Patent Publication Number: US-2015076980-A1

Title: Fastener assembly for a door

Description:
TECHNICAL FIELD 
     The present disclosure relates to a door for an enclosure, and more particularly to a fastener assembly for fastening the door to the enclosure. 
     BACKGROUND 
     Cabinets, such as inverter cabinets include doors that can be detached from an enclosure of the cabinet. The doors are generally fastened and/or sealed to a frame of the enclosure using fasteners and have gasket seals. Fastening the doors to the enclosure may require a manual force to be applied on the door against the enclosure. However, applying too much force on the door may damage the fasteners and/or the gasket seals. Additionally, while fastening and/or unfastening the door from the enclosure, the fasteners tend to fall out of the door, which may not be desired as per safety regulations. Also, according to various safety requirements, it may be important to ground the doors to the enclosure. 
     SUMMARY OF THE DISCLOSURE 
     In one aspect of the present disclosure, a fastener assembly arranged about a perimeter of a door for an enclosure is provided. The fastener assembly includes a compression limiter, a bolt and a retaining ring. The compression limiter is disposed on an inner surface of the door and configured to press against a fastener receptacle block on the enclosure. The compression limiter has an opening. The bolt passes through the opening of the compression limiter and is configured to be fastened to a threaded opening in the fastener receptacle block. The retaining ring is disposed in the opening of the compression limiter and is configured to retain the bolt with the door. 
     In another aspect of the present disclosure, a door for an enclosure is provided. The door includes a panel configured to cover an entrance of the enclosure. Further, the door includes a fastener assembly arranged about a perimeter of a door for an enclosure is provided. The fastener assembly includes a compression limiter, a bolt and a retaining ring. The compression limiter is disposed on an inner surface of the door and configured to press against a fastener receptacle block on the enclosure. The compression limiter has an opening. The bolt passes through the opening of the compression limiter and is configured to be fastened to a threaded opening in the fastener receptacle block. The retaining ring is disposed in the opening of the compression limiter and is configured to retain the bolt with the door. 
     In a yet another aspect, an inverter cabinet including an enclosure is provided. The enclosure includes a housing and an entrance to the housing. The enclosure further includes a fastener receptacle block arranged about a perimeter of the entrance and the fastener receptacle block has a threaded opening. Furthermore, the inverter cabinet includes a door for an enclosure is provided. The door includes a panel configured to cover an entrance of the enclosure. Further, the door includes a fastener assembly arranged about a perimeter of a door for an enclosure is provided. The fastener assembly includes a compression limiter, a bolt and a retaining ring. The compression limiter is disposed on an inner surface of the door and configured to press against a fastener receptacle block on the enclosure. The compression limiter has an opening. The bolt passes through the opening of the compression limiter and is configured to be fastened to a threaded opening in the fastener receptacle block. The retaining ring is disposed in the opening of the compression limiter and is configured to retain the bolt with the door. 
     Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an exemplary cabinet, according to an embodiment of the present disclosure; 
         FIG. 2  illustrates a perspective view of a fastener assembly for the cabinet; and 
         FIG. 3  illustrates another view of the fastener assembly according to the embodiment of this disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure relates to a fastener assembly for a door of an enclosure.  FIG. 1  illustrates an exemplary cabinet  100  having an enclosure  102  and a door assembly  104  for the enclosure  102 . In an exemplary embodiment, the cabinet  100  is an inverter cabinet for an electric drive over haul truck. In various other embodiments, the cabinet  100  may be any cabinet used for various purposes such as a generator set cabinet, a wall/floor mounted cabinet or an independent cabinet used for any purposes. 
     The enclosure  102  of the cabinet  100  includes a housing  106  and a frame  108  defining an entrance to the housing  106  to facilitate access to the various components with the housing  106 . The frame  108  may be an elevated frame disposed about a perimeter of the housing  106 . In an aspect of the present disclosure, the door assembly  104  may be detachably coupled to the frame  108  to cover the entrance to the housing  106 . The enclosure  102  may include a number of fastener receptacle blocks  110  which may be arranged about a perimeter of the frame  108 . In an aspect of the present disclosure, the fastener receptacle block  110  may include a counter bore  111  and a threaded opening  112  extending beyond the counter bore  111  within the fastener receptacle block  110 . An inner diameter of the threaded opening  112  may be lesser than an inner diameter of the counter bore  111 . For example, the inner diameter of the counter bore  111  may be 1.5 times larger than the inner diameter of the threaded receptacle  112 . 
     In an aspect of the present disclosure, the door assembly  104  may include a panel  114  and a flange  116  laterally extending about a perimeter of the panel  114 . The flange  116  of the door assembly  104  may be configured to fit the door assembly  104  over the frame  108  to cover the entrance to the housing  106  of the enclosure  102 . In an exemplary embodiment, the enclosure  102 , and the door assembly  104  may all be made of a metal, such as steel, aluminum, etc. In alternate embodiments, the cabinet  100 , the enclosure  102  and the door assembly  104  may be made of any other material such as composites, plastic etc. 
     Further, the door assembly  104  includes a seal  118  disposed on an inner surface  120  of the panel  114  and around the perimeter of the panel  114 . As will be understood by a person having ordinary skill in the art, that the seal  118  may be a gasket configured to seal a junction between the frame  108  of the enclosure  102  and the panel  114  of the door assembly  104 . 
     In an aspect of the present disclosure, the door assembly  104  may be further fastened to the frame  108  of the enclosure  102  by using a number of fastener assemblies  200 . Each of the fastener assembly  200  may be arranged about a perimeter of the panel  114  of the door assembly  104 . The fastener assembly  200  is further described in greater detail with reference to  FIGS. 2 and 3 . 
