Patent Publication Number: US-2007113710-A1

Title: Ratchet wrench

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates to a ratchet wrench, particularly to one having an upper portion of a rod of a metal rod member covered with an outer layer made of soft material, and a lower portion of the rod combined with a grip that is possible to be made to have different shapes or colors for lowering cost for molds and diversifying the shapes of the ratchet wrench for selection.  
      2. Description of the Prior Art  
      A conventional ratchet wrench shown in  FIG. 1 , includes a metal strip  1  formed by pressing, and an outer layer  2  completely surrounding the metal strip  1 . The metal strip  1  is provided with a plurality of ribs  3  and holes  4 , so the outer layer  2  may be combined as integral with the metal strip  1  when it is formed in a mold. Further, the outer layer  2  is made of soft material such as plastic, carbon fiber, etc, so the outer layer with some elasticity may protect the ratchet wrench from damaging a work in case of the ratchet wrench collides with the work. Moreover, the outer layer  2  may have a separating function for preventing the metal strip  1  from hurting a person by shielding static electricity on the metal strip  1 .  
      As the conventional ratchet wrench has the metal strip  1  surrounded with the outer layer  2 , the metal strip  1  has to be provided with a shaft hole  5  in a front section, and the outer layer  2  has to be provided with a hollow space  6  corresponding to the shaft hole  5  for injecting molding of the outer layer  2 , and further the surrounding precision of the shaft hole  5  and the hollow space  6  are needed to be taken care of during injecting, so the mold for the outer layer  2  is rather difficult to make. Besides, the outer layer  2  has to be formed connected with a grip  7  in a lower portion of the ratchet wrench, and the grip  7  has a big diameter, thicker than the outer layer  2 . So the grip  7  needs much material, and a finished grip  7  may not have the needed size because injecting speed and pressure of the material for the grip  7  may be insufficient. Further, the larger the volume of the material, the longer the time for molding, so productive speed may be slow, in addition to low percentage of qualified products.  
      Next, the metal strip  1  and the outer layer  2  in the conventional ratchet wrench are made with a single mold, so one mold can be used for only one kind of product. Then makers will be forced to make a new mold, if a customer asks a ratchet wrench of a different shape or size, complicating manufacturing processes for makers, who are compelled to prepare many molds for different ratchet wrenches. In view of the most ratchet wrenches seen in the market being only different in the grip  7 , and if a new mold is needed to make a ratchet wrench of a different grip, it is not economical for manufacturing.  
     SUMMARY OF THE INVENTION  
      The feature of the ratchet wrench in the invention is a metal rod member, an outer layer and a grip, and metal rod member is provided with a head formed in an upper section and a hollow formed in the head for receiving a ratchet therein, and a rod extending down from the head. The outer layer made of soft material surrounds the head and an upper portion of the rod, with a lower portion of the rod is not surrounded by the outer layer so that the lower portion of the rod may be combined with the grip. The grip is made of plastic, having a gripping surface formed in an intermediate portion of the grip, and a thickness a little larger than that of the outer layer surrounding the upper portion of the rod. Further, the grip is provided with a lengthwise center hollow for receiving the lower portion of the rod therein. Then after the grip is combined with the lower portion of the rod, the lower end of the outer layer contacts with an upper end of the grip. Thus, the grip and the outer layer are small in the dimensions, easier for making separately by means of injecting molding. Moreover, a wide variety of grips can be made with a variety of molds for customers to choose from to match the outer layer together with the metal rod member.  
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
      This invention will be better understood by referring to the accompanying drawings, wherein:  
       FIG. 1  is a cross-sectional view of a conventional ratchet wrench;  
       FIG. 2  is a perspective view of a first embodiment of a ratchet wrench in the present invention;  
       FIG. 3  is an exploded perspective view of the fi r s t embodiment of a ratchet wrench in the present invention;  
       FIG. 4  is a partial cross-sectional view of the first embodiment of a ratchet wrench in the present invention;  
       FIG. 5  is an exploded perspective view of a second embodiment of a ratchet wrench in the present invention;  
       FIG. 6  is a front view of another outer layer and another grip in the present invention;  
       FIG. 7  is a front view of another outer layer and another grip in the present invention;  
       FIG. 8  is a perspective view of another separating ring in the present invention;  
       FIG. 9  is a front view of another grip in the present invention; and,  
       FIG. 10  is a partial cross-sectional view of a third embodiment of a ratchet wrench in the present invention.  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      A first embodiment of ratchet wrench in the present invention, as shown in  FIGS. 2, 3  and  4 , includes a metal rod member  1 , an outer layer  20 , a grip  30  and a secarating ring  4 .  
