Abstract:
A hand-driven mechanical screwdriver includes a holding assembly, a drive mechanism supported by the holding assembly, and a working element. The holding assembly includes a bracket and a sliding channel defined in the bracket. The drive mechanism includes a connecting element and a screw rod threadably engaged within the connecting element. An activator is rotatably connected to the connecting element and slidably positioned within the holding assembly bracket sliding channel. The working element is attached to the second end of the screw rod. When the activator is slid along the sliding channel, the connecting element moves from near the second end of the bracket towards the first end of the bracket rotating the threadably engaged screw rod and the working element attached to the screw rod.

Description:
FIELD 
     The subject matter herein generally relates to a mechanical device. 
     BACKGROUND 
     In mechanical processing, a screw is widely used as a joining member. To improve operating efficiency and reduce labor cost, it is necessary to apply a screwdriver to screw or unscrew the screw. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the present technology will now be described, by way of example only, with reference to the attached figures, wherein: 
         FIG. 1  is an isometric view of a hand-driven mechanical screwdriver according to an embodiment of the present disclosure. 
         FIG. 2  is a cross-sectional view of the hand-driven mechanical screwdriver shown in  FIG. 1  taken along line II-II. 
         FIG. 3  is an exploded, isometric view of the hand-driven mechanical screwdriver shown in  FIG. 1 . 
         FIG. 4  is a cross-sectional, isometric view of a connecting element of the hand-driven mechanical screwdriver shown in  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure. 
     Several definitions that apply throughout this disclosure will now be presented. 
     The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “outside” refers to a region that is beyond the outermost confines of a physical object. The term “inside” indicates that at least a portion of a region is partially contained within a boundary formed by the object. The term “substantially” is defined to be essentially conforming to the particular dimension, shape, or other word that substantially modifies, such that the component need not be exact. For example, substantially cylindrical means that the object resembles a cylinder, but can have one or more deviations from a true cylinder. The term “comprising”, when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like. 
     The present disclosure is described in relation to a hand-driven mechanical screwdriver. 
       FIG. 1  illustrates a hand-driven mechanical screwdriver  100  can include a housing  10 , a driving mechanism  30 , a holding assembly  50 , and a working element  70  driven by the driving mechanism  30 . The driving mechanism  30  can be movably connected to the housing  10  and partially received inside the housing  10 . The driving mechanism  30  can be configured to drive the working element  70  to rotate. The holding assembly  50  can be connected to an exterior of the driving mechanism  30 . The holding assembly  50  can be configured to control the movement of the driving mechanism  30  and to secure the housing  10  and the driving mechanism  30 . The working element  70  can be connected to an end of the driving mechanism  30  and can be exposed outside the housing  10 . The working element  70  can be configured to be driven by the driving mechanism  30  and engage with a screw for fastening. 
       FIGS. 2-3  illustrate that the housing  10  can be hollow, substantially cylindrical and include a first end portion  11  and a second end portion  13  facing each other. The housing  10  can further include a latching portion  12  connected to the first end portion  11 . The latching portion  12  can be substantially circular and substantially perpendicularly extend to an axis of the housing  10  from the first end portion  11 . 
     The housing  10  can further include a through hole  15  adjacent to the first end portion  11 , and an elastic portion  17  adjacent to the second end portion  13 . The elastic portion  17  can have a plurality of folds  171  evenly distanced from each other, configured to provide an elastic property for the housing  10 . When a downward pressure is applied to the first end portion  11 , the second end portion  13  can be vertically compressed and adjusted to a compressed state. When the applied pressure is removed, the second end portion  13  can rebound to a relaxed state. In other embodiments, the elastic portion  17  can be made of an elastic material, such as a rubber or plastic. 
