The contact assembly  184  includes a platform  186  to support a pair of contacts  188  spaced from one another thereon. The contacts  188  are generally mounted and oriented to extend in the axial direction A to coordinate with the axial movement of the contact assembly  102  during assembly. In this example, the contact assembly  184  is positioned relative to the half-shell  162  at a height for alignment with, and insertion in, an opening  190  defined by the end plug  86 . As described further below, the contact assembly  184  has an axial profile shaped to be cooperatively received within the opening  190 . As a result, exposed faces  192  of the contacts  188  can slidably engage the portions (i.e., the connection interfaces  122 ) of the contacts  120  disposed on the platform  108  within the opening  190 . 
     The contact assembly  184  is generally disposed at the end of a slot or groove  194  that extends into the housing  34  from the hole  78 . The slot  194  may be defined by a number of guides or retaining walls, including in this example outer rails  196  and inner rails  198 . In some cases, the guides or retaining walls may be integrally formed with either one of the half-shells  162 ,  178 . More generally, the outer and inner rails  196 ,  198  and other guides or retaining walls run along a direction parallel to the axial direction A to retain the leg  32  within the housing  32  both during and after assembly, as well as direct the end plug  86  toward the contact assembly  184 . In this example, the leg  32  may ride on the inner rails  198  during assembly (e.g., the movement in the axial direction A), while being contained from non-axial movement by the outer rails  196 . The inner rails  198  may also serve another function, extending to a height relative to the half-shell  162  to position the leg  32  at a height relative to the half-shell  162  that aligns the opening  190  with the contact assembly  184 . The outer and inner rails  196 ,  198  may form part of an injection mold distribution that forms other parts of the molded structure. The outward facing half-shell  178  may also include any number of guides, rails, or walls (not shown) for retaining and guiding the leg  32 . 
     The half-shell  162  also includes a cylindrical recess  200  or other structure configured to complete the snap-based structural connection with the leg  32 . The recess  200  is spaced axially from the contact assembly  184  a distance that corresponds with the length of the snap connector described above ( FIG. 4 ). More specifically, the recess  200  is configured to receive the snap button  146  ( FIG. 4 ) that extends through the hole  150  formed in the leg  32 . In this way, the leg  32  snaps into a fixed position within the housing  34  in which the contact assemblies  120  and  184  are engaged to establish the electrical connection. In some cases, the recess  200  may be formed from a circular wall  202  integrally formed with the inner rails  198  as part of a common mold. 
       FIGS. 7 and 8  depict the housing components of the intrinsic electrical connection in greater detail. The contact assembly  184  of this example includes an insert  204  shaped to engage the shell  162  between the outer rails  196  and, in so doing, position the contacts  192  for the electrical connection. To this end, the insert  204  defines the platform  186  on which the contacts  192  are mounted as part of a cantilevered support structure  206  that extends in the axial direction ( FIG. 6 ) from an upstanding key  207  shaped to be received in a way  208 . The support structure  206  in this example is shaped as a semi-cylindrical slug  209  to provide a flat surface for the platform  186 , as well as a semi-circular front surface  210  that engages the end plug  86  of the leg  32 . More specifically, the slug  209  and its front surface  210  are configured as a male projection to be received within the female receptacle formed by the semicircular opening  190  ( FIG. 6 ) defined by the end plug  86 . As the leg  32  is inserted into the housing  34  during assembly, the end plug  86  eventually reaches the support structure  206 . As shown in  FIG. 3 , the end plug  86  includes a wall  212  defined by the base segment  130  of the end plug  86 . After the support structure  208  is received within the opening  190 , eventually the wall  212  contacts the front surface  210  of the support structure  206 . In this way, the front surface  210  acts as a stop to limit axial travel of the leg  32  within the housing  34 , and establish the structural connection at a position that ensures the electrical connection of the leg contact pair and the housing contact pair. 
