Abstract:
An apparatus is provided comprising an enclosure for enclosing a printed circuit board (PCB). The PCB has a tab extending therefrom. The enclosure comprises first and second portions, one of which includes a recess arranged to receive the tab of the PCB.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit and priority of Great Britain Patent Application No. GB 1203492.2 filed Feb. 28, 2012. The entire disclosure of the above application is incorporated herein by reference. 
       FIELD 
       [0002]    The invention relates to methods of locating a printed circuit board (PCB) within an enclosure. 
       BACKGROUND 
       [0003]    It is known to secure a PCB within an enclosure for various applications, for example during the construction of a drive unit. 
         [0004]    In known methods of locating a PCB within an enclosure, the PCB is mounted on supports extending from the enclosure. Part of the enclosure is removable to provide access to the interior of the enclosure. The supports extend from the back face of the enclosure into its interior. Each support receives a screw. 
         [0005]    A PCB to be located in the enclosure has a number of mounting holes. Each mounting hole corresponds to one of the supports extending from the back face of the enclosure. To locate the PCB in the enclosure, the PCB is positioned in the enclosure such that the supports of the enclosure are aligned with the mounting holes of the PCB. A screw is then fastened through each of the mounting holes of the PCB to the supports of the enclosure, thereby locating the PCB in the enclosure. Additional components may be located into the enclosure as required, and the removable side of the enclosure is replaced. 
         [0006]    Thus, in known methods, the PCB must be carefully positioned in the enclosure during assembly. Furthermore, the PCB must be fixed to the supports extending from the back face of the enclosure whilst the PCB is being positioned before the removable part of the enclosure is replaced to complete the assembly. Both of these steps add complexity to the assembly procedure, increasing the time taken to locate the PCB within the enclosure. 
       SUMMARY 
       [0007]    An invention is set out in the claims. 
         [0008]    According to an aspect an apparatus is provided comprising an enclosure for enclosing a printed circuit board (PCB), the PCB having a tab extending therefrom. The enclosure comprises a first portion and a second portion, wherein one of the first and second portions includes a recess arranged to receive the tab of the PCB. The PCB may be located between the first and second portions of the enclosure when the apparatus is assembled with the PCB. The PCB may be secured within the enclosure due to the tab of the PCB being received within the recess in the first or second portion of the enclosure. 
         [0009]    According to an aspect a printed circuit board (PCB) is provided wherein that PCB comprises a tab for locating the PCB within an enclosure, for example an enclosure having first and second portions one of which has a recess arranged to receive the tab of the PCB. 
         [0010]    According to an aspect a method is provided for locating a printed circuit board (PCB) within an enclosure, wherein the PCB includes a tab extending therefrom. The enclosure comprises a first portion and a second portion wherein the first portion includes a recess arranged to receive the tab of the PCB. The method comprises locating the PCB with respect to the first portion such that the tab of the PCB is received into the recess and then securing the second portion of the enclosure to the first portion of the enclosure. The PCB may thus be located between the first and second portions of the enclosure. The second enclosure may also comprise a recess which assists in location of the PCB within the enclosure. For example, the tab of the PCB may be partly located in the recess of the first portion and partly located in the recess of the second portion of the enclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Specific embodiments are described below by way of example only and with reference to the accompanying drawings, in which: 
           [0012]      FIG. 1  shows a plan view of a first portion of an enclosure; 
           [0013]      FIG. 2  shows a plan view of a PCB; 
           [0014]      FIG. 3  shows a side view of the first portion of the enclosure, a second portion of the enclosure and the PCB before assembly; and 
           [0015]      FIG. 4  shows a side view of the first and second portions of the enclosure and the PCB after assembly. 
       
    
    
     OVERVIEW 
       [0016]    A PCB is supported within an enclosure where space is at a premium. The enclosure is split into two portions to allow assembly. The first portion of the enclosure, the PCB and the second portion of the enclosure form a ‘sandwich’ when assembled with the PCB supported in the centre. No additional fixing means are required to support the PCB in the enclosure. To further support and locate the PCB within the enclosure, tabs protruding from the edge of the PCB are provided and located within cut-out portions provided in the walls of the first and second portions of the enclosure. 
       DETAILED DESCRIPTION 
       [0017]    An enclosure comprises a first portion  100  and a second portion  200 . As shown in  FIG. 1 , the first portion  100  comprises a back face  102  and a surrounding wall  104  extending in a substantially perpendicular direction from the back face  102  around its perimeter. The surrounding wall  104  has a thickness in the plane of the back face  102  of the first portion  100 . The first portion  100  of the enclosure has cut-out portions  106  in the surrounding wall  104  distal to the back face  102 . The cut-out portions  106  extend across the thickness of the surrounding wall  104 , and have a depth perpendicular to the plane of the back face  102  of the first portion  100 . 
