Grate Basket For Hammer Crushers

Abstract

A grate basket for hammer crushers composed of at least two segments respectively made up of a plurality of parallel grate basket walls in the form of ring sections arranged coaxially with regard to the rotor and of grate bars extending parallel to the rotor axis while being exchangeably connected to the grate basket walls interconnected by longitudinal connecting elements. The grate basket is characterized primarily in that the grate basket walls are respectively divided into a base wall held by the longitudinal connecting elements and into a bar carrier which is adapted to receive the grate bars and which is secured against rotation in circumferential direction and against displacement in axial direction, the grate bar carrier being exchangeably connected to the inner surface of the base wall.

Description

The present invention relates to a grate basket for hammer crushers. Such grate basket is composed of at least two segments, and each of these segments consists of a plurality of grate basket side walls which are arranged parallel to each other and coaxially with regard to the rotor and of grate bars which are exchangeably connected to the grate basket side walls interconnected by longitudinal arms. The grate basket side walls have the shape of annular sections. The grate bars are arranged parallel to the axis of the rotor.

With heretofore known grate baskets of this type, the grate bars are inserted in hole-shaped recesses in the grate basket side walls. Therefore, the grate basket side walls which project beyond the grate bars in the direction toward the rotor are exposed to an increased wear. As soon as the grate basket side walls are worn down to the grate bars, the entire grate basket has to be replaced or has to be repaired by an expensive depositing of welding material. similarly, a completely new grate basket is needed when the quality or condition of the material to be crushed makes it necessary to use a different gap width of the grates or when the granular size of the finish-crushed material is to be varied by using a different gap width of the grates. If the necessity of employing different gap widths of the grates is due, for instance, in view of the changing moisture content of the material to be crushed during the various seasons, it is necessary to stock a plurality of complete grate baskets of different gap widths between the grates. This results in a expensive stock keeping.

Attempts have been made to reduce the wear of the grate basket side walls by having the grate bars project beyond the side walls of the grate basket in the direction toward the rotor and, more specifically, by having a portion of their cross sectional surface project beyond the grate basket side walls. With this known design, the grate bars are fixed by means of individual welded-on form pieces.

This design has the considerable drawback that the welded-on form pieces may deform or may be displaced by the buffer effect of the grate bars. The result will be an insufficient anchoring of the grate bars. If is is desired to provide the grate basket with a different gap width of the grate, or if it becomes necessary to exchange the worn down grate bars, a time consuming and expensive cutting off and welding-on of the form pieces becomes necessary. After a more or less frequent welding-on of the form pieces, the unilateral application of the welding heat will cause a distortion of the grate basket side walls so that an additional aligning operation will have to be carried out, which means a further increase in the repair costs for the grate basket.

It is, therefore, an object of the present invention to provide a grate basket for hammer crushers of the described general type which will permit an exchange of those parts which are subjected to wear in a simple manner and within a minimum of time.

This object and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIG. 1 illustrates a cross section through a grate basket according to the invention which is composed of two segments.

FIG. 2 is a perspective view of a grate basket segment according to the invention.

FIG. 3 is a perspective view of a grate bar according to the invention.

FIG. 4 illustrates a cutout of a grate basket made up of grate bars of the type shown in FIG. 3.

The grate basket according to the present invention is characterized primarily in that the grate basket side walls are respectively divided into a base side wall and a bar carrier for receiving the grate bars, the bar carrier being secured against rotation in circumferential direction and also being secured against displacement in axial direction while being exchangeably connected to the inner surface of the base side wall.

According to a further feature of the invention, the bar carrier is connected to the base side wall by clamping screws which are insertable into a bore in the bar carrier and by means of a connecting plate are adapted to rest against the outer surface of the base side wall. According to a preferred embodiment of the invention, each clamping screw comprises two screw bolts arranged parallel to each other so that a connection on two sides is effected.

According to a further development of the grate basket according to the invention, the bar carriers are secured against rotation in the circumferential direction by means of protrusions engaging recesses in the base side walls. The bar carriers are furthermore secured against displacement in axial direction by guiding strips which extend parallel to the longitudinal arms. The guiding strips are provided with slots for the bar carriers.