     The driving mechanism  30  can include a screw rod  31 , two bearings  32 , and a fixing element  33 . The screw rod  31  can pass through the housing  10  and extend outside the first end portion  11  and second end portion  13 . The screw rod  31  can define a plurality of first helical grooves  311  in an exterior surface. The two bearings  32  can be coiled on either end of the screw rod  31  and be positioned respectively adjacent to the first end portion  11  and second end portion  13 . The fixing element  33  can be coiled around an end of the screw rod  31  adjacent to the first end portion  11 . The fixing element  33  can be stacked on the bearing  32  adjacent to the first end portion  11 , configured to secure the bearing  32 . In at least one embodiment, the fixing element  33  can be a screw nut. 
     The driving mechanism  30  can further include a connecting element  35 , a plug block  37 , a plurality of ball bearings  38 , and a resetting element  39 . The connecting element  35  can be hollow and substantially cylindrical, and can be received inside the housing  10 . The connecting element  35  can be coiled around the screw rod  31  and threadedly engage the screw rod  31 . The connecting element  35  can define a substantially circular latching groove  351  to receive and engage the latching portion  12 . The connecting element  35  can be coupled to the housing  10  by the engagement of the latching groove  351  and latching portion  12 , and at the same time can keep contaminants such as dust from entering. The connecting element  35  can further define a connecting portion  354  and a resisting portion  353 . The connecting portion  354  can be defined adjacent to the latching groove  351 . The connecting portions  354  can be a pair of projections substantially projecting from a periphery of the connecting element  35  in a radial direction. The resisting portion  353  can be located axially facing the connecting portion  354 . The latching groove  351  can be located between the resisting portion  353  and the connecting portion  354 . 
     An opening  358  can be defined in the periphery of the connecting element  35  can be configured to receive the plug block  37 . The opening  358  can be substantially parallel with an axial direction of the connecting element  35 . The opening  358  and resisting portion  353  can be located in opposite radial sides of the connecting element  35 . The plug block  37  can mate with the opening  358  and can be received in the opening  358 . The plug block  37  can prevent ball bearings  38  from moving out. Furthermore, the plug block  37  can define a slot  371  in a middle portion, two fixing holes  372 , and two fixing members  373  to engage the fixing holes  372 . The slot  371  can be configured to receive the ball bearings  38  and can match size and shape of the ball bearings  38 . The two fixing holes  372  can be located away from the slot  371  at either end of the plug block  37 . The fixing member  373  can be inserted into the fixing hole  372  to connect the plug block  37  to the connecting element  35 . 
     The connecting element  35  can further define a ball bearing sliding slot  359 . The ball bearing sliding slot  359  can be a cyclic channel to allow the ball bearings  38  to roll. The ball bearing sliding slot  359  can be partially formed by the slot  371  functioning as a part of the ball bearing sliding slot  359 . A remaining part of the ball bearing sliding slot  359  can be defined between the screw rod  31  and the connecting element  35 , and can be cooperatively formed by an inner side of the connecting element  35  and a plurality of the first helical grooves  311  of the screw rod  31 . The resetting element  39  can be hollow and elastic. The resetting element  39  can be coiled around the screw rod  31  and can be received inside the housing  10 . The resetting element  39  can be located adjacent to the second end portion  13 . In at least one embodiment, the resetting element  39  can be a spring. 
     The holding assembly  50  can include a bracket  51 , an activator  53 , an elastic member  54 , and two control members  55 . The bracket  51  can include a main body  511 , a first supporting seat  513  and a second supporting seat  515 . The main body  511  can be installed outside and can be connected to the housing  10 . The main body  511  can define a substantially oval sliding channel  5111  in the axial direction. The main body  511  can further define a first engaging portion  5113  along the inner periphery of the sliding channel  5111 . The first engaging portion  5113  can be substantially saw-tooth shaped. 
     The first supporting seat  513  and second supporting seat  515  can be hollow and substantially cylindrical, and located on opposite ends of the bracket  51  extending to substantially a same direction. The first supporting seat  513  and second supporting seat  515  can be substantially perpendicular to the main body  511  and extend to the driving mechanism  30 . The first supporting seat  513  can include a substantially circular flange  5131  and can be configured to support the bearing  32  adjacent to the first end portion  11 . The flange  5131  can be positioned inside the first supporting seat  513 . The screw rod  31  can pass through the first supporting seat  513  and second supporting seat  515 , and either end of the screw rod  31  can be rotatably installed on the first supporting seat  513  and second supporting seat  515  via the two bearings  32 . 
