Abstract:
A torque socket essentially comprises an inner socket, and an outer socket. Besides a function of torque value setting and adjustment, the torque socket utilizes a ratchet structure design to produce a sound to warn the user, when the torque applied by the torque socket has reached a predetermined value, allowing the user to know the torque applied to the fastener by the torque wrench has reached the predetermined value easily. Further, the torque socket is simple in structure, thus reducing the production and assembly cost.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a wrench, and more particularly to a torque socket. 
         [0003]    2. Description of the Prior Art 
         [0004]    A conventional socket is normally mounted on a power tool or wrench to screw or unscrew a fastener, and the screwing or unscrewing force is manually controlled by the user. Too large force will cause damage to the fastener, and too small force may cause looseness of the fastener. 
         [0005]    To solve the abovementioned drawbacks, normally, the socket is structurally designed to have a predetermined value which prevents the inappropriate force caused deadlock or looseness of the fastener. 
         [0006]    For example, GB Patent No. 856136 discloses torque limiting wrench which comprises three smaller balls abutted against the lower end of a larger ball, an elastic member vertically pressing against the larger ball, and a cylindrical housing defined with slots for receiving the smaller balls. These parts cooperate with one another to screw and unscrew a fastener. However, the cylindrical housing is brought into contact with the smaller balls by smooth arc surfaces, in other words, there is no ratchet structure in the cylindrical housing, so that when the torque wrench is operated, it is too difficult to detect if the toque applied to the fastener by the torque wrench has reached the predetermined value, thus needing improvement. In addition, the torque wrench needs to be defined with multiple holes to cooperate with the respective elements, such as the larger ball, the three smaller balls, the elastic member, etc. Furthermore, the respective elements need to be produced independently, and it also requires holding spaces to be formed to hold the elements, so the production difficulty and cost are increased. 
         [0007]    Further, U.S. Pat. No. 3,693,381 discloses torque responsive clutch which comprises a larger central ball under a predetermined spring pressure, three smaller balls abutted against the lower end of the larger central ball, and a hosing with six identical recesses. With these parts, the output torque of the wrench can be detected in time during the operation of the torque clutch. However, such a conventional torque responsive clutch also has the above drawbacks of difficult to detect if the toque applied to the fastener by the torque wrench has reached a predetermined value, complicated machining procedure, and high production difficulty and cost. 
         [0008]    GB Patent No. 2180476 discloses quick change adapter with a torque limiter for a tapping chuck which comprises a tap holder, a driving element, a casing and an inner toque means. These parts cooperate with one another to allow the fastener to be appropriately screwed or unscrewed. However, the torque means includes plural pairs of balls that cooperate with a plain washer and plural Belleville type springs, the torque limiter need to be defined with multiple holes to cooperate with the respective elements, thus increasing assembly difficulty and the production cost. 
         [0009]    In addition, U.S. Pat. No. 4,063,474 discloses torque limiting screwdriver which essentially comprises a sliding sleeve, a torque adjusting rod and a torque adjusting means therein. The torque adjusting means includes plural balls, a clutch and plural springs. Since the configuration is complicated, multiple holes need to be defined to cooperate with the respective elements, and the respective elements need to be produced independently, and it also requires holding spaces to be formed to hold the elements, the production difficulty and cost of the torque socket are greatly increased. Further, it is also too difficult to detect if the torque applied to the fastener by the torque wrench has reached a predetermined value, so improvement is also needed. 
         [0010]    Finally, U.S. Pat. No. 4,272,973 discloses socket joint for torque wrench which is orderly provided with a first engaging element, a second engaging element to be engaged with the first engaging element, a spring pressing against the second engaging element and an adjusting bolt pressing against the spring in a housing. When the toque joint is in use, once the force applied by the spring to the second engaging element is insufficient, idle rotation of the second engaging element will be caused, and the torque joint will become ineffective. 
         [0011]    The present invention has arisen to mitigate and/or obviate the afore-described disadvantages. 
       SUMMARY OF THE INVENTION 
       [0012]    The primary objective of the present invention is to provide a torque socket, which utilizes an inner ratchet structure to produce a sound when the torque has reached a predetermined value, allowing the user to easily detect that the torque applied by the torque wrench to the fastener has reached the predetermined value. 
         [0013]    The secondary objective of the present invention is to provide a torque socket which is simple in structure, thus reducing the production and assembly cost. 
         [0014]    Hence, in order to achieve the above objectives, a torque socket in accordance with the present invention comprises an inner socket and an outer socket. The inner socket is interiorly provided with an axially movable positioning ball, a spring and a radially movable loading ball, the positioning ball and the loading ball are pushed against each other, and the loading ball is allowed to partially protrude out of the inner socket. 
