Abstract:
A structure of a plug-in device with a foldable plug for connecting a power supply to a power-receiving device is provided. The plug-in device includes an upper housing, a blade element, and a lower housing.

Description:
RELATED APPLICATION 
       [0001]    The present application claims priority to U.S. Provisional Application No. 61/897,180, filed Oct. 29, 2013 and incorporates the provisional application in its entirety. 
     
    
     FIELD 
       [0002]    The present invention relates to an plug in device, and more particularly to a plug-in device having a foldable plug. 
       BACKGROUND 
       [0003]    A plug-in device, such as an electrical charger, generally includes an insulating housing, a plug and a circuit mounted within the housing. The plug is used to accept power supplied by an external power source and deliver the power to the circuit. The plug of a typical plug-in device has two conducting blades extending from the housing. The actual configuration of the blades depends on the country for which the plug-in device is designed. 
         [0004]    One prior art charger with a foldable plug is the charger provided by PALM COMPUTING®. Their charger has a cylindrical housing base, with a circuit board arranged in the housing base. There is a plastic positioner placed on top of the circuit elements. The paired blades are placed on top of the plastic positioner. The paired blades rest on a holder in the plastic positioner. A housing cover, made of the same material as the housing, is then placed over the blades, and the plastic positioner is bonded to the housing cover. The housing cover is then permanently coupled to the housing base. A force is applied to the blades by a bending tab on the plastic positioner, when a user opens or closes the blades, which snaps the blades into the open and closed positions. The blades exert pressure on the plastic holder continuously, whether they are open or closed. 
         [0005]    However, this device has a number of drawbacks. First, it has an extra element that needs to be assembled, bonded to the housing cover, in addition to the two housing pieces. This means that manufacturing and assembly tolerances between the separate pieces may cause issues. Second, use introduces significant stress on the bending tab of the plastic positioner, reducing the feel of the opening and closing click. Third, over time the constant force on the bending tab in the open and closed positions will permanently deform the bending tab and further reduce the feel of the opening and closing force. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0006]    The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which: 
           [0007]      FIG. 1A  is an exploded top-view illustrating the assembly of a plug-in device having a foldable plug according to one embodiment of the present invention. 
           [0008]      FIG. 1B  is an exploded bottom-view illustrating the assembly of a plug-in device having a foldable plug according to one embodiment of the present invention. 
           [0009]      FIGS. 2A-2E  are cross-sectional views, showing the foldable plug assembly, in the open and closed configuration according to one embodiment of the present invention. 
           [0010]      FIGS. 3A-3B  are top and bottom views of embodiments of the blade element, including the pivot and the cams. 
           [0011]      FIGS. 4A-4D  are views of the top housing, including the bending tab and pivot positioner according to one embodiment of the present invention. 
           [0012]      FIGS. 5A-5D  are the views of the bottom of the housing, including the plug assembly seat, blade positioner, and locking tab according to one embodiment of the present invention. 
           [0013]      FIGS. 6A-6G  are views of the circuit board where a contact clip element is attached, including views with the contact clip element according to one embodiment of the present invention. 
           [0014]      FIGS. 7A-7P  are views of embodiments of the contact clip element, designed to clip into a circuit board, to provide an electronic contact without soldering. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    The present invention is a plug-in device having a foldable plug, and the configuration of the foldable plug and contacts in the plug-in device. The system in one embodiment includes a housing having a top and a bottom, a circuit board, and a blade element. Rather than three pieces having to fit together to hold the blade assembly, only two elements are needed, the top and bottom housing. No additional elements are needed to hold the plug in place and provide the satisfactory clicking open and closed features. Furthermore, because the plug element is positioned such that when the blade is open no pressure is exerted on the elements of the housing, the foldable plug opening and closing force does not deteriorate with use. In one embodiment, the system utilizes a contact clip to couple a circuit board to the plugs. The contact clip enables solid contact without soldering. 
         [0016]    The following detailed description of embodiments of the invention makes reference to the accompanying drawings in which like references indicate similar elements, showing by way of illustration specific embodiments of practicing the invention. Description of these embodiments is in sufficient detail to enable those skilled in the art to practice the invention. One skilled in the art understands that other embodiments may be utilized and that logical, mechanical, electrical, functional and other changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims. Although the example shown is of a charger device, having US-standard plug-in blades, one of skill in the art would understand that any plug-in device with any blade configuration would work in the present invention. 
