Abstract:
The instant disclosure relates to a power supply unit that is compatible with different plug types and can be plugged to the power outlet at different directions. The power supply unit comprises a main body and a plug. The plug can be assembled to and connected electrically with the main body with ease. The power supply unit can be used more broadly in different regions and provide more options when plugging to the power outlet.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The instant disclosure relates to a power supply unit; more particularly, to a power supply unit that is compatible with different plug types and can be plugged in different directions. 
     2. Description of Related Art 
     The electrical plugs of power supply units and their corresponding sockets adapted by various countries often differ in shapes and sizes. The voltage of the power supply varies regionally as well. Therefore, a user may not be able to use his/her electronic device while traveling abroad, since the power plug may not fit into the local power outlet. 
     To address the issue, some manufacturers have developed universal power adaptors compatible to different kinds of plugs and outlets. However, these universal power adaptors tend to have complex physical structures and are problem-prone. Another solution was to use a power supply unit with interchangeable plugs. Such power supply unit works with a latch. This latch has a simple design but is structurally vulnerable to external forces. Thereby, the mounted plug tends to unseat easily. 
     In addition, the pin direction for conventional power supply units is fixed. The fixed direction creates more inconvenience and constraint when plugging the power supply units. Moreover, the plug itself can vary in shapes from country to country and from place to place. For example, some plugs have two flat parallel non-coplanar blades, some are non-parallel, and others have round pins instead. Therefore, the compatibility of the power supply units involves several factors. 
     Consequently, because of the above limitations resulting from the technical design of prior art, the inventors strive via industrial experience and academic research to develop the instant disclosure, which can effectively improve the limitations described above. 
     SUMMARY OF THE INVENTION 
     The instant disclosure provides a power supply unit that is compatible with different plug types and can be plugged in different directions. Being compatible with different types of plugs, the power supply unit can be used in different countries. The ability to plug in different directions allows the power supply unit to have more flexibility in sharing the power strip with other electronic devices. In addition, the power supply unit can be easily assembled, is more reliable, has better structural integrity, etc. 
     The power supply unit of the instant disclosure comprises a main body and a plug. The main body has a protruding frame-like plug mounting seat and at least one guide rail formed thereon. A receiving region is formed by the area enclosed by the plug mounting seat. The guide rail is arranged in the receiving region. Two conducting elements and a plurality of engagement blocks are mounted in the receiving region. The engagement blocks are specifically arranged within the periphery of the receiving region opposite to each other. An engagement slot is formed on each engagement block. The plug has a base and at least two pins disposed thereon. The pins protrude from the base and are connected to a plurality of first contact pieces and a plurality of second contact pieces, respectively. The first contact pieces are of one polarity and may be formed separately or integrally formed into one piece. Likewise, the second contact pieces of a different polarity may be formed in a similar fashion. The first and second contact pieces are arranged opposite to each other on the base and exposed therefrom. At least a pair of fixing blocks and at least a pair of stoppers are formed protrudingly on the base. Each stopper has a fixing portion formed on one end thereof. A plurality of guide slots are also formed on the base. The plug is movably received by the receiving region, and the guide slots work in cooperation with the corresponding guide rails. The fixing portions are received by the corresponding engagement slots, and the conducting elements abut to the first contact pieces and second contact pieces, respectively, for creating electrical connection. 
     The power supply unit of the instant disclosure has the following advantages. First, the power supply unit can be fitted with different types of plugs, which provides more flexibility for using in different countries. In particular, the plug can be assembled to the main body of the power supply unit in different angles (e.g., 0, 90, 180, and 270). The angular variation allows more space-wise flexibility for the power supply unit when sharing the same power strip with other electronic devices. 
     The design of the instant disclosure incorporates the use of guide rail, guide slots, plug mounting seat, fixing blocks, stoppers, etc. Thereby, when assembling the plug onto the base, the plug can be easily assembled thereon and secured in three different directions (x, y, and z axis) to ensure a firm connection. 