     As shown more clearly in  FIG. 8 , the key  206  includes a support wall  214  that extends orthogonally away from the flat surface of the platform  186  at a rear side  216  of the insert  204 . The support wall  214  is configured for cooperative engagement with a slot  218  of the way  207 . In this example, the slot  218  is defined by a pair of parallel walls  220 ,  222 , as well as the outer rails  196 . The walls  220 ,  222  may be integrally formed with the outer rails  196 , as well as any other component of the housing  34  or the half-shell  162  thereof. 
     The inner rails  198  are shown in the example of  FIGS. 7 and 8  as terminating at the cylindrical recess  200  for ease in illustrating the components of the insert  204  and its engagement of the housing  34 . Thus, the example is shown with the understanding that the inner rails  198  may continue to run beyond the cylindrical recess  200 , as shown, for instance, in  FIG. 6 . The cylindrical recess  200  is also shown in  FIGS. 7 and 8  as integrally formed with the inner rails  198 , as well as a support rib  224  running in parallel and between the inner rails  198 . The support rib  224  extends as an upstanding wall relative to the half-shell  162  in a sloped manner to act as a ramp for the snap connection. The support rib  224  may also provide axial strength for the structural connection of the housing  34  and the leg  32  ( FIG. 6 ) once the components are in place. 
     With continued reference to  FIGS. 7 and 8 , the speaker basket  176  ( FIG. 6 ) has been removed from the speaker chamber  174  to reveal the wiring path for the lines connected to the contact assembly  184 . Grooves or notches  226 ,  228  are formed in a wall  230  that defines the speaker chamber  174  to allow wires  232 ,  234  to run from the contact assembly  186  to the electronics and other devices within the housing  34 . This wiring path may be useful in cases where the outer rails  196  and other guides or walls (not shown) of the housing  34  enclose the leg  32  in the structural connection, thereby otherwise blocking the passage of wires. 
     In  FIGS. 9A-9C , the insert  204  is removed from the housing  34  to depict the contact assembly  184  in greater detail. In this example, each contact  188  includes a U-shaped clip  236  configured to engage a rear edge  238  of the platform  186 . Each clip  236  includes a strip bent to form upper and lower clasp sections  240 ,  242  ( FIG. 9B ) that grip and engage opposite sides of the platform  186 . The clasp section  240  extends along the platform  186  a desired distance before folding over to form a spring  244  of the contact  188 . Each spring  244  slopes upward from platform  186  when not engaged in the electrical connection to form a leaf-spring configuration, providing space for the spring  244  to be elastically deflected toward the platform  186  upon engagement with one of the contacts of the leg  32 . A variety of other contact configurations may alternatively be used. 
     The contact assembly  184  may include an insulating spacer or divider  246  to help prevent a short circuit between the contacts  188 . In this example, the spacer  246  includes an upstanding wall  248  that extends along and from the platform  186  to a desired extent. The wall  248  need not extend farther along the platform  186  than the length of the contacts  188 , as in the example shown, and as best shown in  FIG. 9B . The wall  248  may be integrally formed with the other, non-conductive components of the assembly  184 , such as the support structure  206 . 
     The key  207  of the exemplary contact assembly  184  shown in  FIGS. 9A-9C  may form part of a wall  250  that acts as a riser for the platform  186 . In this case, the wall  250  includes a semi-circular opening  252  to accommodate the insertion of the clips  236  of the contacts  188 . The shape of the opening  252  ( FIG. 9A ) generally corresponds with the shape of the semi-cylindrical slug  209 , as the structure may be formed from an integral mold. The wall  250  may also include a pair of end posts  254  that extend orthogonally from the platform  186 . Each post  254  helps to further confine one of the contacts  188 , limiting any lateral movement and maintaining the axial orientation thereof The posts  254  may also engage the other half-shell of the housing  34  to secure the position of the contact assembly  184 . 
     With reference now to  FIG. 10 , the intrinsic electrical connection may involve a variety of different contacts or contact assemblies. That is, the electrical connection need not involve the leaf-spring or strip-based contacts described above. For instance, one other exemplary contact configuration involves a leg  300  with an end  302  configured with a single jack plug  304  or other male projection to be received within another structural component of the swing, such as the housing  34  described above. In this example, the jack  304  includes a conventional headphone jack plug to be received by a matching socket in the other structural component. 
