Structure of case

Abstract

An improved structure of case body includes receiving containers for receiving wheel sets to stow therein. When the case is moved, especially when the case is pushed or pulled, the wheel sets stowed in the receiving containers can be selectively extended outside the case to allow 360 degree rotation with the aid of wheels of the wheel sets and when a user wishes to place the case for the purposes of for example shipping or transportation of baggage, the wheel sets mounted to the bottom of the case can be first retracted back into and stowed in the receiving containers of the case to avoid undesired impact of the wheel sets during the transportation of the case to thereby extend the service life thereof and also to reduce the amount of space needed between adjacent case.

What is claimed is: 
     
         1 . A structure of case, comprising:
 a case body, which has a top and a bottom and forms therein a receiving space adapted to receive and hold at least one article;   a plurality of receiving containers, each of which is arranged inside the bottom of the case body and has a top and a bottom, the bottom forming an opening;   a plurality of wheel sets, which is respectively receivable in the receiving containers and each comprises an elastic element, a base, and a wheel, the elastic element having a first end fixed to the top of the respective receiving container and a second end fixed a top of the base, the wheel being fixed to a bottom of the base; and   a plurality of fastener assemblies, each of which comprises a handle, a support section, and a stop section, the handle being pivotally mounted to an outside wall of the case body at a location adjacent to the bottom of the case body and corresponding to a corresponding one of the receiving containers, the support section projecting from the handle to extend through the outside wall of the case body and be partially received in the corresponding receiving container, the support section being positionable against the bottom of the base to support the base, the stop section being arranged at the bottom of the case body, wherein the fastener assemblies are of a number corresponding to the number of the wheel sets and that of the receiving container.   
     
     
         2 . The structure of case as claimed in  claim 1 , wherein when the handle is moved in a direction away from the outside wall of the case body, the support section is caused to separate from the base of the wheel set to allow the base and the wheel to be sprung by the elastic element in a direction to extend outside the bottom of the case body until the base leans against the bottom of the corresponding receiving container and the wheel of the wheel set projects outside the bottom of the case body, whereby the handle is allowed to return to lean against the outside wall of the case body and the support section is allowed to return inside the corresponding receiving container of the case body to be positioned against the top of the base of the wheel set. 
     
     
         3 . The structure of case as claimed in  claim 1 , wherein when the handle is moved away from the outside wall of the case body and the support section is moved from the corresponding receiving container of the case body toward the outside wall of the case body, the case body is allowed to apply an external force in a downward direction to compress and force the wheel set and the elastic element back into the corresponding receiving container of the case body and the handle is returned back to leaning against the outside wall of the case body, the support section being returned back into the corresponding receiving container of the case body and leaning against the bottom of the base of the wheel set to stow the wheel set in the corresponding receiving container of the case body. 
     
     
         4 . The structure of case as claimed in  claim 1 , wherein each of the wheel sets comprises a wheel mount, which is fixed to the bottom of the base and pivotally connected to the wheel set. 
     
     
         5 . The structure of case as claimed in  claim 1 , wherein the wheel of each of the wheel sets is rotatable in a range of 360 degrees. 
     
     
         6 . The structure of case as claimed in  claim 1  further comprising a pull bar mounted to the top of the case body. 
     
     
         7 . The structure of case as claimed in  claim 1 , wherein the support section of each of the fastener assemblies received in the corresponding receiving container at a vertical position that substantially corresponding to vertical position where the base is located in the bottom of the case body when the wheel set is extended outside the case body. 
     
     
         8 . The structure of case as claimed in  claim 1 , wherein the handle, the support section, and the stop section of the fastener assembly are integrated together as a unitary member. 
     
     
         9 . The structure of case as claimed in  claim 1 , wherein the elastic element comprises a spring.