     In order to further appreciate the characteristics and technical contents of the instant disclosure, references are hereunder made to the detailed descriptions and appended drawings in connection with the instant disclosure. However, the appended drawings are merely shown for exemplary purposes, rather than being used to restrict the scope of the instant disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of a power supply unit of the instant disclosure. 
         FIG. 2  is another exploded view for the power supply unit of  FIG. 1  taken from a different angle. 
         FIG. 3  is a perspective view of the power supply unit of the instant disclosure. 
         FIG. 4  is a cross-sectional view of the power supply unit of the instant disclosure. 
         FIG. 5  is another cross-sectional view of the power supply unit of the instant disclosure. 
         FIG. 6  is a bottom view of a plug of the instant disclosure. 
         FIG. 7  is a perspective view showing the power supply unit with the plug assembled at a different direction. 
         FIG. 8  is an exploded view of a power supply unit for another embodiment of the instant disclosure. 
         FIG. 9  is another exploded view for the power supply unit of  FIG. 8  taken from a different angle. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     [First Embodiment] 
     Please refer to  FIGS. 1˜5 , which show a power supply unit that is compatible with different plug types and can be plugged to the power outlet at different directions. The power supply unit may be, but is not limited to, power adaptors, chargers, power converters, or combinations thereof. The power supply unit comprises a main body  1  and a plug  2 . For explanation purposes, the crosswise direction of the main body  1  is defined by the x-axis as a first direction X. The longitudinal direction of the main body  1  is defined by the y-axis as a second direction Y. The direction normal to the first and second directions X and Y is represented by the z-axis as a third direction Z. 
     The main body  1  is a housing structure, which houses various electrical components therein. A plug mounting seat  11  upwardly protrudes from the main body  1 . The plug mounting seat  11  is recessed to form a frame-like and square-shaped body that defines a receiving region  12  therein. The plug mounting seat  11  may also be formed as any other regular polygon-shaped structure. The equilateral characteristic of the regular polygon allows the plug  2  to be assembled onto the main body  1  at different angles with respect to a reference plane defined by the x and y axes. At least one guide rail  13  upwardly protrudes from the main body  1  in the receiving region  12 . In this embodiment, two guide rails  13  are preferred herein but not restricted thereto. The guide rails  13  extend along the second direction Y and merge with the retaining walls that define the plug mounting seat  11  on opposite ends. The height of the guide rails  13  can be equal to or greater than the retaining walls of the plug mounting seat  11 . The two guide rails  13  are spaced apart parrallely in forming an opening  111  therebetween. 
     Two conducting elements  14  are mounted in the receiving region  12  on the main body  1 . Specifically, the conducting elements  14  are arranged between the two guide rails  13  for protection. The guide rails  13  also act as stops to keep the plug  2  from detaching unintentionally from the plug mounting seat  11 . Thereby, electric shock due to accidental contact to the exposed conducting elements  14  can be prevented. Alternatively, four guide rails  13  can be formed on the main body  1 . In such case, the conducting elements  14  would be bounded by two guide rails  13  on each of both sides thereof. The conducting elements  14  may be metallic resilient strips, cylinders, or any other shapes. The conducting elements  14  are connected electrically with the electrical components inside the main body  1 . 
     Four engagement blocks  15  are preferred herein but not restricted thereto and further disposed inside the receiving region  12  on the main body  1 . These engagement blocks  15  are arranged symmetrically within the periphery of the receiving region  12  opposite to each other. Each engagement block  15  can be formed by extending upwardly from the upper surface of the main body  1  and/or inwardly from corresponding retaining walls of the plug mounting seat  11 . The locations of forming the engagement blocks  15  on the main body  1  are not restricted. The height of the engagement blocks  15  is equal to or less than the height of the retaining walls of the plug mounting seat  11 . An engagement slot  151  is formed between each engagement block  15  and the upper surface of the main body  1 . The engagement slots  151  function to secure the plug  2 . 
