Coal-cutting pick

Abstract

 A coal cutting pick is secured in the holder of a cutting machine by a protrusion (4) at the forward end side of the shank (1) and a replacable insert (6) mounted in a gap (12) between the backward end side of the shank (1) and the holder.

Description

[0001] The subject of this present invention is a coal combine cutter, particularly the design of the cutter shank part intended for locking the coal combine cutter in a holder of the working member. A number of the designs of flat coal combine cut­ters and correspondingly designed coal combine cutter holders mounted in the working member of the coal combine are known and used. They in­clude a coal combine cutter known from Polish Specification No. 98,986 and having a shank with a hole running through the front and rear faces and intended for a locking pin also mounted in the coal combine cutter holder hole. By tighten­ing a nut, it is possible to more the wedge face of the pin hard against a coal combine cutter shank to press the latter against the inner face of the holder.

[0002] A disadvantage of such a design is that the nut frequently works loose due to high vibration of the working member cauling the cutters to work loose and then to become lost.

[0003] The design known from West German Specification No. 2,121,314 provides a cutter prevent from fal­ling out with a crew placed in the cutter hole and whose end is fixed in the cutter shank recess. Another design known from Polish Specification No. 77,315 provides for a cutter shank to have a small hole at its end to connect the side sur­faces of the cutter.

[0004] A cotter pin passes through the hole and pre­ vents the cutter from falling out. The disadvan­tage of that design is that the forces pulling the cutter out of the holder cause the cotter pin to be sheared and then the cutter to fall out. An improved cotter pin for preventing the cutters from falling out of the holders is also known from Polish Useful Pattern Specification No. W 67,001.

[0005] A number of other known designs for preventing the cutters from falling out of the holders have disadvantages and inconvenences in that shapes are intricate and holder seats are knocked out or deformed.

[0006] The design as per this present invention relates to one of the holder of the cutter mounted in a known holder of the working member.

[0007] As per this present invention the cutter holder end has a protrusion from the rake surface side. At the side opposite to that protrusion there is a gap accommodating a disjointly mounted insert contacting a surface of the holder and locking the protrusion in the holder recess, the insert also preventing the cutter from sliding out of the holder.

[0008] Besides, the insert has a fixed plate adhering to the side surface of the shank. A cotter pin is run through the holes made in the plate and these in the shank, thereby preventing the in­sert from being disconnected from the cutter. The shank surface is inclined from the thrust coller towards the shank end.

[0009] The cutter as per this present invention effi­ciently improves its being secured in the holder of the working member.

[0010] The cutter is shown in more detail in an embodi­ment in the drawing where Fig. 1 presents a side view of the cutter mounted in the holder; Fig. 2, a front view of the cutter mounted in the holder, Fig. 3, a view of the cotter pin; Fig. 4, an axonometric projection of the insert; and Fig. 5, a view of another version of the cutter mounted in the holder.

[0011] The cutter as per this present invention has shank 1 whose end 3 has protrusion 4 from its rake surface and disjointly mounted insert 6 at the side opposite to protrusion 4. After the cutter has been inserted into holder 11, insert 6 is placed in gap 12 formed between taper surface 7 and the hole wall of holder 11, whereas protrusion 4 occupies recess 13 of holder 11. The cutter is prevented from sliding out of holder 11 since holder1 is locked between thrust coller 2 and protrusion 4. On the other hand, insert 6 is prevented from becoming disconnected from shank 1 by means of fixed plate 8 which adhers to a side surface of the cutter through whose holes 9 and holes 10 of end 3 or holder 1 has been run cotter pin 14. Another embodiment /Fig. 5/ of the cutter has shank 1 having a parallel and domewhat narrowed shape and forming gap 12 between surface 7 and wall of holder 11 in order to freely mount insert 6 in it.

Claims

1. A coal combine cutter provided with a thrust coller and a rectangular-sectioned shank and characterised in that end 3 or shank 1 has prot­rusion 4 from rake surface side 5 and, in gap 12 on the side opposite to protrusion 4, it has a disjointly mounted insert 6 contacting surface 7 locking protrusion 4 in recess 13 of holder 11, thereby preventing the cutter from sliding there­out.

2. A cutter as per Claim 1 characterised in that in­sert6 has fixed plate 8 adher ing to a side sur­face of shank 1 and cotter pin 14 is run through side surface holes 9 and holes 10 to prevent in­sert 6 from becoming disconnected from the cut­ter.

3. A cutter as per Claim 1 characterised in that surface 7 is inclined from thrust coller 2 to­wards end 3.

Drawing