Patent Publication Number: US-2016229042-A1

Title: Barrel type ratchet wrench with a snap-in structure

Description:
BACKGROUND OF THE INVENTION 
     1. Fields of the Invention 
     The present invention relates to a barrel type ratchet wrench with a snap-in structure, and more particularly to the snap-in structure capable of latching an external socket with an external adapter to prevent them from falling out unexpectedly or affecting the normal smooth operation of the wrench. 
     2. Description of the Related Art 
     The ratchet wrench refers to a professional wrench having a ratchet direction controlling mechanism for controlling the driving direction to apply a force, and barrel type ratchet wrench refers to a wrench having a ratchet acting head designed as a hollow barrel provided for plugging a component module such as an external socket or an external adapter and controlling the rotation direction of a screw (not shown in the figure). 
     Although the conventional barrel type ratchet wrench has been used for years and common to users, yet the connection between the external socket and the external adapter with the hollow barrel is simply by abutting a top bead (installed on a side of the external socket and the external adapter) or latching a ring (installed at an inner periphery of the hollow barrel), so that the two produce a combining strength of a certain level and will not be separated easily. As we all know, the wrench probably hits a surrounding object or the operator moves too much in the process of applying a force for the operation of the wrench, so that the external socket and the external adapter may be separated from the hollow barrel easily, and the operation or construction may be affected adversely, or the external socket and external adapter may even be lost or missing, and thus resulting gin an unexpected difficult situation. Obviously, the conventional design requires further improvements. 
     SUMMARY OF THE INVENTION 
     It is a primary object of the present invention to prevent the external socket and the external adapter from being separated from the wrench unexpectedly, so as to achieve the effects of maintaining a smooth operation of the construction effectively, preventing unnecessary losses caused by any unsmooth operation, and enhancing the practicality of the wrench to overcome the aforementioned problems. 
     According to the invention, a barrel type ratchet wrench with a snap-in structure includes a wrench body having a ratchet acting head with a shallow groove adjacent to a hollow barrel. Moreover, a positioning bolt hole and a guide slot are positioned within the shallow groove. The positioning bolt hole is provided for receiving a direction switching lever and a positioning bolt of the ratchet module. A fixing plate and a snap plate are positioned under the direction switching lever. The lock plate has an external shape similar to the profile of the shallow groove and includes a snap portion, a long hole, a pushing portion and a bottom guide projection. The bottom guide projection and an elastic element are firmly positioned in the guide slot of the wrench body in such a way that the bottom guide projection of the engaging piece is constantly biased by the elastic element. The lock plate is fixed by screwing two screwing elements into corresponding screw holes of the wrench body. the snap portion of the engaging piece projects into the hollow barrel of the ratchet acting head. By means of the combination of the above-mentioned components, the snap portion can firmly snap into a corresponding annular groove of an external socket or an external bit. In this way, an unexpected disengagement is avoided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accomplishment of this and other objects of the invention will become apparent from the following description and its accompanying drawings of which: 
         FIG. 1  is an exploded perspective view of a preferred embodiment of the present invention; 
         FIG. 2  is a perspective view of the assembly as depicted in  FIG. 1 ; 
         FIG. 3  is a top view of  FIG. 2  (before mounting the external socket); and 
         FIG. 4  is a schematic view of the operation of the invention as depicted in  FIG. 3  (before mounting the external socket). 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention will now be described in more detail hereinafter with reference to the accompanying drawings that show various embodiments of the invention. 
     The present invention is an improved invention of prior application Ser. No. 14/195,818. 
     With reference to  FIGS. 1 to 3  for a preferred embodiment of the present invention, the ratchet wrench comprises a wrench body  70 , a fixing plate  83  and a snap plate  87 . 
     The wrench body  70  has a ratchet acting head  71  with a ratchet module  80  disposed at an end of the wrench body  70 . A hollow barrel  72  is positioned in the ratchet acting head  71 . A shallow groove  73  is formed on a side adjacent to the hollow barrel  72  and has a positioning bolt hole  74  and a guide slot  75 . The positioning bolt hole  74  is provided for plugging a direction switching lever  81  and a positioning bolt  82  of the ratchet module  80 . 
     The fixing plate  83  is positioned under the direction switching lever  81  and includes a central through hole  84  and two positioning holes  85 . Two screwing elements  86  are screwed through the positioning holes  85  into corresponding screw holes  76  for locking the snap plate  87  in place. 
     The snap plate  87  with an external shape similar to the profile of the shallow groove  73  is positioned under the direction switching lever  81  and disposed horizontally in the shallow groove  73 . The snap plate  87  includes a snap portion  88 , a long hole  89 , a pushing portion  90  and a bottom guide projection  91 . The bottom guide projection  91  and an elastic element  92  are positioned in the guide slot  75  of the wrench body  70  in such a way that the bottom guide projection  91  of the engaging piece  87  is constantly biased by the elastic element  92 . 
     As shown in  FIGS. 2 through 4 , the snap portion  88  of the engaging piece  87  projects into the hollow barrel  72  of the ratchet acting head  71 . After an external socket  50  is inserted into the hollow barrel  72 , the snap portion  88  can firmly snap into a corresponding annular groove  51  of the external socket  50 . In this way, an unexpected disengagement is avoided. In removing the external socket  50 , it is only needed to push the pushing portion  90  of the engaging piece  87  in a reverse direction (see  FIG. 4 ) for disengaging the snap portion  88  of the engaging piece  87  from the annular groove  51  of the external socket  50 . In this way, an easy removal and replacement is ensured. Moreover, the movement of the engaging piece  87  won&#39;t affect the control/operation of the direction switching lever  81  of the ratchet module  80 . 
     The ratchet module  80 , the direction switching lever  81  and the positioning bolt  82  belong to the prior art and are not objects of the invention so that no further description thereto is given hereinafter. 
     Many changes and modifications in the above-described embodiments 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.