     A locking member  16  is arranged on the main body  1  adjacent to the plug mounting seat  11 . One end of the locking member  16  is connected to the main body  1 , while a free end thereof is projected in a sloped manner toward the opening  111  of the plug mounting seat  11 . A first stopping portion  161  is formed on the free end of the locking member  16  and extends into the opening  111 . A second stopping portion  112  is formed on one of the retaining wall of the plug mounting seat  11  away from the locking member  16 . 
     The plug  2  has a base  21  and a pair of pins  22 . However, the plug  2  may be provided with more than two pins, such as a three-prong plug having a grounding pin. The base  21  matches in shape with the plug mounting seat  11  structurally. The pins  22  protrude from a front surface of the base  21  along the third direction Z. As shown in  FIG. 6 , one pin  22  is connected to first contact pieces  221  of one polarity, while the other pin  22  is connected to second contact pieces  222  of a different polarity. The first and second contact pieces  221  and  222  are arranged opposite to each other on a rear surface of the base  21  under exposure. These first and second contact pieces  221  and  222  can be metallic resilient strips, cylinders, or any other type of contact piece. For the instant embodiment, the two conducting elements  14  are resilient strips (as shown in  FIG. 4 ), and the first contact pieces  221  and the second contact pieces  222  are cylindrically-shaped. 
     Four fixing blocks  211  are preferred herein but not restricted thereto and further protrude downwardly from the base  21  on the same side with the exposing contact pieces  221  and  222 . Each fixing block  211  primarily takes a U-shaped form. The fixing blocks  211  can be separately arranged or connected in one piece. For the instant embodiment, these fixing blocks  211  are separately arranged in symmetry. To prevent accidental human contact, the first and second contact pieces  221  and  222  are arranged inside the U-shaped fixing blocks  211 . 
     Four stoppers  212  are preferred herein but not restricted thereto and further formed on the base  21  adjacent to the fixing blocks  211 . A fixing portion  212   a  is formed on one end of each stopper  212  in correspondence to the engagement slots  151 . The stoppers  212  are arrayed in symmetry on the base  21 , and each stopper  212  is arranged between two fixing blocks  211 . On the same side with the stoppers  212 , a plurality of guide slots  213  is formed between the protruding fixing blocks  211  and the protruding stoppers  212 . The number of the guide slots  213  is preferably four but is not restricted thereto. The guide slots  213  are formed symmetrically on the base  21 , and each guide slot  213  extends along the first direction X and the second direction Y. 
     For other embodiments, the number of fixing blocks  211 , stoppers  212 , guide slots  213 , and guide rails  13  can be varied according to the needs. For example, only two stoppers  212  can be used instead. In such case, the two stoppers  212  are arranged on opposite corners of the base  21 . The fixing blocks  211 , the stoppers  212 , and the guide slots  213  are arranged in a symmetrical manner on the plug  2  to be structurally balanced in allowing the plug  2  to stay seated securely on the main body  1 . Also, the guide slots  213  are not restricted to be formed between the fixing blocks  211  and the stoppers  212 . For example, the guide slot  213  may be formed between any two protruding objects on the base  21 . 
     Please again refer to  FIGS. 1˜5 . When assembling the power supply unit, the plug  2  can be movably inserted into the receiving region  12  of the main body  1 , along the third direction Z. Each guide slot  213  of the plug  2  pairs with the corresponding guide rail  13  of the main body  1  for enabling the plug  2  to move along the second direction Y. Meanwhile, the pairings between the guide slots  213  with the corresponding guide rails  13  allow the plug  2  to be fixed in the first direction X. By moving the plug  2  along the second direction Y for a short distance (in positive second direction Y), the fixing portions  212   a  can be received by the corresponding engagement slots  151 , which allow the plug  2  to be fixed in the third direction Z. Once the plug  2  is fixed along the first direction X and the third direction Z, one of the fixing blocks  211  would abut to the second stopping portion  112 . Concurrently, the locking member  16  would eject, with the first stopping portion  161  abutting the other fixing block  211 . Thereby, the plug  2  is fixed in the second direction Y. By securing the plug  2  onto the main body  1  in all three directions, the two conducting elements  14  of the main body  1  are brought in contact with the first contact pieces  221  and the second contact pieces  222 , respectively. Thus, the plug  2  is connected electrically to the main body  1 . To change out the plug  2 , the locking member  16  can be switched to unlocked position to disengage the first stopping portion  161  away from the fixing block  211  of the plug  2 . The disengagement loosens the plug  2  in the negative second direction Y. Thus, the plug  2  can be easily removed off the main body  1 . 
     [Second Embodiment] 
     Please refer to  FIGS. 8˜9 , which show a power supply unit of another embodiment of the instant disclosure. For the instant disclosure, the guide rails  13 , the conducting elements  14 , the locking member  16 , the fixing blocks  211 , and the guide slots  213  can all be varied structurally, as illustrated in this embodiment. When comparing to the first embodiment, the middle portions of the two guide rails  13  of the main body  1  are removed. The two conducting elements  14  are replaced with metallic cylindrical bodies and mounted between the two guide rails  13 . The shape of the locking member  16  also takes on a different form. The four fixing blocks  211  of the plug  2  are interconnected into one piece in forming a recessed cross-like structure. Aside from structural variations, the assembling process and functions of the power supply unit is generally the same as the previous embodiment, therefore are not repeated herein. Notably, when the conducting elements  14  are cylindrically shaped, the first and second contact pieces  221  and  222  take on the form of resilient strips (not shown). 
     As with the first embodiment, the number of the fixing blocks  211 , the stoppers  212 , guide slots  213 , and the guide rails  13  for the second embodiment can be varied according to the needs. For example, only two stoppers  212  can be used instead. Under such configuration, the two stoppers  212  are arranged on opposite corners of the base  21 . The fixing blocks  211 , the stoppers  212 , and the guide slots  213  are arranged in a symmetrical manner on the plug  2  to maintain structural stability. 
     For the power supply unit of the instant disclosure, different types of plugs  2  may be assembled onto the main body  1 . Thus, the power supply unit can be used in different countries having different power outlets. Moreover, the plug  2  is symmetric structurally, namely the fixing blocks  211 , the stoppers  212 , and the guide slots  213  are all arranged in a symmetrical manner. Therefore, the plug  2  can be assembled onto the main body  1  in different orientations. For the instant disclosure, with reference to the horizontal plane formed by the x and y axes, the plug  2  can be oriented at 0, 90, 180, and 270 degrees on the main body  1  of the power supply unit. A comparison between  FIGS. 3 and 7  demonstrate such characteristic. Thereby, base on needs, the power supply unit of the instant disclosure can change its plug direction to avoid being interfered by other electronic devices while sharing the same power strip. 
     For the instant disclosure, the plug  2  is secured onto the main body  1  in three directions, i.e., the first direction X, the second direction Y, and the third direction Z. The multi-directional securing capability allows the plug  2  to be firmly secured and provides better structural stability. Plus, the assembling process of the plug  2  onto the main body  1  is less involved. The power supply unit can be easily assembled by first fitting the plug  2  into the receiving region  12  of the main body  1 . Then, the plug  2  is moved along the second direction Y for a short distance, which allows the fixing portions  212   a  to engage the corresponding engagement slots  151 . The assembling process is simple and efficient. 
     The descriptions illustrated supra set forth simply the preferred embodiments of the instant disclosure; however, the characteristics of the instant disclosure are by no means restricted thereto. All changes, alternations, or modifications conveniently considered by those skilled in the art are deemed to be encompassed within the scope of the instant disclosure delineated by the following claims.