Patent Publication Number: US-2009218461-A1

Title: Base assembly capable of reducing the number of assembling steps

Description:
This application is based upon and claims the benefit of priority from Japanese patent application No. 2008-047069, filed on Feb. 28, 2008, the disclosure of which is incorporated herein in its entirety by reference. 
     TECHNICAL FIELD 
     This invention relates to an apparatus having a base and a shelf or a bracket mounted on the base (hereinafter this apparatus will be referred to as a “base assembly”), which is for use with main equipment for a communication apparatus, or the like. 
     BACKGROUND ART 
     As a first related art of this type of base assembly, there is one having a base and a bracket, as a separate component, fixed to the base using screws, as will be described in detail later with reference to the drawings. In this case, the number of assembling steps is large, the number of components is large, there is a disadvantage in terms of design because the heads of the screws are visible from the outside, and further the cost increases. 
     A second related art is disclosed in Japanese Unexamined Utility Model Application Publication (JP-U) No. Sho 57-48687, wherein attaching portions of an attaching component engage with coupling portions (insertion seats) of a mounting plate on both sides of the attaching component and thus positioning of the attaching component in its attaching direction cannot be carried out. Therefore, the structure becomes large in size, which is inconvenient. 
     A third related art is disclosed in Japanese Unexamined Patent Application Publication (JP-A) No. Hei 02-271597, wherein a mounting plate has claws and a locking piece with a locking claw and a chassis has square holes, cutouts, and a locking hole. Thus, the structure is complicated. 
     SUMMARY OF THE INVENTION 
     It is therefore an exemplary object of this invention to provide a base assembly requiring a less number of assembling steps, having a simple structure, and enabling a size reduction. 
     Other objects of the present invention will become clear as the description proceeds. 
     According to an exemplary embodiment of this invention, there is provided a base assembly comprising a base and a bracket mounted on the base, wherein the base comprises at least two L-shaped hook receivers and at least one claw receiver, the bracket comprises at least two L-shaped hooks each having a shape corresponding to that of the hook receiver and at least one elastically deformable claw engageable with the claw receiver, and when mounting the bracket on the base, positioning of the bracket is carried out by engagement of the hooks with the hook receivers and locking of the bracket is carried out by engagement of the claw with the claw receiver. 
     An exemplary effect of this invention is that laborious fixing means such as a screw is not required, the number of assembling steps is small, and further the structure is simple. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view illustrating a base assembly according to an exemplary embodiment of this invention in a state before assembling thereof; 
         FIG. 1B  is a perspective view illustrating the base assembly in a state after assembling thereof; 
         FIG. 2A  is a plan view of a base included in the base assembly of  FIGS. 1A and 1B ; 
         FIG. 2B  is a sectional view taken along line  2   b - 2   b  in  FIG. 2A ; 
         FIG. 3  is a front view of a bracket included in the base assembly of  FIGS. 1A and 1B ; 
         FIG. 4A  is a plan view of a state where the bracket is placed on the base, but is not fixed thereto; 
         FIG. 4B  is a sectional view taken along line  4   b - 4   b  in  FIG. 4A ; 
         FIG. 4C  is an enlarged view of a portion  4   c  in  FIG. 4B ; 
         FIG. 4D  is an enlarged view of a portion  4   d  in  FIG. 4B ; 
         FIG. 4E  is an enlarged view of a portion  4   e  in  FIG. 4B ; 
         FIG. 5A  is a plan view of a state where the bracket is placed on the base and fixed thereto; 
         FIG. 5B  is a sectional view taken along line  5   b - 5   b  in  FIG. 5A ; 
         FIG. 5C  is an enlarged view of a portion  5   c  in  FIG. 5B ; 
         FIG. 5D  is an enlarged view of a portion  5   d  in  FIG. 5B ; 
         FIG. 5E  is an enlarged view of a portion  5   e  in  FIG. 5B ; 
         FIG. 6A  is a perspective view illustrating one example of a base assembly according to a related art in a state before assembling thereof; and 
         FIG. 6B  is a perspective view illustrating the related-art base assembly in a state after assembling thereof. 
     
    
    
     DESCRIPTION OF THE EXEMPLARY EMBODIMENT 
     Referring to  FIGS. 1A and 1B , description will be made as regards an outline of a base assembly according to an exemplary embodiment of this invention. 
