Abstract:
A shell assembly includes a first shell having an elastic joint component securely formed on a side face of the first shell, a second shell received in the first shell having a concavity to correspondingly partially receive therein the joint component, such that the first shell and the second shell are separably connected together for a replacement application.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the priority of Taiwanese Utility Model Application, No. 101204663, filed on Mar. 15, 2012, the disclosure of which is herein incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention is related to a shell assembly for a lock, where the shell assembly is separable to provide an interchangeability of the appearance covering the lock. 
         [0004]    2. Description of the Related Art 
         [0005]    For door decoration, the region of latch bolt is an important part to concern. That is, whenever there is a need to change the lock, the entire lock mechanism as well as the appearance of the lock assembly is also changed. People often use a shell configured to the position where a latch bolt mechanism is exposed, so as to make the door stylish in appearance. For that purpose, there are many shells of different appearances provided in the market for multiple decorative applications. 
         [0006]    However, in conventional application, the shell is firmly attached to the latch bolt or the door with irremovable configuration, and it is hard to dismantle the shell because the shell is not separably designed. It may take a lot of cost, such as money and time, to change the latch bolt shell. 
       SUMMARY OF THE INVENTION 
       [0007]    The purpose of the present invention is to provide a separable shell structure which enables the aforementioned shell outside the lock to be easily removed and replaced. 
         [0008]    According to one aspect of the present invention, a shell assembly comprises: a first shell having an elastic joint component securely formed on a side face of the first shell and a cavity defined therein; and a second shell received in the cavity of the first shell and having a concavity defined in a periphery thereof to correspond to and partially engage therein the joint component, such that the first shell and the second shell are separably connected together due to resilience provided by the joint component. 
         [0009]    According to another aspect of the present invention, a shell assembly comprises: a rectangular-shaped first shell having at least one elastic joint component securely formed on a side face of the first shell and a cavity defined therein, where the side face has at least one protruding component; and a disc-shaped second shell received in the cavity of the first shell and having at least one concavity defined in a periphery thereof to correspond to and partially receive and engage therein the joint component, at least one aperture defined on the second shell to correspond to and receive the protruding component of the first shell, such that the first shell and the second shell are separably connected together due to the resilience provided by the joint component. 
         [0010]    According to still another aspect of the present invention, a shell assembly comprises: a rectangular-shaped first shell having two elastic joint components respectively and securely formed in diagonal corners of the rectangular-shaped first shell and a cavity defined therein, wherein a side face of the first shell has two protruding components; and a disc-shaped second shell received in the cavity of the first shell and having two concavities defined in a periphery thereof to correspond to and partially receive therein the joint components, two apertures defined on the second shell to correspond to and receive the protruding components of the first shell, such that the first shell and the second shell are separably connected together due to the resilience provided by the joint components, wherein the first shell further includes two accepting parts to respectively allow fasteners to secure the joint components thereon the accepting parts, and the second shell has two guiding elements defined to correspond to the joint components of the first shell, and the concavities are defined to be adjacent to the guiding elements to facilitate entrance of the joint components in the concavities respectively. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The invention, as well as its many advantages, may be further understood by the following detailed description and drawings in which: 
           [0012]      FIG. 1  is an exploded perspective view illustrating a shell assembly of the preferred embodiment of the present invention, wherein a handle and an elastic mechanism constructed in accordance with the present invention are shown; 
           [0013]      FIG. 2  is a perspective view of a joint component of the present invention; 
           [0014]      FIG. 3  is a plan view of the combination of the shell assembly of the preferred embodiment of the present invention; and 
           [0015]      FIG. 4  is a cross-sectional view of the shell assembly of the present invention, according to line  4 - 4  indicated in  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]      FIG. 1  illustrates a preferred embodiment of the invention, in which a shell assembly  2  is used to cover an elastic mechanism  5 , where the elastic mechanism  5  is connected to a handle  1  penetrating the shell assembly  2  and a lock mechanism (not shown), such that the lock mechanism is functional by operating the handle  1 , and the lock mechanism (such as a latch bolt), is able to anchored into a door or other lock apparatuses. 
         [0017]    The shell assembly  2  of the preferred embodiment of the present invention comprises a first shell  3  and a second shell  4 , wherein the first shell  3  includes: a plate  31 , a cavity  32  defined in the plate  31  of the first shell  3 , a centrally defined hole  33  penetrating the plate  31  to provide a channel for extension of the handle  1  and the elastic mechanism  5 , at least two protruding components  34  formed near corners of the plate  31 , at least two accepting components  35  formed near the corners of the plate  31  for insertion of a fastener  37  individually, and at least two joint components  36  respectively having a second hole  363  defined to allow the fastener  37  to penetrate therethrough in order to enable the joint components  36  to be positioned on the first shell  3  individually. Here, the fastener  37  is selected from a group consisted of a screw, a rivet, a clasp and a buckle. 
         [0018]    With the reference of  FIG. 2 , the joint component  36  is a tortuous body composed of a first plate  361 , a second plate  362  integrally formed with the first plate  361  and an arc  364  extending from a distal peripheral edge of the second plate  362 , wherein the second hole  363  is defined in the first plate  361 . Moreover, the joint component  36  is made of an elastic material, such that the joint component  36  is resilient. 
         [0019]    Referring back to the  FIG. 1 , the second shell  4  includes: a second plate  41 , a third hole  42  penetrating the second plate  41  to correspond to the hole  33  of the first shell  3 , at least two apertures  43  penetrating the plate  41  and individually corresponding to the protruding components  34  of the first shell  3 , a ring  44  surrounding the second plate  41  to form a space for receiving therein the elastic mechanism  5 , at least two guiding elements  45 , e.g. track or a slanted surface in the preferred embodiment, configured to the outside of the ring  44  and positioned correspondingly to the joint components  36  individually, and a concavity  46  (or a groove) defined near a distal end of each of the guiding elements  45 . The second shell  4  is able to attach to the door to cover the exposed elastic mechanism  5  and the aforementioned lock mechanism. It is to be noted that in this embodiment of the present invention, the track  45  is a recessed area to guide movement of the arc  364 . 
         [0020]    For the purpose of easy description of the preferred embodiment of the present invention, the following description focuses on the function and operation of a single element when there are two identical elements involved. Here, the size of the second plate  41  is smaller than that of the first plate  31  of the first shell  3 , such that the second shell  4  is able to be received in the cavity  32  of the first shell  3 . After the second shell  4  is received in the cavity  32  of the first shell  3 , the joint component  36  is able to slide into the guiding element  45  (the track or a slanted surface) so as to allow the arc  364  to be received and engaged therein the concavity  46  which is defined near a distal end of the track  45 . Thus, the first shell  3  is capable of conjointly combing with the second shell  4  (as shown in  FIG. 3  and  FIG. 4 ) and optionally removing from the second shell  4 , via the joint components  36  which is resilient to be unstuck from the concavity  46 . 
         [0021]    In this preferred embodiment, as shown in  FIG. 1 , the plate  31  is in rectangular shape, thus the first shell  3  appears rectangular shape from the direction of the handle  1 . However, the first shell  3  is able to be removed from the second shell  4  in a simple way because the joint component  36  is resilient. There are many options for the shapes or styles of the first shell  3  to be applied for decorative applications. 
         [0022]    For another preferred embodiment, the joint component  36  is able to be securely connected to the first shell  3  via riveting. 
         [0023]    Many changes and modifications in the above described embodiment of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims.