US3614004A

US3614004A - Concave ring for cone crushers

Info

Publication number: US3614004A
Application number: US827712A
Authority: US
Inventors: Edgar S Burkhardt; James D Torrence
Original assignee: Allis Chalmers Corp
Current assignee: Allis Chalmers Corp
Priority date: 1969-05-26
Filing date: 1969-05-26
Publication date: 1971-10-19
Anticipated expiration: 1988-10-19
Also published as: GB1239538A; SE358309B; FR2048783A5; BR7019298D0; BE750964A; ZA703554B; DE2025802A1

Abstract

A crusher is disclosed of the type having a crushing chamber defined between a vertical conical head and a surrounding replaceable concave ring. The inside of the concave ring is provided with a stepped surface comprising alternately, annular crushing surfaces and annular connecting surfaces. The inside of the concave ring is also provided with vertical corrugations defined by alternate grooves and ridges which begin at the top and material inlet end of the concave ring, and extend downwardly to one of the annular crushing surfaces at a horizontal level above at least the lowermost annular crushing surface. The ridges of the corrugations provide a proper nip angle for crushing at the top of the chamber while the grooves provide a larger area feed opening than could be provided by a noncorrugated surface making a proper nip angle for crushing. The bottom crushing surface, which is below the corrugations, provides a smooth annular surface for fine crushing. When wear of this bottom crushing surface requires the cone to be raised, to restore predetermined spacing, the size of the feed opening at top is not reduced because wear is deliberately accelerated at the top of the chamber by providing the corrugations which cause the feed material to be nipped only by the ridges of the corrugations which are thereby worn away at a relatively rapid rate. Thus, the wearing away of the ridges of the corrugations means that when the cone is raised to compensate for wear at the bottom of the chamber the feed opening is not thereby made smaller than when the ring was new.

Description

ited States Patent [72] inventors Edgar S. Burlrhardt [54] CONCAVE RING FOR CONE CRUSHERS 10 Claims, 3 Drawing Figs.

52 U.S.Cl 241/214,

- 214/299 51 int. Cl B02c 2/04 501 Field ofSearch 241/207,

[56] References Cited UNITED STATES PATENTS 20,941 7/1858 Erkson 241/214 X 1,894,601 H1933 Symons 241/215 Primary Examiner-Othell M. Simpson Attameys- Arthur M. Streich, Robert B. Benson and John P.

Hines ABSTRACT: A crusher is disclosed of the type having a crushing chamber defined between a vertical conical head and a surrounding replaceable concave ring. The inside of the concave ring is provided with a stepped surface comprising alternately, annular crushing surfaces and annular connecting surfaces The inside of the concave ring is also provided with vertical corrugations defined by alternate grooves and ridges which begin at the top and material inlet end of the concave ring, and extend downwardly to one of the annular crushing surfaces at a horizontal level above at least the lowermost annular crushing surface. The ridges of the corrugations provide a proper nip angle for crushing at the top of the chamber while the grooves provide a larger area feed opening than could be provided by a noncorrugated surface making a proper nip angle for crushing. The bottom crushing surface, which is below the corrugations, provides a smooth annular surface for fine crushing. When wear of this bottom crushing surface requires the cone to be raised, to restore predetermined spacing, the size of the feed opening at top is not reduced because wear is deliberately accelerated at the top of the chamber by providing the corrugations which cause the feed material to be nipped only by the ridges of the corrugations which are thereby worn away at a relatively rapid rate. Thus, the wearing away of the ridges of the corrugations means that when the cone is raised to compensate for wear at the bottom of the chamber the feed opening is not thereby made smaller than when the ring was new.

PATENTEnncr 19 |97| @5223 MUM CONCAVE RING FOR CONE CRUSHERS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to rock-crushing machines having a conical head and a surrounding shell that defines therebetween and an.-annular crushing chamber, and in particular to such a machine having a replaceable concave ring liner supported by the shell, in which the concave ring is providedwith a special internal configuration which defines an outer wall of the crushing chamber around the conical head.

2. Description of the Prior Art Crushers known to the prior art of the type referred to are of perhaps three types. One type discloses a concave ring having intemal'corrugations in vertical planes, a second type-dis-' closes a concave ring having internal horizontal annular steps, and a third type discloses combinations of the first and second type.