     The illustrated base assembly is for use with main equipment for a communication apparatus and comprises a base  1  formed by molding a synthetic resin into a rectangular parallelepiped frame shape and a bracket  11  mounted on the base  1 . The base  1  comprises a pair of vertical side walls or side plates  3  and  4  facing each other with a predetermined distance therebetween, a horizontal bottom wall or bottom plate  2  coupled between lower ends of the side plates  3  and  4 , and a vertical rear wall or rear plate  5  coupled between rear ends of the side plates  3  and  4 . A space between front ends of the side plates  3  and  4  is open. 
     On the other hand, the bracket  11  is formed by molding a synthetic resin and comprises a main plate portion  11 - 1  in the form of a rectangular plate and an auxiliary plate portion  11 - 2  coupled to the main plate portion  11 - 1  on its one side. That is, the bracket  11  has a generally T-shape in cross section. The bracket  11  is mounted on the base  1  between the side walls  3  and  4  with its main plate portion  11 - 1  perpendicular to the bottom plate  2 . 
     When mounting the bracket  11  on the base  1 , the bracket  11  is first lowered in the vertical direction of arrows  21  in  FIG. 1A  until the lower end of the bracket  11  reaches an inner bottom surface of the base  1 , i.e. an upper surface of the bottom plate  2 . Subsequently, the bracket  11  is moved rearward in the horizontal direction of arrows  21 . Then, by means of an engaging structure described later, the bracket  11  engages with the base  1  so as to be fixed thereto. 
     Hereinbelow, referring also to  FIGS. 2A to 5E , the engaging structure will be described in detail. 
     A direction from the right side to the left side of the bottom plate  2  is given as an X-direction, a direction from the lower side to the upper side of the bottom plate  2  is given as a Y-direction, a direction from the front side to the rear side of the bottom plate  2  is given as a Z-direction, and a direction opposite to the Z-direction is given as a -Z-direction. Note that the base  1  is fixed to a housing of a communication apparatus (not illustrated) in order to prevent movement thereof in any of the X-, Y-, Z-, and -Z-directions. 
     As illustrated in  FIGS. 2A and 2B , the bottom plate  2  of the base  1  is formed with a first hook receiver  2   a,  a single claw receiver  2   c,  and a second hook receiver  2   b  that are located on a straight line, i.e. aligned with each other, in this order from the front where the space between the side plates  3  and  4  is open. The first hook receiver  2   a  and the second hook receiver  2   b  are formed as illustrated in  FIGS. 4E and 4C , respectively. Specifically, the first and second hook receivers  2   a  and  2   b  are each formed into a shape equivalent to a shape obtained by cutting a portion of the bottom plate  2  to form a generally U-shaped slit and then bending an inner portion surrounded by the slit toward the inside of the base  1  so as to form it into an L-shape. As illustrated in  FIG. 4D , the claw receiver  2   c  is formed by opening a hole in the bottom plate  2 . 
     Incidentally, necessary structures known in this art are provided at the other portions of the bottom plate  2  and on the inner sides of the side plates  3  and  4  and the rear plate  5 . 
     As illustrated in  FIG. 3 , the bracket  11  is formed with a first hook  11   a,  a single elastically deformable claw  11   c,  and a second hook  11   b  that are located on a straight line, i.e. aligned with each other, in this order from the front at three portions of the bottom of the main plate portion  11 - 1 . The claw  11   c  has a free end formed with a projection  11   c   1  which is engageable with the hole, i.e. the claw receiver  2   c,  of the bottom plate  2 . 
     The first hook  11   a  and the second hook  11   b  are formed as illustrated in  FIG. 3  and  FIGS. 4E and 4C . Specifically, the first and second hooks  11   a  and  11   b  are each formed into a shape equivalent to a shape obtained by projecting a portion of the main plate portion  11 - 1  downward from the bottom and then bending it rearward into an L-shape. As illustrated in  FIGS. 3 and 4D , the claw  11   c  is formed elastically deformable and parallel to the bottom plate  2 . 
     Incidentally, necessary structures known in this art are provided on both left and right sides of the bracket  11 . 
       FIGS. 4E ,  4 C, and  4 D respectively illustrate the positions after the bracket  11  is lowered in the vertical direction of arrows  21  in  FIG. 1A  until the lower end of the bracket  11  reaches the inner bottom surface of the base  1 . At these positions, the first hook receiver  2   a  and the first hook  11   a  face each other, the second hook receiver  2   b  and the second hook  11   b  face each other, and the claw  11   c  does not yet engage with the claw receiver  2   c.    
