Patent Publication Number: US-2013239758-A1

Title: Open wrench

Description:
FIELD OF THE INVENTION 
     The present invention relates to an open wrench, and more particularly, to an open wrench with ratchet function. 
     BACKGROUND OF THE INVENTION 
     The conventional open wrench with ratchet function is disclosed in U.S. Pat. No. 1,320,668 and generally includes a head with two jaws. One jaw has a curved guide slot defined in the inside thereof and the curved guide slot has a closed top or closed bottom. An engaging member is movably received in the guide slot. The other jaw has a through hole in which a spring is located. The shaping has one end biasing the engaging member so that the engaging member is movable and performs as a ratchet wrench. The head has a curved outer surface so that it is difficult to drill the through hole for receiving the spring because the drill tends to shift when drilling. Besides, the through hole is exposed on the outside of the head and affects the aesthetic appearance of the wrench. 
     U.S. Pat. No. 7,827,887 discloses an open wrench and includes a head with two jaws. One jaw has a curved guide slot defined in the inside thereof and the curved guide slot has a closed top and a closed bottom. A spring and a movable engaging member are received in the guide slot. The spring biases the engaging member so that the engaging member is movable and performs as a ratchet wrench. The engaging member has a guide rod extending therethrough and the spring is located in a notch defined in the inside of the guide slot. However, the guide slot with the enclosed top and bottom is difficult to be machined and the engaging member has less structure strength due to the guide rod extending through the engaging member. The open wrench provides one side of the engaging member and one jaw to clamp the two opposite sides of a hexagonal object lacks sufficient contact area to apply sufficient torque to the object. The two opposite sides of the hexagonal object are located at a distance from the axis of the hexagonal object so that the torque cannot be properly applied to the hexagonal object. The corner of the hexagonal object tends to impact the engaging member to cause wearing. 
     The present invention intends to provide an open wrench which is easily machined and manufactured, and performs as a ratchet wrench. 
     SUMMARY OF THE INVENTION 
     The present invention relates to an open wrench and comprises an elongate body with a head located on an end of the body. The head includes two jaws and a mounting hole is defined between the two jaws. One of the jaws has a curved recess, a curved guide slot and a notch defined in the inside thereof. The other jaw has a curved convex contact face protruding from the inside thereof. An engaging member is movably located in the curved guide slot and a resilient member biases the engaging member which performs as a ratchet wrench. Two covers are respectively connected to the top and the bottom of the head to cover up the engaging member and the resilient member. 
     The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view to show the open wrench of the present invention; 
         FIG. 2  is a top view of the open wrench of the present invention; 
         FIG. 3  is a top view of the engaging member of the open wrench of the present invention; 
         FIG. 4  is a top view to show that the open wrench of the present invention is mounted to an object; 
         FIG. 5  shows the first action position of the open wrench of the present invention relative to the object; 
         FIG. 6  shows the second action position of the open wrench of the present invention relative to the object; 
         FIG. 7  shows the third action position of the open wrench of the present invention relative to the object; 
         FIG. 8  is an exploded view to show the second embodiment of the open wrench of the present invention; 
         FIG. 9  is a top view of the third embodiment of the open wrench of the present invention, and 
         FIG. 10  is an exploded view to show the fourth embodiment of the open wrench of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 to 3 , the open wrench of the present invention comprises an elongate body  10 , an engaging member  20 , a resilient member  30  and at least one cover  40 . 
     Referring to  FIGS. 1 to 3 , the body  10  has a head  100  located on an end thereof and the head  100  has two jaws  101 ,  102 . A mounting hole  11  is defined between the two jaws  101 ,  102  and an opening  113  is defined between two distal ends of the two jaws  101 ,  102  and the opening  113  communicates with the mounting hole  11 . The axis of the mounting hole  11  is perpendicular to the axis of the body  10 . The jaw  101  has a curved recess  111 , a curved guide slot  12  and a notch  13  defined in the inside thereof. The curved recess  111 , the curved guide slot  12  and the notch  13  open toward the direction of the axis of the mounting hole  11 . The other jaw  102  has a curved convex contact face  112  protruding from the inside thereof. The opening  113  is located between two flat insides  1130 ,  1131  which extend outwardly to form a gradually enlarged opening. The curved guide slot  12  has a first curved face  121  defined in the inside thereof. The notch  13  has a first side  130  which has the first end connected with and tangential to an end of the first curved face  121 . The second end of the first side  130  is bent to be a second side  131 . The head  100  is cut to have the two jaws  101 ,  102  with the mounting hole  11 , the curved recess  111 , the contact face  112 , the opening  113 , the curved guide slot  12  and the notch  13  by way of laser cutting or linear cutting. 