     The structural assembly involving the leg  300  may have a number of snap buttons  306  or other projections to limit and prevent any undesired axial displacement of the structural connection. Preventing axial displacement may be useful in connection with the electrical connection utilizing the jack plug  304  and other jacks similar to headphone jacks because the contact points in such connections are stacked cylindrical elements. In the example shown, for instance, the jack plug  304  includes contacts  308  and  310  separated by an insulator  312 . The structural assembly may also include further components or features to prevent or avoid short circuits arising from an incorrect assembly or disassembly that would change the axial position of the contacts  308  and  310 . 
     Turning to  FIG. 11 , a power source control circuit  350  may be electrically coupled to the above-described electrical connection to accommodate swings having a battery power source. The circuit  350  may be located along the conductive path that delivers power via the electrical connection. For instance, the circuit  350  may be located in the housing  34  to follow the electrical connection. In some cases, the circuit  50  may be disposed on the circuit board described above, to which both the battery power and AC line-derived power is delivered. In the example shown, the lines carrying the battery power are represented by, and coupled to, battery terminal lines  352 ,  354 , while the line-derived power is represented by, and coupled to, AC adapter lines  356 ,  358 . As described herein, the AC adapter lines are coupled to the circuit  350  by one or more intrinsic electrical connections not shown in  FIG. 11 . The DC voltages carried by these lines, as well as the battery lines, are conditioned by capacitors C 9  and C 10 , respectively, to remove any transient, high-frequency noise, before being provided to respective isolation circuits  360 ,  362 . Generally speaking, the isolation circuits  360 ,  362  isolate the power sources (or power source delivery paths) from one another, so that both power sources can remain connected to the electrical load(s) concurrently, as desired. In this way, the possibility for reverse current flow through, for instance, the battery(ies) is eliminated. The isolation circuits  360 ,  362  thus provide a safe mechanism for merging the two power delivery paths at a node  364 . As a result, the electrical load(s) can switch between the power sources without requiring any action from the user if, for instance, the swing is plugged into the wall outlet, or the AC line power is lost. 
     In the example shown, each isolation circuit  360 ,  362  includes one or more Schottky diodes to provide the above-described isolation. The isolation circuit  360  includes Schottky diode D 12 , and the isolation circuit  362  includes Schottky diode D 14 . The isolation circuit  360  includes a further Schottky diode D 13  to establish a voltage drop for the battery source line that is not mirrored in the AC line-derived power delivery path. The diode D 13  also acts as a redundant safety device, insofar as failure of either of the diodes D 12  or D 13  does not result in loss of isolation, i.e., current flow from the AC adapter into the battery. In other cases, the diode D 13  may be replaced with a resistor configured to provide the desired voltage drop. Commercially available Schottky diodes may be used for each of the diodes D 12 , D 13 , D 14 , including for instance the surface mount power rectifiers available under product number MBRS2040LT3G from ON Semiconductor (www.onsemi.com), although a wide variety of other diodes may be used. 
     In operation, the diode circuits  360 ,  362  rely on the similar and maximum levels of the two power sources to ensure that the node  364  is driven by the AC line-derived power when the swing is plugged into the wall outlet. When the two DC levels are roughly equal, the battery path does not conduct as the Schottky diode D 13  introduces a voltage drop commensurate with a forward bias state. As a result, the diode D 13  is effectively reverse-biased. The diode D 13  is also reverse-biased when the AC line-derived voltage level is higher than the battery level. In the event that AC line-derived voltage level drops below the battery level, the AC line will continue to drive the voltage at the node  364  until the voltage differential exceeds the forward bias of the diode D 13 . The AC adapter may then be configured to maintain a DC voltage level above the maximum net battery voltage level to prevent this event from occurring under normal AC line power conditions. For example, in a three D-cell battery source embodiment, the maximum net battery voltage may be approximately 3.6 Volts (i.e., 4.5 Volts−0.45 Volts−0.45 Volts). 