To facilitate the insertion of the grate bars into the grate bar side walls and to reduce the wear of the grate basket side walls in view of the protrusion of the grate bars, it is suggested according to the present invention to provide the grate bars within the region of the grate basket side walls with holding noses which increase the grate bar cross section. The grate bars protrude in a manner known per se with a portion of their rectangular, trapezoidal or triangular cross sectional surface from the grooves in the grate basket side walls toward the rotor. The holding noses are insertable in axial direction in undercut portions of the grooves provided in the grate basket side walls.

In view of this design, the grate bars can easily from above be inserted into the unilaterally open grooves of the grate basket side walls and can be secured against dropping out by a slight axial displacement. The length of this displacement corresponds merely to the width of the holding noses. In this way a grate basket is obtained which can be produced at low costs and can easily be repaired without the employment of complicated holding elements for the grate bars which holding elements are liable to disorders and are composed of a plurality of individual elements.

Referring now to the drawings in detail, the grate basket according to the invention for a hammer crusher (not shown) comprises two segments and is arranged coaxially with regard to the rotor 1 which latter is connected to a rotatable shaft 2. Connected to the rotor 1 is a plurality of crushers 4 which are adapted freely to rotate on crusher shafts 3 journalled on the rotor 1. The direction of rotation of rotor 1 is indicated by an arrow in FIG. 1.

Each grate basket segment comprises a plurality of grate basket side walls 5 which extend parallel to each other and are located coaxially with regard to the rotor 1. Each grate basket segment furthermore comprises grate bars 7 which extend in a direction parallel to the rotor shaft 2.

Each grate basket side wall 5 is composed of a base side wall 5a and a bar carrier 5b. The base side walls 5a are interconnected by tubular longitudinal arms 6 and by guiding strips 10. The bar carriers 5b are provided with recesses 5f for receiving the grate bars 7. The exchangeable connection of the grate bars 5b to the base side walls 5a is effected by means of clamping screws 8 which in the specific embodiment shown consist of two screw bolts of U-shaped configuration which are arranged parallel to each other. These clamping screws 8 can be inserted into the bores 5c of the bar carrier 5b. The fixing of the clamping screws 8 is effected by means of a plate 9 which rests on the outer surface of the base side walls 5a.

To prevent a rotation of the bar carriers 5b in circumferential direction on the base side walls 5a, each inner surface of the base side walls 5a is provided with a recess 5d engaged by a protrusion 5e on the outer surface of the bar carriers 5b. A displacement of the bar carriers 5b carrying the grate bars 7 in axial direction is prevented by the fact that the bar carriers 5b are inserted into slots of the guiding strips 10. These guiding strips 10 are arranged parallel with regard to the longitudinal arms 6 on the base side walls 5a. According to the embodiment illustrated in FIGS. 1 and 2, each grate basket segment is provided with three guiding strips 10.

Whereas with the embodiment of FIGS. 1 and 2 the grate bars 7 are arranged in bore-shaped recesses 5f within the bar carriers 5b, the grate bars 7 according to FIGS. 3 and 4 are located within unilaterally open grooves 5g of the grate bar side walls 5. Each grate bar 7 is within the region of the grate basket side walls 5 provided with a holding nose 7a which increases the cross section of the grate bar. These holding noses 7a engage undercut portions 5h of the grooves 5g when the grate bars 7 are displaced in longitudinal direction by approximately the width of the holding noses 7a after the grate bars have been inserted in radial direction from the top into the open grooves 5g of the grate basket side walls 5.

Whereas with the embodiment of FIGS. 1 and 2 the grate bars 7 have to be inserted over their entire length in axial direction thereof into the recesses 5f of the grate basket side walls 5, it is possible with the embodiment of FIGS. 3 and 4 to insert the grate bars 7 from above into the open grooves 5g. For fixing the bars 7 to the side walls 5, it is merely necessary to displace the grate bars slightly in axial direction and, more specifically, by a distance which corresponds approximately to the width of the holding noses 7a. As a result thereof, the assembly and repair of the grate baskets is greatly simplified while the design of the grate bars 7 illustrated in FIGS. 3 and 4 may, of course, also be employed for grate basket side walls 5 which are divided into base side wall 5a and bar carrier 5b.

As will be evident from the above, the dividing up of the grate basket side walls into base side wall and bar carrier and the exchangeable connection of the bar carrier to the base side wall makes it possible within a minimum of time to exchange the bar carrier of the grate basket with the grate bars for a new grate bar carrier. The design of the grate basket according to the present invention thus reduces the idling time of the hammer crusher as it is required for repair work due to excessive wear to a minimum without the necessity of stockpiling expensive replacement parts. The exchangeable parts of the grate basket according to the invention are those parts which are subject to wear and which can anyhow not be used again.

