Abstract:
A hard tool handle with a rotary cap comprises a handle; a seat section having a convex cambered shape and protruded from a rear end of the handle; an integral formed rotary cap rotatably disposed at a rear end of the handle, the inner side of the rotary cap being formed as a cavity; an inner bottom of the rotary cap being a flat surface so that the contact area between the inner bottom wall of the rotary cap and the seat section being smaller than a cross-sectional area of the rotary cap or the rear end of the handle, and a gap being formed between the rotary cap and the seat section. When the rotary cap rotates on the handle, the seat section serves as a support point for the rotary cap.

Description:
[0001]     The present invention is a division application of the U.S. Pat. No. 10/299,715, filed at Nov. 20, 2002 which is invented by and assigned to the inventor of the present invention. The content of the U.S. Pat. No. 10/299,715 amended in the response for the first official action is now incorporated into the specification as a part of the present invention. The claims of the present invention claim the feature in  FIG. 5  of the drawings of the present invention. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention is related to a hand tool, and more particularly to a hand tool handle having a rotary cap at rear end. The rotary cap has little rotational resistance and is easy to rotate.  
         [0003]     When operating a conventional screwdriver, a user&#39;s hand must repeatedly turn back and forth so as to one-way rotate the handle. After clockwise rotating the screwdriver, the user&#39;s hand must release the handle and move back and then tightly hold the handle to clockwise turn the handle again. Such operation is inconvenient for the user.  
         [0004]      FIG. 1  shows a conventional screwdriver  10  in which a rotary cap  14  is rotatably disposed at rear end of the handle  12 . When a user operates the screwdriver and the user&#39;s hand turns back, the palm keeps in contact with the rotary cap without totally separating from the handle. Therefore, the operation is facilitated. Moreover, when the hand turns back, the screwdriver will not deflect or detach from the screw.  
         [0005]     By means of the rotary cap  14 , when the hand and the rotary cap turn back, the handle keeps still. However, in the conventional structure, the inner wall of the rotary cap  14  contacts with the rear end face of the handle  12  face to face as shown by notation A. This leads to great frictional resistance so that the rotary cap can be hardly smoothly rotated. When the user&#39;s hand turns back, the frictional force between the handle and the rotary cap often makes the screwdriver driven by the rotary cap to synchronously turn back. Therefore, the expected effect can be hardly achieved.  
       SUMMARY OF THE INVENTION  
       [0006]     It is therefore a primary object of the present invention to provide a hand tool handle having with rotary cap. The rotary cap has little rotational resistance and is easy to rotate so as to facilitate the operation.  
         [0007]     To achieve above object, the present invention provides a hard tool handle with rotary cap which comprises a handle; a seat section having a convex cambered shape and protruded from a rear end of the handle; an integral formed rotary cap rotatably disposed at a rear end of the handle, the inner side of the rotary cap being formed as a cavity; an inner bottom of the rotary cap being a flat surface so that the contact area between the inner bottom wall of the rotary cap and the seat section being smaller than a cross-sectional area of the rotary cap or the rear end of the handle, and a gap being formed between the rotary cap and the seat section. When the rotary cap rotates on the handle, the seat section serves as a support point for the rotary cap.  
         [0008]     The present invention can be best understood through the following description and accompanying drawings wherein: 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a front partially sectional view of a conventional screwdriver;  
         [0010]      FIG. 2  is a perspective assembled view of a preferred embodiment of the present invention;  
         [0011]      FIG. 3  is a front partially sectional exploded view of the preferred embodiment of the present invention;  
         [0012]      FIG. 4  is a partially sectional assembled view of the preferred embodiment o the present invention;  
         [0013]      FIG. 5  is a front partially sectional view of another embodiment of the present invention;  
         [0014]      FIG. 6  is a partially sectional view of still another embodiment of the present invention;  
         [0015]      FIG. 7  is a partially sectional view of still another embodiment of the present invention;  
         [0016]      FIG. 8  is a partially sectional view of still another embodiment of the present invention;  
         [0017]      FIG. 9  is a partially sectional view of still another embodiment of the present invention; and  
         [0018]      FIG. 10  is a partially sectional view of still another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]     Please refer to  FIGS. 2 and 3 . In a preferred embodiment of the present invention, a handle  20  of a screwdriver is exemplified.  
         [0020]     A stem  22  is disposed at front end of the handle  20  for driving a screw or a bolt.  
         [0021]     The rotary cap  30  is rotatably disposed at rear end of the handle  20 . The inner face of the top of the rotary cap contacts with the rear end of the handle by a small area, whereby the rotary cap is rotatable.  
         [0022]     The rear end of the handle  20  is formed with a seat section  24 . An engagement section  28  which is an annular rib is formed on the circumference of the seat section  24 .  
         [0023]     The rotary cap  30  has a circular cavity  32  inward extending from a bottom end of the rotary cap  30 . An engagement section  34  which is an annular groove is formed on an lower inner wall of the rotary cap  30 . The engagement section  34  of the rotary cap  30  is engaged with the engagement section  28  of the handle as shown in  FIG. 4 , whereby the rotary cap  30  is rotatably fitted on the seat section  24  of the handle  20  without easy detachment. In this embodiment, a diameter of the seat section  24  and an inner diameter of an inner wall of the rotary cap  30  are tapered. A gap  29  is defined between the seat section  24  and the wall of the cavity  32  so that an inner wall of the rotary cap  30  is preferably not in contact with the seat section  24 .  