         [0018]    The second portion  200  is substantially identical to the first portion  100  and comprises a front face  202  and a surrounding wall  204  extending in a substantially perpendicular direction from the front face  202  around its perimeter. The surrounding wall  204  has a thickness in the plane of the front face  202  of the second portion  200 . The second portion  200  of the enclosure has cut-out portions  206  in the surrounding wall  204  distal to the front face  202 . The cut-out portions  206  extend across the thickness of the surrounding wall  204 , and have a depth perpendicular to the plane of the front face  202  of the second portion  200 . 
         [0019]    As shown in  FIG. 2 , a PCB  300  comprises a substantially planar surface  302  defined by a continuous edge. The edge of the PCB  300  includes a first side  306  and a second side  308  opposite thereto. The PCB  300  has tabs  304  extending from the first  306  and second  308  sides of the PCB  300  substantially co-planar with the planar surface  302 . The tabs  304  have a height in a direction perpendicular to the plane of the planar surface  302 . The height of each tab  304  substantially corresponds to the combined depths of a cut-out portion  106  in the first portion  100  and a cut-out portion  206  in the second portion  200 . 
         [0020]    To locate the PCB  300  in the enclosure, the tabs  304  of the PCB  300  are located in the cut-out portions  106  of the first  100  portion of the enclosure. The second portion  200  of the enclosure is then placed over the PCB  300  and the first portion  100 , such that the tabs  304  of the PCB  300  are received into the cut-out portions  206  of the second portion  200 , thereby securing the PCB  300  within the enclosure as shown in  FIG. 4 . Because the PCB  300  is secured by the tabs  304  of the PCB  300 , no additional means are required to locate the PCB  300  within the enclosure. 
         [0021]    The assembly may be secured using any known method. For example, the first  100  and second  200  portions of the enclosure may be fixed together by a clip or with some other mechanical fastener. 
         [0022]    Thus, the PCB  300  is sandwiched between the first and second portions of the enclosure and does not require any additional fixing. The tabs  304  of the PCB  300  and the cut-out portions  106  and  206  of the first  100  and second  200  portions of the enclosure serve both to position the PCB  300  in the enclosure and to secure the PCB  300  in the completed assembly. An electronic device is therefore provided that can be assembled quickly and easily. 
         [0023]    Whilst a particular embodiment has been shown and described in detail herein, it is not intended to be limiting and variations are possible. In an alternative embodiment, the cut-out portions  106  and  206  may only partially extend across the thickness of the surrounding walls  104  and  204 . In this embodiment, the tabs  304  of the PCB  300  are correspondingly smaller so that the PCB  300  is entirely enclosed when the enclosure is assembled. 
         [0024]    Although the first  100  and second  200  portions of the enclosure are described above as being substantially identical, the first  100  and second  200  portions may differ. For example, the cut-out portions  106  of the first portion  100  may be have a depth suitable to accommodate the full height of the tabs  304 , and the second portion  200  may have no cut-out portions  206 , or vice versa. The first  100  and second  200  portions may also differ from one another in other aspects, for example in size and shape. 
         [0025]    The PCB  300  may include any number of tabs  304 . The tabs  304  may be of any shape or size, and tabs  304  on the first side  306  of the PCB  300  may be aligned with tabs  306  on the second side  308 , or the tabs  304  on each side of the PCB  300  may be offset with respect to one another. The position, shape or size of tabs  304  may be chosen to correspond with the cut-out portions  106 ,  206  on the first  100  and second  200  portions of the enclosure so as to ensure correct orientation of the PCB  300  with respect to those first  100  and second  200  portions. 
         [0026]    References to “first”, “second”, “back”, “side” and “front” herein are merely descriptive and refer to the orientation of the device as shown in the figures. They are not intended to be limiting. 
         [0027]    The cut-out portions  106  and  206  referred to above are not necessarily formed by a cutting process, and may instead be referred to as, inter alia, recesses, holes, openings or indentations. 
         [0028]    Thus a straightforward and efficient means for locating and fixing a PCB within an enclosure is provided. Because no screws are required in order to locate the PCB within the enclosure, the process of locating the PCB and assembling the enclosure is quicker, more straightforward and less susceptible to human error. Furthermore, the tabs on the PCB can help to ensure that the PCB is oriented properly with respect to the first and second portions of the enclosure. 
         [0029]    The solution described herein can be used in any type of device in which a PCB must be sandwiched or otherwise located within an enclosure. The solution is scalable and can be used with any size or type of PCB. Furthermore, several PCB&#39;s can be located within the same enclosure or device using mating tabs and recesses such as the ones described herein. Thus a straightforward solution that is very useful in practice is provided.