Solid material comminution or disintegration – Apparatus – Cooperating comminuting surfaces
Reexamination Certificate
1999-02-02
2001-01-09
Husar, John M. (Department: 3725)
Solid material comminution or disintegration
Apparatus
Cooperating comminuting surfaces
C241S253000, C241S254000
Reexamination Certificate
active
06170771
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to devices and methods for crushing rocks and the product produced from crushing.
BACKGROUND OF THE INVENTION
It has been known to crush rock to produce, for example, gravel, sand, chips or the like. Manufactured sand, that is sand produced by crushing as opposed to naturally occurring sand, is often specified to be used in manufacturing cement for road construction or the like since, unlike natural sand which has been weathered and the facets worn, manufactured sand has sharp facets which provide for binding in the cement product. Hence, manufacturing sand from crushing rock is an important industry to supply sand and, for that matter, manufactured aggregate for cement.
In addition to manufacturing sand, rocks are crushed to produce gravel and rock chips for use in aggregate and cement and, for example, decorative rock gravel. In the manufacture of gravel it is important to produce a consistent and predictable crushed product such that there is a minimum of non-conforming product, e.g., sand where chips are being manufactured, which must be screened. It would be advantageous to be able to substantially select the product to be produced (whether it be sand, aggregate or chips) and crush the rocks such that a substantial portion of the crushed material falls in the range of the desired product and that a minimum of the product is lost to non-conforming output.
One approach to rock crushing is as shown in Pamplin, U.S. Pat. No. 4,257,564 which has a rotating, planar and circular crushing jaw which operates with a conical jaw. The jaws are spaced to define an annular discharge opening. The conical crushing jaw is defined, in annular fashion, about an axially disposed feed tube which supports the rotating components associated with the conical jaw. Rock is fed axially down the axial tube and the jaws rotated which feeds the rock, through centrifugal force, between the jaws where they are crushed. The lower jaw is round and flat and coacts with the conical upper jaw to define a circular nip for crushing of rock. A drawback to this type of rock crusher is that upper jaw is conical which provides an irregular, non-planar crushing face and which, it turn, increases manufacture and replacement costs of the wear surfaces. The bottom jaw is flat and as a result does not cooperate to urge rock to the nip instead relying completely upon centrifugal force. There is no technique to positively feed and direct rock between the jaws.
There is, therefore, a need for a rock crusher which overcomes the problems of prior rock crushers by, among other features and advantages, positively feeding the rocks to be crushed and which provides for less expensive construction and replacement of wear surfaces.
SUMMARY OF THE INVENTION
Toward this end, a device for crushing rocks is set forth which includes a housing with a feed port to receive the rocks to be crushed and a discharge opening for discharging the crushed product. A first rotor is disposed in the housing and has a first axis. The first rotor defines a first crushing surface. A second rotor is disposed in the housing and has a second axis. The second rotor includes an axial cavity to pass rocks and a face defining at the perimeter thereof a second crushing surface adapted to be spaced from the first crushing surface to define a circumferential nip for crushing rocks therebetween. Opposite the second crushing surface, the second rotor has a cover with at least one feed opening disposed radially from the second axis to admit rocks into the cavity. Means are provided for rotating the first and second rotors about their respective axises to centrifugally direct rocks between the nip for crushing thereof, and for discharging the crushed rocks discharged from the housing.
Accordingly, an axial feed tube is not required and the rocks may be fed into the cavity at one or more spaced locations from the axis of the second rotor. Preferably, the feed openings of the second rotor have associated therewith angular scoops to forcibly direct rocks into the axial cavity for crushing thereof.
In a further aspect, the device includes means to adjust the relative positions of the first and second axises to offset the first crushing surface from the second crushing surface, and to alter the spacing between the crushing surfaces to accommodate larger size rocks and larger size output.
In a further aspect, the first crushing surface is provided angular shoes adapted to direct rocks from the cavity to the nip for crushing thereof.
In still a further embodiment of the present invention, the second crushing surface has a variable radial distance from the second axis to define a non-circular, polygonal, circumferential nip for crushing rocks. In the preferred embodiment, the second crushing surface is hexagonal which acts not only to impose forces normal to the crushing surfaces but also provides circumferential and axial forces to further act to crush and guide rocks through the nip. The imposition of these forces in addition to the centrifugal forces urging the rocks through the nip provides for efficient crushing of the rocks and the production of a substantially predictable product.
REFERENCES:
patent: 2121275 (1938-06-01), Zober et al.
patent: 2985391 (1961-05-01), Parmele
patent: 3424388 (1969-01-01), Reichel
patent: 4196224 (1980-04-01), Falk
patent: 4257564 (1981-03-01), Pamplin
patent: 4889428 (1989-12-01), Hodson
Anderson Philip J.
Anderson & Morishita, LLC
HRW Limited Partnership
Husar John M.
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