         [0017]    The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which: 
         [0018]      FIG. 1A  is an exploded top-view illustrating the assembly of the plug-in device having a foldable plug according to one embodiment of the present invention. As can be seen, the plug-in device includes a bottom  110 , which includes locking tab and a blade holder, where the plug assembly  120  fits. The bottom  110  is an integral element, in one embodiment. A circuit board  130  fits into the bottom  110 . In one embodiment, the circuit board  130  is supported on small support steps in the side of the bottom  110 . The circuit board  130  has a cut-out  135  in one embodiment, around the blade assembly area. The top  140  fits over the bottom, and provides the pivot positioner and the bending tab, which provides force for locking the blade into the closed position. In one embodiment, the top  140  and bottom  110  are permanently coupled together once the plug-in device is assembled. In one embodiment, the top  140  and bottom  110  are plastic, and are coupled together using ultrasonic welding. In one embodiment, the housing is made of Lexan 940 polycarbonate plastic. Using Lexan 940 provides a non-flammable and impact resistant housing. 
         [0019]      FIG. 1B  is an exploded bottom-view illustrating the assembly of the plug-in device having a foldable plug according to one embodiment of the present invention. In one embodiment, the top and/or the bottom elements are each made in a single piece, by a process such as injection molding. In another embodiment, the top  140  or bottom  110  may be made by attaching the blade holder, pivot positioner, and/or bending tab to the appropriate housing element  110 ,  140 . In one embodiment, such attachment may be via adhesive, ultrasonic welding, or another mechanism. Note that the blade element is slightly different in configuration between  FIGS. 1A and 1B . In  FIG. 1A  the contacts for the blade element are on the side, whereas in  FIG. 1B  the contacts for the blade elements are on the top. 
         [0020]      FIG. 2A-2E  are cross-sectional views, showing the foldable plug assembly, in the open and closed configuration according to one embodiment of the present invention.  FIG. 2A  illustrates the top of the case, showing the cut for the cross-sectional views. As can be seen in  FIG. 2B , and in more detail in  FIG. 2C , with the blade closed the bending tab  210  coupled to the top of the housing  220  pushes the pivot  250  of the blade assembly against the blade holder  270  in the bottom of the housing  260 . 
         [0021]    In one embodiment, the pivot  250  is shaped with two cams, referred to as the bending cam and the locking cam. An embodiment of the pivot including the two cams can be seen in  FIGS. 3A and 3B  in more detail. When the blade is closed, as shown in  FIGS. 2B and 2C , the bending cam is positioned against the bending tab, ensuring that the blades remain closed. 
         [0022]    When the blades are open, as shown in  FIGS. 2D and 2E , the locking cam is on the blade holder, and the bending tab has minimal force or no force exerted on it. The locking cam ensures that the blades remain open. 
         [0023]      FIGS. 3A-3B  are top and bottom views of embodiments of the blade element, including the pivot and the cams. The central pivot element includes the two cams, discussed above. The cams lock the blade elements into the two positions, open and closed.  FIG. 3A  shows one embodiment of the locking cam, which ensure that the blades remain open once opened.  FIG. 3B  shows one embodiment of the locking cam, which ensure that the blades remain closed, and open with a satisfying click, when closed. Additionally, the cam of  FIG. 3A  shows an electrical contact at the sides of the blade element.  FIG. 3B  in contrast, shows the electrical contact at the bottom of the blade element. Other locations for the electrical contact may also be used. 
         [0024]      FIGS. 4A-4D  are views of the top housing, including the bending tab and pivot positioner according to one embodiment of the present invention. As can be seen, in one embodiment the top housing has a positioner consisting of rounded plastic elements integral with the housing, that ensure that the blade element stays in place and can rotate. It also has a bending tab, which provides force to provide the click-feel of the blade opening and closing. The click-feel is the snapping motion and sound that people expect when opening and closing a foldable plug. 
         [0025]    In one embodiment, though not specifically shown, the entire top housing may be injection-molded from a single piece of plastic. In another embodiment, the cross-ribs shown which provide support for the housing and stability for the elements of the blade are attached to the housing. In one embodiment the plastic is Polycarbonate. 
