Abstract:
A cutting tool includes a base assembly and a cutting head. The base assembly has a base member and a rotating support. The cutting head has a cutting member, a motor for driving the cutting member, and a head housing comprising a boosting sleeve. The boosting sleeve defines a sleeve cavity for accommodating a spring member arranged between the cutting head and the rotating support. The spring is provided to assist a user in moving the cutting head relative to the base.

Description:
[0001]    This application claims the benefit of CN 201410097654.0, filed on Mar. 17, 2014, and CN 201420121003.6, filed on Mar. 17, 2014, the disclosures of which are incorporated herein by reference in their entirety. 
       FIELD OF THE DISCLOSURE 
       [0002]    The present disclosure relates generally to cutting tools, and more particularly to miter saws. 
       BACKGROUND OF THE DISCLOSURE 
       [0003]    Generally, a cutting head of a cutting tool rotatably connects with the base for changing cutting depth. Cutting depth of the saw changes with the working head rotation position. 
         [0004]    At the end of the cutting process, user should put up the working head. But, the working head comprises a motor and a transmission mechanism, and it is very hard to put up the working head owing to the heavy weight. 
         [0005]    The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
       SUMMARY 
       [0006]    The disclosure describes a cutting tool, comprising: a base assembly and a cutting head; wherein the base assembly comprises: a base member and a rotating support; wherein the cutting head comprises: a cutting member; a motor for driving the cutting member; and a head housing comprising a boosting sleeve; the boosting sleeve defines a sleeve cavity for accommodating a spring member arranged between the cutting head and the rotating support; the cutting head rotatably connects with the rotating support about a rotation axis and has a first rotation position, a second rotation position and a middle rotation position which is between the first rotation position and the second rotation position; when the cutting head is in the first rotation position, the spring member bends in a first direction; when the cutting head is in the second rotation position, the spring member bends in a second direction which is different from the first direction. 
         [0007]    Furthermore, when the cutting head is in the middle rotation position, the spring member may extend in a line. 
         [0008]    Furthermore, when the cutting head is in the middle rotation position, the gravity center of the cutting head may be in the highest position relative to the rotation axis of the cutting head. 
         [0009]    Furthermore, when the cutting head is in the middle rotation position, the gravity center of the cutting head may be in the farthest position relative to the rotation axis of the cutting head. 
         [0010]    Furthermore, when the cutting head is in the middle rotation position and the rotation axis is parallel to the horizontal plane, the gravity center of the cutting head may be in a position right above the rotation axis. 
         [0011]    Furthermore, when the cutting head is in the first rotation position, the spring member may have a first compression length; when the cutting head is in the second rotation position, the spring member may have a second compression length; when the cutting head is in the middle rotation position, the spring member may have a middle compression length; wherein the first compression length is greater than the second compression length; wherein the middle compression length is less than the first compression length and is greater than the second compression length. 
         [0012]    Furthermore, the spring member may bend synchronously with the rotation of the cutting head. 
         [0013]    Furthermore, the angular value associated with the cutting head rotating from the first position to the middle position may be less than the angular value associated with the cutting head rotating from the second position to the middle position. 
         [0014]    Furthermore, the angular value associated with the cutting head rotating from the first position to the middle position may be from about 22 degrees to about 25 degrees and the angular value associated with the cutting head rotating from the second position to the middle position may be from about 25 degrees to about 30 degrees. 
         [0015]    Furthermore, the angular value associated with the cutting head rotating from the first position to the middle position may be about 22 degrees and the angular value associated with the cutting head rotating from the second position to the middle position may be about 28 degrees. 
         [0016]    Furthermore, the cutting tool may comprise a supporting tray for supporting the bottom end of the spring member, wherein the supporting tray fixedly connects with the rotation support. 
         [0017]    Furthermore, the cutting tool may comprise a limiting pin for limiting the bottom portion of the spring member, wherein the spring member is a helical spring and the top end of the limiting pin is arranged in the helical spring. 