     Referring to  FIGS. 1 to 3 , the engaging member  20  is movably received in the curved guide slot  12  and movable along the first curved face  121 . The engaging member  20  has a first engaging portion  21  and a second engaging portion  22  which is connected to the first engaging portion  21  at an angle. The first and second engaging portions  21 ,  22  are two curved and convex portions. The engaging member  20  has an end face  200  located corresponding to the second side  131  and the end face  200  has a recess  24 . A restriction portion  23  extends from one side of the end face  200  and is located corresponding to the first side  130 . The end face  200 , the first side  130 , the second side  131  and the restriction portion  23  define a space  14 . The engaging member  20  has a protrusion  25  which is parallel with the axis of the mounting hole  11 . An arc recessed area  26  is defined at the conjunction area between the two engaging portions  21 ,  22 . 
     Referring to  FIGS. 1 to 3 , when a hexagonal head  500  of an object  50  is clamped in the mounting hole  11 , the diameter of the first curved face  121  is equal to or smaller than the shortest distance  51  of two opposite sides of the hexagonal head  500 . The contact face  112  and one flat inside  1130  of the opening  113  are in contact with one side  501  of the hexagonal head  500 . The contact face  112  is tangential to the center of the side  501 . The two engaging portions  21 ,  22  respectively contact another two opposite sides  502 ,  503  of the hexagonal head  500 . A corner  504  of the hexagonal head  500  is received in a recessed area  26  between the two engaging portions  21 ,  22 . The longest distance  61  between the curved recess  111  and the contact face  112  is larger than the distance between two diagonal corners of the hexagonal head  500 . The first curved face  121  is located on a circle C 1  and a center  62  of the circle C 1  is located within the mounting hole  11 . An angle  63  is defined between a shortest distance L 1  between the center  62  and the axis  52  of the hexagonal head  500  and the side  501  of the hexagonal head  500 . The angle  63  is about 35 to 50 degrees. 
     Referring to  FIG. 3 , the resilient member  30  is located in the space  14  and one end of the resilient member  30  contacts the guide slot  12  and the other end of the resilient member  30  is engaged with the recess  24  to bias the engaging member  20 . 
     Referring to  FIGS. 1 and 3 , two covers  40  each has the same shape as that of the head  100  and are mounted to top and bottom of the head  100  to seal the engaging member  20  and the resilient member  30  in the space  14 . Each cover  40  has a curved slot  41  which shares a common axis  62  with the first curved face  121 . The protrusion  25  extends through the curved slot  41  so as to guide the movement of the protrusion  25 . The covers  40  are welded to the head  100  and the seams are flattened and polished to have smooth surface. The cover  40  is cut to have the curved slot  41  by way of laser cutting or linear cutting. The way of weld is melt welding, press welding, laser welding, argon welding, carbon dioxide electric welding, electric liquid arc welding, arc welding, air welding or electric resistance welding. 
     As shown in  FIG. 4 , the hexagonal head  500  of the object  50  is clamped by the open wench and the engaging member  20  is biased by the resilient member  30 , the first and second engaging portions  21 ,  22  are in contact with two adjacent sides  502 ,  503  of the hexagonal head  500 . The contact face  112  contacts another side  501  of the hexagonal head  500 . The body  10  is rotated clockwise to rotate the object  50 . 
     As shown in  FIGS. 5 to 7 , when the body  10  drives the object  50  to an angle, the body  10  is rotated counter clockwise, because the distance  61  is larger than the distance between two diagonal corners of the hexagonal head  500 , the hexagonal head  500  changes the relative position in the mounting hole  11 , and the contact face  112  is removed from the side  501  of the hexagonal head  500 . The engaging member  20  is pushed by the hexagonal head  500 , the two engaging portions  21 ,  22  are removed from the two sides  502 ,  503 , and the engaging member  20  compresses the resilient member  30  and moves along the curved slot  41  to move away from the axis of the object  50  as shown in  FIGS. 5 and 6 . The body  10  continuously rotates counter clockwise, to the status as shown in  FIG. 7 , the mount the object  50  by another angular position, the body  10  can be rotated clockwise to rotate the object  50 . This is functioned as a ratchet wrench. 
     As shown in  FIG. 8 , which shows the second embodiment, wherein two outer pieces  70  are respectively mounted onto the two covers  40  and the outer pieces  70  have the same shape of the cover  40  so as to cover up the curved slot  41  and the protrusion  25 . 
     As shown in  FIG. 9 , which shows the third embodiment, wherein the contact face  112  is a flat surface and has multiple protrusions  1120  formed thereon. 
     As shown in  FIG. 10 , which shows the fourth embodiment, wherein only one cover  40  is used to the body  10 . 
     The open wrench of the present invention is functioned as a ratchet wrench and easily manufactured. The present invention is manufactured at low cost and has better strength. The present invention clamps three sides of the hexagonal head to apply sufficient torque to the object. The body  10  and the engaging member  20  have complete structure which has better strength. The engaging member  20  and the contact face  112  clamp the sides  501 / 502 / 503  of the hexagonal head  500  of the object  50  and are located close to the center of the object  50  so that sufficient torque can be applied to the object  50 . The recessed area of the engaging member  20  accommodates the corner  504  of the hexagonal head  500  to avoid wearing. The diameter of the first curved face  121  is equal to the shortest distance  51  of two opposite sides of the hexagonal head  500  so that the machining is made according the curvature to match the size of the object  50 . 
     While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.