         [0015]    The outer socket axially includes a holding groove in one end thereof, the holding groove of the outer socket is formed with a ratchet surface on an inner periphery thereof, on the ratchet surface is equidistantly provided plural annularly-arranged teeth, the respective teeth include two side surfaces, and a resisting surface connected between the two side surfaces, between two opposite side surfaces of each two neighboring teeth is formed a U-shaped engaging recess with respect to the ratchet surface, the outer socket is allowed to be pivotally engaged on the inner socket, when the loading ball is engaged into the one of the engaging recesses, the outer socket and the inner socket will be fixed relative to each other, when the loading ball is pushed against by one of the resisting surfaces of the teeth, the outer socket and the inner socket are allowed to pivot relative to each other. 
         [0016]    By such arrangements, during a pivoting process of the inner socket and outer socket, the loading ball will move into and out of the inner socket due to its position changes with respect to the engaging recesses and the teeth, and when the loading ball passes over the teeth and engages into the engaging recess, a sound will be produced. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is an exploded view of a torque socket in accordance with the present invention; 
           [0018]      FIG. 2A  is a cross-sectional view showing an operating state of the torque socket in accordance with the present invention; 
           [0019]      FIG. 2B  is a cross-sectional view along the line  2 B- 2 B of  FIG. 2A , showing the operating state of the torque socket in accordance with the present invention; 
           [0020]      FIG. 3A  is a cross-sectional view showing a non operating state of the torque socket in accordance with the present invention; 
           [0021]      FIG. 3B  is a cross-sectional view along the line  3 B- 3 B of  FIG. 3A , showing the non operating state of the torque socket in accordance with the present invention; 
           [0022]      FIG. 4  is a perspective view showing the torque socket in accordance with the present invention is engaged with different tool heads; 
           [0023]      FIG. 5  is a perspective view showing the torque socket in accordance with the present invention is assembled to a wrench; 
           [0024]      FIG. 6  is a perspective view showing the torque socket in accordance with the present invention is assembled to a gripping handle; 
           [0025]      FIG. 7  is a cross sectional view shown how the adjusting rod for the torque socket in accordance with the present invention is adjusted; 
           [0026]      FIG. 8  is a perspective view showing that the torque socket in accordance with the present invention is engaged with a sleeve; 
           [0027]      FIG. 9  is an exploded view showing another torque socket in accordance with the present invention is not provided with an adjusting rod; and 
           [0028]      FIG. 10  is a cross sectional view of the torque socket in accordance with the present invention of  FIG. 9 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    The present invention will be clearer from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention. 
         [0030]    Referring to  FIGS. 1 ,  2 A and  2 B, a torque socket in accordance with a first embodiment of the present invention essentially comprises an inner socket  20  and an outer socket  30  that are allowed to pivot relative to each other after being assembled. 
         [0031]    The inner socket  20  axially includes a recess  21  and a first assembling portion  22  in two opposite ends thereof. The inner socket  20  is radially defined with a through hole  23  in communication with the recess  21 . Further, the inner socket  20  is formed with a flange  24  radially extending outwards from a middle portion thereof. In addition, between the recess  21  and the first assembling portion  22  is axially defined a threaded adjusting hole  25 . A positioning ball  41 , a first stopper  42 , a spring  43  and a second stopper  44  are orderly disposed in the recess  21  and abutted against one another. The first assembling portion  22  is an inner tetragonal or hexagonal groove for engaging with a tool head D (as shown in  FIG. 4 ). In the through hole  23  is disposed a loading ball  45 . The positioning ball  41  and the loading ball  45  are pushed against each other, and the loading ball  45  is allowed to partially protrude out of the inner socket  20 . In the adjusting hole  25  is disposed an adjusting rod  46  which can be axially adjusted. The adjusting rod  46  is in the form of a screw, and one end  461  of the screw  46  protrudes out of the first assembling portion  22  for the user to adjust the depth that the adjusting rod  46  is screwed into the adjusting hole  25 , thus providing a function of value setting and adjustment. The other end  462  of the adjusting rod  46  is abutted against the positioning ball  41 . 