         [0018]    The disclosure also describes a miter saw, comprising: a base assembly and a cutting head; wherein the base assembly comprises: a base member and a rotating support; wherein the cutting head comprises: a cutting member; a motor for driving the cutting member; and a head housing comprising a boosting sleeve; the boosting sleeve defines a sleeve cavity for accommodating a spring member arranged between the cutting head and the rotating support; the cutting head rotatably connects with the rotating support about a rotation axis and has a first rotation position, a second rotation position and a middle rotation position which is between the first rotation position and the second rotation position; when the cutting head is in the first rotation position, the spring member bends in a first direction; when the cutting head is in the second rotation position, the spring member bends in a second direction which is different from the first direction. 
         [0019]    Furthermore, when the cutting head is in the middle rotation position, the spring member may extend in a line. 
         [0020]    Furthermore, when the cutting head is in the middle rotation position, the gravity center of the cutting head may be in the highest position relative to the rotation axis of the cutting head. 
         [0021]    Furthermore, when the cutting head is in the middle rotation position, the gravity center of the cutting head may be in the farthest position relative to the rotation axis of the cutting head. 
         [0022]    Furthermore, when the cutting head is in the middle rotation position and the rotation axis is parallel to the horizontal plane, the gravity center of the cutting head may be in a position right above the rotation axis. 
         [0023]    Furthermore, when the cutting head is in the first rotation position, the spring member may have a first compression length; when the cutting head is in the second rotation position, the spring member may have a second compression length; when the cutting head is in the middle rotation position, the spring member may have a middle compression length; wherein the first compression length is greater than the second compression length; wherein the middle compression length is less than the first compression length and is greater than the second compression length. 
         [0024]    Furthermore, the spring member may bend synchronously with the rotation of the cutting head. 
         [0025]    Furthermore, the angular value associated with the cutting head rotating from the first position to the middle position may be less than the angular value associated with the cutting head rotating from the second position to the middle position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is a structure schematic view of a working head of a cutting tool according to the present disclosure in a first position; 
           [0027]      FIG. 2  is a structure schematic view of the working head of a cutting tool in a second position; 
           [0028]      FIG. 3  is a structure schematic view of the working head of a cutting tool in a middle position; 
           [0029]      FIG. 4  is a structure schematic view of the base assembly and locating assembly of a cutting tool; 
           [0030]      FIG. 5  is a partial enlarged structure schematic view of the working head of a cutting tool in the first position; 
           [0031]      FIG. 6  is a partial enlarged structure schematic view of the working head of a cutting tool in the second position; 
           [0032]      FIG. 7  is a partial enlarged structure schematic view of the working head of a cutting tool in the middle position. 
       
    
    
       [0033]    The drawings are for illustrative purposes only of exemplary embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0034]    The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
         [0035]    The cutting tool  100  as shown in  FIGS. 1-7  may include: a base assembly  10 , a cutting head  20  and a locating assembly  30 . 
         [0036]    Preferably, the cutting tool  100  is a miter saw. 
         [0037]    The base assembly  10  may include: a base member  11  and a rotating support  12 . The rotating support  12  is arrange on the base member  11 . 
         [0038]    Specifically, the base member  11  is arranged to support the cutting tool  100  and locate the timber to be cut, and rotating support  12  may be arranged to connect with the cutting head  20 , the dust box  40  and so on. The rotating support  12  may rotatably connect with the base member  11  about a horizontal axis. 
         [0039]    The cutting head  20  may include: a cutting member  21  and a head housing  22 . The cutting member  21  is rotatably or slidably connected with the head housing  22 . 
         [0040]    Specifically, as shown in  FIGS. 1-5 , the cutting member  21  preferably is a circular saw blade and is capable of rotating to cut. Certainly the cutting member  21  also may be another kind of saw blade and may be capable of moving in a straight line or a curved line. 
         [0041]    The head housing  22  may accommodate a motor and a transmission mechanism, etc. The cutting head  20  is a whole body when it rotates. Furthermore, the head housing  22  forms a handle portion  222 . 
         [0042]    The head housing  22  include a boosting sleeve  221  which has a sleeve cavity for accommodating a spring member  50 . The spring member  50  is arranged to provide support between the cutting head  20  and the rotating support  12 . 
         [0043]    Specifically, the top end of spring member  50  supports the closed end of the boosting sleeve  221 , and a portion of the rotating support  12  supports the bottom end of the spring member  50 . 
         [0044]    The cutting head  20  rotatably connects with the rotating support  12  about a rotation axis A and has a first rotation position, a second rotation position and a middle rotation position. The middle rotation is between the first rotation position and the second rotation position. 