      The metal rod member  10  has a head  11  formed in an upper section, a hollow space  12  formed in the head  11  for receiving a ratchet  13  therein, and a rod  14  extending down from the head  11  and having a nearly oval cross-section.  
      The outer layer  20  is made of soft plastic by means of injecting molding process, surrounding the head  11  and a front portion of the rod  1   4 , and a lower portion  141  of the rod  14  not surrounded by the outer layer  20  for fitting in the grip  30 . The hollow space  12  has an opening  121  and the outer layer  20  has a hole corresponding to the opening  121  for the ratchet  13  to fit therein to be set with the rod member  10 . Further, a cap  15  closes on the hole of the outer layer  20 , which has an end edge  21  at a lower end.  
      The grip  30  is made of plastic and shaped as preset, having a gripping surface  31  formed in an intermediate portion for a hand to grip, and a same thickness as that of the outer layer  20 . However, the grip  30  can also be made of two kinds of plastic mixed, so the gripping surface  31  may have gripping effect of two different materials. Further, the grip  30  has a lengthwise center hollow  32  with an opening  321  in an upper end for the lower portion  141  of the rod  14  to fit therein, with the end edge  21  fitting with the opening  321  for closing it up.  
      The separating ring  40  is elastic, fitted tightly around the end edge  21  of the outer layer  20  at the front end of the grip  30  for making the connection part of the rod member  14  and the grip  30  close and pretty. In addition, the separating ring  40  can be colored black, rod, or yellow to match with the whole appearance for users to select.  
      Referring to  FIGS. 3 and 4 , as the outer layer  20  surrounds the head  11  and the upper portion of the rod  14  for protecting the metal rod member  10 , and the thickness of the outer layer  20  are even so that plastic material for the outer layer  20  in a mold may be moved and pressured evenly and formed with high qualified percentage of finished products. Moreover, the grip  30  has the gripping member  31  comparatively thick, but its length is short, it can be formed in an independent mold wherein small mass of the material needed is easily controlled in molding speed and pressure to get high qualified percentage of finished products. Therefore, makers can prepare plural molds for the grips  30 , needless of a large mold needed for the conventional ratchet wrench having the metal rod together with the grip, saving largely the expenditure for the molds. Thus, various requirements of customers can be satisfied by supplying a large variety of grips  30  to match with the metal rod  10  together with the outer layer  20  for customers to choose from.  
      Next, the separating ring  40  can be made to have different colors for customers to choose from, and for benefit of managing and identifying the ratchet wrenches for marketing.  
      However, the separating ring  40  can also be omitted to let the grip  30  directly contact the lower end of the outer layer  20 , still obtaining close mutual combination with the outer layer  20  and grip  30 .  
      In addition,  FIG. 6  shows another embodiment of the outer layer  20  and the grip  30 , wherein the lower end of the outer layer  20  is saw-toothed and the upper end of the grip  30  is also saw-toothed to fit closely with that of lower end of the outer layer  20 . Further,  FIG. 7  shows one more embodiment of the outer layer  20  and the grip  30 , wherein the lower end of the outer layer  20  and the upper end of the grip  30  are both shaped as waved one  203  and  302  to fit closely with each other, giving different outer appearance to the ratchet wrench.  
      Next,  FIG. 8  shows another embodiment of a separating ring  50 , wherein the separating ring  50  has some elasticity, a different shape from that of the first embodiment, and a projecting edge  51  on a lower surface to fit in the opening  321  of the center hollow  32  of the grip  30 , and an upper flat surface to fit with a flat lower end surface of the outer layer  20  after inserted through the lower portion  141  of the rod  14 .  
       FIG. 9  shows another embodiment of a grip  60  to match with the other components of the ratchet wrench, offering various shapes of a ratchet wrench.  
      Next,  FIG. 10  shows a third embodiment of a ratchet wrench in the invention, which has almost the same structure as the first and the second embodiment, except that the lower end of the outer layer  20  is fitted around directly with the separating ring  30 , and then the lower portion  141  of the rod  14  is inserted in the grip  30 , speeding assemblage of the ratchet wrench.  
      Lastly, the invention has the following advantages as can be seen from the foresaid description.  
      1. The outer layer and the grip are separately made by injection molding process, enhancing the percentage of qualified finished products, increasing injecting molding speed, enhancing producing speed, and lowering producing cost.  
      2. The grip can be made to have various shapes and colors to match the rod member and the outer layer, offering a large variety of ratchet wrenches for customers to choose from, very beneficial to compete in the market.  
      3. The outer layer of the ratchet wrench can protect it from hurting a work, prevent it from generating static electricity and offer soft touch for gripping as well.