     The activator  53  can be substantially “L” shaped. The activator  53  can be received inside the sliding channel  5111  to engage the first engaging portion  5113 . The activator  53  can include a rod portion  531 , and the rod portion  531  can define a second engaging portion  5311  to engage the first engaging portion  5113 . An end of the rod portion  531  can be connected to the connecting portion  354 . 
     The activator  53  can further define a block  5313  to engage the elastic member  54 . The elastic member  54  can be hollow and substantially cylindrical. In one embodiment, the elastic member  54  can be a spring. The elastic member  54  can be coiled around the block  5313 . An end of the elastic member  54  adjacent to the activator  53  can resist against the rod portion  531 , and an end of the elastic member  54  extending to the screw rod  31  can pass through the through hole  15  to resist against the resisting portion  353 . When a pressure is exerted on the activator  53 , the elastic member  54  can be compressed to release the second engaging portion  5311  from the first engaging portion  5113 . Thus, the activator  53  can be adjusted to be movable in the sliding channel  5111 , and in this situation the connecting element  35  can be exerted with a downward pressure to move downward. When the pressure exerted on the activator  53  is removed, the elastic member  54  can rebound to drive the second engaging portion  5311  to engage the first engaging portion  5113 . Thus the activator  53  can be adjusted to be immobile in the sliding channel  5111 . 
     The two control members  55  can be fixed on opposite ends of main body  511  and extend into the sliding channel  5111 . In one embodiment, the control member  55  can be a screw. One control member  55  away from the working element  70  can abut against the activator  53 . A length of the control member  55  extending into the sliding channel  5111  can be variable to adjust the movement of the activator  53  in the sliding channel  511  whereby a sliding length of the activator  53  in the sliding channel  511  can be adjusted. Each control member  55  can have a reserved length which is convenient for adjustment. 
     The working element  70  can be installed on the screw rod  31  adjacent to the second supporting seat  515 . The working element  70  can include a rotary joint  71 , a working portion  73 , and a connecting portion  75 . An end of the rotary joint  71  can be coiled around the end of the screw rod  31  adjacent to the second supporting seat  515 . The working portion  73  can be inserted into and connected to an end of the rotary joint  71  adjacent the second supporting seat  515 . The connecting portion  75  can be coiled on a joint of the rotary joint  71  and the working portion  73 . The connecting portion  75  can be configured to prevent a loosening of the joint of the rotary joint  71  and working portion  73  and enhance the joint of the two. In at least one embodiment, the working portion  73  can be a hand-driven mechanical screwdriver bit. 
       FIG. 4  illustrates that the connecting element  35  can further define a receiving channel  356 . The receiving channel  356  can include a first receiving channel  3561 , a second receiving channel  3563 , and a shaft shoulder  3562  between the two. The first receiving channel  3561  can be located inside an end of the connecting element  35  away from the connecting portion  354 . The second receiving channel  3563  can be located inside an end of the connecting element  35  adjacent to the connecting portion  354 . The first receiving channel  3561  can communicate with the second receiving channel  3563  in the axial direction. A diameter of the first receiving channel  3561  can be greater than the second receiving channel  3563 . The shaft shoulder  3562  can be located in the joint of the first receiving channel  3561  and the second receiving channel  3563 , and can be connected to first receiving channel  3561  and the second receiving channel  3563 . One end of the resetting element  39  (shown in  FIG. 3 ) away from the working element  70  can be inserted into the first receiving channel  3561  and resist against the shaft shoulder  3562 . 