     As a result, when the swing is plugged into the AC wall outlet, the diode circuit  362  sets the node  364  at a higher voltage than the diode circuit  360 . The Schottky diode D 13  is reverse-biased, thereby isolating the batteries, and the electrical load(s) are powered by the line-derived power In this way, the user need not make any adjustments or engage any switches when plugging the swing into the wall outlet. 
     In other cases, one or more of the diodes may be replaced with a respective transistor, such as a power MOSFET or bipolar junction transistor arranged to block reverse current flow. Each transistor would be configured to turn off when the AC adapter voltage is present. In this way, the voltage drop may be less than that resulting from having two isolation diodes in series, as in the example shown. A lower voltage drop may be useful in extending the overall battery life. More generally, a variety of other rectifying devices, circuits, and schemes may alternatively be used to allow the uni-directional current from the battery source. In each of these cases, the electrical load is powered either by the battery power source or via the power delivery path based on whether a power source voltage is present on the power delivery path. In this way, the juvenile product can automatically switch between power sources without requiring action by the caregiver. Yet another alternative approach to blocking reverse current flow (while avoiding the voltage drop of the above-described diode-based circuits) involves a mechanical switch in the AC-to-DC converter that also does not require action by the caregiver, as described further below. 
     The voltage level at the node  364  may be processed further before delivery to the circuit board or other electrical load(s). In the example shown in  FIG. 11 , a fuse F 1  couples the above-described diode circuits to a voltage regulator  366  configured to establish a desired DC power source level, Vcc. The DC voltage level upstream of the regulation may also be used by one or more electrical loads (e.g., a DC motor), and is made available as V-fuse. The voltage source Vcc is generally set by a reverse-biased Zener diode D 15 , which, in this example, is configured to clamp any short-duration voltage spikes to a 6.2 Volt level. The desired level of the voltage source may be lower than the breakdown voltage of the Zener diode D 15 , and set by the AC adapter or the batteries. Capacitors C 7  and C 8  are provided to smooth the voltage sources Vcc and V-fuse, shunting away any current fluctuations from the power sources, such as any 60 Hz noise lingering from the AC line. In this way, the capacitors C 7  and C 8  help to provide a high-quality power supply for any microprocessor circuitry on the circuit board, and help to avoid any 60 Hz noise in audio reproduction. More generally, the capacitors C 7  and C 8  effectively act as a local DC power reserve downstream of the diode isolation circuitry described above. Also, a diode D 8  and the capacitor C 7  together help to isolate and protect the Vcc supply, which may provided to a microcontroller or processor, from large voltage dips at the voltage V-fuse, which may result from large currents going to a DC motor. 
     A resistor R 18  is provided to bleed charge from the capacitors C 7  and C 8  when power delivery ceases. Otherwise, the charge stored in the capacitors C 7  and C 8  can keep the voltage at Vcc high for an undesirably long period of time, which, in turn, can keep the microcontroller or processor running for an undesirable time period. Such extension of processor operation may be inconvenient for a user attempting to reset the processor after, for instance, a processor lock-up due to a power dip or other issue. With the resistor R 18 , the voltage provided to the processor may decay to zero within 5-10 seconds, and the processor can then be reset. 
     A variety of different control and load circuits can be suitably coupled to, and powered by, the above-described circuitry and intrinsic electrical connection. Exemplary control circuits, control techniques, and electrical load devices for child swings are described in the above-referenced, commonly assigned, pending U.S. patent application. Examples of suitable motor drive systems and related techniques are described in U.S. Pat. No. 5,525,113 (“Open Top Swing and Control”), U.S. Pat. No. 6,339,304 (“Swing Control for Altering Power to Drive Motor After Each Swing Cycle”), and U.S. Pat. No. 6,875,117 (“Swing Drive Mechanism”), the entire disclosures of which are hereby incorporated by reference. In these and other examples, the load devices may include control circuitry with one or more microcontrollers for directing and monitoring the swing drive mechanism for startup, speed control, and other features, as well as directing audio and visual entertainment features for the child occupant, and a variety of user interface elements for the caregiver of either an input nature (e.g., touchscreen) or output nature (e.g., status LEDs or other lights). Exemplary control circuits, control techniques, microcontrollers, and other electrical load devices are also described in co-pending and commonly assigned U.S. application Ser. No. 11/932,641, entitled “Motor Drive Feedback Control for a Child Motion Device,” and published as U.S. Patent Publication No. 2008/0139327, the entire disclosure of which is incorporated by reference. 