It may be mentioned that an exchange of the parts subjected to wear may not have to be effected exclusively due to wear of these parts, but may, for instance, also be effected when the hammer crusher is to be equipped with a grate of different gap width between the bars. Such exchange becomes necessary, for instance, with varying moisture content of the material to be crushed or when a different granular size of the finish-crushed material is desired.

It is, of course, to be understood that the present invention is, by no means, limited to the specific showing in the drawings but also comprises any modifications within the scope of the appended claims.

Claims

What I claim is:

1. A grate basket for hammer crushers, which includes a rotor, at least two segmental members, each of said segmental members comprising a plurality of subdivided wall members arranged parallel and in spaced relationship to each other and being located coaxially with regard to said rotor, a plurality of grate bars extending substantially parallel to the axis of said rotor, connecting means extending in the axial direction of said grate basket and being exchangeably connected to said wall members, said subdivided wall members respectively comprising a base wall and bar carrier means, said connecting means supporting said base walls, and said grate bars being supported by said bar carrier means, and means for preventing said bar carrier means from moving in the circumferential direction of said rotor and from displacement in axial direction, said bar carrier means being readily interchangeable and detachably connected to said base walls.

2. A grate basket for hammer crushers, which includes a rotor, at least two segmental members comprising a plurality of wall members arranged parallel and in spaced relationship to each other and being located coaxially with regard to said rotor, a plurality of grate bars extending substantially parallel to the axis of said rotor, connecting means extending in the axial direction of said grate basket and being exchangeably connected to said wall members, said wall members respectively comprising a base wall and bar carrier means, said connecting means supporting said base walls, and said grate bars being supported by said bar carrier means, and means for preventing said bar carrier means from moving in the circumferential direction of said rotor and from displacement in axial direction, said bar carrier means being detachably connected to said base walls, said bar carrier means including bore means, and comprising clamping screw means insertable in said bore means for connecting said bar carrier means to said base walls, and lashing means for resting said clamping screw means onto the inner surface of said base walls.

3. A grate basket according to claim 2, in which each of said clamping screw means comprises two screw bolts extending substantially parallel to each other.

4. A grate basket for hammer crushers, which includes a rotor, at least two segmental members comprising a plurality of wall members arranged parallel and in spaced relationship to each other and being located coaxially with regard to said rotor, a plurality of grate bars extending substantially parallel to the axis of said rotor, connecting means extending in the axial direction of said grate basket and being exchangeably connected to said wall members, said wall members respectively comprising a base wall and bar carrier means, said connecting means supporting said base walls, and said grate bars being supported by said bar carrier means, and means for preventing said bar carrier means from moving in the circumferential direction of said rotor and from displacement in axial direction, said bar carrier means being detachably connected to said base walls, said base walls being provided with recess means, and said bar carrier means being provided with protrusion means for engaging said recess means to prevent said bar carrier means from turning in the circumferential direction of said rotor, guiding strip means being provided which extend substantially parallel to said connecting means and are provided with slots for respectively receiving said bar carrier means, said bar carrier means being prevented by said guiding strip means from accidental displacement in axial direction of said bar carrier means.

5. A grate basket for hammer crushers, which includes a rotor, at least two segmental members comprising a plurality of wall members arranged parallel and in spaced relationship to each other and being located coaxially with regard to said rotor, a plurality of grate bars extending substantially parallel to the axis of said rotor, connecting means extending in the axial direction of said grate basket and being exchangeably connected to said wall members, said wall members respectively comprising a base wall and bar carrier means, said connecting means supporting said base walls, and said grate bars being supported by said bar carrier means, and means for preventing said bar carrier means from moving in the circumferential direction of said rotor and from displacement in axial direction, said bar carrier means being detachably connected to said base walls, said wall members being provided with grooves having an undercut section, and said grate bars within the region of said wall members being provided with holding noses for engagement with said undercut sections to hold said grate bars in said grooves, said grate bars being insertable into said grooves in axial direction of said grate bars.

6. A grate basket according to claim 5, in which said grate bars have a trapezoidal cross section.

7. A grate basket according to claim 5, in which said grate bars have a polygonal cross section.

8. A grate basket according to claim 5, in which said grate bars protrude from said grooves in the direction toward said rotor.