         [0045]    As shown in  FIGS. 1 and 5 , when the cutting head  20  is in the first rotation position, the spring member  50  bends in a first direction. 
         [0046]    As shown in  FIGS. 2 and 6 , when the cutting head  20  is in the second rotation position, the spring member  50  bends in a second direction which is different from the first direction. 
         [0047]    As shown in  FIGS. 3 and 7 , when the cutting head  20  is in the middle rotation position, the spring member  50  extends in a line. Preferably, the spring member  50  is a helical spring which includes a top support ring  51  and a bottom ring  52 . Spring member  50  extending in a line specifically means the axis of top support ring  51  and axis of bottom support ring  52  are all, in the illustrated example, perpendicular to the horizontal plane, e.g., the spring member  50  is shown to extend in a vertical line. 
         [0048]    As shown in  FIGS. 3 and 7 , when the cutting head  20  is in the middle rotation position, the gravity center G of the cutting head  20  is in the highest position and in the farthest position relative to the rotation axis A of the cutting head  20 . 
         [0049]    Furthermore, as shown in  FIGS. 3 and 7 , when the cutting head  20  is in the middle rotation position and the rotation axis A is parallel to the horizontal plane, the gravity center G of the cutting head  20  is in a position right above the rotation axis A. 
         [0050]    As shown in  FIGS. 3 and 7 , when the cutting head  20  is in the middle rotation position and the rotation axis is parallel to the horizontal plane, the gravity center of the cutting head  20  is in a position right above the rotation axis. 
         [0051]    As shown in  FIGS. 1-3  and  5 - 7 , when the cutting head  20  is in the first rotation position, the spring member  50  has a first compression length; when the cutting head  20  is in the second rotation position, the spring member  50  has a second compression length; when the cutting head  20  is in the middle rotation position, the spring member  50  has a middle compression length. 
         [0052]    The first compression length is greater than the second compression length; and the middle compression length is less than the first compression length and is greater than the second compression length. 
         [0053]    As shown in  FIGS. 1-3  and  5 - 7 , when the cutting head  20  rotates from the first position to the second position, the spring member bends synchronously with the rotation of the cutting head  20 . 
         [0054]    Specifically, when the cutting head  20  rotates from the first position to the second position, the top ring  51  rotates a same angular value as the cutting head  20  rotates. 
         [0055]    As shown in  FIGS. 1-3  and  5 - 7 , the angular value of the cutting head  20  as the cutting head  20  rotates from the first position to the middle position is less than the angular value of the cutting head  20  as the cutting head  20  rotates from the second position to the middle position. 
         [0056]    Specifically, the angular value associated with the cutting head  20  rotating from the first position to the middle position is from about 22 degrees to about 25 degrees, preferably 22 degrees; and the angular value associated with the cutting head  20  rotating from the second position to the middle position is from about 25 degrees to about 30 degrees, preferably 28 degrees. 
         [0057]    As shown in  FIGS. 1-3  and  5 - 7 , when the cutting head  20  rotates from the first position to the middle position and when the cutting head  20  rotates from the second position to the middle position, the energy generated by compressing and bending the spring member  50  functions to provide a lifting force upon the cutting head  20  so as to help the users lift the cutting head  20 . 
         [0058]    When the cutting head  20  rotates from the middle position to the first position and the cutting head  20  rotates from the middle position to the second position, gravity urges the cutting head  20  downward to help the cutting head  20  rotate downward. 
         [0059]    As shown in  FIGS. 4-7 , the locating assembly  30  may include a supporting tray  31  for supporting the bottom end of the spring member  50  and the supporting tray  31  fixedly connects with the rotation support  12 . 
         [0060]    The locating assembly  30  may also include a limiting pin  32  for limiting the bottom portion of the spring member  50 , and the top end of limiting pin  32  is arranged in the spring member  50 . 
         [0061]    As shown in  FIGS. 4-7 , the boosting sleeve has a disc member  221   a  in the top portion of the sleeve cavity which is arranged to contact with the spring member  50 . 
         [0062]    The above illustrates and describes basic principles, main features and advantages of the present invention. Those skilled in the art should appreciate that the above embodiments do not limit the present invention in any form. Technical solutions obtained by equivalent substitution or equivalent variations all fall within the scope of the present invention.