     The receiving channel  356  can further define a plurality of second helical grooves  3564  to engage the first helical grooves  311  (shown in  FIG. 3 ). The second helical grooves  3564  can be located inside the second receiving channel  3563  and distanced evenly from each other. The second helical grooves  3564 , the first helical grooves  311 , and the slot  371  can cooperatively form the ball bearing sliding slot  359  which is a cycling channel to receive the ball bearings  38  and allow the rolling ball bearings  38  to roll (shown in  FIGS. 2-3 ), when the downward pressure is exerted on the connecting element  35  to allow the connecting element  35  to move axially, by the threaded engagement of the connecting element  35  with the screw rod  31 , the screw rod  31  can be driven to rotate relative to the connecting element  35 . At the same time, the ball bearings  38  can roll in the cyclic ball bearing sliding slot  359  cooperatively formed by the second helical grooves  3564 , the first helical grooves  311 , and the slot  371 . The rolling of the ball bearings  38  between the connecting element  35  and the screw rod  31  can generate a rolling friction instead of a sliding friction, for reducing the necessary prior downward pressure to allow the connecting element  35  to move, improving the driving effects and driving accuracy between the connecting element  35  and the screw rod  31 . (shown in  FIG. 2 ). 
     In assembly, the connecting element  35  and the resetting element  39  can be coiled around in the screw rod  31  and be received in the housing  10 , and the latching portion  12  can be latched in the latching groove  351  to connect the connecting element  35  to the housing  10 . Either opposite ends of the screw rod  31  can be connected to the two bearings  32 , and can pass through the bracket  51  to be rotatably coupled to first supporting seat  513  and second supporting seat  515  by the two bearings  32 . The resetting element  39  can be inserted into the first receiving channel  3561  and be restricted between the shaft shoulder  3562  and second supporting seat  515 . The elastic member  54  can be coiled around the block  5313  and restricted between the activator  53  and the resisting portion  353 . An end of the activator  53  adjacent to the first supporting seat  513  can be fixed to the connecting portion  354 . The rotary joint  71  can be coiled on the screw rod and the working portion  73  can be inserted into an end of the rotary joint  71  adjacent the second supporting seat  515 , to be installed on the screw rod  31 . The connecting portion  75  can be coiled on the joint of the rotary joint  71  and the working portion  73 . Thus, an assembly of the screw device  100  can be completed. 
     In operation, the working portion  73  can be resisted against a head of a screw to be fastened, and the activator  53  can be pressed downward and moved along the sliding channel  5111  to the working portion  73 . In this situation, the connecting element  35  can be moved downward by the activator  53  to elastically compress the resetting element  39  and the housing  10 . Thus, the screw rod  31  can be driven by the connecting element  35  to rotate relative to the connecting element  35 , and the working portion  73  can rotate with a rotation of the screw rod  31  to fasten the screw. 
     When the screw is fastened, the activator  53  can be released and the second engaging portion  5311  can engage the first engaging portion  5113  and be latched by the first engaging portion  5113 . In this situation, the screw rod  31  and the working portion  73  can be immobile. When the working portion  73  is moved away from the head of the fastened screw, the activator  53  again can be compressed to drive the connecting element  35  and the housing  10  to reset by a rebounding elastic portion  17  and resetting element  39 . 
     In other embodiments, the second engaging portion  5311  and the first engaging portion  5113  can be omitted and the activator  53  can be adjusted to be immobile by a way of an exerted pressure. 
     In other embodiments, the elastic member  54  can be omitted and the activator  53  can be reset manually. 
     In other embodiments, the through hole  15  of the housing  10  can be omitted and the elastic member  54  can directly resist between the resisting portion  353  of the connecting element  35  and the rod portion  531 . 
     In other embodiments, the resetting element  39  can be omitted. When the activator  53  moves away from the working portion  73  after performing a fastening operation, the connecting element  35  can be reset by the activator  53 . 
     The hand-driven mechanical screwdriver  100  can adjust the motion of the activator  53  to control a rotary speed and a rotary number of the working portion  73 . 
     The embodiments shown and described above are only examples. Many details are often found in the art such as the other features of a hand-driven mechanical screwdriver. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, including in matters of shape, size and arrangement of the parts within the principles of the present disclosure up to, and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.