         [0026]      FIGS. 5A-5D  are the views of the bottom of the housing, including the plug assembly seat, blade positioner, and locking tab according to one embodiment of the present invention. As can be seen, the blade positioner includes grooves for the blades to reside in, when the blades are in the closed position, as well as rounded areas in which the pivot is placed. In one embodiment, the locking tab is a small element, on top of which the locking cam rests when the blade is in the open position. This ensures that the blades do not turn too far when they are opened. It also enables the blade assembly not to exert force on the bending tab when the blade is in the open position. 
         [0027]    In one embodiment, though not specifically shown, the entire bottom housing may be injection-molded from a single piece of plastic. In another embodiment, some elements may be glued into the housing. In one embodiment the plastic is Polycarbonate. This means, however, that the blade element, which is designed to conduct power from the AC outlet to a circuit board located within the housing, requires an electrical contact. 
         [0028]    In one embodiment, the blade element, shown in  FIG. 3A  has a contact point at the ends of the pivoting element, shown as the small extending piece in the drawing. In another embodiment, shown in  FIG. 3B , the blade element has a contact at the top of the blade enclosure. Other configurations may be used. The contact point(s) are designed to couple the metal of the blade to the circuit board (not shown here, but which can be seen in  FIGS. 1A and 1B ). The contact point is electrically coupled to the circuit board, in one embodiment, via a contact clip element. 
         [0029]      FIGS. 6A-6G  are views of the circuit board where the contact clip element is attached, including views with the contact clip element according to one embodiment of the present invention. 
         [0030]      FIG. 6A  illustrates the circuit board  610  and clip  620  attached to the circuit board. Printed circuit boards, in general, connect components using conductive tracks on a substrate. Various elements may be mounted on a circuit board using through-holes into which the pins of the elements are inserted, or surface pads onto which pins of the elements are attached. In one embodiment, conductors on different layers are connected through electrically conductive holes called via. 
         [0031]    When the circuit board is prepared, in one embodiment, alignment holes are placed for each contact clip element. In one embodiment, two holes are placed a particular distance apart. The holes are electrically connected through a surrounding surface pad. In one embodiment, the holes themselves are conductive vias that attach to traces or electrical layers on the circuit board. In one embodiment, the alignment holes may be mounting holes that are not conductive. In one embodiment, in that instance surrounding pads in proximity to the mounting holes may be used to electrically connect the contact clip element to the elements on the circuit board. 
         [0032]    In the configuration shown, where the circuit board is designed to fit into the plug-in device, the holes  630  for the contact clip elements are placed on either side of the cut-out which surrounds the blade enclosure, and which is in close proximity, therefore, to the blade element, and thus the blade element contacts. The clips are, in one embodiment, shaped to snap into the holes. This enables the placement of the contact clips without any soldering.  FIG. 6G  shows the cross-section, showing that a dimple in the clip fits into a drilled alignment hole securely. Although the contact clips are removable, they are securely attached. In one embodiment, the clips are gold plated. 
         [0033]      FIGS. 7A-7P  are views of two exemplary embodiments of the contact clip, designed to clip onto a circuit board, to provide an electronic contact without soldering according to one embodiment of the present invention. 
         [0034]      FIG. 7A-H  show one embodiment of the contact clip element, showing the upward extending contact point. This configuration is designed to be coupled to a blade element that has as its contact points at the ends of the pivoting element. 
         [0035]      FIG. 7I-P  show another embodiment of the contact clip element, showing the sideways extending contact point. This configuration is designed to be coupled to a blade element that has as its contact points at the top of the pivoting element. 
         [0036]    Alternative configurations of the clip may be used. It should be understood by one of skill in the art that such snap-on contacts may be used in designs other than a plug in-device or charger. A snap-on contact may be used in any system that requires a contact with an off-circuit-board connection. The shapes of the contact clip elements shown in the figures are merely exemplary. At its core, the contact clip element encompasses any clip-on connection that is designed to be coupled to the edge of a circuit board using a drilled hole on a circuit board, to electrically connect an off-board element with the circuit board. 
         [0037]    In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.