       FIGS. 5E ,  5 C, and  5 D respectively illustrate the positions after the bracket  11  is moved rearward in the horizontal direction of arrows  21  in  FIG. 1A . At these positions, the first hook receiver  2   a  and the first hook  11   a  abut against each other, the second hook receiver  2   b  and the second hook  11   b  abut against each other, and the projection  11   c   1  of the claw  11   c  engages with the claw receiver  2   c  because of an elastic restoring force of the claw  11   c.  Thus, the bracket  11  is fixedly mounted on the base  1 . In this case, positioning of the bracket  11  is carried out by the engagement between the first hook  11   a  and the first hook receiver  2   a  and the engagement between the second hook  11   b  and the second hook receiver  2   b  and locking of the bracket  11  is carried out by the engagement between the claw  11   c  and the claw receiver  2   c.  As a result, the bracket  11  is fixedly assembled to the base  1 . 
     Since the first hook receiver  2   a  and the first hook  11   a  have symmetrical shapes and the second hook receiver  2   b  and the second hook  11   b  have symmetrical shapes, the bracket  11  is tightly mounted on the base  1 . 
     The engaging structure described above exhibits the following effects: 
     1. Since a base assembly comprises a base having at least two L-shaped hook receivers and at least one claw receiver and a bracket having at least two L-shaped hooks each having a shape corresponding to that of the hook receiver and at least one elastically deformable claw engageable with the claw receiver, laborious fixing means such as a screw is not required, the number of assembling steps is small, and further the structure is simple. 
     2. Since the claw receiver is formed between the hook receivers and the claw is formed between the hooks, the bracket is stably fixed to the base by a locking mechanism half the number of positioning mechanisms. 
     3. The hook receivers and the hooks are formed into symmetrical shapes and thus the bracket is brought into tight contact with the base when mounting the bracket on the base. Therefore, the base assembly is compact in structure. 
     4. Since the claw has a projection at its free end and the claw receiver is a hole, the structure is simple. 
     5. Since the hook receivers and the claw receiver are formed so as to be located on a straight line and the hooks and the claw are formed so as to be located on a straight line, the manufacture is easy. 
     6. The base and the bracket are each easily manufactured from a synthetic resin and the cost is low. 
     In the base assembly described above, the claw and the claw receiver in a pair are arranged between the hooks and the hook receivers in two pairs. However, this arrangement order may be suitably changed in design. The number of pairs of hooks and hook receivers and the number of pairs of claws and claw receivers can be increased. The first hook receiver  2   a,  the single claw receiver  2   c,  and the second hook receiver  2   b  in the base  1  may be formed at positions slightly offset from a straight line and, likewise, the first hook  11   a,  the single claw  11   c,  and the second hook  11   b  in the bracket  11  may be formed at positions slightly offset from a straight line. Further, the base assembly is applicable not only to the main equipment for the communication apparatus, but also to other apparatuses, for example, the whole range of household electrical apparatuses. 
     Now, referring to  FIGS. 6A and 6B , the description will be directed to the first related art mentioned in the column of “Background Art”. 
       FIG. 6A  illustrates a state before fixing a bracket  31  to a base  21  using three screws  41 . The base  21  has a rectangular parallelepiped frame structure. As illustrated in  FIG. 6B , a bottom plate  22  of the base  21  is formed with a three screw holes  22   a.  To this bottom plate  22 , the bracket  31  is fixed by the three screws  41 . The bracket  31  is in the form of a rectangular plate and has female threaded portions  31   a  for the screws  41  at three portions of the bottom. Known necessary structures are formed on both left and right sides of the bracket  31 . 
     When fixing the bracket  31  to the base  21 , the bracket  31  is first moved downward in an arrow direction by operator&#39;s fingers in  FIG. 6A , thereby positioning the three female threaded portions  31   a  of the bracket  31  in registry with the corresponding screw holes  22   a  of the bottom plate  22  as illustrated in  FIG. 6B . Then, the three screws  41  are screwed into the corresponding female threaded portions  31   a  of the bracket  31  through the corresponding screw holes  22   a  from the back side of the bottom plate  22 . Thereupon, the bracket  31  is fixed to the base  21 . 
     However, with the structure illustrated in  FIGS. 6A and 6B , the number of assembling steps is large, the number of components is large, there is a disadvantage in terms of design because the heads of the screws are visible from the outside, and further the cost increases.