Typical examples of the first type, disclosing corrugations on the'inner surface of a chamber-defining ring,-with.crests and valleys each disposed in a vertical plane, include: U.S.- Pat. No. 112,560 of 1871;,U .S. Pat. No.41 1,881 of 1889; U.S. Pat. No."759,643 'of 1904; U.S. Pat. No. 845,067 and 859,835 of 1907; U.S. Pat. No. 1,083,283 of 1914; U.S. Pat. No. 1,706,944 of 1929; and U.S. Pat. No. 2,934,277 of 1960.

Typical examples of the secondtype, disclosing horizontal annular steps on the inner surface of a chamber-defining ring, include: U.S. Pat. No. 669,060 of 1901: U.S. Pat. No. 1,366,985 of 1921; U.S. ,Pat.No.'1,574,142 of 19.26 and US. Pat. No. 1,775,750 of 1930.

- Typical examples of the type combining corrugationsand steps include U.S. Pat. No. 27,246 of .1860; BritishPat. No. 15,954 of 1885; and BritishPat. No- 16,837 of 1897.

A more recent example of a prior art patent disclosing concepts of the foregoing sort is U.S. Pat. No. 3,312,404 of 1967 which discloses spiral grooves which are neither horizontal steps or vertical corrugations but nevertheless have some characteristics of both. 1t will appear from thedescription ofthe present invention to follow, that the present invention distinguishes from all such prior art both in its objectives, and in the design and construction of the apparatus to achieve the objectives.

ln order to understand the following description of the present invention, it is believed important to understand the teachings of the aforesaid U.S. Pat. No. 1,574,142 of 1926 to W. S. Weston and 1,775,750 of 1930 to D. Cole. The Cole patent explains that a proper nip angle in a crushing chamber between a cone and concave, for passing material through the crushing chamber, is one which does not exceed a maximum (defined by Weston as being 24 and now known to be as much as 28). A nip angle greater than this maximum causes material to back up rather than pass through.

Cole also explains earlier patents to E. B. Symons and the zone of parallelism between lower portions of the cone and concave ring where opposing surfaces, that provide fine crushing, are approximately parallel at their position of maximum approach. This zone must be long enough that all particles are caught at least once by the cone and concave ring at the instant of their closest approach. The need for this bottom zone to be of a certain fixed length plus the fact that the angle of the chamber above this zone cannot exceed the maximum nip (about 24 or slightly larger), and the fact that projecting the concave ring upwardly above the conical crushing head in order to enlarge the feed opening would not provide addi tional crushing (i.e. no crushing takes place above the cone), are factors that collectively limit the range of particle size reduction that can be attained in a single crusher.

Thus Cole explains that prior to his invention, it was necessary in order to obtain efficient cone crushing of rock to small particle sizes, to do it with two crushers. That is, a coarse crusher could be provided with a feed opening large enough to accept the biggest particles and the discharge therefrom could be the feed to a second crusher having the zone of parallelism long enough and close enough for fine crushing, but with a correspondingly limited feed opening. The invention of the Cole patent provided designers a second choice, that is the same size reduction could be achieved in one crusher as formerly required two, by providing a stepped chamber which could open wide enough to accept the largest pieces but without any portion of the chamber exceeding the maximum nip angle of 24 to 28.

A problem associated with Cole s solution to the previously long-standing problem, arises from the fact that the large pieces make up a very small percentage of total feed. Most feed therefore passes through Coles chamber without touchingthe upper stepped surfaces which therefore wear away very slowly compared to the wear of the surfaces defining the zone of parallelism where the fine crushing is accomplished. It therefore becomes necessary to raise the cone and close the gap to restore the original spacing'in the zone of parallelism before any appreciable wear has-taken place to the feed opening at the top of the chamber. Raising the cone under these circumstances has the unwanted efiect of bringing theunwomtop of the cone closer to the unwom top of the chamber and thereby making the feed opening smaller. It then becomes necessary to replace concave rings because not enough wear has taken place at the top to maintain the desired feed opening. I 7

One of the objects of the present invention, as will be explained, is directed to solving the foregoing problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new and improved cone crusher and a concave ring therefore, with provisions to deliberately accelerate wear at the top thereof to the bottom of the concave ring.