         [0024]     The present invention includes at least one projection. In this embodiment, the projection is a convex (or spherical) face  26  formed on an end face of the seat section  24 . In addition, a bottom wall of the rotary cap  30  is formed with a convex (or spherical) face  36 . When the rotary cap  30  is rotatably disposed at the rear end of the handle, the centers of the two convex faces  26 ,  36  contact with each other by small areas as shown in  FIG. 4 . The contact areas are much smaller than the cross-sectional area of the rotary cap  30  and the handle  20 .  
         [0025]     In use, a user holds and turns the handle  20  in a direction (for example, clockwise). After turned by a certain angle, the user&#39;s hand can loosen the handle and turn back in a reverse direction (for example, counterclockwise). During turning back, the palm can attach to the rotary cap  30  which serves as a fulcrum, whereby the hand and the rotary cap can turn synchronously with the handle keeping still. After turning back by a certain angle, the user again holds the handle and turns the screwdriver.  
         [0026]     When the rotary cap  30  is turned, the contact points of the two convex faces  26 ,  36  serve as the support point and fulcrum of the rotary cap on the handle  20 . The contact area is small so that the frictional resistance against the rotary cap is little. Accordingly, the rotary cap can be smoothly rotated. The annular rib  28  and the annular groove  34  are not tightly engaged with each other so as to prevent the rotary cap from detaching from the seat section without affecting the rotation of the rotary cap.  
         [0027]      FIG. 5  shows another embodiment of the present invention, in which a seat section  42  is also formed at rear end of the handle  40 . A rotary cap  45  is freely rotatably disposed on the seat section. The engagement structure of the rotary cap is identical to the above embodiment and will not be further described hereafter. In this embodiment, the projection is a convex face  44  formed on the end face of the seat section  42 . The inner face  47  of at an upper side of the inner wall the rotary cap  45  is a plane face in contact with the convex face  44 . When the rotary cap is rotatably disposed at the rear end of the handle, the contact point between the inner face  47  and the convex face  44  serves as the fulcrum and the convex face  44  contacts with the plane face  47  by small area.  
         [0028]      FIG. 6  shows still another embodiment of the present invention, in which the end face of the seat section  52  is a plane face  54 , while the inner face of the top wall of the rotary cap  55  is a convex face  56  in contact with the plane face  54 . The contact point between the plane face  54  and the convex face  56  also serves as the fulcrum and forced portion.  
         [0029]      FIG. 7  shows still another embodiment of the present invention, in which the end face of the seat section  62  is a plane face  64 , and the inner face of the top wall of the rotary cap  65  is also a plane face  66  spaced from the plane face  64  by a certain distance. The projections are two hard pads  68  respectively fixedly disposed on the end face  64  and the inner face  66  in contact with each other. The pads  68  are preferably made of anti-wear material for reducing frictional force.  
         [0030]     When the rotary cap  65  is rotated on the handle  60 , the contact point between the pads  68  serves as the fulcrum and support portion. The pads contact with each other by small areas which much smaller than the cross-sectional area of the handle and the rotary cap so that the rotary cap can be smoothly rotated.  
         [0031]     It should be noted that the number of the pads  68  is not limited to two. Alternatively, there can be only one pad fixedly disposed on the end face of the seat section or the top wall of the cavity.  
         [0032]      FIG. 8  shows still another embodiment of the handle  70  of the present invention, in which an engagement section  77  which is an annular rib is formed on a lower circumference of an inner wall of the rotary cap  75 , while an engagement section  73  which is an annular groove is formed on the outer circumference of the seat section  72 . The engagement section  77  is engaged with the engagement section  73  to rotatably connect the rotary cap  75  with the handle  70 . The projection is a ball body  79  positioned between the end face of the seat section and the bottom top wall of the cavity. Speaking in more detail, the end face of the seat section and an inner bottom wall of the rotary cap  75  are respectively formed with two dents  74 ,  78  corresponding to each other. The ball body  79  is placed in the dents  74 ,  78 .  
         [0033]     As shown in  FIG. 8 , the ball body  79  serves as the contact point between the rotary cap  75  and the seat section  72 . When the rotary cap rotates on the seat section, the ball body  79  serves as the fulcrum and rolls, whereby the rotary cap suffers little frictional force.  
         [0034]      FIGS. 9 and 10  show two other embodiments of the present invention, which are similar to the embodiment of  FIG. 8 . In  FIG. 9 , the end face of the seat section  82  is formed with a dent  84 , while the top wall of the cavity  86  of the rotary cap  85  is a plane face. The ball body  89  is positioned in the dent  84  in contact with the inner bottom wall of the rotary cap  75 . In  FIG. 10 , the end face of the seat section  92  is a plane face, while the top wall of the cavity  96  is formed with a dent  98 . The ball body  99  is placed in the dent  98  in contact with the end face of the seat section  92 . In these two embodiments, the ball body serves as the support point for the rotary cap  75 . The contact area is small and the frictional force is low.  
         [0035]     It should be noted that there can be more than one ball body.  
         [0036]     In conclusion, the rotary cap contacts with the rear end of the handle by small areas. The contact portion serves as the support portion for the rotary cap during rotation. Accordingly, the frictional force against the rotary cap during rotation is effectively lowered so that the rotary cap can be more easily rotated. When a user-operates the screwdriver and the user&#39;s hand turns back, the palm keeps in contact with the rotary cap without totally separating from the handle. At this time, the handle keeps still without being driven by the rotary cap. Therefore, the operation is facilitated.  
         [0037]     The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.