         [0032]    The outer socket  30  axially includes a holding groove  31  and a second assembling portion  32  at two ends thereof. The second assembling portion  32  is provided for engaging with hand tools such as a wrench A or a gripping handle B (as shown in  FIGS. 5 and 6 ). The holding groove  31  is formed with a ratchet surface  311  on an inner periphery thereof, and on the ratchet surface  311  are equidistantly provided annularly-arranged plural teeth  33 . The respective teeth  33  include a first side surface  331 , a second side surface  332 , and a resisting surface  333  connected between the first side surface  331  and the second side surface  332 . Between each two neighboring teeth  33  is formed a U-shaped engaging recess  35  with respect to the ratchet surface  311 , namely two opposite side surfaces of each two neighboring teeth  33  and the ratchet surface  311  define a U-shaped engaging recess  35 . The outer socket  30  can be pivotally engaged on the inner socket  20 . When the outer socket  30  and the inner socket  20  are assembled, the outer socket  30  will be stopped against the flange  24 , so that when the loading ball  45  is engaged into one of the engaging recesses  35 , the inner socket  20  and the outer socket  30  will be fixed relative to each other, and when the loading ball  45  is pushed against by one of the resisting surfaces  333  of the teeth  33 , the inner socket  20  and the outer socket  30  are allowed to pivot relative to each other. 
         [0033]    By such arrangements, during the pivoting process of the inner socket  20  and outer socket  30 , the loading ball  45  will move into and out of the inner socket  20  due to its position changes with respect to the engaging recesses  35  and the teeth  33 , and when the loading ball  45  passes over the teeth  33  and engages into the engaging recess  35 , a sound will be produced. 
         [0034]    The aforementioned is the key technology and the summary of the positional and structural relationship of the respective components of the preferred embodiment in accordance with the present invention. 
         [0035]    For a better understanding of the present invention, its operation and function, reference should be made to  FIGS. 2A and 2B  and  FIGS. 3A and 3B  again. 
         [0036]    When the torque applied to the torque socket during operation is lower than the value preset by the user, the torque socket can be used to screw or unscrew the fastener due to secure engagement between the loading ball  45  and one of the engaging recesses  35  of the outer socket  30 . 
         [0037]    When the torque applied to the torque socket during operation is greater than the value preset by the user, the outer socket  30  can be rotated in a clockwise direction to allow the loading ball  45  to retract into the through hole  23  of the inner socket  20  along the first side surface  331  and the resisting surface  333  of one of the teeth  33  of the outer socket  30 . At this moment, the loading ball  45  will push the positioning ball  41  to ascend a certain distance. Upon ascending, the positioning ball  41  will compress the spring  43 . After that, the outer socket  30  is continuously rotated, so that when the engaging recess  35  of the outer socket  30  is aligned with the loading ball  45 , the loading ball  45  will be biased toward the corresponding engaging recess  35  from the resisting surface  333  of the tooth  33  by the elastic force of the spring  43  and quickly engaged into the engaging recess  35 , that is to say, the loading ball  45  is restricted in the space defined by the second side surface  332  of one of the teeth  33 , the first side surface  331  of the neighboring tooth  33  and the ratchet surface  311  of the outer socket  30 . Therefore, while the loading ball  45  quickly touches the second side surface  332  of the one of the teeth  33 , the first side surface  331  of the neighboring tooth  33  and the ratchet surface  311  of the outer socket  30 , the sound will thus be produced. As a result of this, when the torque achieves the predetermined value during the operation of the toque socket, the sound will be produced to warn the user that the torque applied to the fastener by the toque wrench has reached the predetermined value. 
         [0038]    The torque socket in accordance with the present essentially comprises an outer socket, an inner socket, a spring, a positioning ball and a loading ball, so that the present invention is simple in structure. Especially, only one set of a positioning ball and a loading ball is needed, so the present invention is more convenient to assemble. 
         [0039]    Referring to  FIG. 7 , when the user needs to adjust the torque applied to the fastener, the user can adjust the depth that the adjusting rod  46  is screwed into the adjusting hole  25  to control the compression extent of the spring  43 . When the spring  43  is not compressed, the force which the user applies to the spring  43  to compress the spring  43  is the greatest torque which the spring  43  can bear. Thereby, the greater the compression extent of the spring  43  is, the greater the predetermined pressure will be, such that the force which makes the loading ball  45  move will be reduced, that is to say, the force for screwing the fastener will be smaller. 
         [0040]    Referring to  FIG. 8  showing a torque socket in accordance with a second embodiment of the present invention, the first assembling portion  22  of the inner socket  20  is a tetragonal column to be engaged into a sleeve C. 
         [0041]    Referring to  FIGS. 9 and 10  showing a torque socket in accordance with a third embodiment of the present invention, the first assembling portion  22  of the inner socket  20  is a tetragonal column. A protruding block  26  is disposed at a bottom of the recess  21  and abutted against the positioning ball  41 . No adjusting rod is provided at the inner socket  20 , such that the torque can only be controlled according to the elasticity coefficient of the spring  43 . 
         [0042]    While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.