It is another objectof the present invention to provide a new and improved conelcrusher having a concave ring with a material inlet opening that will admit pieces larger than pieces of a size that can becrushed in the nip at the inlet opening.

According to a preferred embodiment of the present invention a crusher is provided with a crushing chamber defined between a vertical conical head and a surrounding replaceable concave ring the inside of which is provided with a stepped surface comprising alternately, annular-crushing surfaces and annular connecting surfaces. The inside of theconcave ring is also provided with vertical corrugations defined by alternate grooves and ridges which begin at the top and material inlet end of the concave ring, and extend downwardly to one of the annular crushing surfaces at a horizontal level above at least the lowermost annular crushing surfaces. The ridges of the corrugations provide a proper nip angle for crushing at the top" of the chamber while the grooves provide a larger area feed opening than could be provided by a noncorrugatedsurface making a proper nip angle for crushing. This larger feed area will also admit to the chamber pieces of a size larger than the size that can be nipped at the entrance to the crushing chamber. The bottom crushing surface, which is below the corrugations provides a smooth annular surface for fine crushing. When wear of this bottom crushing surface requires the cone to be raised, to restore predetermined spacing, the size of the feed opening at top is not reduced because wear is deliberately accelerated at the top of the chamber by providing the corrugations which cause the feed material to be nipped only by the ridges of the corrugations which are thereby worn away at a relatively rapid rate. Thus, the wearing away of the ridges of the corrugations means that when the cone is raised to compensate for wear at the bottom of the chamber the feed opening is not thereby made smaller than when the ring was new.

Other features and objects of the invention that have been attained will appear from the more detailed description to follow with reference to an embodiment of the present invention shown in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 of the accompanying drawing shows diagrammatically a side elevation, partly in section, a crusher according to the present invention;

FIG. 2 is an enlarged view of a fragment of FIG. 1; and

FIG. 3 is an enlarged fragmentary view taken along line III-Ill in FIG. 2 and viewing the structure in the direction indicated by arrows.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, an upper portion of a gyratory crusher is shown comprising a shaft 1 which carries a conical head 2 with a conical mantle 3 mounted thereon and defining a space 4 between mantle 3 and head 2 which may be filled with zinc or resin. The head 2 and mantle 3 are surrounded by an annular shell within which is hung a replaceable conical and concave ring 11 which is supported in a fixed position by bolts 12 that project downwardly through a shell flange 13 and an aligned ring flange 14. The concave ring 11 cooperates with conical mantle 3 on head 2, to define a material feed opening 15 at the top and apex end of the conical concave ring 11, a material-discharging opening 16 at the bottom and base end of the conical concave ring 11, and a material-crushing chamber 17 therebetween. Crushing action is provided by an eccentric l8 rotated (by means not shown) which gyrates the shaft, about a central axis A-B passing through ring 11, as indicated by the broken line A-C. The gap between the mantle 3 and ring 11 may be adjusted by raising or lowering shaft 1. Shaft 1 may be raised and lowered by a piston 19 as disclosed in U.S. Pat. No. 2,448,936.

The inner surface of concave ring 11 is provided with a stepped and corrugated configuration that will be described with reference to FIGS. 2 and 3. The stepped configuration on the inside of ring 11 comprises, alternately, an annular crushing surface 20 and an annular connecting surface 21 between each adjacent pair of crushing surfaces 20. The annular crushing surfaces 20 each slope outwardly away from the central axis A-B in a direction from the apex (top and inlet) end 15 toward the base (bottom and outlet) end 16. The annular connecting surfaces 21 each slope inwardly toward the central axis A-B in a direction from the apex-inlet end 15 toward the base-outlet end 16.

