Cutting tool for breaking mineral and artificial materials

Abstract

The invention relates to the mining industry, in particular to a cutting tool for breaking mineral and artificial materials. The inventive tool comprises a working head provided with a hard-alloy insert on one end thereof and a three-part stem on the other end. A clamping sleeve made of elastic material is arranged on the second part of the stem and provided with a slopping element in order to prevent said sleeve from the displacement thereof longitudinally with respect to the stem A protective element provided with a through hole, in which the first part of the stem can be accommodated, is disposed at a distance ranging from 0.6 to 0.85 of the length of the clamping sleeve with respect to the end of said sleeve oriented towards the working head along the longitudinal symmetrical axis of the tool, the diameter of the first part of the stem is larger than the diameter of the third part thereof. Said invention makes it possible to improve the operating reliability of the tool by reducing the deformation of the clamping sleeve by the protective element by shaping said clamping sleeve in such a way that it is conical.

1 . A cutting tool for breaking mineral and artificial materials, adapted for installation with the possibility for free rotation in a channel of a support secured on an actuator, the tool having the form of a body of revolution with a longitudinal axis of symmetry and comprising a working head, an insert made of a hard-alloy material and secured to one end of the working head, a stem connected to the other end of the working head and comprising a first part arranged on one end of the stem from the side of the working head, a second part adjacent the first part and having a diameter less than the diameter of the first part, and a third part adjacent the second part, positioned on the other end of the stem and having a diameter that is not less than the diameter of the second part, a split clamping sleeve made of an elastic material, arranged on at least the second part of the stem and having a stopping element serving to fix it against movement along the longitudinal axis of symmetry of the tool relative to the stem, a protective element having a through axial hole with a diameter exceeding the diameter of the first part of the stem and mounted on the clamping sleeve with the possibility for axial movement along the sleeve for positioning it on the first part of the stem during the installation of the cutting tool in the channel of the support, characterized in that the protective element is disposed at a distance ranging from 0.6 to 0.85 of the length of the clamping sleeve with respect to the end of the sleeve oriented towards the working head along the longitudinal axis of symmetry of the tool, wherein the diameter of the first part of the stem is greater than the diameter of the third part thereof.  
   
   
       2 . The tool according to  claim 1 , characterized in that the diameter of the through hole in the protective element exceeds the diameter of the channel of the support.  
   
   
       3 . The tool according to  claim 1 , characterized in that the protective element is made in the form of a flat washer.  
   
   
       4 . The tool according to  claim 1 , characterized in that the protective element is made in the form of a washer having a U-shaped form in cross section.  
   
   
       5 . The tool according to  claim 1 , characterized in that the protective element is made in the form of a disk spring washer.  
   
   
       6 . The tool according to  claim 3 , characterized in that the washer is provided with an annular projection positioned along a through axial hole of the washer, facing the third part of the stem and adapted for arrangement in a corresponding input aperture of the channel of the support of the tool.  
   
   
       7 . The tool according to  claim 1 , characterized in that the clamping sleeve is arranged on the second and third parts of the stem, and its length along the longitudinal axis of symmetry of the tool exceeds the sum length of the second and third parts of the stem along that axis.  
   
   
       8 . The tool according to  claim 7 , characterized in that the stopping element is made in the form of at least one projection positioned on an inner surface of the clamping sleeve, while the second part of the stem has an annular recess for the arrangement of that projection.  
   
   
       9 . The tool according to  claim 8 , characterized in that the stopping element is made in the form of three projections uniformly positioned along the circumference of the cross section of the inner surface of the clamping sleeve, the center of which is positioned on the longitudinal axis of symmetry of the tool.  
   
   
       10 . The tool according to  claim 8 , characterized in that the projection on the clamping sleeve is made in the form of a figured tongue.  
   
   
       11 . The tool according to  claim 1 , characterized in that the length of the clamping sleeve along the longitudinal axis of symmetry of the tool is less than the length of the second part of the stem along that axis.  
   
   
       12 . The tool according to  claim 11 , characterized in that the stopping element is an end surface of the clamping sleeve, which surface faces the third part of the stem.  
   
   
       13 . The tool according to  claim 1 , characterized in that the two surfaces of the clamping sleeve that are formed when it is split are positioned parallel to the longitudinal axis of symmetry of the tool.  
   
   
       14 . The tool according to  claim 1 , characterized in that the two surfaces of the clamping sleeve that are formed when it is split are positioned inclined to a plane passing through the longitudinal axis of symmetry of the tool.  
   
   
       15 . The tool according to  claim 14 , characterized in that it has equal angles of inclination of the two surfaces that are formed when the sleeve is split, relative to the plane passing through the longitudinal axis of symmetry of the tool.  
   
   
       16 . The tool according to  claim 1 , characterized in that the insert comprises a base secured on the working head, an intermediate part adjacent the base and formed by a body of revolution with an outer side surface of concave shape, and a head part adjacent the intermediate part and formed by a body of revolution with an outer side surface of convex shape, smoothly matching the outer side surface of the intermediate part.  
   
   
       17 . The tool according to  claim 16 , characterized in that the length of the intermediate part of the insert along the longitudinal axis of symmetry of the tool does not exceed the length of the head part of the insert along that axis.  
   
   
       18 . The tool according to  claim 16 , characterized in that the length of the head part of the insert along the longitudinal axis of the tool does not exceed the length of the intermediate part of the insert along that axis.