       FIGS. 2 and 3  illustrate two different views of the fastener assembly  200 , according to an embodiment of the present disclosure. The fastener assembly  200  includes a fastener such as a bolt  202 , a compression limiter  204 , a retaining ring  206 , and washer rings such as a first washer ring  218  and a second washer ring  220 . The fastener assembly  200  may be configured to fasten the door assembly  104  to the frame  108 . 
     The fastener assembly  200  is configured to be attached to the panel  114  extending from an outer surface  122  to the inner surface  120  of the panel  114 . The panel  114  is configured to have a plurality of attachment points, at which, a fastener assembly  200  may be provided. The panel  114  includes a first circular opening  203  at the plurality of attachment points. 
     The compression limiter  204  is disposed on the inner surface  120  of the panel  114  and configured to press against the fastener receptacle block  110  on the frame  108  of the enclosure  102 . In an aspect of the present disclosure, the compression limiter  204  is an unpainted rectangular pad and is made of a metal, such as aluminum, steel etc. In various other embodiments, the compression limiter  204  may be made of any other material such as the material of the door assembly  104 , or plastic or any other composite material. The compression limiter  204  has a second circular opening  208 . Furthermore, the compression limiter  204  is attached to the inner surface  120  of the panel  114  such that the second circular opening  208  of the compression limiter  204  aligns with the first circular opening  203  on the panel  114  of the door assembly  104 . In an exemplary embodiment, the compression limiter  204  may be welded to the inner surface  120  of the panel  114 . 
     Further, in the fastener assembly  200 , the bolt  202  passes through the second circular opening  208  of the compression limiter  204 . As shown in  FIGS. 2 and 3 , the bolt  202  includes a bolt head  210 , a shank portion  212  and a threaded portion  214 . In an aspect of the present disclosure, an outer diameter of the shank portion  212  is less than an outer diameter of the threaded portion  214 . The threaded portion  214  of the bolt  202  is configured to be fastened to the threaded opening  112  of the fastener receptacle block  110 . The counter bore  111  may be configured to facilitate the aligning of the bolt  202  as it enters into the fastener receptacle block  110 . 
     Furthermore, the fastener assembly  200  includes the retaining ring  206  configured to be disposed within the second circular opening  208  of the compression limiter  204 . An outer diameter of the retaining ring  206  is less than an inner diameter of the second circular opening  208 , such that the retaining ring  206  fits within the second circular opening  208  of the compression limiter  204  without slipping out of the second circular opening  208 . 
     In an aspect of the present disclosure, the retaining ring  206  further includes a number of tabs  216  protruding radially inwards and overlying the shank portion  212  of the bolt  202 . The tabs  216  of the retaining ring  206  are configured to retain the bolt  202  with the door assembly  104 . In an exemplary embodiment, the retaining ring  206  and the tabs  216  may be made of metal. Alternatively, the retaining ring  206  and the tabs  216  may be made up of plastic. 
     Furthermore, according to an aspect of the present disclosure, the fastener assembly  200  includes the first washer ring  218  and the second washer ring  220 . The first washer ring  218  is configured to abut the bolt head  210  at one side and the outer surface  122  of the panel  114  at the second side. Further, the second washer ring  220  is configured to abut the retaining ring  206  at one side and the inner surface  120  of the panel  114  on the other side. 
     INDUSTRIAL APPLICABILITY 
     Cabinets, such as inverter cabinets include doors that can be detached from an enclosure of the cabinet. The doors are generally fastened and/or sealed to a frame of the enclosure using fasteners and gasket seals. Fastening the doors to the enclosure may require a manual force to be applied on the door against the enclosure. However, applying too much force on the door may damage the fasteners and the seals. Also, when using such inverter cabinets in an electric drive machine, high electric shocks and high vibrations tend to bend and/or deform the doors and damage the fasteners. Additionally, while fastening and/or unfastening the door from the enclosure, the fasteners may tend to fall off from the door, which may not be desired. 
     In an aspect of the present disclosure, the flange  116  extending laterally around the perimeter of the panel  114  of the door assembly  104  prevents the door assembly  104  from bending and/or deforming during high strain vibrations, while maintaining durability of the seal  118 . Furthermore, the flange  116  provided on the panel  114  prevents water ingression into the cabinet  100 . 
     Further, the compression limiter  204  limits the amount of pressure or compression that can be applied while fastening the door assembly  104  to the enclosure  102 . The compression limiter  204  is an unpainted metal pad which provides metal to metal contact with the fastener receptacle block  110  on the frame  108  of the enclosure  102  to limit the amount of compression that can be applied. Also, the unpainted metal surface of the compression limiter  204  provides earthing of the door assembly  104  to the enclosure  102  to prevent electrical shocks that may be harmful to an operator installing or uninstalling the cabinet  100 . Furthermore, the compression limiter  204  of the fastener assembly  200  provides a cheap and compact solution for preventing the door assembly  104 , the seal  118 , and the fastener assembly  200  from being damaged. 
     Further, the retaining ring  206  is placed within and rotates freely within the second circular opening  208  of the compression limiter  204  which protects the retaining ring  206  from being damaged. Furthermore, the retaining ring  206  retains the bolt  202  with the door assembly  104 , when the door assembly  104  is unfastened or detached from the enclosure  102 . The tabs  216  of the retaining ring  206  provide retaining of the bolt  202  with the door assembly  104 . For example, by virtue of the design of the tabs  216  being radially inward and the outside diameter of the threaded portion  214  being greater than the outside diameter of the shank portion  212 , the bolt  202  may be pushed in through the compression limiter  204  and the retaining ring  206  but cannot be pulled out. 
     While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.