The corrugated configuration is superimposed upon the stepped configuration and the corrugations are formed by curved surfaces defining alternate ridges 25 and grooves 26. As shown in FIG. 3 the convex curvature of ridges 25 and concave curvature of grooves 26 each initially represent half of the radial distance between the crest of a ridge and the bottom of groove but operation such as will be described results in the ridges wearing away as indicated by a broken line 25a. The ridges 25 and grooves 26 as shown in FIG. 2 begin at the apexinlet end 15 of chamber 17 and extend downwardly, each in a plane parallel to central axis A-B, to one of the crushing surfaces 20 inwardly and upwardly of the crushing surface 20" adjacent the base-outlet end 16. Preferably, the crushing surface 20, into which the ridges 25 and grooves 26 merge is a crushing surface closer to the apex-inlet end 15 than to the basecutlet end. Crushing surface 20" presents a considerably greater surface area to face the conical mantle 3, as it is here where the fine crushing occurs.

In the operation of a crusher according to the present invention having a concave ring according to the present invention, rock of various and irregular sizes may be fed into the material feed inlet 15. As shown in FIG. 3, the feed inlet 15 will admit a piece of rock of a size represented by the circle 30, which is larger than a piece of rock of a size represented by the circle 31, which can be nipped at the entrance 15 to the crushing chamber 17. The advantage of this feature of the present invention can be considered from two viewpoints. From one viewpoint, as shown in FIG. 3, by providing the grooves 26 the present invention permits pieces 30, which are larger than nipsize pieces 31, to be admitted to the crushing chamber. From a second viewpoint, as shown in FIG. 3, by providing ridges 25 the present invention permits pieces 31, which are smaller than admission-size pieces 30 to be broken at the very entrance to the crushing chamber. From either viewpoint, it can be seen from FIG. 3, that contact provided by the present invention between rock and the inner surface of ring 11 is concentrated at the crests of the ridges 25, which as shown in FIG. 2 are also stepped to maintain good nip angles to the top of ring 3, thus tending to promote crushing and accelerate wear of the surfaces of ridges 25 back to a surface represented by broken line 25a, and thereby tending to enlarge the opening 15. Therefore, when wear of the lowermost annular crushing surface 20 occurs, particles larger than desired sizes will begin to pass through discharge opening 16. Piston 19 must then be operated (in the manner disclosed in U.S. Pat. No. 2,448,936) to raise shaft 1 and reduce the gap between surface 20" and mantle 3. Raising mantle 3 to restore the original predetermined gap with surface 20" tends to move the top of the cone (mantle 3) closer to the top of the conical chamber and close inlet opening 15. But this tendency has been countered by the present invention which provides for the acceleration of wear, by concentrating wear on but a portion of the total surface area of ridges 25 and grooves 26, and that portion is the crests of ridges 25 which relatively rapidly wear back to line 25a.

From the foregoing detailed description of the present invention, it has been shown how the objects of the invention have been attained in a preferred manner. However, modifications and equivalents of the disclosed concepts such as readily occur to those skilled in the art are intended to be included within the scope of this invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a crusher having a vertical conical crushing head surrounded by an annular shell:

A. a concave ring mounted in a fixed position within the shell and surrounding the conical head to define therebetween a top material feed opening, a materialcrushing chamber below the feed opening with a predetermined minimum spacing between the head and surrounding concave ring and a bottom discharge opening;

B. an inner surface of the ring within the material-crushing chamber having a stepped configuration defining a plurality of annular crushing surfaces sloped downwardly and outwardly of the head alternately with connecting surfaces sloped downwardly and inwardly toward the head;

C. the inner surface of the ring also defining corrugations of alternate ridges and grooves with the entire length of each being disposed in a vertical plane; and

D. The grooves and ridges of the corrugations extend downwardly from the top of the ring to and terminate at one of the annular crushing surfaces at a horizontal level above at least the lowermost one of the annular crushing surfaces.

2. In a crusher according to claim 1, means for raising and lowering the conical head within and relative to the surrounding concave ring and operable to raise the conical head after use has resulted in a wearing away of the lowermost of the annular crushing surfaces and the ridges of the corrugations, to thereby restore the predetermined minimum spacing between the conical head and the lowermost crushing surface of the concave ring and maintain the desired feed opening at the top of the concave ring.

3. A crusher according to claim 1 in which the lowermost annular crushing surface of the concave ring presents a greater surface area than the next higher of such plurality of crushing surfaces.

4. A crusher according to claim 1 in which the feed opening at the top of the ring defines an opening of smaller outer diameter than the outer diameter of the crushing chamber defined by the bottom of the ring, and the ridges and grooves of the corrugations extend downwardly and radially outward of the conical head to merge into one of the annular crushing surfaces closer to the feed opening than to the discharge openmg.

