Abstract:
Disclosed herein is a breaker tool, which is provided in breakers or excavators to break materials, such as rocks, hard soil, etc. In the breaker tool of the present invention, slit-grooves are formed around a breaking part, and each slit-groove extends from the breaking part a predetermined height.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates generally to a breaker tool provided in breakers or excavators to break materials such as rocks, hard soil, etc., and, more particularly, to a breaker tool which comprises slit-grooves around a breaking part thereof. 
       BACKGROUND ART 
       [0002]    Generally, breaker tools are classified into a chisel type breaker tool  1   a,  as shown in  FIG. 1A , a blunt type breaker tool  1   b,  as shown in  FIG. 1B , a moil point type breaker tool  1   c,  as shown in  FIG. 1C , and a conical type breaker tool, as shown in  FIG. 1D , according to the shape of a breaking part  3   a,    3   b,    3   c,    3   d.  In such breaker tools, the breaking part requires the highest durability. Furthermore, the breaking part is worn by direct contact with a material such as rock so that the end thereof becomes blunt with the passage of time. Therefore, typically, the breaking part is made by heat-treating SCM440 alloy steel, mixed with a small amount of nickel (Ni), chrome (Cr) and molybdenum (Mo), to increase the strength thereof. 
         [0003]    However, in the case where the breaking part of the breaker tool is heat-treated using a conventional technique, as shown in  FIG. 2A through 2D , because the depth to which the breaking part is heat-treated is relatively shallow, there is a disadvantage in that the breaking part is easily worn. 
         [0004]    The information disclosed in this Background Art section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art. 
       SUMMARY OF THE INVENTION 
       [0005]    Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a breaker tool, which has slit-grooves around a breaking part thereof, so that, when the breaking part is heat-treated, the heat treatment depth is increased, thus extending the lifetime of the breaker tool and enhancing the breaking performance thereof. 
         [0006]    In order to accomplish the above object, one aspect of the present invention provides a breaker tool comprising a plurality of slit-grooves formed around a breaking part thereof, each of the plurality of slit-grooves extending a predetermined height from the breaking part. 
         [0007]    Other aspects of the invention are discussed infra. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0009]      FIGS. 1A through 1D  are perspective views respectively illustrating a chisel type breaker tool, a blunt type breaker tool, a moil point type breaker tool and a conical type breaker tool, according to conventional techniques; 
           [0010]      FIGS. 2A through 2D  are sectional views taken along the respective lines A-A, B-B, C-C and D-D of  FIGS. 1A through 1D ; 
           [0011]      FIGS. 3A through 3D  are perspective views respectively illustrating a chisel type breaker tool, a blunt type breaker tool, a moil point type breaker tool and a conical type breaker tool, according to preferred embodiments of the present invention; and 
           [0012]      FIGS. 4A through 4D  are sectional views taken along the respective lines e-e, f-f, g-g and h-h of  FIGS. 3A through 3D . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0013]    Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the drawings attached hereinafter, wherein like reference numerals refer to like elements throughout. The embodiments are described below so as to explain the present invention by referring to the figures. 
         [0014]    More particularly, a chisel type breaker tool, a blunt type breaker tool, a moil point type breaker tool and a conical type breaker tool will be described in detail with reference to the attached drawings. 
         [0015]    In the case of the chisel type breaker tool  10   a,  shown in  FIG. 3A  as an example, slit-grooves  20  are formed in respective corners of a chisel type breaking part  11   a.  Each slit-groove  20  extends from the lower end of a corresponding corner of the chisel type breaking part  11   a  to a predetermined height h. Therefore, when the chisel type breaking part  11   a  of the chisel type breaker tool  10   a,  which has the four slit-grooves  20 , is heat-treated, as shown in  FIG. 4A , the heat-treated surface area is increased, and the heat treatment depth P is also increased. 
         [0016]    In the case of the blunt type breaker tool  10   b  shown in  FIG. 3B  as an example, slit-grooves  20  are formed in the circumferential outer surface of a blunt type breaking part  11   b  at positions spaced apart from each other at regular intervals. Each slit-groove  20  extends from the lower edge of the breaking part  11   b  to a predetermined height h. Therefore, when the blunt type breaking part  11   b  of the blunt type breaker tool  10   b,  which has the slit-grooves  20 , is heat-treated, as shown in  FIG. 4B , the heat-treated surface area is increased, and the heat treatment depth P is also increased. 
         [0017]    In the case of the moil point type breaker tool  10   c  shown in  FIG. 3C  as an example, slit-grooves  20  are formed in respective corners of a moil point type breaking part  11   c.  Each slit-groove  20  extends from the lower end of a corresponding corner of the moil point type breaking part  11   c  to a predetermined height h. Therefore, when the moil point type breaking part  11   c  of the moil point type breaker tool  10   c,  which has the four slit-grooves  20 , is heat-treated, as shown in  FIG. 4A , the heat-treated surface area is increased, and the heat treatment depth P is also increased. 
         [0018]    In the case of the conical type breaker tool  10   d  shown in  FIG. 3D  as an example, slit-grooves  20  are formed in the conical outer surface of a conical type breaking part  11   d  at positions spaced apart from each other at regular intervals. Each slit-groove  20  extends from the lower end of the conical outer surface of the breaking part  11   d  to a predetermined height h. Therefore, when the conical type breaking part  11   d  of the conical type breaker tool  10   d,  which has the slit-grooves  20 , is heat-treated, as shown in  FIG. 4D , the heat-treated surface area is increased, and the heat treatment depth P is also increased. 
         [0019]    As described above, in breaker tools according to preferred embodiments of the present invention, because slit-grooves are formed in the outer surface of a breaking part of the breaker tool, when it is heat-treated, the heat treatment depth is increased. Therefore, the lift time of the breaker tool is increased, and the breaking performance thereof is enhanced. 
         [0020]    Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.