     Although a number of the examples described above involved a structural connection between a leg and a housing, the structural connection underlying the intrinsic electrical connection may involve one or more other legs, or one or more other frame components. Thus, the structural connection need not involve a housing, and accordingly may involve a coupling of two frame components, such as two sections of a frame leg to name but one example. 
     The above-described electrical and structural connections may also be useful in product shipping. With the structural connection between leg tubes and the housing (or other structural components), the structural components of the product may fit more compactly in a shipping arrangement. The leg tubes may also be shorter if, for instance, the structural connection involves two leg tubes. As a result, a smaller shipping carton or other container may be used. 
     The above-described approach to juvenile product power supply involves the minimal, if any, impact on the circuitry or functionality of the AC wall plug. The conversion circuitry in the AC wall plug can conveniently be housed in an enclosure of a typical size for AC/DC adapters. Moreover, practice of the above-described approach to juvenile product power supply may rely on conventional conversion electronics in the AC/DC adapter. Nevertheless, in some cases, the AC-to-DC converter may include a mechanical switch to provide the isolation features of the above-described diode-based circuitry. For example, the converter may be configured such that insertion of the plug into an AC wall socket causes a mechanical switch to toggle and disconnect the battery(ies) from the electrical load(s). In that case, a third wire may be routed through the cord(s) coupling the juvenile product to the converter to connect the switch and the battery power delivery path. 
     The other aspects of the power delivery paths may also be conventional, or vary as desired, as the disclosed intrinsic electrical connections need not involve or require any electrical wiring, cords or conduits of any specific type, size, form, or other characteristic. Accordingly, the power derived from the AC line may be carried by any electrical wire or set of wires, and thus may utilize any type of electrical line or conduit. Furthermore, the AC power need not be converted immediately at the wall plug jack, but rather may be transformed, converted, or otherwise adjusted at any point along the power delivery path. 
     Practice of the disclosed intrinsic electrical connection approach is not limited to any particular contact structure or design. For instance, in addition to the multiple examples of contacts described above, commercially available barrel connectors may be mounted within a end plug and a housing constructed with features similar to those described above to guide and establish the structural and electrical connections. 
     As described above, the structural connection between two structural components includes additional connective elements to establish an electrical connection intrinsically. While the connection itself may be more complex as a result of the additional connective elements, the assembly of the product remains easy for the caregiver. This simplification of assembly leads to a number of other advantages, including without limitation (i) avoiding pinched or short circuited wires, (ii) hidden wires as much as possible, (iii) a visually attractive design, (iv) a wall plug connection near the floor, (v) easy disconnection of the wall plug and swing to prevent tripping, (v) minimal, if any, impact to AC wall plug size, (vi) minimal cost, and (vii) compatibility with conventional AC wall outlet plugs and converter circuits. 
     The components and structures described above may be constructed from a variety of materials. Support structures may, for instance, be formed from various plastic materials, and the conductive elements from any one or more metals or metallic materials. In some cases, the end plugs described above may be formed as a plastic structure that is sufficiently rigid to guide the contacts together and shield the contacts during shipping and before assembly. Nevertheless, practice of the disclosed intrinsic electrical connection approach is not limited to any specific materials or material combinations. 
     The intrinsic electrical connections and isolation circuits described above may be used in connection with power sources other than one derived from an AC power line. For example, a juvenile product may have multiple battery power sources (conventional or rechargeable), or include a connection to a DC power source, such as an automobile battery. 
     Although certain products and devices have been described herein in accordance with the teachings of the present disclosure, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all embodiments of the teachings of the disclosure that fairly fall within the scope of permissible equivalents.