Patent Publication Number: US-5890666-A

Title: Impact crusher

Description:
FIELD OF THE INVENTION 
     Our present invention relates to an impact crusher of the type in which a rotor is provided with crushing elements which cooperate with impact members which cooperate to form a crushing gap and to an impact member assembly suitable for use with such a rotor. More particularly the invention relates to an impact crusher comprising a rotor and two or more impact members interconnected to form an adjustable impact member system, a first impact member being mounted pivotally around a first horizontal axis by way of at least one drive means, and having a second horizontal axis on which a second impact member, pivotal by way of at least one drive means, is provided. 
     BACKGROUND OF THE INVENTION 
     An impact crusher for crushing material of various consistencies is known for example from DE 23 31 729 A1 in which the impact plates are interconnected in articulated manner to form a coherent composite pivotal impact member, each of the interconnected impact plates deriving adjustable support individually from the housing. 
     The impact plates may have impact surfaces which are at angles to one another or are stepped along the path of the material as it is entrained from the inlet side of the machine. The principles of such machines have also been developed in the Chemical Engineers Handbook, Perry and Chilton, 5th edition, McGraw Hill Book Company, New York, 1973, at Chapter 8, pages 19 ff. 
     This known impact crusher, just like impact other crushers of the same genus, suffers from the substantial drawback that the upper impact member, provided downstream of the machine inlet yields outwardly due to foreign objects which cannot be crushed entering the machine, so that the crushing gap between the rotor and the lower impact member is decreased to such an extent, due to the upper impact member pivoting outwardly, that a risk arises of foreign objects getting wedged between the rotor and the impact member, leading to possible damage to the rotor and/or the impact member, so that the continued operability of the installation can no longer be ensured. 
     OBJECTS OF THE INVENTION 
     It is the principal object of the present invention to provide an improved impact crusher such that the damage which can be caused by the entry of a noncrushable foreign object can be minimized. 
     Another object of the invention is to provide an improved impact crusher which is free from the drawbacks of earlier devices or apparatuses of this type and particularly the drawbacks mentioned above. 
     Still another object of this invention is to provide improved impact assembly for a rotor-type crusher or breaker whereby drawbacks which could have resulted in down time can be avoided. 
     SUMMARY OF THE INVENTION 
     These objects are attained, in accordance with the invention in an impact crusher of the type in which a rotor and two or more impact members are provided along the path of the crusher members of the rotor to form an adjustable impact assembly. A first impact member is pivotally mounted at a first horizontal axis and a second impact member is pivotally mounted on the first impact member by a second horizontal axis and respective drive means is provided for controlling the displacement of the impact members. 
     According to the invention, the horizontal axis pivotally supporting the second impact member is provided in the region of that end of the first impact member which is remote from the first horizontal axis and the second impact member comprises one or more levers. 
     It is an important feature of the invention that due to the specific arrangement of the point of engagement for the support and the point of articulation of the lower impact member to the lever, the crushing gap between the lower impact member and the rotor is enlarged in the event of the upper impact member yielding due to foreign object interference. 
     Because of the geometrical relationships with regard to the cylinder hinge point and the axes of the impact members, the edge of the lower impact member closest to the rotor is moved automatically in such a manner during opening of the impact member, for which purpose a housing member is swiveled around the pivotal axis, that the edge does not collide with the rotor or the beater bars, thus preventing damage. 
     Different drive means, preferably hydraulic cylinders, may be employed in order to adjust the two impact members. 
     More particularly, the impact crusher can comprise: 
     a housing; 
     an impact crusher rotor rotatable in the housing about a horizontal rotor axis; and 
     at least one impact member assembly in the housing adjustable relative to the rotor, the assembly including: 
     a first impact member having impact surfaces juxtaposed with the rotor and pivotally mounted in the housing for movement about a first horizontal pivot axis to shift the surfaces toward and away from the rotor, 
     a first drive means articulated to the first impact member for angularly displacing the first impact member about the first horizontal pivot axis, 
     a second impact member having impact surfaces juxtaposed with the rotor and pivotally mounted in the housing for movement about a second horizontal pivot axis on the first impact member at a location remote from the first horizontal pivot axis to shift the surfaces of the second impact member toward and away from the rotor, 
     at least one lever swingable about the second horizontal pivot axis and operatively connected with the second impact member for pivotally displacing same about the second horizontal pivot axis, and 
     second drive means articulated to the lever for angularly displacing the second impact member about the second horizontal pivot axis. 
     The impact crusher according to the invention is characterized by a particularly high operational reliability and, therefore, a particularly long useful life due to the advantageous arrangement of the point of engagement for the support of the lower impact member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which: 
     FIG. 1 is a diagrammatic transverse section through an impact crusher according to the invention; 
     FIG. 1A is the impact crusher of FIG. 1, shown with pivotal housing in open position; 
     FIG. 2 is a section taken along the line II--II of FIG. 1; and 
     FIG. 3 is a detail view of the connection of the levers with extensions of the second impact member. 
    
    
     SPECIFIC DESCRIPTION 
     The impact crusher illustrated in FIG. 1 comprises a housing member 9 adapted to swing open around a pivotal axis 8 in order to open the impact crusher, and includes a rotor 10 adapted to be rotationally-driven, equipped with crushing elements, not shown in the drawing. 
     Two impact members 1 and 4, equipped with a multitude of impact elements 11 are provided in a manner facing the rotor 10. 
     The impact member 1 disposed above the impact member 4, is pivotally mounted around a horizontal axis 2 by way of at least one cylinder 3 or a different drive element engaging in a hinge point 3a. At an end of the impact members in the region remote from the axis 2, i.e. at a lower end, a further horizontal axis 6 is provided for pivotally mounting the impact member 4. The gap between the impact members 1, 4 and the rotor 10 can be denoted as crushing chute. 
     The impact member 4 comprises one or more levers 4a on which one or a plurality of cylinders 5 or other drive elements engages/engage at the associated hinge point 5a. 
     The crushing gap 7 is formed by the impact member 4 and the rotor 10. 
     The material to be crushed, reaching the impact crusher in the direction of the arrow 22, is pre-crushed in the upper region of the crusher and is further crushed by the upper impact member 1, being finally crushed to the pre-set particle size by the lower impact member 4 in the crushing gap 7. 
     From FIG. 2, it will be apparent that two hydraulic cylinder drivers 5 are provided on each side of the impact member 1 and are connected to respective levers 4a and from FIG. 3 it can be seen that each lever 4a which is rigid with the member 4 is on an extension 4b of that impact member to the respective side of the impact member 1. 
     The impact surfaces of the impact members 1 and 4 are provided at 12 and 13 on the impact members and the pivot axis 8 for the housing part 9 carrying the axis 2 is so arranged with respect to the articulation points 5a and the axis 6 that, when the housing part 9 is swung open in the counterclockwise direction and the drives 3 and 5 are correspondingly actuated, there will be no collision between the impact members 1 and 4 and the rotor 10 or the crushing elements thereon.