5. A crusher according to claim 1 in which the ridges of the corrugations are curved surfaces.

6. A crusher according to claim 5 in which the curved surface defining each ridge of the corrugations is a convex surface which in a horizontal plane extends radially outward at least approximately one-half of the distance to the radially outermost portions of the adjacent grooves.

7. A concave ring having an inner surface defining a conical concave chamber about a central axis passing therethrough and having an apex end thereof of smaller diameter than a base end thereof remote of the apex end, for defining in a cone-type crusher an outer wall of a crushing chamber, and the inner surface of the concave ring having a configuration defining:

A. a plurality of annular steplike surfaces comprising alternately an annular crushing surface each sloped outwardly of the central axis in a direction from the apex end toward the base end and an annular connecting surface between crushing surfaces, the connecting surfaces each sloped inwardly toward the central axis in a direction from the apex end toward the base end;

B. a plurality of corrugations of alternately adjacent ridges and grooves with the entire length of each being disposed in a plane parallel to the central axis; and

C. the grooves and ridges begin at the apex end of the conical concave chamber and extend therefrom to and terminate at one of the annular crushing surfaces spaced inwardly of the crushing surface adjacent the base end of the conical concave chamber.

8. A ring according to claim 7 in which at least the annular crushing surface adjacent the base end of the conical concave chamber presents a greater surface area than the next inwardly adjacent of such plurality of crushing surfaces.

9. A ring according to claim 7 in which the ridges of the corrugations are curved surfaces.

10. A ring according to claim 9 in which the curved surface defining each ridge of the corrugations is a convex surface which in a plane perpendicular to the central axis extends radially outward of the central axis at least approximately onehalf of the distance to the radially outermost portions of adjacent grooves.

Claims

1. In a crusher having a vertical conical crushing head surrounded by an annular shell: A. a concave ring mounted in a fixed position within the shell and surrounding the conical head to define therebetween a top material feed opening, a material-crushing chamber below the feed opening with a predetermined minimum spacing between the head and surrounding concave ring and a bottom discharge opening; B. an inner surface of the ring within the material-crushing chamber having a stepped configuration defining a plurality of annular crushing surfaces sloped downwardly and outwardly of the head alternately with connecting surfaces sloped downwardly and inwardly toward the head; C. the inner surface of the ring also defining corrugations of alternate ridges and grooves with the entire length of each being disposed in a vertical plane; and D. The grooves and ridges of the corrugations extend downwardly from the top of the ring to and terminate at one of the annular crushing surfaces at a horizontal level above at least the lowermost one of the annular crushing surfaces.

4. A crusher according to claim 1 in which the feed opening at the top of the ring defines an opening of smaller outer diameter than the outer diameter of the crushing chamber defined by the bottom of the ring, and the ridges and grooves of the corrugations extend downwardly and radially outward of the conical head to merge into one of the annular crushing surfaces closer to the feed opening than to the discharge opening.

7. A concave ring having an inner surface defining a conical concave chamber about a central axis passing therethrough and having an apex end thereof of smaller diameter than a base end thereof remote of the apex end, for defining in a cone-type crusher an outer wall of a crushing chamber, and the inner surface of the concave ring having a configuration defining: A. a plurality of annular steplike surfaces comprising alternately an annular crushing surface each sloped outwardly of the central axis in a direction from the apex end toward the base end and an annular connecting surface beTween crushing surfaces, the connecting surfaces each sloped inwardly toward the central axis in a direction from the apex end toward the base end; B. a plurality of corrugations of alternately adjacent ridges and grooves with the entire length of each being disposed in a plane parallel to the central axis; and C. the grooves and ridges begin at the apex end of the conical concave chamber and extend therefrom to and terminate at one of the annular crushing surfaces spaced inwardly of the crushing surface adjacent the base end of the conical concave chamber.

10. A ring according to claim 9 in which the curved surface defining each ridge of the corrugations is a convex surface which in a plane perpendicular to the central axis extends radially outward of the central axis at least approximately one-half of the distance to the radially outermost portions of adjacent grooves.